(2001). "[Parkinson disease: diagnostic and therapeutic criteria]." Presse Med 30(8): 379-85.

Abe, K. and H. Saito (2001). "Effects of basic fibroblast growth factor on central nervous system functions." Pharmacol Res 43(4): 307-12.
Basic fibroblast growth factor (bFGF), initially identified as mitogens with prominent angiogenic properties, is now recognized as multifunctional growth factors with notable actions on neuronal cells. bFGF promotes the survival and neurite growth of brain neurons in vitro and in vivo, suggesting that it functions as a neurotrophic factor. This effect of bFGF could be beneficial for improving the survival of grafted neurons in transplantation. Furthermore, bFGF acutely modulates synaptic transmission in the hippocampus, suggesting that it has a role like a neurotransmitter or neuromodulator. In this article, we make a brief review of multiple biological activities of bFGF for brain neurons and discuss its potential usefulness for the treatment of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease.

Abell, C. W. and S. W. Kwan (2001). "Molecular characterization of monoamine oxidases A and B." Prog Nucleic Acid Res Mol Biol 65: 129-56.
Monoamine oxidase A and B (MAO A and B) are the major neurotransmitter-degrading enzymes in the central nervous system and in peripheral tissues. MAO A and B cDNAs from human, rat, and bovine species have been cloned and their deduced amino acid sequences compared. Comparison of A and B forms of the enzyme shows approximately 70% sequence identity, whereas comparison of the A or B forms across species reveals a higher sequence identity of 87%. Within these sequences, several functional regions have been identified that contain crucial amino acid residues participating in flavin adenine dinucleotide (FAD) or substrate binding. These include a dinucleotide-binding site, a second FAD-binding site, a fingerprint site, the FAD covalent-binding site, an active site, and the membrane-anchoring site. The specific residues that play a role in FAD or substrate binding were identified by comparing sequences in wild-type and variants of MAO with those in soluble flavoproteins of known structures. The genes that encode MAO A and B are closely aligned on the X chromosome (Xp11.23), and have identical exon-intron organization. Immunocytochemical localization studies of MAO A and B in primate brain showed distribution in distinct neurons with diverse physiological functions. A defective MAO A gene has been reported to associate with abnormal aggressive behavior. A deleterious role played by MAO B is the activation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a proneurotoxin that can cause a parkinsonian syndrome in mammals. Deprenyl, an inhibitor of MAO B, has been used for the treatment of early-stage Parkinson's disease and provides protection of neurons from age-related decay.

Adams, J. D., Jr., M. L. Chang, et al. (2001). "Parkinson's disease--redox mechanisms." Curr Med Chem 8(7): 809-14.
Parkinson's disease occurs in 1% of people over the age of 65 when about 60% of the dopaminergic neurons in the substantia nigra of the midbrain are lost. Dopaminergic neurons appear to die by a process of apoptosis that is induced by oxidative stress. Oxygen radicals abstract hydrogen from DNA forming DNA radicals that lead to DNA fragmentation, activation of DNA protective mechanisms, NAD depletion and apoptosis. Oxygen radicals can be formed in dopaminergic neurons by redox cycling of MPP+, the active metabolite of MPTP. This redox cycling mechanism involves the reduction of MPP+ by a number of enzymes, especially flavin containing enzymes, some of which are found in mitochondria. Tyrosine hydroxylase is present in all dopaminergic neurons and is responsible for the synthesis of dopamine. However, tyrosine hydroxylase can form oxygen radicals in a redox mechanism involving its cofactor, tetrahydrobiopterin. Dopamine may be oxidized by monoamine oxidase to form oxygen radicals and 3,4-dihydroxyphenylacetaldehyde. This aldehyde may be oxidized by aldehyde dehydrogenase with the formation of oxygen radicals and 3,4-dihydroxyphenylacetic acid. The redox mechanisms of oxygen radical formation by MPTP, tyrosine hydroxylase, monoamine oxidase and aldehyde dehydrogenase will be discussed. Possible clinical applications of these mechanisms will be briefly presented.

Ahlskog, J. E. (2001). "Parkinson's disease: medical and surgical treatment." Neurol Clin 19(3): 579-605, vi.
It has been over three decades since the introduction of L-dihydroxyphenylalanine or levodopa therapy for Parkinson's disease (PD). The early levodopa trials were driven by recognition of a profound cerebral dopamine deficiency state in this disorder. Whereas dopamine fails to cross the blood brain barrier and hence is ineffective as therapy, the amino acid precursor, dopa, is transported across this barrier and provides a substrate for dopamine synthesis. Levodopa is converted to dopamine within the brain by dopa decarboxylase, replenishing central dopamine stores and potentially reversing the motor symptoms of PD.

Akamatsu, W. and H. Okano (2001). "[Neural stem cell, as a source of graft material for transplantation in neuronal disease]." No To Hattatsu 33(2): 114-20.
Self-renewing and multipotent neural stem cells are present in the adult human brain. We successfully harvested neural stem cells from mice and humans using misexpressed EGFP proteins under the control of the nestin second intron enhancer. High-level EGFP expressors derived from mouse embryos included a distinct subpopulation of cells that were self-renewable and multipotent. Further, we obtained that neural progenitor cells from rat fetal spinal cords using a neurosphere technique, and demonstrated their ability to divide and differentiate into neurons in vivo, where they were integrated into the host tissue in the injured rat spinal cord with resultant behavioral improvement of the recipient rat. We also harvested tyrosine hydroxylase-positive neurons from a transgenic mouse expressing GFP under the control of the tyrosine hydroxylase promoter, and successfully transplanted them into the striatum of rats with parkinsonism with marked improvement of the neurological symptoms. Since neural stem cells can adapt well in the host CNS, studies should focus on their application as a vector in gene therapy and on the introduction in vivo or ex vivo of genes to control their proliferation and differentiation. Neural stem cells are a potential, useful source for developing new therapy for CNS disorders.

Albers, D. S. and S. J. Augood (2001). "New insights into progressive supranuclear palsy." Trends Neurosci 24(6): 347-53.
Increased oxidative damage and mitochondrial dysfunction have been suggested to play crucial roles in the pathogenesis of several neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. In this review, we will focus on progressive supranuclear palsy (PSP), a rare parkinsonian disorder with tau pathology. Particular emphasis is placed on the genetic and biochemical data that has emerged, offering new perspectives into the pathogenesis of this devastating disease, especially the contributory roles of oxidative damage and mitochondrial dysfunction.

Aminoff, M. J. (2001). "Parkinson's disease." Neurol Clin 19(1): 119-28, vi.
A number of changes have occurred in the management of Parkinson's disease in recent years, with the development of new therapeutic strategies based upon advances in pharmacotherapy and interventional procedures. The treatment of patients with Parkinson's disease is considered here with these advances in mind. Potential neuroprotective agents that might slow disease-progression are also considered, but at the present time these agents are more of academic interest than clinical relevance and their role remains to be established. Ablative surgery and stimulation procedures are also helpful in the management of Parkinson's disease, and the utility and limitations of these approaches are briefly summarized.

Andersen, J. K. (2001). "Does neuronal loss in Parkinson's disease involve programmed cell death?" Bioessays 23(7): 640-6.
Recently it has been hypothesized that apoptotic cell death is involved in several neuropathological conditions including Parkinson's disease (PD). Initial morphological studies assessing the presence of apoptosis in Parkinsonian brain tissues yielded mixed results. Based on more recent studies in human PD brains as well in animal and cell culture models of the disease, a picture is emerging, however, that strongly suggests that many of the molecular players thought to participate in this type of neuronal cell death are active in the disease. The task of researchers in the field is now to deduce how these players may be interacting with one another to bring about cell death in PD and to design effective therapies to interfere with these processes.

Andersen, J. K. (2001). "Do alterations in glutathione and iron levels contribute to pathology associated with Parkinson's disease?" Novartis Found Symp 235: 11-20; discussion 20-5.
A growing body of evidence has implicated oxidative stress as an important factor in the neuropathology associated with Parkinson's disease. Dopaminergic nigrostriatal neurons, the predominant cells lost in Parkinson's, are believed to be highly prone to oxidative damage due to the propensity for dopamine to auto-oxidize and thereby produce elevated levels of hydrogen peroxide and catecholamine quinones. Hydrogen peroxide formed during this process can either be converted by iron to form highly reactive hydroxyl radicals or removed through reduction by glutathione. Glutathione can also conjugate with quinones formed during dopamine oxidation preventing them from facilitating the release of iron from the iron-storage molecule ferritin. Alterations in both iron and glutathione levels in the substantia nigra have been correlated with the neuronal degeneration accompanying Parkinson's disease but a direct causative role for either has yet to be definitively proved. We will discuss the use of genetically engineered cell and mouse lines generated in our laboratory as models to examine the role that alterations in iron and glutathione levels may play in neurodegeneration of dopaminergic neurons of the substantia nigra associated with Parkinson's disease, and how these two parameters may interact with one another to bring this about.

Andoh, T. (2001). "[Effects of general anesthetics on neuronal nicotinic acetylcholine receptors and their roles in the mechanism of anesthesia]." Masui 50(10): 1072-84.
Neuronal nicotinic acetylcholine receptors (nAchRs) are widely expressed in the central and autonomic nervous systems and have subunit compositions with biophysical and pharmacological properties distinct from those of the receptors at the neuromuscular junction. They are thought to modulate synaptic transmission in the central nervous system (CNS) mainly by regulating the release of neurotransmitters. Although roles of neuronal nAchRs in the CNS are poorly understood, these receptors are involved in cognitive performance, nociception and psychoneurological disorders such as Alzheimer's and Parkinson disease. It is known that both central and peripheral neuronal nAchRs are sensitive to various types of anesthetics. Among those, barbiturates, ketamine, volatile and gaseous anesthetics depress neuronal nAchRs at or below clinical concentrations. Inhibition of neuronal nAchRs by barbiturates is unlikely to contribute to the anesthetic action of barbiturates, since this effect does not correlate with the anesthetic potencies of barbiturate stereoisomers. Relevance of inhibition of these receptors is controversial for anesthetic effects of other anesthetics, because conflicting results have been obtained from comparison of this effect with anesthetic actions of stereoisomers or structurally related compounds. However, it is possible that inhibition of central nAchRs contributes to secondary effects attributed to anesthesia such as impairment in memory and cognitive performance.

Andrews, R. J. (2001). "Neuroprotection for the new millennium. Matchmaking pharmacology and technology." Ann N Y Acad Sci 939: 114-25.
A major theme of the 1990s in the pathophysiology of nervous system injury has been the multifactorial etiology of irreversible injury. Multiple causes imply multiple opportunities for therapeutic intervention--hence the abandonment of the "magic bullet" single pharmacologic agent for neuroprotection in favor of pharmacologic "cocktails". A second theme of the 1990s has been the progress in technology for neuroprotection, minimally- or non-invasive monitoring as well as treatment. Cardiac stenting has eliminated the need, in many cases, for open heart surgery; deep brain stimulation for Parkinson's disease has offered significant improvement in quality of life for many who had exhausted cocktail drug treatment for their disease. Deep brain stimulation of the subthalamic nucleus offers a novel treatment for Parkinson's disease where a technological advance may actually be an intervention with effects that are normally expected from pharmacologic agents. Rather than merely "jamming" the nervous system circuits involved in Parkinson's disease, deep brain stimulation of the subthalamic nucleus appears to improve the neurotransmitter imbalance that lies at the heart of Parkinson's disease. It may also slow the progression of the disease. Given the example of deep brain stimulation of the subthalamic nucleus for Parkinson's disease, in future one may expect other technological or "hardware" interventions to influence the programming or "software" of the nervous system's physiologic response in certain disease states.

Arvanitakis, Z. and Z. K. Wszolek (2001). "Recent advances in the understanding of tau protein and movement disorders." Curr Opin Neurol 14(4): 491-7.
Tau plays an important role in movement disorders. The accumulation of pathological tau is a major substrate of frontotemporal dementia and parkinsonism linked to chromosome 17, progressive supranuclear palsy, and corticobasal degeneration. Over the past year, several new mutations on the tau gene have been found. These mutations have been classified into three groups: (i) mutations in constitutively spliced exons; (ii) mutations in the alternatively spliced exon 10; and (iii) mutations of the exon 10 5' splice site. Some patients presenting with frontotemporal dementia and parkinsonism linked to chromosome 17 transiently respond to levodopa therapy. The significance of Pick bodies was recognized by a recent study on kindred with the Glu342Val tau mutation. In sporadic cases of progressive supranuclear palsy, the presence of the H1 haplotype was found to be a risk factor. Corticobasal degeneration shares a common genetic background with progressive supranuclear palsy. This opens the question of whether corticobasal degeneration represents a separate disorder or a spectrum of disease with progressive supranuclear palsy. However, distinguishing features are observed, and include oculomotor abnormalities, which may help to differentiate these two disorders on clinical grounds. Despite recent advances in the understanding of the tauopathies, there are still no curative therapies available. It is hoped that studies in transgenic tau animal models will lead to the development of successful treatments.

Autret, A., B. Lucas, et al. (2001). "Sleep and brain lesions: a critical review of the literature and additional new cases." Neurophysiol Clin 31(6): 356-75.
We present a comprehensive review of sleep studies performed in patients with brain lesions complemented by 16 additional personal selected cases and by discussion of the corresponding animal data. The reader is cautioned about the risk of establishing an erroneous correlation between abnormal sleep and a given disorder due to the important inter and intra variability of sleep parameters among individuals. Salient points are stressed: the high frequency of post-stroke sleep breathing disorders is becoming increasingly recognised and may, in the near future, change the way this condition is managed. Meso-diencephalic bilateral infarcts induce a variable degree of damage to both waking and non-REM sleep networks producing and abnormal waking and sometimes a stage 1 hypersomnia reduced by modafinil or bromocriptine, which can be considered as a syndrome of cathecholaminergic deficiency. Central pontine lesions induce REM and non-REM sleep insomnia with bilateral lateral gaze paralysis. Bulbar stroke leads to frequent sleep breathing disorders. Polysomnography can help define the extent of involvement of various degenerative diseases. Fragmented sleep in Parkinson's disease may be preceded by REM sleep behavioural disorders. Multiple system atrophies are characterised by important sleep disorganization. Sleep waking disorganization and a specific ocular REM pattern are often seen in supra-nuclear ophtalmoplegia. In Alzheimer patients, sleep perturbations parallel the mental deterioration and are possibly related to cholinergic deficiency. Fronto-temporal dementia may be associated with an important decrease in REM sleep. Few narcoleptic syndromes are reported to be associated with a tumour of the third ventricle or a multiple sclerosis or to follow a brain trauma; all these cases raise the question whether this is a simple coincidence, a revelation of a latent narcolepsy or, as in non-DR16/DQ5 patients, a genuine symptomatic narcolepsy. Trypanosomiasis and the abnormal prion protein precociously after sleep patterns. Polysomnography is a precious tool for evaluating brain function provided it is realised under optimal conditions in stable patients and interpreted with caution. Several unpublished cases are presented: one case of pseudohypersomnia due to a bilateral thalamic infarct and corrected by modafinil, four probable late-onset autosomal recessive cerebellar ataxias without sleep pattern anomalies, six cases of fronto-temporal dementia with strong reduction in total sleep time and REMS percentage on the first polysomnographic night, one case of periodic hypersomnia associated with a Rathke's cleft cyst and four cases of suspected symptomatic narcolepsy with a DR16-DQ5 haplotype, three of which were post-traumatic without MRI anomalies, and one associated with multiple sclerosis exhibiting pontine hyper signals on MRI.

Banaclocha, M. M. (2001). "Therapeutic potential of N-acetylcysteine in age-related mitochondrial neurodegenerative diseases." Med Hypotheses 56(4): 472-7.
Increasing lines of evidence suggest a key role for mitochondrial damage in neurodegenerative diseases. Brain aging, Parkinson's disease, Alzheimer's disease, Huntington's disease and Friedreich's ataxia have been associated with several mitochondrial alterations including impaired oxidative phosphorylation. Mitochondrial impairment can decrease cellular bioenergetic capacity, which will then increase the generation of reactive oxygen species resulting in oxidative damage and programmed cell death. This paper reviews the mechanisms of N-acetylcysteine action at the cellular level, and the possible usefulness of this antioxidant for the treatment of age-associated neurodegenerative diseases. First, this thiol can act as a precursor for glutathione synthesis as well as a stimulator of the cytosolic enzymes involved in glutathione regeneration. Second, N-acetylcysteine can act by direct reaction between its reducing thiol group and reactive oxygen species. Third, it has been shown that N-acetylcysteine can prevent programmed cell death in cultured neuronal cells. And finally, N-acetylcysteine also increases mitochondrial complex I and IV specific activities both in vitro and in vivo in synaptic mitochondrial preparations from aged mice. In view of the above, and because of the ease of its administration and lack of toxicity in humans, the potential usefulness of N-acetylcysteine in the treatment of age-associated mitochondrial neurodegenerative diseases deserves investigation.

Bar-Gad, I. and H. Bergman (2001). "Stepping out of the box: information processing in the neural networks of the basal ganglia." Curr Opin Neurobiol 11(6): 689-95.
The Albin-DeLong 'box and arrow' model has long been the accepted standard model for the basal ganglia network. However, advances in physiological and anatomical research have enabled a more detailed neural network approach. Recent computational models hold that the basal ganglia use reinforcement signals and local competitive learning rules to reduce the dimensionality of sparse cortical information. These models predict a steady-state situation with diminished efficacy of lateral inhibition and low synchronization. In this framework, Parkinson's disease can be characterized as a persistent state of negative reinforcement, inefficient dimensionality reduction, and abnormally synchronized basal ganglia activity.

Barbieri, S., K. Hofele, et al. (2001). "Mouse models of alpha-synucleinopathy and Lewy pathology. Alpha-synuclein expression in transgenic mice." Adv Exp Med Biol 487: 147-67.

Barnes, J. and A. S. David (2001). "Visual hallucinations in Parkinson's disease: a review and phenomenological survey." J Neurol Neurosurg Psychiatry 70(6): 727-33.
OBJECTIVES: Between 8% and 40% of patients with Parkinson's disease undergoing long term treatment will have visual hallucinations during the course of their illness. There were two main objectives: firstly, to review the literature on Parkinson's disease and summarise those factors most often associated with hallucinations; secondly, to carry out a clinical comparison of ambulant patients with Parkinson's disease with and without visual hallucinations, and provide a detailed phenomenological analysis of the hallucinations. METHODS: A systematic literature search using standard electronic databases of published surveys and case-control studies was undertaken. In parallel, a two stage questionnaire survey was carried out based on members of a local branch of the Parkinson's Disease Society and followed up with a clinical interview. RESULTS: The review disclosed common factors associated with visual hallucinations in Parkinson's disease including greater age and duration of illness, cognitive impairment, and depression and sleep disturbances. The survey comprised 21 patients with visual hallucinations and 23 without. The hallucinators had a longer duration and a greater severity of illness, and tended to show more depressed mood and cognitive impairment. The typical visual hallucination in these patients is a complex visual image experienced while they are alert and have their eyes open. The image appears without any known trigger or voluntary effort, is somewhat blurred, and commonly moves. It stays present for a period of "seconds" or "minutes". The content can be variable within and between hallucinators, and includes such entities as people, animals, buildings, or scenery. These features resemble those highlighted in hallucinations in the visually impaired (Charles Bonnet's syndrome). CONCLUSION: A consistent set of factors are associated with visual hallucinations in Parkinson's disease. The results of the phenomenological survey and those of visual hallucinations carried out in other settings suggest a common physiological substrate for visual hallucinations but with cognitive factors playing an as yet unspecified role.

Barraquer, I. B. L. (2001). "[Nightmares and behavior during REM sleep]." Neurologia 16(5): 214-20.
This study reports the current neurobiologic data on REM sleep including psychoanalysis, distinguishing between the "instincts of pleasure" and the "instincts of death" (Beyond the principles of pleasure, S. Freud, 1920). The award and punishment systems are also reported and current data related to nightmares and mainly dream behavior during REM sleep without atonia are presented underlining the frequency of parasomnia in ponto-cerebellous atrophy and Parkinson's disease. The author emphasizes the need for establishing discussions among the different neuroscientific fields related to these questions.

Barzilai, A., E. Melamed, et al. (2001). "Is there a rationale for neuroprotection against dopamine toxicity in Parkinson's disease?" Cell Mol Neurobiol 21(3): 215-35.
Parkinson's disease is a progressive neurological disease caused by rather selective degeneration of the dopaminergic neurons in the substantia nigra. Though subject to intensive research, the etiology of this nigral loss is still undetermined and treatment is basically symptomatic. The current major hypothesis is that nigral neuronal death in PD is due to excessive oxidative stress generated by auto and enzymatic oxidation of the endogenous neurotransmitter dopamine (DA), the formation of neuromelanin (NM) and the presence of a high concentration of iron. In this review article although we concisely describe the effects of NM and iron on neuronal survival, we mainly focus on the molecular mechanisms of DA-induced apoptosis. DA exerts its toxic effects through its oxidative metabolites either in vitro or in vivo The oxidative metabolites then activate a very intricate web of signals, which culminate in cell death. The signal transduction pathways and genes, which are associated with DA toxicity are described in detail.

Basson, R. (2001). "Sex and idiopathic Parkinson's disease." Adv Neurol 86: 295-300.

Beal, M. F. (2001). "Experimental models of Parkinson's disease." Nat Rev Neurosci 2(5): 325-34.
Research into the pathogenesis of Parkinson's disease has been rapidly advanced by the development of animal models. Initial models were developed by using toxins that specifically targeted dopamine neurons, the most successful of which used 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a toxin that causes parkinsonism in man. More recently, the identification of alpha-synuclein mutations as a rare cause of Parkinson's disease has led to the development of alpha-synuclein transgenic mice and Drosophila. Here, I discuss the merits and limitations of these different animal models in our attempts to understand the physiology of Parkinson's disease and to develop new therapies.

Becker, G., D. Berg, et al. (2001). "Basal limbic system alteration in major depression: a hypothesis supported by transcranial sonography and MRI findings." Int J Neuropsychopharmacol 4(1): 21-31.
The pathogenesis of major depression (MD) remains unclear despite intensive research in the last decades which brought up a multitude of findings illustrating the complexity of this disorder. In this paper we will summarize the evidence pointing towards a structural alteration of the basal limbic system in MD and depression in Parkinson's disease (PD). Transcranial ultrasound and MRI studies in both depressive syndromes revealed altered signal intensity of the brainstem midline comprising fibre tracts of the basal limbic system. The hypothesis of a structural disruption of the basal limbic system is supported by biochemical and histopathological findings. The similarity of findings in MD and depression in PD might reflect a relationship between MD and neurodegenerative disorders.

Becker, G. and D. Berg (2001). "Neuroimaging in basal ganglia disorders: perspectives for transcranial ultrasound." Mov Disord 16(1): 23-32.
Transcranial sonography is a new diagnostic tool, allowing not only the evaluation of cerebral arteries but also the two-dimensional display of the brain parenchyma. In this review we will summarize basics of the application, the ultrasound anatomy of the brain and sonographic findings in some movement disorders. While in normal adults basal ganglia nuclei are hypoechogenic, they are hyperechogenic in certain basal ganglia disorders. In Parkinson's disease, for example, the substantia nigra can be depicted as a distinctly echogenic area. An elevated echogenicity of the lentiform nuclei was noticed in patients with primary adult-onset dystonia. In both disorders the altered echogenicity may arise from higher heavy metal tissue content (i.e. iron in Parkinson's disease and copper in primary dystonia). Our findings converge to the hypothesis that transcranial ultrasound sensitively detects pathological metal accumulation not identified by other neuroimaging techniques (CT and MRI) and therefore provides new insights in the diagnosis of basal ganglia disorders. The implications of these findings for the understanding of the pathogenesis and its usefulness for the early diagnosis of movement disorders are outlined.

Ben-Jonathan, N. and R. Hnasko (2001). "Dopamine as a prolactin (PRL) inhibitor." Endocr Rev 22(6): 724-63.
Dopamine is a small and relatively simple molecule that fulfills diverse functions. Within the brain, it acts as a classical neurotransmitter whose attenuation or overactivity can result in disorders such as Parkinson's disease and schizophrenia. Major advances in the cloning and characterization of biosynthetic enzymes, transporters, and receptors have increased our knowledge regarding the metabolism, release, reuptake, and mechanism of action of dopamine. Dopamine reaches the pituitary via hypophysial portal blood from several hypothalamic nerve tracts that are regulated by PRL itself, estrogens, and several neuropeptides and neurotransmitters. Dopamine binds to type-2 dopamine receptors that are functionally linked to membrane channels and G proteins and suppresses the high intrinsic secretory activity of the pituitary lactotrophs. In addition to inhibiting PRL release by controlling calcium fluxes, dopamine activates several interacting intracellular signaling pathways and suppresses PRL gene expression and lactotroph proliferation. Thus, PRL homeostasis should be viewed in the context of a fine balance between the action of dopamine as an inhibitor and the many hypothalamic, systemic, and local factors acting as stimulators, none of which has yet emerged as a primary PRL releasing factor. The generation of transgenic animals with overexpressed or mutated genes expanded our understanding of dopamine-PRL interactions and the physiological consequences of their perturbations. PRL release in humans, which differs in many respects from that in laboratory animals, is affected by several drugs used in clinical practice. Hyperprolactinemia is a major neuroendocrine-related cause of reproductive disturbances in both men and women. The treatment of hyperprolactinemia has greatly benefited from the generation of progressively more effective and selective dopaminergic drugs.

Benabid, A. L., A. Koudsie, et al. (2001). "Deep brain stimulation for Parkinson's disease." Adv Neurol 86: 405-12.

Berardelli, A., J. C. Rothwell, et al. (2001). "Pathophysiology of bradykinesia in Parkinson's disease." Brain 124(Pt 11): 2131-46.
Bradykinesia means slowness of movement and is one of the cardinal manifestations of Parkinson's disease. Weakness, tremor and rigidity may contribute to but do not fully explain bradykinesia. We argue that bradykinesia results from a failure of basal ganglia output to reinforce the cortical mechanisms that prepare and execute the commands to move. The cortical deficit is most apparent in midline motor areas. This leads to particular difficulty with self-paced movements, prolonged reaction times and abnormal pre-movement EEG activity. Movements are often performed with normally timed EMG bursts but the amount of EMG activity is underscaled relative to the desired movement parameters. There are also abnormalities in sensory scaling and sensorimotor integration. The brain appears to be able to compensate to some degree for the basal ganglia deficit. There is overactivity in the lateral premotor areas during task performance and movements can be speeded by giving sensory cues. Attention to movement is also beneficial. However, we propose that the engagement of compensatory processes may also lead to reduced performance in other tasks. For example, patients' problems in performing more than one task at the same time could result from lack of sufficient resources both to compensate for their basal ganglia deficit and to run two tasks simultaneously. Surgical therapies are unlikely to work solely by normalizing basal ganglia output to that seen in healthy individuals. It seems more plausible that surgery removes an interfering signal that allows more efficient compensation by other structures.

Berciano, J. (2001). "[Genetics in Parkinson's disease: toward a new nosological era]." Med Clin (Barc) 116(16): 614-6.

Berg, D., M. Gerlach, et al. (2001). "Brain iron pathways and their relevance to Parkinson's disease." J Neurochem 79(2): 225-36.
A central role of iron in the pathogenesis of Parkinson's disease (PD), due to its increase in substantia nigra pars compacta dopaminergic neurons and reactive microglia and its capacity to enhance production of toxic reactive oxygen radicals, has been discussed for many years. Recent transcranial ultrasound findings and the observation of the ability of iron to induce aggregation and toxicity of alpha-synuclein have reinforced the critical role of iron in the pathogenesis of nigrostriatal injury. Presently the mechanisms involved in the disturbances of iron metabolism in PD remain obscure. In this review we summarize evidence from recent studies suggesting disturbances of iron metabolism in PD at possibly different levels including iron uptake, storage, intracellular metabolism, release and post-transcriptional control. Moreover we outline that the interaction of iron with other molecules, especially alpha-synuclein, may contribute to the process of neurodegeneration. Because many neurodegenerative diseases show increased accumulation of iron at the site of neurodegeneration, it is believed that maintenance of cellular iron homeostasis is crucial for the viability of neurons.

Bezard, E., J. M. Brotchie, et al. (2001). "Pathophysiology of levodopa-induced dyskinesia: potential for new therapies." Nat Rev Neurosci 2(8): 577-88.
Involuntary movements--or dyskinesias--are a debilitating complication of levodopa therapy for Parkinson's disease, and is experienced in most patients. Despite the importance of this problem, little was known about the cause of dyskinesia until recently; however, this situation has changed significantly in the past few years. Our increased understanding of levodopa-induced dyskinesia is not only valuable for improving patient care, but also in providing us with new insights into the functional organization of the basal ganglia and motor systems.

Bhatia, K., D. J. Brooks, et al. (2001). "Updated guidelines for the management of Parkinson's disease." Hosp Med 62(8): 456-70.
New data on diagnosis, drug therapy, surgery and psychosocial concerns have emerged since the publication of the 1998 Guidelines for the Management of Parkinson's Disease. This article reviews new data and addresses issues left unanswered in the previous guidelines.

Bjarkam, C. R., J. C. Sorensen, et al. (2001). "New strategies for the treatment of Parkinson's disease hold considerable promise for the future management of neurodegenerative disorders." Biogerontology 2(3): 193-207.
Neurodegenerative diseases are often considered incurable with no efficient therapies to modify or halt the progress of disease, and ultimately lead to reduced quality of life and to death. Our knowledge of the nervous system in health and disease has, however, increased considerably during the last fifty years and today, neuroscience reveals promising new strategies to deal with disorders of the nervous system. Some of these results have been implemented with success in the treatment of Parkinson's disease, a common neurodegenerative illness affecting approximately 1% of the population aged seventy or more. Parkinson's disease is characterized by a massive loss of dopaminergic neurons in the substantia nigra, leading to severe functional disturbance of the neuronal circuitry in the basal ganglia. A thorough description of basal ganglia circuitry in health and disease is presented. We describe how the functional disturbances seen in Parkinson's disease may be corrected at specific sites in this circuitry by medical treatment or, in advanced stages of Parkinson's disease, by neurosurgical methods. The latter include lesional surgery, neural transplantation and deep brain stimulation, together with future treatment strategies using direct or indirect implantation of genetically modified cell-lines capable of secreting neurotrophic factors or neurotransmitters. Advantages and disadvantages are briefly mentioned for each strategy and the implications for the future and the possible use of these interventions in other neurodegenerative diseases are discussed, with special emphasis on deep brain stimulation.

Blass, J. P. (2001). "Brain metabolism and brain disease: is metabolic deficiency the proximate cause of Alzheimer dementia?" J Neurosci Res 66(5): 851-6.
The potential of impairments in oxidative/energy metabolism to cause diseases of the brain had been proposed even before the major pathways of oxidative/energy metabolism were described. Deficiencies associated with disease are known in all the pathways of oxidative/energy metabolism and are associated with some of the most common disorders of the nervous system, including Alzheimer's disease (AD) and Parkinson's disease. A common mechanism in these conditions appears to be a downward mitochondrial spiral, involving abnormalities in energy metabolism, calcium metabolism, and free radicals (reactive oxygen and nitrogen species). In AD, the spiral appears to interact with abnormalities in the metabolism of the Alzheimer amyloid precursor protein (APP) and its Abeta fragment. Several lines of evidence indicate that the mitochondrial spiral may be a proximate cause of the clinical disabilities in AD. Decreases in cerebral metabolic rate (CMR) characteristically occur in AD and in other dementias. Inducing decreases in CMR leads to clinical disabilities characteristically associated with AD and with analogous problems in experimental animals. Treatments directed toward normalizing CMR appear to help at least some patients. Further studies of this possibility and of treatments designed to ameliorate the mitochondrial spiral may prove useful for treating AD and perhaps some other dementing disorders.

Block, F. and C. M. Kosinski (2001). "[Glutamate antagonists in neurology]." Nervenarzt 72(6): 393-405.
Glutamate is the major excitatory neurotransmitter of the central nervous system. Besides its importance in many physiological processes, increased glutamate release and subsequent excessive stimulation of the various glutamate receptors are thought to play critical roles in the pathophysiological mechanisms underlying many neurologic diseases. Experimental data suggest that blockade of glutamate receptors or inhibition of glutamate release has positive effects in many disease models. Glutamate antagonists are already in clinical use for the treatment of Parkinson's disease, epilepsy, spasticity, and neuropathic pain. Overall, glutamate antagonists have not been found clinically effective for neuroprotective treatment of cerebral ischemia or chronic neurodegenerative diseases, with one exception. Side effects of glutamate antagonists can be mainly attributed to central mechanisms and include psychosis, agitation, and disorientation. It is to be hoped that further development of new glutamate antagonists that block disease-relevant subtypes of glutamate receptors will lead to more effective drugs with fewer side effects.

Bloem, B. R., J. P. van Vugt, et al. (2001). "Postural instability and falls in Parkinson's disease." Adv Neurol 87: 209-23.

Blum, D., S. Torch, et al. (2001). "Molecular pathways involved in the neurotoxicity of 6-OHDA, dopamine and MPTP: contribution to the apoptotic theory in Parkinson's disease." Prog Neurobiol 65(2): 135-72.
Parkinson's disease (PD) is a neurodegenerative disorder characterized by a preferential loss of the dopaminergic neurons of the substantia nigra pars compacta. Although the etiology of PD is unknown, major biochemical processes such as oxidative stress and mitochondrial inhibition are largely described. However, despite these findings, the actual therapeutics are essentially symptomatical and are not able to block the degenerative process. Recent histological studies performed on brains from PD patients suggest that nigral cell death could be apoptotic. However, since post-mortem studies do not allow precise determination of the sequence of events leading to this apoptotic cell death, the molecular pathways involved in this process have been essentially studied on experimental models reproducing the human disease. These latter are created by using neurotoxic compounds such as 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or dopamine (DA). Extensive study of these models have shown that they mimick, in vitro and in vivo, the histological and/or the biochemical characteristics of PD and thus help to define important cellular actors of cell death presumably critical for the nigral degeneration. This review reports recent data concerning the biochemical and molecular apoptotic mechanisms underlying the experimental models of PD and correlates them to the phenomena occurring in human disease.

Borbely, K. (2001). "[Functional neuroimaging in movement disorders]." Orv Hetil 142(43): 2347-55.
Positron Emission Tomography (PET) and Single Photon Emission. Computed Tomography (SPECT) highly contribute to the management of patients with movement disorders by measuring regional cerebral metabolism/blood flow and dopamine receptors. Imaging of the dopaminergic system is a powerful tool for distinguishing patients with neurodegenerative disorders, such as Parkinson's disease. Parkinsonism is most of the time caused by idiopathic Parkinson's disease. Considering the differences in therapeutic response and prognosis, differentiation between Parkinson's disease and "parkinsonism-plus syndromes" is important. Visualisation of pre- and post-synaptic D2 dopamine receptors by using receptor ligands helps to discriminate between Parkinson's disease and "parkinsonism-plus syndromes" as Parkinson's disease is a presynaptic disease. Early disease detection in subjects suspected at risk for developing Parkinson's disease has become possible using ligands for the dopamine transporter. Functional imaging modalities are useful in the management of patients with movement disorders, are able to monitor in an objective way the efficacy of new pharmacological therapies, can document the effect of neuronal grafting for Parkinson's disease, and delineate the progression of these diseases.

Boulu, R. G., C. Mesenge, et al. (2001). "[Neuronal death: potential role of the nuclear enzyme, poly (ADP-ribose) polymerase]." Bull Acad Natl Med 185(3): 555-63; discussion 564-5.
Poly(ADP-ribose) polymerase (PARP, EC 2.4.2.30) is known as a nuclear enzyme that is activated by DNA strand breaks to participate in DNA repair. It is also called poly(ADP-ribose) synthase (PARS) or poly(ADP-ribose) transferase (PADRT). In physiological conditions, PARP plays an important role in maintaining genomic stability. However, for several pathological situations, which include massive DNA injury (brain ischemia for example), excessive activation of PARP can deplete stores of nicotinamide adenine dinucleotide (NAD+), the PARP substrate, which, with the subsequent ATP depletion, leads to cell death. PARP activation appears to play a major role in neuronal death induced by cerebral ischemia, traumatic brain injury, Parkinson disease and other pathologies. PARP inhibitors (3-aminobenzamide and other compounds) and PARP gene deletion induced dramatic neuroprotection in experimental animals (rats, mice). Accordingly, these data suggest that PARP inhibitors could provide a novel therapeutic approach in a wide range of neurodegenerative disorders including cerebral ischemia and traumatic brain injury.

Brody, J. A. and M. D. Grant (2001). "Age-associated diseases and conditions: implications for decreasing late life morbidity." Aging (Milano) 13(2): 64-7.
We discuss two types of age-associated diseases; aging-dependent such as Alzheimer's disease and congestive heart failure which increase logarithmically with age, versus age-dependent such as multiple sclerosis and amyotrophic lateral sclerosis which occur at proscribed ages, and then occurrence of new cases ceases or diminishes with further aging. Prevention strategies with both types emphasize postponement or delay of onset. The non-fatal aging-dependent diseases and conditions are an accumulating burden as we age, and increase overall morbidity in late years. These include Alzheimer's disease and other dementias, Parkinson's disease, loss of vision and hearing, incontinence, osteoporosis and hip fracture, osteoarthritis and depression. With mortality postponed, we will be living for many years at old and vulnerable ages. Life's quality will be reasonable for most. Still, increasing the chance that all will experience this desirable outcome requires pursuing the means to delay the onset of the physical and social events which we categorize as the non-fatal aging-dependent diseases and conditions. We must recognize that each added year occurs at the tip of an exponential curve where risk is maximal.

Brooks, D. J. (2001). "Cerebral blood flow activation studies in Parkinson's disease." Adv Neurol 86: 225-35.

Brooks, D. J. and M. Doder (2001). "Depression in Parkinson's disease." Curr Opin Neurol 14(4): 465-70.

Burn, D. J. and E. Jaros (2001). "Multiple system atrophy: cellular and molecular pathology." Mol Pathol 54(6): 419-26.
Multiple system atrophy is an adult onset neurodegenerative disease, featuring parkinsonism, ataxia, and autonomic failure, in any combination. The condition is relentlessly progressive and responds poorly to treatment. Death occurs on average six to seven years after the onset of symptoms. No familial cases of multiple system atrophy have been reported, and no environmental factors have been robustly implicated as aetiological factors. However, analytical epidemiological studies are hampered because the condition is relatively rare. The discovery of the glial cytoplasmic inclusion (GCI) in 1989 helped to define multiple system atrophy as a clinicopathological entity, and drew attention to the prominent, if not primary, role played by the oligodendrocyte in the pathogenesis of the condition. Subsequently, GCIs were shown to be positive for alpha-synuclein, with immunostaining for this protein indicating that white matter pathology was more widespread than had previously been recognised. The presence of alpha-synuclein in GCIs provides a link with Parkinson's disease, dementia with Lewy bodies, and neurodegeneration with brain iron accumulation, type 1 (or Hallervorden-Spatz syndrome), in which alpha-synuclein is also found within Lewy bodies. This has led to the term "synucleinopathy" to embrace this group of conditions. The GCIs of multiple system atrophy contain a range of other cytoskeletal proteins. It is unknown how fibrillogenesis occurs, and whether there is primary oligodendrocytic dysfunction, which then disrupts the neurone/axon as a consequence of the glial pathology, or whether the oligodendrocytic changes merely represent an epiphenomenon. Further research into this devastating condition is urgently needed to improve our understanding of the pathogenesis, and also to produce new treatment approaches.

Bush, A. I. and L. E. Goldstein (2001). "Specific metal-catalysed protein oxidation reactions in chronic degenerative disorders of ageing: focus on Alzheimer's disease and age-related cataracts." Novartis Found Symp 235: 26-38; discussion 38-43.
Abnormalities of protein aggregation and deposition may play an important role in the pathophysiology of a diverse set of chronically progressive degenerative disorders including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease and age-related cataracts. We propose that aberrant metalloprotein reactions may be a common denominator in these diseases. In these instances, an abnormal reaction between a protein and redox active metal ions (especially copper or iron) promotes the generation of reactive oxygen species, and possibly, protein radicalization. These products then lead to chemical modification of the protein, alterations in protein structure and solubility, and oxidative damage to surrounding tissue. In this review, we explore these ideas by focusing on two common diseases of ageing, Alzheimer's disease and age-related cataracts. Understanding the metalloprotein biochemistry in both diseases may lead to a better understanding of the underlying pathophysiology in both disorders and suggest novel targets for therapeutic agents.

Butterfield, D. A. and J. Kanski (2001). "Brain protein oxidation in age-related neurodegenerative disorders that are associated with aggregated proteins." Mech Ageing Dev 122(9): 945-62.
Protein oxidation, one of a number of brain biomarkers of oxidative stress, is increased in several age-related neurodegenerative disorders or animal models thereof, including Alzheimer's disease, Huntington's disease, prion disorders, such as Creutzfeld-Jakob disease, and alpha-synuclein disorders, such as Parkinson's disease and frontotemporal dementia. Each of these neurodegenerative disorders is associated with aggregated proteins in brain. However, the relationship among protein oxidation, protein aggregation, and neurodegeneration remain unclear. The current rapid progress in elucidation of mechanisms of protein oxidation in neuronal loss should provide further insight into the importance of free radical oxidative stress in these neurodegenerative disorders.

Byerly, M. J., M. T. Weber, et al. (2001). "Antipsychotic medications and the elderly: effects on cognition and implications for use." Drugs Aging 18(1): 45-61.
Despite being frequently prescribed in the elderly, antipsychotic medications are commonly associated with adverse effects in this population, including sedative, orthostatic and extrapyramidal adverse effects. Growing evidence suggests that antipsychotics can also cause deleterious cognitive effects in some elderly patients. Preclinical and growing clinical evidence indicates that inhibitory effects on dopaminergic, cholinergic and histaminergic neurochemical systems may account for antipsychotic-associated cognitive impairment in the elderly. A review of published reports of the cognitive effects of antipsychotics in the elderly suggests that newer antipsychotic medications may possess a more favourable cognitive profile than that of traditional agents in this population. The cognitive effect that a specific antipsychotic will have in the elderly, however, is likely better predicted by considering the pharmacodynamic action of an individual agent in combination with the pathophysiology of the condition being treated. Agents with relatively weak dopamine inhibiting effects (e.g. clozapine and quetiapine), for example, would theoretically have a cognitive profile superior to that of agents with higher degrees of dopaminergic inhibition (all traditional agents, risperidone, olanzapine and ziprasidone) when used for conditions associated with diminished dopamine function (e.g. idiopathic Parkinson's disease). Drugs with weak anticholinergic effects (high-potency traditional agents, risperidone, quetiapine and ziprasidone) would theoretically be less likely to cause cognitive impairment than agents with high degrees of cholinergic receptor blocking actions (clozapine and olanzapine) when treating patients with impaired cholinergic function (e.g. Alzheimer's disease). Cholinergic agonist effects of clozapine and olanzapine may, however, mitigate potential adverse cognitive effects associated with the cholinergic blocking actions of these agents. Large, rigorous trials comparing the cognitive effects of antipsychotics with diverse pharmacodynamic actions are lacking in the elderly and are needed.

Calabrese, V., G. Scapagnini, et al. (2001). "Mitochondrial involvement in brain function and dysfunction: relevance to aging, neurodegenerative disorders and longevity." Neurochem Res 26(6): 739-64.
It is becoming increasingly evident that the mitochondrial genome may play a key role in neurodegenerative diseases. Mitochondrial dysfunction is characteristic of several neurodegenerative disorders, and evidence for mitochondria being a site of damage in neurodegenerative disorders is partially based on decreases in respiratory chain complex activities in Parkinson's disease, Alzheimer's disease, and Huntington's disease. Such defects in respiratory complex activities, possibly associated with oxidant/antioxidant balance perturbation, are thought to underlie defects in energy metabolism and induce cellular degeneration. Efficient functioning of maintenance and repair process seems to be crucial for both survival and physical quality of life. This is accomplished by a complex network of the so-called longevity assurance processes, which are composed of genes termed vitagenes. A promising approach for the identification of critical gerontogenic processes is represented by the hormesis-like positive effect of stress. In the present review, we discuss the role of energy thresholds in brain mitochondria and their implications in neurodegeneration. We then review the evidence for the role of oxidative stress in modulating the effects of mitochondrial DNA mutations on brain age-related disorders and also discuss new approaches for investigating the mechanisms of lifetime survival and longevity.

Carpenter, D. O. (2001). "Effects of metals on the nervous system of humans and animals." Int J Occup Med Environ Health 14(3): 209-18.
Several metals have toxic actions on nerve cells and neurobehavorial functioning. These toxic actions can be expressed either as developmental effects or as an increased risk of neurodegenerative diseases in old age. The major metals causing neurobehavioral effects after developmental exposure are lead and methylmercury. Lead exposure in young children results in a permanent loss of IQ of approximately 5 to 7 IQ points, and also results in a shortened attention span and expression of anti-social behaviors. There is a critical time period (<2 years of age) for development of these effects, after which the effects do not appear to be reversible even if blood lead levels are lowered with chelation. Methylmercury has also been found to have effects on cognition at low doses, and prenatal exposure at higher levels can disrupt brain development. Metals have also been implicated in neurodegenerative diseases, although it is unlikely that they are the sole cause for any of them. Elevated aluminum levels in blood, usually resulting from kidney dialysis at home with well water containing high aluminum, result in dementia that is similar to but probably different from that of Alzheimer's disease. However, there is some epidemiological evidence for elevated risk of Alzheimer's in areas where there is high concentration of aluminum in drinking water. Other metals, especially lead, mercury, manganese and copper, have been implicated in amvotrophic lateral sclerosis and Parkinson's disease.

Ceravolo, M. G., L. Paoloni, et al. (2001). "Rehabilitation of parkinsonian patients." Funct Neurol 16(2): 157-62.

Chan, D. K. (2001). "Parkinson disease and its differentials. Diagnoses made easy." Aust Fam Physician 30(11): 1053-6.
BACKGROUND: Parkinson disease is a common neurological disorder that is both underdiagnosed and inaccurately diagnosed. There is no reliable biological marker or test that can differentiate between causes of parkinsonism. Even for experienced clinicians, the clinical diagnostic accuracy compared to post mortem findings is about 80%. OBJECTIVE: To discuss the clinical features that differentiate Parkinson disease from other important causes of parkinsonism. DISCUSSION: Although Parkinson disease is a common cause of parkinsonism, other candidates such as drug reactions, benign essential tremor, vascular disease and Lewy body dementia need to be differentiated. Incorrect diagnosis can result in complications related particularly to the use of levodopa and antipsychotic agents. Diagnostic accuracy is important to ensure appropriate management, to avoid complications and to assist patients to have realistic expectations and prognostic information about their condition.

Chan, D. T., V. C. Mok, et al. (2001). "Surgical management of Parkinson's disease: a critical review." Hong Kong Med J 7(1): 34-9.
Parkinson's disease is a progressive disabling movement disorder that is characterised by three cardinal symptoms: resting tremor, rigidity, and bradykinesia. Before the availability of effective medical treatment with levodopa and stereotactic neurosurgery, the objective of surgical management was to alleviate symptoms such as tremor at the expense of motor deficits. Levodopa was the first effective medical treatment for Parkinson's disease, and surgical treatment such as stereotactic thalamotomy became obsolete. After one decade of levodopa therapy, however, drug-induced dyskinesia had become a source of additional disability not amenable to medical treatment. Renewed interest in stereotactic functional neurosurgery to manage Parkinson's disease has been seen since the 1980s. Local experience of deep-brain stimulation is presented and discussed in this paper. Deep-brain stimulation of the subthalamic nucleus is an effective treatment for advanced Parkinson's disease, although evidence from randomised control trials is lacking.

Chan, P. L. and N. H. Holford (2001). "Drug treatment effects on disease progression." Annu Rev Pharmacol Toxicol 41: 625-59.
Degenerative diseases are characterized by a worsening of disease status over time. The rate of deterioration is determined by the natural rate of progression of the disease and by the effect of drug treatments. A goal of drug treatment is to slow disease progression. Drug treatments can be categorized as symptomatic or protective. Symptomatic treatments do not affect the rate of disease progression whereas protective treatments have the ability to slow disease progression down. Many current methods for describing disease progression have two common drawbacks: a linear relationship between time and disease status is assumed, and within- and between-subject variability is ignored. Disease progress models combined with pharmacokinetic pharmacodynamic models and hierarchical random effects statistical models provide insights into understanding the time course and management of degenerative disease.

Chase, T. N., S. Konitsiotis, et al. (2001). "Striatal molecular mechanisms and motor dysfunction in Parkinson's disease." Adv Neurol 86: 355-60.

Chaudhuri, K. R. (2001). "Autonomic dysfunction in movement disorders." Curr Opin Neurol 14(4): 505-11.
Dysfunction of the autonomic nervous system is an under-recognised but important aspect of the aetiological and clinical manifestation of primary degenerative dysautonomias such as multiple system atrophy (MSA) and Parkinson's disease (PD). Although the clinical presentation of dysautonomia in these two disorders may overlap, yet pathological and in vivo imaging studies suggest considerable differences. Functional imaging studies suggest that selective cardiac sympathetic denervation may occur early in PD but not in other parkinsonian syndromes. The clinical implication of this apparently disease specific peripheral dysautonomia is unknown and would be the subject of much interest in future years. Dysautonomia in degenerative disorders also affect respiration, genitourinary function and sleep. Sleep related disorders such as rapid eye movement behaviour disorder and urinary voiding dysfunction appear to precede the development of PD related symptoms while patients with sporadic ataxia have been shown to progress to develop MSA. Dysautonomia has also been recognised in other movement disorders, examples being the combination of dystonia and complex regional pain syndrome with elevated HLA-DR13 and late onset Huntington's disease presenting with dominant parkinsonism and minimal chorea. These studies have helped progress in various diagnostic and management parameters in relation to autonomic dysfunction and movement disorders.

Chazot, P. L. (2001). "Safinamide (Newron Pharmaceuticals)." Curr Opin Investig Drugs 2(6): 809-13.
Safinamide (formerly PNU-151774E), a sodium and calcium channel modulator that also inhibits monoamine oxidase B (MAOB), is under development by Newron Pharmaceuticals for the potential treatment of epilepsy, Parkinson's disease (PD), pain and stroke [345222], [348351]. Phase I trials for epilepsy and PD have been completed, and dose-finding studies for both indications had commenced in March 2001 [401685]. The compound was previously developed by Pharmacia & Upjohn (P&U) for the potential treatment of epilepsy, an indication for which it initially reached phase I trials [294891], [345007]. Newron acquired the rights to safinamide from P&U at the end of 1998. Results from two phase I trials of the compound (single ascending dose and steady state at three doses), completed in March 2000, demonstrated that the drug is well tolerated with good bioavailability and linear pharmacokinetics [359652].

Chollet, F., I. Loubinoux, et al. (2001). "[Pharmacologic modification of cerebral activity: value of functional neuroimaging]." Rev Neurol (Paris) 157(8-9 Pt 1): 827-31.

Clarke, C. E. and M. Lowry (2001). "Systematic review of proton magnetic resonance spectroscopy of the striatum in parkinsonian syndromes." Eur J Neurol 8(6): 573-7.
It has been suggested that proton magnetic resonance spectroscopy (MRS) of the striatum can differentiate between parkinsonian syndromes. The present study aims to examine this claim by performing a systematic review of the existing literature. A MEDLINE search was performed between 1966 and October 1999, along with searches of conference abstracts and reference lists of papers identified. Eleven groups have used MRS to examine metabolite ratios in the striatum in Parkinsonian syndromes. A number of these have shown reduced N-acetylaspartate/choline (NAA/Cho) and/or N-acetylaspartate/creatine (NAA/Cr) ratios in either idiopathic Parkinson's disease (IPD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP) or corticobasal degeneration. However, the heterogeneity in the results precludes the use of any of these findings in differential diagnosis at the present time. The only group to use absolute metabolite concentrations rather than ratios showed that the decreased NAA/Cho ratio in IPD was because of an increase in choline which is of uncertain biological significance. Further large multicentre trials are required using absolute quantitation of tissue metabolite concentrations and a standardized technique. The patients entering such studies must be rigorously assessed to establish the diagnosis of the type of parkinsonism as accurately as possible. Any discriminatory abnormality must be tested in a large prospective study of newly presenting parkinsonian patients with long-term clinical follow up and ultimate pathological confirmation of the diagnosis as far as possible.

Clarke, C. E. and K. D. Deane (2001). "Cabergoline versus bromocriptine for levodopa-induced complications in Parkinson's disease." Cochrane Database Syst Rev(1): CD001519.
BACKGROUND: Long term levodopa therapy in Parkinson's disease is associated with the development of motor complications including abnormal involuntary movements and a shortening response to each dose (wearing off phenomenon). It is thought that dopamine agonists can reduce the duration of immobile off periods and the need for levodopa therapy whilst maintaining or improving motor impairments and only minimally increasing dopaminergic adverse events. OBJECTIVES: To compare the efficacy and safety of adjuvant cabergoline therapy versus bromocriptine in patients with Parkinson's disease, already established on levodopa and suffering from motor complications. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with Pharmacia Upjohn Limited. SELECTION CRITERIA: Randomised controlled trials of cabergoline versus bromocriptine in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data were abstracted independently by the authors and differences settled by discussion. The outcome measures used included Parkinson's disease rating scales, levodopa dosage, off time measurements and the frequency of withdrawals and adverse events. MAIN RESULTS: Cabergoline has been compared with bromocriptine in five randomised, double-blind, parallel group studies including 1071 patients. Only one of the phase II studies was medium term (36 weeks), the others all being short term (12 -15 weeks). The non-significant difference in off time reduction produced by cabergoline compared with bromocriptine was 0.29 hours/day in favour of the former (weighted mean difference; 95% CI -0.10, 0.68; p = 0.15). Dyskinesia reported as an adverse event was significantly increased with cabergoline compared with bromocriptine (Peto odds ratio 1.57; 95% CI 1.05, 2.35; p = 0.03). Motor impairment and disability were measured in four of the studies using the UPDRS rating scale but the small differences in UPDRS ADL (part II) and motor (part III) scores were not statistically significant in any study. Similarly, no significant difference in Schwab and England score was seen. The number of patients rated as much or very much improved on a clinician's global impression scale was similar with both agonists. Levodopa dose reduction was no different between cabergoline and bromocriptine. There was more confusion with cabergoline (Peto odds ratio 2.02; 95% CI 1.09, 3.76; p = 0.03). Otherwise, dopaminergic adverse events were comparable with these agonists and no significant difference in all cause withdrawal rate was found. REVIEWER'S CONCLUSIONS: Cabergoline produces similar benefits to bromocriptine in off time reduction, motor impairment and disability ratings, and levodopa dose reduction over the first three months of therapy. Dyskinesia and confusion were increased with cabergoline but otherwise the frequency of adverse events and withdrawals from treatment were similar with the two agonists.

Clarke, C. E. and K. H. Deane (2001). "Cabergoline for levodopa-induced complications in Parkinson's disease." Cochrane Database Syst Rev(1): CD001518.
BACKGROUND: Long term levodopa therapy in Parkinson's disease is associated with the development of motor complications including abnormal involuntary movements and a shortening response to each dose (wearing off phenomenon). It is thought that dopamine agonists can reduce the duration of immobile off periods and the need for levodopa therapy whilst maintaining or improving motor impairments and only minimally increasing dopaminergic adverse events. OBJECTIVES: To compare the efficacy and safety of adjuvant cabergoline therapy versus placebo in patients with Parkinson's disease, already established on levodopa and suffering from motor complications. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with Pharmacia Upjohn Limited. SELECTION CRITERIA: Randomised controlled trials of cabergoline versus placebo in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by the authors and differences settled by discussion. The outcome measures used included Parkinson's disease rating scales, levodopa dosage, off time measurements and the frequency of withdrawals and adverse events. MAIN RESULTS: Cabergoline has been compared with placebo in two phase II (6 - 12 weeks) and one phase III randomised controlled trials (24 weeks). These were double-blind, parallel group, multicentre studies including 268 patients with Parkinson's disease and motor complications. The reduction of 1.14 hours (WMD; 95% CI -0.06, 2.33; p = 0.06) in off time in favour of cabergoline was not statistically significant. Inadequate data on dyskinesia was collected either on rating scales or as adverse event reporting to allow a conclusion to be drawn. A small but statistically significant advantage of cabergoline over placebo was seen in one study for UPDRS ADL (part II) score and UPDRS motor score. No such advantage was seen in one other study due to small numbers of patients and the comparatively low doses of cabergoline used. No significant differences in Schwab and England scale were seen in two studies. Levodopa dose reduction was significantly greater with cabergoline (WMD 149.6 mg/d; 95% CI 94.1, 205.1; p < 0.00001). There was a trend towards more dopaminergic adverse events with cabergoline but this did not reach statistical significance at the p < 0.01 level. However, there was a trend towards fewer withdrawals from cabergoline. REVIEWER'S CONCLUSIONS: In the management of the motor complications seen in Parkinson's disease, cabergoline can be used to reduce levodopa dose and modestly improve motor impairment and disability with an acceptable adverse event profile. These conclusions are based on, at best, medium term evidence.

Clarke, C. E. and K. H. Deane (2001). "Ropinirole versus bromocriptine for levodopa-induced complications in Parkinson's disease." Cochrane Database Syst Rev(1): CD001517.
BACKGROUND: Long-term levodopa therapy for Parkinson's disease is complicated by the development of motor fluctuations and abnormal involuntary movements. One approach is to add a dopamine agonist at this stage of the disease to reduce the time the patient spends immobile or off and to reduce the dose of levodopa in the hope of reducing such problems in the future. OBJECTIVES: To compare the efficacy and safety of adjuvant ropinirole therapy with bromocriptine in patients with Parkinson's disease already established on levodopa therapy and suffering from motor complications. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with SmithKline Beecham. SELECTION CRITERIA: Randomised controlled trials of ropinirole versus bromocriptine in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by the authors and differences settled by discussion. The outcome measures used included Parkinson's disease rating scales, levodopa dosage, 'off' time measurements and the frequency of withdrawals and adverse events. MAIN RESULTS: In the 3 trials identified, no significant differences between ropinirole and bromocriptine were found in off time reduction, dyskinesia as an adverse event, motor impairment and disability, or levodopa dose reduction. Withdrawal rates and adverse event frequency were similar with the two agents apart from significantly less nausea with ropinirole (odds ratio 0.50; 0.29, 0.84 95% CI; p =0.01). REVIEWER'S CONCLUSIONS: Ropinirole is at least as good as bromocriptine in patients with Parkinson's disease with motor complications in terms of improving off time and reducing levodopa dose, without increasing adverse events including dyskinesia. However, these comparitor studies may have been underpowered to detect clinically meaningful differences between the agonists. Further, much larger, phase IV studies are required to examine the efficacy, effectiveness, and safety of all of the dopamine agonists as adjuvant therapy in Parkinson's disease.

Clarke, C. E. and K. H. Deane (2001). "Ropinirole for levodopa-induced complications in Parkinson's disease." Cochrane Database Syst Rev(1): CD001516.
BACKGROUND: Long-term levodopa therapy for Parkinson's disease is complicated by the development of motor fluctuations and abnormal involuntary movements. One approach is to add a dopamine agonist at this stage of the disease to reduce the time the patient spends immobile or off and to reduce the dose of levodopa in the hope of reducing such problems in the future. OBJECTIVES: To compare the efficacy and safety of adjuvant ropinirole therapy versus placebo in patients with Parkinson's disease already established on levodopa therapy and suffering from motor complications. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with SmithKline Beecham. SELECTION CRITERIA: Randomised controlled trials of ropinirole versus placebo in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by the authors and differences settled by discussion. The outcome measures used included Parkinson's disease rating scales, levodopa dosage, 'off' time measurements and the frequency of withdrawals and adverse events. MAIN RESULTS: Three double-blind, parallel group, randomised, controlled trials have been conducted on 263 patients. The two phase II studies were relatively small, were conducted over the short term (12 weeks), and used relatively low doses of ropinirole (mean administered doses 3.3 and 3.5 mg/d) in a twice daily regime. In view of this clinical heterogeneity and some statistical heterogeneity, the results of these trials have not been included in a meta-analysis. The conclusions of this review are based on the evidence from a single phase III study which was medium term (26 weeks) and used ropinirole doses in line with the current UK licensed maximum in a thrice daily regime. In view of difficulties in assessing changes in off time in ~~ Leiberman 98~~, caused by the initial imbalance between the arms of the trial, it is unsafe to draw any firm conclusion about the effect of ropinirole on off time. However, as an adverse event, dyskinesia was significantly increased in those who received ropinirole (~~ Leiberman 98~~; odds ratio 2.90; 1.36, 6.19 95% CI; Table 8). Measurements of motor impairments and disability were poor in this study with incomplete information available. Levodopa dose could be reduced in ~~ Leiberman 98~~ with a significantly larger reduction on ropinirole than on placebo (weighted mean difference 180 mg/d; 106, 253 95% CI; Table 2). No significant differences in the frequency of adverse event reports were noted between ropinirole and placebo apart from the increase in dyskinesia with ropinirole. There was a trend towards fewer withdrawals from ropinirole in ~~ Leiberman 98~~ but this did not reach statistical significance. REVIEWER'S CONCLUSIONS: Ropinirole therapy can reduce levodopa dose but at the expense of increased dyskinetic adverse events. No clear effect on off time reduction was found but this may have been due to the under-powering of the single evaluable trial. Inadequate data on motor impairments and disability was collected to assess these outcomes. These conclusions apply to short and medium term treatment, up to 26 weeks. Further longer term trials are required, with measurements of effectiveness, and also studies to compare the newer with the older dopamine agonists.

Clarkson, E. D. (2001). "Fetal tissue transplantation for patients with Parkinson's disease: a database of published clinical results." Drugs Aging 18(10): 773-85.
Over the past 13 years approximately 300 patients with Parkinson's disease have received transplants of human fetal dopamine cells in an attempt to reduce or control disease symptoms. Many of these patients have had improvements in their motor skills and a reduction in their daily levodopa administration. However, improvements are far from guaranteed and questions need to be answered before this technique can be widely applied. To help address some of these issues, a search of all the published results of patients with Parkinson's disease transplanted with human fetal tissue was conducted. This generated a database of 70 transplant recipients who had their levodopa administration and clinical benefit reported both prior to transplant and at least 6 months post-transplant. Furthermore, the number of years of disease onset prior to transplant was available for all recipients. This database was examined for motor improvement and reduction in levodopa dosage for up to 2 years post-transplant to determine the effects of time on transplant outcome. The database showed that most recipients had significant improvements in motor skills and levodopa administration, and that most benefits were observed in the first 6 months post-transplant. In addition, the database demonstrated that the number of years of disease onset prior to transplantation was not a predictor of patient outcome 1-year post-transplant. Current and future directions in fetal tissue transplantation research and replacements for fetal tissue are discussed.

Clostre, F. (2001). "[Mitochondria: recent pathophysiological discoveries and new therapeutic perspectives]." Ann Pharm Fr 59(1): 3-21.
Until about a decade ago, few researchers in clinical or evolutionary biology paid much attention to mitochondria. But over the years, as technological advances in molecular biology made nuclear functions more accessible to them, interest in mitochondria began to revive. First, geneticists started tracing certain rare inherited disorders to mutations in the mitochondria's circular genome. More recently, other researchers have speculated that mitochondria might contribute to aging, either by releasing tissue-damaging reactive oxygen molecules or by impairing and depriving the cell of the energy it needs to function. One the most important recent developments has been the recognition that mitochondria play a central role in the regulation of programmed cell death, or apoptosis. Now, we know that mitochondria play a decisive role in life-death decisions for the cell and may choose between the apoptotic and necrotic pathways. Mitochondria can trigger cell death in a number of ways: by disrupting electron transport and energy metabolism, by activating the mitochondrial permeability transition, by releasing and/or activating proteins that mediate apoptosis. Any or all of these mechanisms may help to explain how mitochondrial defects contribute to the pathogenesis of neuronal death or dysfunction in ischemia/reperfusion injury as well as in human degenerative diseases including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and Huntington's disease. This has opened up new avenues for understanding the pathogenesis of neurodegeneration and may lead to new and more effective therapeutic approaches to these diseases.

Connor, B. (2001). "Adenoviral vector-mediated delivery of glial cell line-derived neurotrophic factor provides neuroprotection in the aged parkinsonian rat." Clin Exp Pharmacol Physiol 28(11): 896-900.
1. The long-term delivery of neurotrophic factors to specific regions of the central nervous system via gene therapy offers a new strategy for the treatment of neurodegenerative disorders. 2. The neurotrophic factor glial cell line-derived neurotrophic factor (GDNF) is a potent dopaminergic (DA) trophic factor that ameliorates the behavioural and histological consequences of lesioning DA neurons in rodent and primate models of Parkinson's disease. 3. Glial cell line-derived neurotrophic factor gene therapy may have a potential use in the clinical treatment of Parkinson's disease. 4. We examined whether injection of an adenoviral vector encoding human GDNF preproprotein (Ad GDNF) could protect the rat nigrostriatal DA system from progressive neuronal degeneration. Because Parkinson's disease occurs primarily in the elderly population, we studied the effect of GDNF gene delivery in an aged rat model of Parkinson's disease. 5. In the aged (20 month) Fischer 344 rat, Ad GDNF was injected either near DA cell bodies in the substantia nigra (SN) or at the DA terminals in the striatum. One week following gene delivery, the neurotoxin 6-hydroxydopamine (6-OHDA) was injected unilaterally into the striatum to cause progressive degeneration of the DA neurons. 6. Injection of GDNF vector into either the striatum or the SN provided significant cell protection against 6-OHDA. However, only striatal injection of Ad GDNF protected against the development of behavioural and neurochemical changes that occur in the DA-depleted brain. 7. The results of this study are reviewed here and the behavioural and cellular effects of GDNF gene delivery into striatal versus mesencephalic sites are discussed.

Cunningham, D. A., C. Herring, et al. (2001). "Analysis of patients treated with living pig tissue for evidence of infection by porcine endogenous retroviruses." Trends Cardiovasc Med 11(5): 190-6.
The use of pigs as a source of cells and organs for transplantation has the potential to reduce the current chronic shortage of organs for the treatment of many end-stage diseases. The risk of transmission of infectious agents across the species barrier (zoonoses) has to be assessed. Many such agents can be eliminated from the pig herd. However, porcine endogenous retroviruses, which are carried within the pig genome, are not easily eliminated. They can infect primary and immortalized human cells in vitro, but to date no evidence for in vivo infection has been found in retrospective studies of humans exposed to viable porcine cells. Small-scale clinical trials using porcine cells for the treatment of Parkinson's and Huntington's disease are currently in progress. The prospective monitoring of these patients in conjunction with further research into the biology of this virus will help address safety issues.

Dagher, A. (2001). "Functional imaging in Parkinson's disease." Semin Neurol 21(1): 23-32.
This article reviews the applications of functional neuroimaging with positron emission tomography (PET) and single photon emission computed tomography (SPECT) to the diagnosis and treatment of Parkinson's disease (PD). PET measurements with [18F]deoxyglucose to measure glucose metabolism or with various markers of the pre- and postsynaptic dopamine systems may distinguish idiopathic PD from other conditions presenting with an akinetic-rigid state. Moreover, PET has been used to gain new insights into mechanisms of cell death and the role of heredity in Parkinson's disease. Finally, we discuss the use of functional neuroimaging to study the role of the basal ganglia in movement and cognition in PD.

Damier, P., J. L. Houeto, et al. (2001). "The role of the pallidum in Parkinson's disease gait. Lessons from pallidal stimulation." Adv Neurol 87: 283-8.

Danysz, W. (2001). "Neurotoxicity as a mechanism for neurodegenerative disorders: basic and clinical aspects." Expert Opin Investig Drugs 10(5): 985-9.
This three day meeting focused on chronic neurodegenerative diseases such as Parkinson's disease (PD), Alzheimer's disease (AD), and amylotrophic lateral sclerosis (ALS). It attracted 69 participants from 10 countries with dominance of Chile and USA. Neurodegeneration and its prevention increasingly gain in importance as the number of people affected increases year-by-year. The meeting addressed various basic aspects having pragmatic implications such as: oxidative stress, inflammatory reaction, glial activation, role of glutamatergic system and apoptosis using a plethora of in vitro and in vivo methods.

Davidson, C., A. J. Gow, et al. (2001). "Methamphetamine neurotoxicity: necrotic and apoptotic mechanisms and relevance to human abuse and treatment." Brain Res Brain Res Rev 36(1): 1-22.
Research into methamphetamine-induced neurotoxicity has experienced a resurgence in recent years. This is due to (1) greater understanding of the mechanisms underlying methamphetamine neurotoxicity, (2) its usefulness as a model for Parkinson's disease and (3) an increased abuse of the substance, especially in the American Mid-West and Japan. It is suggested that the commonly used experimental one-day methamphetamine dosing regimen better models the acute overdose pathologies seen in humans, whereas chronic models are needed to accurately model human long-term abuse. Further, we suggest that these two dosing regimens will result in quite different neurochemical, neuropathological and behavioral outcomes. The relative importance of the dopamine transporter and vesicular monoamine transporter knockout is discussed and insights into oxidative mechanisms are described from observations of nNOS knockout and SOD overexpression. This review not only describes the neuropathologies associated with methamphetamine in rodents, non-human primates and human abusers, but also focuses on the more recent literature associated with reactive oxygen and nitrogen species and their contribution to neuronal death via necrosis and/or apoptosis. The effect of methamphetamine on the mitochondrial membrane potential and electron transport chain and subsequent apoptotic cascades are also emphasized. Finally, we describe potential treatments for methamphetamine abusers with reference to the time after withdrawal. We suggest that potential treatments can be divided into three categories; (1) the prevention of neurotoxicity if recidivism occurs, (2) amelioration of apoptotic cascades that may occur even in the withdrawal period and (3) treatment of the atypical depression associated with withdrawal.

Davis, K. M. and J. Y. Wu (2001). "Role of glutamatergic and GABAergic systems in alcoholism." J Biomed Sci 8(1): 7-19.
The pharmacological effects of ethanol are complex and widespread without a well-defined target. Since glutamatergic and GABAergic innervation are both dense and diffuse and account for more than 80% of the neuronal circuitry in the human brain, alterations in glutamatergic and GABAergic function could affect the function of all neurotransmitter systems. Here, we review recent progress in glutamatergic and GABAergic systems with a special focus on their roles in alcohol dependence and alcohol withdrawal-induced seizures. In particular, NMDA-receptors appear to play a central role in alcohol dependence and alcohol-induced neurological disorders. Hence, NMDA receptor antagonists may have multiple functions in treating alcoholism and other addictions and they may become important therapeutics for numerous disorders including epilepsy, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's chorea, anxiety, neurotoxicity, ischemic stroke, and chronic pain. One of the new family of NMDA receptor antagonists, such as DETC-MESO, which regulate the redox site of NMDA receptors, may prove to be the drug of choice for treating alcoholism as well as many neurological diseases.

De Broe, S., F. Christopher, et al. (2001). "The role of specialist nurses in multiple sclerosis: a rapid and systematic review." Health Technol Assess 5(17): 1-47.
BACKGROUND: Multiple sclerosis (MS) is a disease of the central nervous system. The cause is unknown. There are about 80-160 people with MS per 100,000 population, with twice as many women affected as men. The management of individuals with MS includes treatment of acute relapses and chronic symptoms. The care of MS patients is provided by various healthcare professionals, such as general practitioners (GPs), neurologists, physiotherapists, occupational therapists and nurses. Some MS patients have access to an MS specialist nurse, although this provision varies geographically. OBJECTIVES: The aim of this report is to assess the effectiveness and relative cost-effectiveness of MS specialist nurses in improving care and outcomes for patients with MS. METHODS: A systematic review of the literature, involving a range of databases, was performed. Full details are described in the main report. RESULTS: Only one study was identified that tried to evaluate the benefit of MS specialist nurses. The study concluded that MS patients and their carers found the MS specialist nurse to be helpful, particularly in improving their knowledge of MS, ability to cope, mood and confidence about the future. GPs also reported finding the nurse to be helpful with their MS patients, and 40% of the GPs stated they would purchase the services of an MS specialist nurse if their practices became fundholding. However, there were considerable methodological weaknesses inherent in the study design, and it was unclear whether the results of the study could be extrapolated to other settings or to other MS patient groups. RESULTS - ONGOING RESEARCH: There are two ongoing research studies regarding MS specialist nurses. One of these studies involves the provision of MS nurses to several areas, but also has two control populations to allow evaluation of the health benefits of the nurses to MS patients and their carers. This study will help to fill the evidence gap. RESULTS - COSTS: The costs of providing MS specialist nurses consist of their yearly salary (usually NHS grade G), as well as additional costs for travelling, administration, computer and telephone use, a pension scheme, National Insurance and study leave. The MS Society of Great Britain and Northern Ireland allows a generous total yearly cost to the employer of 40,000 pounds. CONCLUSIONS: The present evidence does not make it possible to comment with any certainty on the value of specialist nurses in MS. The best evidence available to the authors is specialist opinion from neurologists and nurses, and comments from patients with MS; this opinion supports the provision of MS specialist nurses. CONCLUSIONS - RECOMMENDATIONS FOR RESEARCH: Further research is needed before it will be feasible to make firm recommendations on the value of MS specialist nurses relative to other possible uses of funds.

Deane, K. H., R. Whurr, et al. (2001). "A comparison of speech and language therapy techniques for dysarthria in Parkinson's disease." Cochrane Database Syst Rev(2): CD002814.
BACKGROUND: Dysarthria is a common manifestation of Parkinson's disease that increases in frequency and intensity with the progress of the disease (Streifler 1984). Up to 20% of Parkinsonian patients are referred for speech and language therapy (S & LT), its aim being to improve the intelligibility of the patient's speech. OBJECTIVES: To compare the efficacy and effectiveness of novel S & LT techniques versus standard S & LT to treat dysarthria in patients with Parkinson's disease. To compare the efficacy and effectiveness of one S & LT technique versus a second form of S & LT to treat Parkinsonian dysarthria. SEARCH STRATEGY: Relevant trials were identified by electronic searches of MEDLINE, EMBASE, CINAHL, ISI-SCI, AMED, MANTIS, REHABDATA, REHADAT, GEROLIT, Pascal, LILACS, MedCarib, JICST-EPlus, AIM, IMEMR, SIGLE, ISI-ISTP, DISSABS, Conference Papers Index, Aslib Index to Theses, the Cochrane Controlled Trials Register, the CentreWatch Clinical Trials listing service, the metaRegister of Controlled Trials, ClinicalTrials.gov, CRISP, PEDro, NIDRR and NRR; and examination of the reference lists of identified studies and other reviews. SELECTION CRITERIA: Only randomised controlled trials (RCT) were included. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by KD and RW and differences settled by discussion. MAIN RESULTS: Only two trials were identified with only 71 patients. The method of randomisation was good in only one trial and the concealment of allocation was inadequate in both trials. These methodological problems could potentially lead to bias from a number of sources. The methods used in the two studies varied so much that meta-analysis of the results was not possible. Scott 83 compared prosodic exercises with visual cues with prosodic exercises alone (See Glossary: Table 01). The authors examined prosody and intelligibility as outcome measures immediately after therapy. Ramig 95 compared the Lee Silverman Voice Therapy (LSVT) which emphasises increased vocal effort, with respiratory therapy which aimed to increase respiratory muscle activity. Ramig 95 examined a wide range of vocal characteristics, activities of daily living affected by speech, depression and the carer's impressions of the patient's speech quality. Some of these outcomes were measured up to 24 months after the end of the therapy. However, in neither study were changes in outcomes due to 'Therapy A' compared with the changes due to 'Therapy B' statistically. Therefore no comment on the comparative efficacy of these types of speech and language therapy can be made. REVIEWER'S CONCLUSIONS: Considering the methodological flaws in both of these studies, the small number of patients examined, and the possibility of publication bias, there is insufficient evidence to support or refute the efficacy of any given form of S & LT over another to treat dysarthria in Parkinson's disease. Given the lack of evidence from RCTs to support or refute the efficacy of S & LT in Parkinson's disease (see Cochrane review 'Speech and Language therapy for Dysarthria in Patients with Parkinson's Disease'), the consensus as to what is considered 'best-practice' S & LT must be proved first through a large well-designed placebo-controlled randomised trial before examining variations in S & LT methodology. The design of these trials should minimise bias and be reported fully using CONSORT guidelines (CONSORT 1996). Outcome measures with particular relevance to patients, their carers, physicians and speech and language therapists should be chosen and the patients followed for at least 6 months to determine the duration of any improvement.

Deane, K. H., R. Whurr, et al. (2001). "Speech and language therapy for dysarthria in Parkinson's disease." Cochrane Database Syst Rev(2): CD002812.
BACKGROUND: Dysarthria is a common manifestation of Parkinson's disease which increases in frequency and intensity with the progress of the disease (Streifler 1984). Up to 20% of Parkinsonian patients are referred for speech and language therapy (S & L T), its aim being to improve the intelligibility of the patient's speech. OBJECTIVES: To compare the efficacy of speech and language therapy versus placebo or no interventions in patients with Parkinson's disease. SEARCH STRATEGY: Relevant trials were identified by electronic searches of MEDLINE, EMBASE, CINAHL, ISI-SCI, AMED, MANTIS, REHABDATA, REHADAT, GEROLIT, Pascal, LILACS, MedCarib, JICST-EPlus, AIM, IMEMR, SIGLE, ISI-ISTP, DISSABS, Conference Papers Index, Aslib Index to Theses, the Cochrane Controlled Trials Register, the CentreWatch Clinical Trials listing service, the metaRegister of Controlled Trials, ClinicalTrials.gov, CRISP, PEDro, NIDRR and NRR; and examination of the reference lists of identified studies and other reviews. SELECTION CRITERIA: Only randomised controlled trials (RCT) were included. DATA COLLECTION AND ANALYSIS: Data were abstracted independently by KD and RW and differences settled by discussion. MAIN RESULTS: Three randomised controlled trials were found comparing speech and language therapy with placebo for speech disorders in Parkinson's disease. A total of 63 patients were examined. The loudness of the patients' voices were increased by between 7-18%, depending on the speaking task being performed. It is likely that this is a clinically significant improvement. After six months the degree of improvement was reduced but was still statistically significant. Overall measures of dysarthria were measured in two trials and also improved. The clinical significance of these improvements was less clear cut as intelligibility of speech was not measured in any of these studies. REVIEWER'S CONCLUSIONS: Considering the small number of patients examined, the methodological flaws in many of the studies, and the possibility of publication bias, there is insufficient evidence to support or refute the efficacy of speech and language therapy for dysarthria in Parkinson's disease. A Delphi-style survey is needed to develop a consensus as to what is 'standard' S< for dysarthria in Parkinson's disease. Then a large well designed placebo-controlled RCT is needed to demonstrate speech and language therapy's effectiveness for dysarthria in Parkinson's disease. The trial should conform to CONSORT guidelines. Outcome measures with particular relevance to patients should be chosen and the patients followed for at least 6 months to determine the duration of any improvement.

Deane, K. H., R. Whurr, et al. (2001). "Non-pharmacological therapies for dysphagia in Parkinson's disease." Cochrane Database Syst Rev(1): CD002816.
BACKGROUND: Dysphagia occurs frequently in Parkinson's disease although patients themselves may be unaware of swallowing difficulties. Speech and language therapists in conjunction with nurses and dietitians use techniques that aim to improve swallowing and reduce the risk of choking, aspiration and chest infections. OBJECTIVES: ~Bullet~To compare the efficacy and effectiveness of non-pharmacological swallowing therapy for dysphagia versus placebo or no intervention in patients with Parkinson's disease. ~Bullet~To compare one form of non-pharmacological swallowing therapy for dysphagia with another in patients with Parkinson's disease. SEARCH STRATEGY: Relevant trials were identified by electronic searches of MEDLINE, EMBASE, CINAHL, ISI-SCI, AMED, MANTIS, REHABDATA, REHADAT, GEROLIT, Pascal, LILACS, MedCarib, JICST-EPlus, AIM, IMEMR, SIGLE, ISI-ISTP, DISSABS, Conference Papers Index, Aslib Index to Theses, the Cochrane Controlled Trials Register, the CentreWatch Clinical Trials listing service, the metaRegister of Controlled Trials, ClinicalTrials.gov, CRISP, PEDro, NIDRR and NRR; and examination of the reference lists of identified studies and other reviews. SELECTION CRITERIA: Only randomised controlled trials (RCT) were included. We did not examine any trials using drugs or surgery to treat the dysphagia. We did not examine any trials where part of the therapist's advice was to insert a nasogastric or percutaneous gastrostomy tube. DATA COLLECTION AND ANALYSIS: Not applicable. MAIN RESULTS: No randomised controlled trials or controlled trials were found that examined the efficacy of non-pharmacological swallowing therapy for the treatment of dysphagia in Parkinson's disease. However there is one large RCT currently recruiting patients that will compare 'chin down' posture with thickened liquids in the treatment of dysphagia. The main outcomes will be the rates of aspiration and pneumonia. REVIEWER'S CONCLUSIONS: There is currently no evidence to support or refute the efficacy of non-pharmacological swallowing therapy for dysphagia in Parkinson's disease. Large well designed placebo-controlled RCTs are required to assess the effectiveness of swallowing therapy for dysphagia in Parkinson's disease and reported according to CONSORT guidelines. Suitable outcome measures should be chosen so that the efficacy and effectiveness of non-pharmacological swallowing therapy can be assessed and an economic analysis performed. Outcomes which have meaning to patients and carers should be used wherever possible since they need to know the value of this therapy in practical terms. The patients should be followed for at least 6 months to determine the duration of any improvement.

Deane, K. H., D. Jones, et al. (2001). "A comparison of physiotherapy techniques for patients with Parkinson's disease." Cochrane Database Syst Rev(1): CD002815.
BACKGROUND: Despite optimal medical and surgical therapies for Parkinson's disease, patients develop progressive disability. The role of the physiotherapist is to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. What form of physiotherapy is most effective in the treatment of Parkinson's disease remains unclear. OBJECTIVES: 1. To compare the efficacy and effectiveness of novel physiotherapy techniques versus 'standard' physiotherapy in patients with Parkinson's disease. Standard physiotherapy is defined as the type of therapy that the physiotherapist would usually use to treat Parkinson's disease. 2. To compare the efficacy and effectiveness of one physiotherapy technique versus a second form of physiotherapy. SEARCH STRATEGY: Relevant trials were identified by electronic searches of MEDLINE, EMBASE, CINAHL, ISI-SCI, AMED, MANTIS, REHABDATA, REHADAT, GEROLIT, Pascal, LILACS, MedCarib, JICST-EPlus, AIM, IMEMR, SIGLE, ISI-ISTP, DISSABS, Conference Papers Index, Aslib Index to Theses, the Cochrane Controlled Trials Register, the CentreWatch Clinical Trials listing service, the metaRegister of Controlled Trials, ClinicalTrials.gov, CRISP, PEDro, NIDRR and NRR; and examination of the reference lists of identified studies and other reviews. SELECTION CRITERIA: Only randomised controlled trials (RCT) were included. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by KD and CEH and differences settled by discussion. MAIN RESULTS: Seven trials were identified with 142 patients. All used small numbers of patients and the method of randomisation and concealment of allocation was poor or not statedin all of the trials. These methodological problems could potentially lead to bias from a number of sources. The methods of physiotherapy varied so widely that the data could not be combined. REVIEWER'S CONCLUSIONS: Considering the small number of patients examined, the methodological flaws in many of the studies and the possibility of publication bias, there is insufficient evidence to support or refute the efficacy of any given form of physiotherapy over another in Parkinson's disease. Another Cochrane review, Physiotherapy for patients with Parkinson's Disease, found that there was insufficient evidence to support or refute the efficacy of physiotherapy compared to no physiotherapy in Parkinson's disease. A wide range of physiotherapy approaches were used in these studies and a survey of UK physiotherapists confirmed that they also use an eclectic combination of techniques in the treatment of Parkinson's disease (Plant 1999). Therefore a consensus must be found as to 'best practice' physiotherapy for Parkinson's disease. The efficacy of 'standard' physiotherapy should be proved first before examining variations in physiotherapy methods. Therefore large well designed randomised controlled trials are needed to judge the effect of physiotherapy in Parkinson's disease. After this large RCTs are needed to demonstrate the most effective form of physiotherapy in Parkinson's disease. Outcome measures with particular relevance to patients, carers, physiotherapists and physicians should be chosen and the patients monitored for at least 6 months to determine the duration of any effect. The trials should be reported according to CONSORT guidelines (CONSORT 1996).

Deecke, L. (2001). "Clinical neurophysiology of Parkinson's disease. Bereitschaftspotential and contingent negative variation." Adv Neurol 86: 257-71.

Defebvre, L. and G. Kemoun (2001). "[Gait disorders in Parkinson disease. Neuroanatomic and physiologic organization of gait]." Presse Med 30(9): 445-51.
GAIT IS A VOLUNTARY, AUTOMATIC AND REFLEX RHYTHMIC ACTIVITY: It is generated by a central pattern generator identified from animal models. This spinal gait generator (SGG) is controlled by various parts of the central nervous system: the descending tracts and locomotor regions of the brainstem, the cerebellum, the basal ganglia, the motor and parietal cortex and the hippocampus. Kinesthetic inputs which project to the SGG and the cerebellum, play an important role in the production of postural reflex responses; vestibular and visual inputs mainly control balance. GAIT MAINLY DEPENDS ON THE RELATIONSHIP BETWEEN POSTURE BALANCE AND MOVEMENT: As concerns posture each segment is under the control of both peripheral and central nervous systems and is used as a system of reference to organize movements of adjacent segments. Balance is maintained by sensory inputs which provide corrective mechanisms: anticipatory postural responses, reflex postural responses and voluntary responses. DIFFERENT DESCRIPTIVE PARAMETERS MAY BE PROPOSED: Analysis of kinematic (displacement, speed and acceleration of segments) and kinetic parameters during the four successive stages of gait (posture, initiation, rhythmic gait and return to the initial posture) provides an understanding of neurological gait disorders. In particular the relationship between the center of pressure and the center of gravity is used to analyze infraclinical gait abnormalities. NEW AND SOPHISTICATED INVESTIGATIONS METHODS ARE AVAILABLE: The optoelectronic system provides a tridimensional analysis of movement and can be combined with forceplate and electromyographic recordings. These methods constitute an interesting contribution to the clinical analysis of gait. CLASSIFICATION: This is established according to clinical data and the positionment of the lesion among the structures of the nervous system. The physiopathological approach is then specified taking into account the lesions of the muscular, skeletal and nervous structures.

Delacourte, A. (2001). "The molecular parameters of tau pathology. Tau as a killer and a witness." Adv Exp Med Biol 487: 5-19.

Delwaide, P. J. (2001). "Parkinsonian rigidity." Funct Neurol 16(2): 147-56.

Depatie, L. and S. Lal (2001). "Apomorphine and the dopamine hypothesis of schizophrenia: a dilemma?" J Psychiatry Neurosci 26(3): 203-20.
The dopamine (DA) hypothesis of schizophrenia implicates an enhancement of DA function in the pathophysiology of the disorder, at least in the genesis of positive symptoms. Accordingly, apomorphine, a directly acting DA receptor agonist, should display psychotomimetic properties. A review of the literature shows little or no evidence that apomorphine, in doses that stimulate postsynaptic DA receptors, induces psychosis in non-schizophrenic subjects or a relapse or exacerbation of psychotic symptoms in patients with schizophrenia. After a detailed review of the literature reporting psychotogenic effects of apomorphine in patients with Parkinson's disease, an interpretation of these data is difficult, in part because of several confounding factors, such as the concomitant use of drugs known to induce psychosis and the advanced state of the progressive neurological disorder. In the context of the DA hypothesis of schizophrenia, the limited ability of apomorphine to induce psychosis, in contrast to indirectly acting DA agonists that increase synaptic DA, may be explained by the relatively weak affinity of apomorphine for the D3 receptor compared with DA. Alternatively, enhancement of DA function, though necessary, may be insufficient by itself to induce psychosis.

Deuschl, G., J. Raethjen, et al. (2001). "The pathophysiology of tremor." Muscle Nerve 24(6): 716-35.
Tremor is defined as rhythmic oscillatory activity of body parts. Four physiological basic mechanisms for such oscillatory activity have been described: mechanical oscillations; oscillations based on reflexes; oscillations due to central neuronal pacemakers; and oscillations because of disturbed feedforward or feedback loops. New methodological approaches with animal models, positron emission tomography, and mathematical analysis of electromyographic and electroencephalographic signals have provided new insights into the mechanisms underlying specific forms of tremor. Physiological tremor is due to mechanical and central components. Psychogenic tremor is considered to depend on a clonus mechanism and is thus believed to be mediated by reflex mechanisms. Symptomatic palatal tremor is most likely due to rhythmic activity of the inferior olive, and there is much evidence that essential tremor is also generated within the olivocerebellar circuits. Orthostatic tremor is likely to originate in hitherto unidentified brainstem nuclei. Rest tremor of Parkinson's disease is probably generated in the basal ganglia loop, and dystonic tremor may also originate within the basal ganglia. Cerebellar tremor is at least in part caused by a disturbance of the cerebellar feedforward control of voluntary movements, and Holmes' tremor is due to the combination of the mechanisms producing parkinsonian and cerebellar tremor. Neuropathic tremor is believed to be caused by abnormally functioning reflex pathways and a wide variety of causes underlies toxic and drug-induced tremors. The understanding of the pathophysiology of tremor has made significant progress but many hypotheses are not yet based on sufficient data. Modern neurology needs to develop and test such hypotheses, because this is the only way to develop rational medical and surgical therapies.

Dhawan, V. and D. Eidelberg (2001). "SPECT imaging in Parkinson's disease." Adv Neurol 86: 205-13.

Dietz, V. (2001). "Gait disorder in spasticity and Parkinson's disease." Adv Neurol 87: 143-54.
The central programming, timing, and reciprocal mode of leg muscle activation during gait are basically intact in patients with spastic paresis. Exaggerated monosynaptic reflexes are associated with a loss of the functionally essential polysynaptic reflex mechanisms, both being dependent on supraspinal control. When this control is either not yet matured (small children) or impaired (spastic paresis), inhibition of monosynaptic stretch reflexes is missing in combination with a reduced facilitation of polysynaptic reflexes. A spinal or cerebral lesion associated with paresis is followed by a transformation of motor units (and most probably shortening of muscle fibers leading to muscle contracture), such that tension development in the muscle occurs in a simpler fashion. Calf muscle tension during gait is normally determined by modulated gastrocnemius or soleus EMG activity. In the spastic leg, calf muscle tension is associated with the stretching of the tonically activated muscle. This regulation of muscle tension at a lower level is efficient insofar as it enables the patient to support body weight during gait. Consequently, physiotherapeutic approaches should be applied primarily and antispastic drug therapy secondarily in mobile patients; whereas antispastic drugs may relieve muscle spasms and improve nursing care in immobilized patients.

Djaldetti, R. and E. Melamed (2001). "New therapies for Parkinson's disease." J Neurol 248(5): 357-62.
In the last decade there has been a surge of new therapeutic strategies for the treatment of Parkinson's disease along with a change of concepts about how the disease should be treated. The gold standard remains levodopa preparations, which have a rapid and dramatic symptomatic effect by replenishing the reduced dopamine levels in caudate and putamen nuclei. However, keeping in mind the complications that may emerge following long-term treatment, its initiation should possibly be delayed to the more advanced stages of the illness, especially in younger patients, in favour of dopamine agonists monotherapy. The adverse reactions that become prominent and disabling in late stages of the disease, i. e., dyskinesias, response fluctuations, and psychiatric side effects, can currently be managed by novel pharmacological as well as surgical strategies. Future therapies will focus on transplantation of dopaminergic embryonic tissue, gene therapy, and neuroprotective treatments.

Dodel, R. C., K. Berger, et al. (2001). "Health-related quality of life and healthcare utilisation in patients with Parkinson's disease: impact of motor fluctuations and dyskinesias." Pharmacoeconomics 19(10): 1013-38.
Idiopathic Parkinson's disease (PD) is a common chronic progressive neuro-degenerative disorder associated with the progressive loss of dopaminergic neurons in the substantia nigra. The natural course of the disease may lead to severe disability despite a variety of pharmacological and surgical treatment options. Levodopa is still the most effective symptomatic treatment for PD; however, long term use can cause a number of adverse effects including motor complications, nausea and vomiting, postural hypotension and changes in mental status. The onset of motor complications marks a crucial point in the management of PD. They may present as changes between akinetic and mobile phases (motor fluctuations) or as abnormal involuntary movements (dyskinesias). After levodopa treatment for 3 to 5 years, motor complications occur in approximately 50% of patients, and after 10 years in >80% of patients. Treatment options have recently expanded as new drugs have been licensed and surgical procedures refined. Patients with motor complications present a demanding task in disease management, and often multiple drugs and high dosages are necessary to achieve only suboptimal control, resulting in increased healthcare utilisation. Costs increase considerably in patients with motor fluctuations and dyskinesias compared with patients without these symptoms. In a French study, 6-month direct medical costs per patient increased from 1648 euros (EUR) to EUR3028 in patients without and with motor fluctuations, respectively. In a recent French study a significant difference in monthly direct medical costs was found in patients with and without dyskinesias (EUR560 vs 170). Unfortunately, no data are available on the effect of motor complications on indirect costs. Several studies have shown that health-related quality of life (HR-QOL) is reduced when motor fluctuations occur. This may also be true of dyskinesias, but because of the limited number of studies a definite conclusion is not yet possible. Recently, surgical treatment options have been used to deal with advanced PD and late stage complications. Although their effect on motor complications and HR-QOL is well documented, they result in increased costs (total medical cost: EUR28920) compared with drug treatment alone and are increasingly restricted by healthcare providers. The purpose of this article is to review the available data from pharmacotherapeutic. surgical and economic studies on HR-QOL and healthcare expenditure in patients with PD, with a major focus on the impact of motor fluctuations and dyskinesias.

Doudet, D. J. (2001). "PET studies in the MPTP model of Parkinson's disease." Adv Neurol 86: 187-95.

Doudet, D. J. (2001). "Monitoring disease progression in Parkinson's disease." J Clin Pharmacol Suppl: 72S-80S.

Drukarch, B. and F. L. van Muiswinkel (2001). "Neuroprotection for Parkinson's disease: a new approach for a new millennium." Expert Opin Investig Drugs 10(10): 1855-68.
Parkinson's disease (PD) is the only neurodegenerative disorder in which pharmacological intervention has resulted in a marked decrease in morbidity and a significant delay in mortality. However, the medium to long-term efficacy of this pharmacotherapy, mainly consisting of dopaminomimetics like L -dopa and dopamine receptor agonists, suffers greatly from the unrelenting progression of the disease process underlying PD, i.e., the degeneration of neuromelanin-containing, dopaminergic neurones in the substantia nigra. Efforts concentrated on understanding the mechanisms of dopaminergic cell death in Parkinson's disease have led to identification of a large variety of pathogenetic factors, including excessive release of oxygen free radicals during enzymatic dopamine breakdown, impairment of mitochondrial function, production of inflammatory mediators, loss of trophic support, and apoptosis. Therapeutic approaches aimed at correcting these abnormalities are currently being evaluated on their efficacy as neuroprotectants for PD. Here, we focus on the process of dopamine auto-oxidation, the chain of reactions leading to the formation of neuromelanin, as an often overlooked, yet obvious pathogenetic factor. In particular, we discuss the option of drug-mediated stimulation of endogenous mechanisms responsible for the detoxification of dopamine auto-oxidation products as a novel means of neuroprotection in Parkinson's disease.

Dunnett, S. B., A. Bjorklund, et al. (2001). "Cell therapy in Parkinson's disease - stop or go?" Nat Rev Neurosci 2(5): 365-9.
The results of the first double-blind placebo-controlled trial using grafts of embryonic tissue to treat Parkinson's disease have aroused widespread interest and debate about the future of cell replacement therapies. What are the key issues that need to be resolved and the directions in which this technology is likely to develop?

Ebadi, M., P. Govitrapong, et al. (2001). "Ubiquinone (coenzyme q10) and mitochondria in oxidative stress of parkinson's disease." Biol Signals Recept 10(3-4): 224-53.
Parkinson's disease is the second most common neurodegenerative disorder after Alzheimer's disease affecting approximately1% of the population older than 50 years. There is a worldwide increase in disease prevalence due to the increasing age of human populations. A definitive neuropathological diagnosis of Parkinson's disease requires loss of dopaminergic neurons in the substantia nigra and related brain stem nuclei, and the presence of Lewy bodies in remaining nerve cells. The contribution of genetic factors to the pathogenesis of Parkinson's disease is increasingly being recognized. A point mutation which is sufficient to cause a rare autosomal dominant form of the disorder has been recently identified in the alpha-synuclein gene on chromosome 4 in the much more common sporadic, or 'idiopathic' form of Parkinson's disease, and a defect of complex I of the mitochondrial respiratory chain was confirmed at the biochemical level. Disease specificity of this defect has been demonstrated for the parkinsonian substantia nigra. These findings and the observation that the neurotoxin 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP), which causes a Parkinson-like syndrome in humans, acts via inhibition of complex I have triggered research interest in the mitochondrial genetics of Parkinson's disease. Oxidative phosphorylation consists of five protein-lipid enzyme complexes located in the mitochondrial inner membrane that contain flavins (FMN, FAD), quinoid compounds (coenzyme Q10, CoQ10) and transition metal compounds (iron-sulfur clusters, hemes, protein-bound copper). These enzymes are designated complex I (NADH:ubiquinone oxidoreductase, EC 1.6. 5.3), complex II (succinate:ubiquinone oxidoreductase, EC 1.3.5.1), complex III (ubiquinol:ferrocytochrome c oxidoreductase, EC 1.10.2.2), complex IV (ferrocytochrome c:oxygen oxidoreductase or cytochrome c oxidase, EC 1.9.3.1), and complex V (ATP synthase, EC 3.6.1.34). A defect in mitochondrial oxidative phosphorylation, in terms of a reduction in the activity of NADH CoQ reductase (complex I) has been reported in the striatum of patients with Parkinson's disease. The reduction in the activity of complex I is found in the substantia nigra, but not in other areas of the brain, such as globus pallidus or cerebral cortex. Therefore, the specificity of mitochondrial impairment may play a role in the degeneration of nigrostriatal dopaminergic neurons. This view is supported by the fact that MPTP generating 1-methyl-4-phenylpyridine (MPP(+)) destroys dopaminergic neurons in the substantia nigra. Although the serum levels of CoQ10 is normal in patients with Parkinson's disease, CoQ10 is able to attenuate the MP