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ALS Reviews 2001

(98 References)

Andersen, P. M. (2001). "[Genetics of amyotrophic lateral sclerosis]." Zh Nevrol Psikhiatr Im S S Korsakova 101(3): 54-63.

Andersen, P. M. (2001). "Genetics of sporadic ALS." Amyotroph Lateral Scler Other Motor Neuron Disord 2 Suppl 1: S37-41.

          The only known gene to be involved in ALS is the CuZn-superoxide dismutase (CuZn-SOD) gene. Since 1993, 89 disease-associated mutations have been found in this gene, 14 of them in cases with apparently sporadic ALS. Most frequent are the D90A (most often with recessive inheritance, but a few with dominant inheritance) and the I113T (dominant inheritance with variable penetrance). Statistical and genealogical evidence suggest that quite a number of diagnosed sporadic cases may in fact be familial cases in pedigrees with very low disease penetrance.

Anger, T., D. J. Madge, et al. (2001). "Medicinal chemistry of neuronal voltage-gated sodium channel blockers." J Med Chem 44(2): 115-37.

Aoki, M., M. Nagai, et al. (2001). "[ALS models by transgenic animals]." No To Shinkei 53(9): 799-807.

Apfel, S. C. (2001). "Neurotrophic factor therapy--prospects and problems." Clin Chem Lab Med 39(4): 351-5.

          Over the past 15 years neurotrophic factors have generated considerable excitement for their potential as therapy for a wide variety of degenerative neurological disorders, for which there is currently no treatment. The first part of this period was marked by the discovery, characterization, and cloning of many new growth factors, and by successful testing of these factors in animal models of neurological disease. In recent years the biotechnology industry and pharmaceutical industry have attempted to replicate the success of the animal studies in clinical trials. Although some studies have demonstrated moderate efficacy, for the most part the clinical trials have been less successful at demonstrating the therapeutic efficacy of this new class of drugs. For example, nerve growth factor appeared to be efficacious in two phase II clinical trials for peripheral neuropathy, but failed in a large scale phase III trial. Ciliary neurotrophic factor, brain derived neurotrophic factor and insulin like growth factor-1 have all been tested in clinical trials for the treatment of amyotrophic lateral sclerosis, with at best, variable indications of efficacy. Nevertheless, there are still many reasons to be optimistic that some of these agents may be useful clinically. Many technical and pharmacological issues remain to be adequately addressed, before neurotrophic factors can live up to their potential. Our collective experience with them has re-adjusted previously wild expectations, so that they are now much more realistic. This is necessary and beneficial for the maturation of this field of study.

Appel, S. H., D. Beers, et al. (2001). "Calcium: the Darth Vader of ALS." Amyotroph Lateral Scler Other Motor Neuron Disord 2 Suppl 1: S47-54.

          Motor neuron dysfunction and loss in amyotrophic lateral sclerosis (ALS) have been attributed to several different mechanisms, including increased intracellular calcium, glutamate excitotoxicity, oxidative stress and free radical damage, mitochondrial dysfunction, and neurofilament aggregation and dysfunction of transport mechanisms. These alterations are not mutually exclusive, and increased calcium could be a common denominator. Furthermore, the selective vulnerability of spinal motor neurons and the relative sparing of eye motor neurons represent striking features of both sporadic and familial ALS. Here we review the evidence that calcium homeostasis is altered in ALS, and that low levels of the calcium binding proteins parvalbumin and calbindin-D28K contribute to selective vulnerability by decreasing the ability of motor neurons to handle an increased calcium load, with cell injury and death as the consequence.

Armon, C. (2001). "Environmental risk factors for amyotrophic lateral sclerosis." Neuroepidemiology 20(1): 2-6.

          In order to evaluate reported associations of environmental risk factors with amyotrophic lateral sclerosis (ALS), consideration is given first to robust clinical and epidemiologic observations. These are observations which have persisted in time, have been replicated consistently and likely reflect the reality of the disease. Sporadic, familial and Western Pacific ALS are considered. In contrast, other associations appear to have emerged due to chance, sometimes compounded by faulty study design, and have dissipated once greater attention was given to methodological rigor. Current data suggest that there are no robust environmental risk factors for sporadic ALS.

Bak, M. I., A. Domzal-Stryga, et al. (2001). "[Proton MR spectroscopy studies of the brain in ALS patients]." Neurol Neurochir Pol 35(1 Suppl): 61-70.

          Nuclear magnetic resonance spectroscopy (MRS) has an ability to measure brain metabolites noninvasively in vivo. The content of N-acetyl-aspartate (NAA) is used as a biochemical marker of neuronal integrity and viability. In amyotrophic lateral sclerosis (ALS) patients the degeneration and neuronal loss of motor cortex was reported. The presence of these changes can lead to the decrease of NAA. The aim of this study was to evaluate the neurochemical status of motor cortex (by using 1H-MRS) in 11 patients with clinically definite or probable forms of ALS (according to the El Escorial criteria). These data were compared with MRS results from 4 healthy controls. The mean NAA/(Cr + PCr) values were decreased by 19% (p < 0.05) when compared with controls. In 4 ALS patients the NAA/(Cr + PCr) ratio was decreased by 31% (p < 0.05) and these patients had rapidly progressing disease. In other 7 ALS patients, we found that NAA/(Cr + PCr) was decreased by 10% (p < 0.05) and they showed less advanced neurological symptoms. 1H-MRS of the motor cortex can be a new diagnostic tool in ALS and it might help to monitor the progress of the disease.

Beck, M., C. Karch, et al. (2001). "Motoneuron cell death and neurotrophic factors: basic models for development of new therapeutic strategies in ALS." Amyotroph Lateral Scler Other Motor Neuron Disord 2 Suppl 1: S55-68.

          Motoneurons are generated in excess during embryonic development of higher vertebrates. In the lumbar spinal cord of the developing rat, about 6000 motoneurons are present at embryonic day 14. These neurons grow out axons which make contact with their target tissue, the skeletal muscle. About 50% of the motoneurons are lost during a critical period from embryonic day 14 until postnatal day 3. This process, which is called physiological motoneuron cell death, has been the focus of research aiming at the identification of neurotrophic factors which regulate motoneuron survival during this developmental period. Motoneuron cell death can also be observed in vitro when the motoneurons are isolated from the embryonic avian or rodent spinal cord. These isolated motoneurons and other types of primary neurons have been a useful tool for studying basic mechanisms underlying neuronal degeneration during development and under pathophysiological conditions in neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS). Accumulating evidence from such studies suggests that some specific requirements of motoneurons for survival and proper function may change during development. These findings might be relevant for understanding the pathophysiological processes underlying ALS and thus could contribute to the development of new therapeutic strategies.

Benders, N. A., I. D. Wijnberg, et al. (2001). "[Equine motor neuron disease: a review based on a case report.]." Tijdschr Diergeneeskd 126(11): 376-80.

          A 10-year-old, non-pregnant Dutch Warmblood mare was referred to the Department of Equine Science because of chronic weight loss, despite good appetite, and dullness. Clinical examination revealed muscle atrophy, trembling of the limb muscles, an abnormal stance in which all four limbs were placed under the body, and an abnormal low head carriage. The plasma vitamin E concentration was markedly decreased (0.2 mumol/l), the electromyographic (EMG) examination was consistent with denervation, and the oral glucose absorption test was below the reference value (40% increase over the resting glucose level). Because of the clinical diagnosis of equine motor neuron disease (EMND), the horse was euthanazed and post-mortem examination confirmed this diagnosis. Based on the similarity in pathological findings, EMND can be compared to amyotrophic lateral sclerosis (ALS) in humans. However, in horses, only the lower motor neurons and occasionally some nuclei of the cranial nerves are affected. Because of the low plasma vitamin E concentration found in horses with EMND, an absolute or a relative antioxidant deficiency can be involved in the pathogenesis. In general, it is a progressive disease process and stabilization of the situation is the best feasible result. There is no specific therapy other than vitamin E supplementation and the prognosis is poor.

Benditt, J. O., T. S. Smith, et al. (2001). "Empowering the individual with ALS at the end-of-life: disease-specific advance care planning." Muscle Nerve 24(12): 1706-9.

Borasio, G. D. (2001). "Palliative care in ALS: searching for the evidence base." Amyotroph Lateral Scler Other Motor Neuron Disord 2 Suppl 1: S31-5.

          The poor prognosis of amyotrophic lateral sclerosis (ALS) makes palliative care a challenge for the neurologist. Most of the disabilities from progressive disease can be effectively relieved by symptomatic treatment. Prognosis and treatment options should be openly discussed with patient and relatives. Adequate assistance and palliative treatment in the terminal phase are of paramount importance. Unfortunately, training in communication skills for young doctors and evidence-based recommendations for palliative care are insufficient at present. In addition, new data from a randomized study question the concept of "health-related quality of life" and favor an individualized approach to the definition of quality of life in ALS.

Borasio, G. D. and R. G. Miller (2001). "Clinical characteristics and management of ALS." Semin Neurol 21(2): 155-66.

          Amyotrophic lateral sclerosis (ALS) is the most common form of degenerative motor neuron disease in adulthood. The clinical picture was accurately described by Charcot over 125 years ago and consists of generalized fasciculations, progressive atrophy and weakness of the skeletal muscles, spasticity and pyramidal tract signs, dysarthria, dysphagia, and dyspnea. Pseudobulbar affect is common. Disease-specific treatment options are still unsatisfactory. However, therapeutic nihilism is not justified as a large array of palliative measures is available to enhance the quality of life of patients and their families. Palliative care in ALS is a multidisciplinary effort requiring careful coordination. An open and frank disclosure of the diagnosis is of paramount importance. Nutritional deficiency due to pronounced dysphagia can be relieved by a percutaneous endoscopic gastrostomy. Respiratory insufficiency can be effectively treated by noninvasive home mechanical ventilation. The terminal phase of the disease should be discussed, at the latest, when symptoms of dyspnea appear in order to prevent unwarranted fears of "choking to death." Collaboration with hospice and completion of advance directives can be of invaluable help in the terminal phase.

Bowen, B. C. and W. G. Bradley (2001). "Amyotrophic lateral sclerosis: the search for a spectroscopic marker of upper motoneuron involvement." Arch Neurol 58(5): 714-6.

Brandt, R. (2001). "Cytoskeletal mechanisms of neuronal degeneration." Cell Tissue Res 305(2): 255-65.

          The cytoskeleton is the major intracellular determinant of neuronal morphology and is required for fundamental processes during the development and maintenance of a neuron. Thus, it is not surprising that many neurodegenerative diseases including Alzheimer's disease and amyotrophic lateral sclerosis (motor neuron disease) are characterized by typical abnormalities in the organization of the cytoskeleton. However, the role of the cytoskeletal changes during the development of the disease, e.g., whether they have a causative role during neuronal degeneration or represent an epiphenomenon of neurons that degenerate by other means, is still disputed. In this review, recent results on the development and the role of cytoskeletal abnormalities during neurodegenerative diseases are discussed and a mechanistic framework for the involvement of cytoskeletal changes during neurodegenerative processes is presented.

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.

Brown, R. H., Jr. and W. Robberecht (2001). "Amyotrophic lateral sclerosis: pathogenesis." Semin Neurol 21(2): 131-9.

          Amyotrophic lateral sclerosis (ALS) is a devastating paralytic disorder caused by motor neuron degeneration. A subgroup of familial cases arises from mutations in the gene encoding cytosolic superoxide dismutase (SOD1). This review considers insight now being gained into ALS pathogenesis from the study of mutant SOD1 protein and its possible mechanisms of adverse effect on nerve cells. Also discussed are the status of other genetic forms of ALS and the elusive question of why this disorder so specifically targets motor neurons. Ultimately, it is hoped that insights from these types of studies will improve the prospects for developing meaningful therapies of ALS.

Bruno, V., G. Battaglia, et al. (2001). "Metabotropic glutamate receptor subtypes as targets for neuroprotective drugs." J Cereb Blood Flow Metab 21(9): 1013-33.

          Metabotropic glutamate (mGlu) receptors have been considered as potential targets for neuroprotective drugs, but the lack of specific drugs has limited the development of neuroprotective strategies in experimental models of acute or chronic central nervous system (CNS) disorders. The advent of potent and centrally available subtype-selective ligands has overcome this limitation, leading to an extensive investigation of the role of mGlu receptor subtypes in neurodegeneration during the last 2 years. Examples of these drugs are the noncompetitive mGlu1 receptor antagonists, CPCCOEt and BAY-36-7620; the noncompetitive mGlu5 receptor antagonists, 2-methyl-6-(phenylethynyl)pyridine, SIB-1893, and SIB-1757; and the potent mGlu2/3 receptor agonists, LY354740 and LY379268. Pharmacologic blockade of mGlu1 or mGlu5 receptors or pharmacologic activation of mGlu2/3 or mGlu4/7/8 receptors produces neuroprotection in a variety of in vitro or in vivo models. MGlu1 receptor antagonists are promising drugs for the treatment of brain ischemia or for the prophylaxis of neuronal damage induced by synaptic hyperactivity. MGlu5 receptor antagonists may limit neuronal damage induced by a hyperactivity of N-methyl-d-aspartate (NMDA) receptors, because mGlu5 and NMDA receptors are physically and functionally connected in neuronal membranes. A series of observations suggest a potential application of mGlu5 receptor antagonists in chronic neurodegenerative disorders, such as amyotrophic lateral sclerosis and Alzheimer disease. MGlu2/3 receptor agonists inhibit glutamate release, but also promote the synthesis and release of neurotrophic factors in astrocytes. These drugs may therefore have a broad application as neuroprotective agents in a variety of CNS disorders. Finally, mGlu4/7/8 receptor agonists potently inhibit glutamate release and have a potential application in seizure disorders. The advantage of all these drugs with respect to NMDA or AMPA receptor agonists derives from the evidence that mGlu receptors do not "mediate," but rather "modulate" excitatory synaptic transmission. Therefore, it can be expected that mGlu receptor ligands are devoid of the undesirable effects resulting from the inhibition of excitatory synaptic transmission, such as sedation or an impairment of learning and memory.

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.

Carter, G. T. and B. S. Rosen (2001). "Marijuana in the management of amyotrophic lateral sclerosis." Am J Hosp Palliat Care 18(4): 264-70.

          Marijuana has been proposed as treatment for a widening spectrum of medical conditions. Marijuana is a substance with many properties that may be applicable to the management of amyotrophic lateral sclerosis (ALS). These include analgesia, muscle relaxation, bronchodilation, saliva reduction, appetite stimulation, and sleep induction. In addition, marijuana has now been shown to have strong antioxidative and neuroprotective effects, which may prolong neuronal cell survival. In areas where it is legal to do so, marijuana should be considered in the pharmacological management of ALS. Further investigation into the usefulness of marijuana in this setting is warranted.

Cassina, P., H. Peluffo, et al. (2001). "Adaptative responses of spinal astrocytes to oxidative stress." Prog Brain Res 132: 413-25.

Charles, T. and M. Swash (2001). "Amyotrophic lateral sclerosis: current understanding." J Neurosci Nurs 33(5): 245-53.

          Amyotrophic lateral sclerosis (ALS), or motor neuron disease (MND) as it is usually termed in the United Kingdom, is a fatal degenerative disease resulting in progressive weakness and wasting of voluntary muscles. The disease is caused by degeneration of upper motor neurons in the motor cortex and of lower motor neurons in the brainstem and spinal cord. This combined loss of function causes spastic paralysis, flaccid muscle weakness, wasting, and fasciculations. The disease process spares the sensory, autonomic, and oculomotor neurons. ALS is the most common of the MND syndromes in adults. Although the cause of ALS is unknown, there is evidence that the excitatory neurotransmitter glutamate plays an important role in neuronal cell death in the disease. Several risk factors, such as exposure to welding and soldering, inhalation of lead vapor, exposure to chemicals, and electrical trauma are postulated as contributing to the pathogenesis of ALS. About 90% of all ALS patients have the sporadic form. Approximately 20% of all familial ALS cases are associated with mutations of the copper/zinc superoxide dismutase-1 gene. What is not clear is what factors contribute to the causation of the more common sporadic cases. The drug riluzole has neuroprotective effects in ALS and is the only disease-specific treatment available to date. Riluzole has been approved by the National Institute for Clinical Excellence for use in the National Health Service of the United Kingdom. Other treatments are aimed at managing the devastating symptoms of ALS.

Chritin, M., G. Besson, et al. (2001). "[Amyotrophic lateral sclerosis and animal models]." Rev Neurol (Paris) 157(11 Pt 1): 1351-61.

          Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease which affects cortical, bulbar and spinal motoneurones. The cause of the disease, probably due to several factors, is still unknown and the survival delay of patients with ALS generally does not exceed 3-5 years. Animals models provide a unique opportunity to study pathological features and to evaluate potential therapeutic effects of news treatments. Natural disease models, neurotoxins or viral-induced models and more recently transgenic models with genetic anomalies mimicking those found in ALS patients have been extensively studied. This review summarizes the most relevant clinical and pathological advances issuing from these animal studies.

Clarke, G., C. J. Lumsden, et al. (2001). "Inherited neurodegenerative diseases: the one-hit model of neurodegeneration." Hum Mol Genet 10(20): 2269-75.

          The clinical manifestations of inherited neurodegenerative diseases are often delayed for periods from years to decades. This observation has led to the idea that, in these disorders, neurons die from cumulative damage. A critical prediction of the cumulative damage hypothesis is that the probability of neuronal death increases with age. However, we recently demonstrated, in 17 examples of neurodegeneration, that the kinetics of neuronal death appear to be exponential. These examples include both monogenic disorders, such as photoreceptor degenerations, as well as others that are partly or entirely acquired (such as the clinical phase of parkinsonism and retinal detachment). Exponential kinetics indicate that (i) the risk of death is constant, (ii) death occurs randomly in time and (iii) the death of each neuron is independent of other neurons. We use the term 'one-hit model' to refer to the single catastrophic intracellular biochemical event, analogous to radioactive decay, which leads to neuronal death in the diseases we analyzed. Here, we examine the major features and implications of the one-hit model and provide preliminary evidence that amyotrophic lateral sclerosis also appears to fit this model. We also discuss a testable biochemical hypothesis, the mutant steady-state hypothesis, that we proposed to account for the one-hit model. Finally, we explore six unresolved issues that appear to challenge this model. The one-hit model appears to capture a novel principle underlying many neurodegenerations. Our findings suggest that any consideration of the biochemical basis of neurodegeneration must include a meticulous examination of the kinetics of cell death.

Cleveland, D. W. and J. D. Rothstein (2001). "From Charcot to Lou Gehrig: deciphering selective motor neuron death in ALS." Nat Rev Neurosci 2(11): 806-19.

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.

Cluskey, S. and D. B. Ramsden (2001). "Mechanisms of neurodegeneration in amyotrophic lateral sclerosis." Mol Pathol 54(6): 386-92.

          Amyotrophic lateral sclerosis (ALS) is the most common variant of motor neurone disease affecting adults that usually strikes during mid to late life. Its aetiology is still poorly understood, although a major breakthrough came with the discovery that mutations in the Cu/Zn superoxide dismutase (SOD1) gene affect approximately 20% of patients with familial ALS. Experiments using both transgenic mice and ALS tissues have been useful in delineating other genetic defects in ALS. However, because only a subset of cases can be attributed to one particular molecular defect (such as mutation of SOD1 or the gene encoding neurofilament H), the aetiology of ALS is likely to be multifactorial. This review discusses the major mechanisms of neurodegeneration in ALS, such as oxidative stress, glutaminergic excitotoxicity, damage to vital organelles, and aberrant protein aggregation.

Costa, V. and P. Moradas-Ferreira (2001). "Oxidative stress and signal transduction in Saccharomyces cerevisiae: insights into ageing, apoptosis and diseases." Mol Aspects Med 22(4-5): 217-46.

          In yeast, as in higher eukaryotes, reactive oxygen species are produced as normal by-products of cellular metabolism. Under physiological conditions, the cell defence mechanisms are able to avoid molecular damages. This balance is disturbed when yeast cells are exposed to diverse environmental stress conditions, such as the presence of oxidants, heat shock, ethanol and metal ions. The increased production of reactive oxygen species is sensed by the cell, leading to the induction of defence mechanisms - the oxidative stress response. The present review discusses the mechanisms by which reactive oxygen species are sensed and the signalling pathways that are coupled with changes in genomic expression programs. Yeast has been used as an eukaryotic cell system to characterise the molecular mechanisms underlying the oxidative stress response. Furthermore, yeast has been utilised to elucidate the role of oxidative stress in ageing, apoptosis, and diseases, such as familial amyotrophic lateral sclerosis and Friedreich's ataxia.

Cotterill, R. M. (2001). "Cooperation of the basal ganglia, cerebellum, sensory cerebrum and hippocampus: possible implications for cognition, consciousness, intelligence and creativity." Prog Neurobiol 64(1): 1-33.

          It is suggested that the anatomical structures which mediate consciousness evolved as decisive embellishments to a (non-conscious) design strategy present even in the simplest unicellular organisms. Consciousness is thus not the pinnacle of a hierarchy whose base is the primitive reflex, because reflexes require a nervous system, which the single-celled creature does not possess. By postulating that consciousness is intimately connected to self-paced probing of the environment, also prominent in prokaryotic behavior, one can make mammalian neuroanatomy amenable to dramatically straightforward rationalization. Muscular contraction is the nervous system's only externally directed product, and the signaling routes which pass through the various brain components must ultimately converge on the motor areas. The function of several components is still debatable, so it might seem premature to analyze the global operation of the circuit these routes constitute. But such analysis produces a remarkably simple picture, and it sheds new light on the roles of the individual components. The underlying principle is conditionally permitted movement, some components being able to veto muscular contraction by denying the motor areas sufficient activation. This is true of the basal ganglia (BG) and the cerebellum (Cb), which act in tandem with the sensory cerebrum, and which can prevent the latter's signals to the motor areas from exceeding the threshold for overt movement. It is also true of the anterior cingulate, which appears to play a major role in directing attention. In mammals, the result can be mere thought, provided that a second lower threshold is exceeded. The veto functions of the BG and the Cb stem from inhibition, but the countermanding disinhibition develops at markedly different rates in those two key components. It develops rapidly in the BG, control being exercised by the amygdala, which itself is governed by various other brain regions. It develops over time in the Cb, thereby permitting previously executed movements that have proved advantageous. If cognition is linked to overt or covert movement, intelligence becomes the ability to consolidate individual motor elements into more complex patterns, and creativity is the outcome of a race-to-threshold process which centers on the motor areas. Amongst the ramifications of these ideas are aspects of cortical oscillations, phantom limb sensations, amyotrophic lateral sclerosis (ALS) the difficulty of self-tickling and mirror neurons.

Danbolt, N. C. (2001). "Glutamate uptake." Prog Neurobiol 65(1): 1-105.

          Brain tissue has a remarkable ability to accumulate glutamate. This ability is due to glutamate transporter proteins present in the plasma membranes of both glial cells and neurons. The transporter proteins represent the only (significant) mechanism for removal of glutamate from the extracellular fluid and their importance for the long-term maintenance of low and non-toxic concentrations of glutamate is now well documented. In addition to this simple, but essential glutamate removal role, the glutamate transporters appear to have more sophisticated functions in the modulation of neurotransmission. They may modify the time course of synaptic events, the extent and pattern of activation and desensitization of receptors outside the synaptic cleft and at neighboring synapses (intersynaptic cross-talk). Further, the glutamate transporters provide glutamate for synthesis of e.g. GABA, glutathione and protein, and for energy production. They also play roles in peripheral organs and tissues (e.g. bone, heart, intestine, kidneys, pancreas and placenta). Glutamate uptake appears to be modulated on virtually all possible levels, i.e. DNA transcription, mRNA splicing and degradation, protein synthesis and targeting, and actual amino acid transport activity and associated ion channel activities. A variety of soluble compounds (e.g. glutamate, cytokines and growth factors) influence glutamate transporter expression and activities. Neither the normal functioning of glutamatergic synapses nor the pathogenesis of major neurological diseases (e.g. cerebral ischemia, hypoglycemia, amyotrophic lateral sclerosis, Alzheimer's disease, traumatic brain injury, epilepsy and schizophrenia) as well as non-neurological diseases (e.g. osteoporosis) can be properly understood unless more is learned about these transporter proteins. Like glutamate itself, glutamate transporters are somehow involved in almost all aspects of normal and abnormal brain activity.

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.

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 Carvalho, M., B. Johnsen, et al. (2001). "Medical technology assessment. Electrodiagnosis in motor neuron diseases and amyotrophic lateral sclerosis." Neurophysiol Clin 31(5): 341-8.

          In motor neuron diseases/amyotrophic lateral sclerosis (MND-ALS), electrodiagnostic techniques are essential in supporting the diagnosis and excluding other conditions that clinically resemble MND-ALS. Electrodiagnostic techniques can also monitor disease progression and provide prognostic information. Electromyography has an important role in the diagnosis of MND-ALS, but some drawbacks should be borne in mind. Although internationally accepted electrophysiological criteria have been defined to support MND-ALS diagnosis, differences in different laboratories can raise unexpected difficulties in application of diagnosis criteria. Much work needs to be done to increase standardisation of the electrodiagnosis of MND-ALS in order to improve quality. Differential diagnosis with motor axonal neuropathies may be particularly difficult. EMG is an essential tool for the early diagnosis of MND-ALS, which increases potential benefit of therapeutic interventions. A wide discussion among neurophysiologists from different schools could create a sound consensus on early diagnosis of MND-ALS.

Domitrz, I., M. Jedrzejowska, et al. (2001). "[Kennedy's disease: expansion of the CAG trinucleotide]." Neurol Neurochir Pol 35(1 Suppl): 107-14.

          Kennedy's disease is a rare X-linked spinal and bulbar muscular atrophy (SBMA). A degenerative process of the motor neurons is associated with an increase in the number of CAG repeats encoding a polyglutamine stretch within the androgen receptor. Despite a distinctive clinical phenotype, SBMA can be misdiagnosed, usually due to the lack of clear family history. Accurate diagnosis is important for genetic counseling and because alternative diagnosis of amyotrophic lateral sclerosis usually means much worse prognosis. We report 2 unrelated patients with Kennedy's disease in whom the clinical diagnosis was confirmed by showing the CAG repeat expansion.

Duff, K. and M. V. Rao (2001). "Progress in the modeling of neurodegenerative diseases in transgenic mice." Curr Opin Neurol 14(4): 441-7.

          Transgenic mouse models exist for the major neurodegenerative diseases, including Alzheimer's disease, tauopathy and amyotrophic lateral sclerosis. Although many of the mice do not completely replicate the human disease they are intended to model, they have provided insight into the mechanisms that underlie disease etiology. In the case of the Alzheimer's disease and amyotrophic lateral sclerosis models, the mice have also provided a therapeutic testing ground for the testing of agents that have been shown to have considerable clinical promise.

Eisen, A. (2001). "Clinical electrophysiology of the upper and lower motor neuron in amyotrophic lateral sclerosis." Semin Neurol 21(2): 141-54.

          Electrophysiology is important in amyotrophic lateral sclerosis (ALS). It helps in the assessment of disease severity and rate of progression, and it plays a role in evaluating the efficacy of therapeutic trials. Presently, electrophysiology is the only means of confirming suspected ALS, and this has been incorporated into the El Escorial criteria. Needle electromyography identifies disease in clinically "unaffected muscles" including bulbar musculature, confirms involvement of anterior horn cells, and can detect early involvement of respiratory muscles (intercostals and diaphragm). Conduction studies are imperative to rule out motor neuropathy with multifocal conduction block. Various techniques (cortical threshold, cortical silent period, double stimulation) employing transcranial magnetic stimulation have demonstrated that the motor cortex in ALS is hyperexcitable. Central motor conduction is normal in ALS but uniquely slow in the D9OA SOD1 mutation. Using peristimulus time histograms (PSTHs) it is possible to estimate the size of a unitary excitatory postsynaptic potential (EPSP). In ALS the EPSP is typically desynchronized. With time it becomes reduced in amplitude and a slow conducting component becomes recognizable in the primary peak of the PSTH. This reflects conduction through a slow motor pathway. Abnormalities of the PSTH are not seen in Kennedy's disease, implying that the changes seen in ALS are due to supraspinal mechanisms.

Eisen, A. and M. Swash (2001). "Clinical neurophysiology of ALS." Clin Neurophysiol 112(12): 2190-201.

          The neurophysiology of amyotrophic lateral sclerosis is important not only in relation to diagnosis, but also in the development of methods to follow progress, and the effects of putative therapies, in the disease. Quantitative techniques can be applied to the measurement of reinnervation using needle electromyogram. The methodology of motor unit number estimation may be useful in measuring loss of functioning motor units in groups of patients but variability in the measurement using current methods limits its sensitivity in the evaluation of individual patients. Conventional neurophysiological measurements, expressed as a multimetric index, may be useful in assessing progress. The cortical and upper motor neuron system can be assessed using transcortical magnetic stimulation protocols, and cortical excitability may be measured by the peristimulus histogram method. In this review the advantages, limitations and promise of these various methods is discussed, in order to indicate the direction for further neurophysiological studies in this disorder.

Eisen, A. and M. Weber (2001). "The motor cortex and amyotrophic lateral sclerosis." Muscle Nerve 24(4): 564-73.

          On theoretical grounds, abnormalities of the motor cortex in patients with amyotrophic lateral sclerosis (ALS) could lead to anterograde ("dying-forward") transneuronal degeneration of the anterior horn cells as suggested by Charcot. Conversely, retrograde ("dying-back") degeneration of the corticospinal tracts could affect the motor cortex. Evidence derived from clinical, neuropathological, static, and functional imaging, and physiological studies, favors the occurrence of anterograde degeneration. It is hypothesized that transneuronal degeneration in ALS is an active excitotoxic process in which live but dysfunctional corticomotoneurons, originating in the primary motor cortex, drive the anterior horn cell into metabolic deficit. When this is marked, it will result in more rapid and widespread loss of lower motor neurons. In contrast, slow loss of corticomotoneurons, as occurs in primary lateral sclerosis (PLS), precludes excitotoxic drive and is incompatible with anterograde degeneration. Preservation of slow-conducting non-M1 direct pathways in PLS is not associated with excitotoxicity, and anterior horn cells survive for long periods of time.

Elliott, J. L. (2001). "Zinc and copper in the pathogenesis of amyotrophic lateral sclerosis." Prog Neuropsychopharmacol Biol Psychiatry 25(6): 1169-85.

          1. Missense mutations in the gene encoding Cu,Zn superoxide dismutase (SOD1) are responsible for causing one form of familial amyotrophic lateral sclerosis (FALS) linked to chromosome 21q. 2. Mutant SOD1-induced disease is clearly related to a toxic gain of function for the abnormal enzyme, and recent work has begun to investigate the mechanisms underlying this toxicity. In addition to its well known and likely beneficial dismutase activity, wild type SOD1 also possesses the ability to participate in other enzymatic reactions that may be injurious to cells including peroxidation or nitration. 3. Many of the SOD1 mutations associated with FALS appear to increase the likelihood that the enzyme will perform either one of these potentially harmful functions resulting in increased hydroxyl radical formation or the addition of nitro groups to tyrosine residues within cellular proteins. (ABSTRACT TRUNCATED)

Finiels, H., D. Strubel, et al. (2001). "[Deglutition disorders in the elderly. Epidemiological aspects]." Presse Med 30(33): 1623-34.

          THE PREVALENCE: The exact prevalence of deglutition disorders in the elderly is not known. It appears frequent in very old patients and in those suffering from polypathological symptoms, affecting 50% of the populations in long-term care units. THE EFFECTS OF AGING: Physiological aging alters various parameters of swallowing, however it seems that these modifications related to age have little effect on healthy subjects. However, they may increase vulnerability in those presenting with intercurrent pathologies. CONCOMITANT DISORDERS: Other than the decrease in efficient mastication and the existence of xerostomia, frequently observed contributing factors, many diseases may be responsible for dysphagia in the elderly. Neurological disorders, particularly cerebral vascular diseases, central nervous system degenerative disorders and neuro-motor diseases predominate. In the aging, muscular disorders and after effects of various diseases can set-in. Modifications in oropharyngeal anatomy generally results from cancerous lesions of the aero-digestive junction, but also, occasionally from extrinsic compression that does not necessarily reflect a neoplastic etiology. Zenker's diverticulitis represents a cause of dysphagia specific to the elderly. Problems in swallowing of iatrogenic origin are also frequent, following cervical radiotherapy or after oropharyngeal surgery, during tracheal intubation or when using feeding tubes and also during various medical treatments. UNDERRATED CONSEQUENCES: Dysphagia leads to multiple morbid after effects, primarily alteration in quality of life, dehydration, undernutrition, asphyxia and congestion and recurrent infections of the respiratory tract. The responsibility of deglutition disorders in the occurrence of these complications is difficult to assess in weak elderly subjects because of the frequent concomitance with multiple deficiencies and incapacities.

Fink, J. K. (2001). "Progressive spastic paraparesis: hereditary spastic paraplegia and its relation to primary and amyotrophic lateral sclerosis." Semin Neurol 21(2): 199-207.

          The syndrome of insidiously progressive spastic weakness of both legs occurs in a number of etiologically distinct disorders including hereditary spastic paraplegia (HSP), primary lateral sclerosis (PLS), and sometimes in amyotrophic lateral sclerosis (ALS). This review summarizes the clinical and pathologic relationship between these disorders.

Gadea, A. and A. M. Lopez-Colome (2001). "Glial transporters for glutamate, glycine, and GABA III. Glycine transporters." J Neurosci Res 64(3): 218-22.

          Glial cells possess transport systems for the three major amino acid neurotransmitters glutamate, gamma-aminobutyric acid (GABA) and glycine, involved in the arrest of neurotransmission mediated by these compounds. Two glycine transporters have been cloned: GLYT1, mainly expressed by glial cells and shown to colocalize with NMDA receptors, and GLYT2, exclusively expressed by neurons and colocalized with the inhibitory glycine receptors. The way in which the regulation of extracellular glycine concentration by glial glycine transporters affects physiological and pathological conditions is discussed. The presence, differential pharmacology and specific regulation of glycine transporters in glial cells strongly support an important role for glia in the modulation of both, excitatory and inhibitory neurotransmission.

Gallo, J. M. (2001). "Kennedy's disease: a triplet repeat disorder or a motor neuron disease?" Brain Res Bull 56(3-4): 209-14.

          Two definite genetic causes of adult motor neuron degeneration have been identified to date: CAG repeat expansion in the androgen receptor gene in Kennedy's disease and point mutations in the SOD1 gene, encoding the enzyme, Cu/Zn superoxide dismutase, in some familial forms of amyotrophic lateral sclerosis. Although both have unrelated genetic causes, Kennedy's disease and SOD1-linked amyotrophic lateral sclerosis share several pathogenic features. First, expanded androgen receptor and mutant Cu/Zn superoxide dismutase have a propensity to aggregate into insoluble complexes and form inclusion bodies in affected neurons. Deposits of mutant proteins could be detrimental to neuronal viability by interfering with the normal housekeeping functions of chaperones and of the ubiquitin/proteasome system. Secondly, cytoskeletal function may be impaired in both diseases as decreased transactivational activity of expanded androgen receptor may cause an abnormal pattern of tubulin expression in motor neurons in Kennedy's disease and disruption of neurofilament organisation is a hallmark of amyotrophic lateral sclerosis. The concept of activation of overlapping cell death cascades by two distinct genetic defects could help elucidating downstream pathogenic processes and may provide novel targets for pharmacological intervention or gene therapy for the treatment of motor neuron disorders.

Gimenez y Ribotta, M. (2001). "Gene therapy strategies in neurodegenerative diseases." Histol Histopathol 16(3): 883-93.

          Treatment of neurodegenerative diseases by classical pharmacotherapy is restricted by blood-brain barrier which prevents access to the brain of potentially therapeutic molecules. Recent progress in the knowledge of pathophysiological molecular processes, and in the development of molecular biotechnology have opened the way to new therapeutic interventions for these disorders. This chapter reviews the most recent gene therapy strategies using experimental models for neurodegenerative diseases.

Gonzalez Deniselle, M. C., S. L. Gonzalez, et al. (2001). "Cellular basis of steroid neuroprotection in the wobbler mouse, a genetic model of motoneuron disease." Cell Mol Neurobiol 21(3): 237-54.

          1. The Wobbler mouse suffers an autosomal recessive mutation producing severe motoneuron degeneration and astrogliosis in the spinal cord. It has been considered a suitable model of human motoneuron disease, including the sporadic form of amyotrophic lateral sclerosis (ALS). 2. Evidences exist demonstrating increased oxidative stress in the spinal cord of Wobbler mice, whereas antioxidant therapy delayed neurodegeneration and improved muscle trophism. 21-Aminosteroids are glucocorticoid-derived hydrophobic compounds with antioxidant potency 3 times higher than vitamin E and 100 times higher than methylprednisolone. They do not bind to intracellular receptors, and prevent lipid peroxidation by insertion into membrane lipid bilayers. 3. In common with the spinal cord of ALS patients, Wobbler mice present astrocytosis with hyperexpression of glial fibrillary acidic protein (GFAP), and increased expression of nitric oxide synthase (NOS) and growth-associated protein (GAP-43) in motoneurons. Here, we review our studies on the effects of a 21-aminosteroid on GFAP, NOS, and GAP-43. 4. First, we showed that 21-aminosteroid treatment further increased GFAP-expressing astrocytes in gray matter of the Wobbler spinal cord. This effect may provide neuroprotection if one considers a trophic and beneficial function of astrocytes during the course of degeneration. Other neuroprotectans used in Wobbler mice (T-588) also increased pre-existing astrocytosis. 5. Second, histochemical determination of NADPH-diaphorase, a parameter indicative of neuronal NOS activity, showed that the 21-aminosteroid down-regulated the high activity of this enzyme in ventral horn motoneurons. Therefore, suppression of nitric oxide by decreasing NADPH-diaphorase (NOS) activity may provide neuroprotection considering that excess NO is highly toxic to motoneurons. 6. Finally, 21-aminosteroid treatment significantly attenuated the aberrant expression of both GAP-43 protein and mRNA in Wobbler motoneurons. Hyperexpression of GAP-43 possibly indicated abnormal synaptogenesis, denervation, and muscle atrophy, parameters which may return to normal following antioxidant steroid treatment. 7. Besides 21-aminosteroids, other steroids also behave as neuroprotectans. In this regard, degenerative diseases may constitute potential targets of these hormones, based on the fact that the spinal cord expresses in a regional and cell-specific fashion, receptors for androgens. progesterone, adrenal steroids, and estrogens.

Grippo, J. and T. Grippo (2001). "[Channelopathies in neurology]." Rev Neurol 33(7): 643-7.

          INTRODUCTION. The main function of ionic channels are the conduction, recognition and selection of specific ions. They open and close in respond answer to electrical, mechanical and chemical stimulus, acting in the excitation or transmission of diverse tissues. DEVELOPMENT. The clinical and molecular manifestations of channelophathies are varied and use to shown up in continuous or paroxystic ways. Alteration of Ca channels cause muscle dysfunction periodic paralysis with or without potassium changes, myasthenia or myasthenic disorders, like Lambert Eaton syndrome, amyotrophic lateral sclerosis, Central Core disease, malignant hyperthermia. Cl and Na channels alterations produce myotonic diseases: Thomsen, Becker and paramyothonies, potassium sensible paralysis, fluctuant congenital myotonic, Andersen s syndrome. Channelopathies also produce various episodic ataxia type 1, type 2, spinocerebellar 6 and familial hemiplegic migraine. Abnormal paroxystic movements are present as channelophaties: episodic nocturnal dystonia, paroxystic dyskinesia. In some families are associates abnormal episodic movements and epilepsy. Several epileptic syndromes are also related with channels dysfunction: frontal lobe nocturnal epilepsy, choreoatetosis epilepsy, benign neonatal convulsions, generalized epilepsy with febrile convulsions plus. CONCLUSIONS. Voltage gated channels dysfunction are related to diseases with episodic phenomena or permanent conditions on muscle or neuronal tissues, with clinical and genetic heterogenous manifestations.

Halliwell, B. (2001). "Role of free radicals in the neurodegenerative diseases: therapeutic implications for antioxidant treatment." Drugs Aging 18(9): 685-716.

          Free radicals and other so-called 'reactive species' are constantly produced in the brain in vivo. Some arise by 'accidents of chemistry', an example of which may be the leakage of electrons from the mitochondrial electron transport chain to generate superoxide radical (O2*-). Others are generated for useful purposes, such as the role of nitric oxide in neurotransmission and the production of O2*- by activated microglia. Because of its high ATP demand, the brain consumes O2 rapidly, and is thus susceptible to interference with mitochondrial function, which can in turn lead to increased O2*- formation. The brain contains multiple antioxidant defences, of which the mitochondrial manganese-containing superoxide dismutase and reduced glutathione seem especially important. Iron is a powerful promoter of free radical damage, able to catalyse generation of highly reactive hydroxyl, alkoxyl and peroxyl radicals from hydrogen peroxide and lipid peroxides, respectively. Although most iron in the brain is stored in ferritin, 'catalytic' iron is readily mobilised from injured brain tissue. Increased levels of oxidative damage to DNA, lipids and proteins have been detected by a range of assays in post-mortem tissues from patients with Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis, and at least some of these changes may occur early in disease progression. The accumulation and precipitation of proteins that occur in these diseases may be aggravated by oxidative damage, and may in turn cause more oxidative damage by interfering with the function of the proteasome. Indeed, it has been shown that proteasomal inhibition increases levels of oxidative damage not only to proteins but also to other biomolecules. Hence, there are many attempts to develop antioxidants that can cross the blood-brain barrier and decrease oxidative damage. Natural antioxidants such as vitamin E (tocopherol), carotenoids and flavonoids do not readily enter the brain in the adult, and the lazaroid antioxidant tirilazad (U-74006F) appears to localise in the blood-brain barrier. Other antioxidants under development include modified spin traps and low molecular mass scavengers of O2*-. One possible source of lead compounds is the use of traditional remedies claimed to improve brain function. Little is known about the impact of dietary antioxidants upon the development and progression of neurodegenerative diseases, especially Alzheimer's disease. Several agents already in therapeutic use might exert some of their effects by antioxidant action, including selegiline (deprenyl), apomorphine and nitecapone.

Ilzecka, J. (2001). "[Superoxide dismutase-1 (SOD-1) gene mutation-dependent mechanisms of neural degeneration in amyotrophic lateral sclerosis]." Neurol Neurochir Pol 35(3): 461-9.

          Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease involving motor neuron degeneration, occurring in sporadic and familial forms. Mutations in Cu/Zn superoxide dismutase gene (SOD-1) play a key role in the pathogenesis of the familial form in which it is present in about 20%. The mechanisms by which the mutated enzyme produces the disease are not sufficiently know. The following hypothesis are considered: oxidative damage, disorganization of neurofilaments, toxic action of intracellular aggregates, disturbed mechanisms of protein synthesis or degradation, and increased glutamic acid toxicity due to damage of EAAT 2 mRNA, transporter of this acid. It is supposed that motor neuron death is due to various mechanisms caused by SOD-1 enzyme mutations. Pathological changes suggest that biochemical processes leading to neurodegeneration in familial ALS form related or unrelated to SOD-1 mutation, and in sporadic form may be very similar.

Imam, S. Z., J. el-Yazal, et al. (2001). "Methamphetamine-induced dopaminergic neurotoxicity: role of peroxynitrite and neuroprotective role of antioxidants and peroxynitrite decomposition catalysts." Ann N Y Acad Sci 939: 366-80.

          Oxidative stress, reactive oxygen (ROS), and nitrogen (RNS) species have been known to be involved in a multitude of neurodegenerative disorders such as Parkinson's disease (PD), Alzheimer's disease (AD), and amyotrophic lateral sclerosis (ALS). Both ROS and RNS have very short half-lives, thereby making their identification very difficult as a specific cause of neurodegeneration. Recently, we have developed a high performance liquid chromatography/electrochemical detection (HPLC/EC) method to identify 3-nitrotyrosine (3-NT), an in vitro and in vivo biomarker of peroxynitrite production, in cell cultures and brain to evaluate if an agent-driven neurotoxicity is produced by the generation of peroxynitrite. We show that a single or multiple injections of methamphetamine (METH) produced a significant increase in the formation of 3-NT in the striatum. This formation of 3-NT correlated with the striatal dopamine depletion caused by METH administration. We also show that PC12 cells treated with METH has significantly increased formation of 3-NT and dopamine depletion. Furthermore, we report that pretreatment with antioxidants such as selenium and melatonin can completely protect against the formation of 3-NT and depletion of striatal dopamine. We also report that pretreatment with peroxynitrite decomposition catalysts such as 5, 10,15,20-tetrakis(N-methyl-4'-pyridyl)porphyrinato iron III (FeTMPyP) and 5, 10, 15, 20-tetrakis (2,4,6-trimethyl-3,5-sulfonatophenyl) porphinato iron III (FETPPS) significantly protect against METH-induced 3-NT formation and striatal dopamine depletion. We used two different approaches, pharmacological manipulation and transgenic animal models, in order to further investigate the role of peroxynitrite. We show that a selective neuronal nitric oxide synthase (nNOS) inhibitor, 7-nitroindazole (7-NI), significantly protect against the formation of 3-NT as well as striatal dopamine depletion. Similar results were observed with nNOS knockout and copper zinc superoxide dismutase (CuZnSOD)-overexpressed transgenic mice models. Finally, using the protein data bank crystal structure of tyrosine hydroxylase, we postulate the possible nitration of specific tyrosine moiety in the enzyme that can be responsible for dopaminergic neurotoxicity. Together, these data clearly support the hypothesis that the reactive nitrogen species, peroxynitrite, plays a major role in METH-induced dopaminergic neurotoxicity and that selective antioxidants and peroxynitrite decomposition catalysts can protect against METH-induced neurotoxicity. These antioxidants and decomposition catalysts may have therapeutic potential in the treatment of psychostimulant addictions.

Jackson, C. E. and J. Rosenfeld (2001). "Motor neuron disease." Phys Med Rehabil Clin N Am 12(2): 335-52, ix-x.

          Motor neuron disease refers to a spectrum of disorders resulting from degeneration of the upper or lower motor neurons or both. Amyotrophic lateral sclerosis is the most common form of motor neuron disease, in which patients demonstrate evidence of both anterior horn cell (lower motor neuron) and corticospinal tract (upper motor neuron) dysfunction. Several theories regarding the pathogenesis of amyotrophic lateral sclerosis have emerged, including glutamate excitotoxicity, free radical oxidative stress, cytoskeletal abnormalities, a deficiency of neurotrophic factor, autoimmunity, apoptosis, and viral infection. Numerous clinical trials have been completed based on these possible mechanisms of the disease propagation including treatment with antiglutamate agents, anti-oxidants, immunosuppressants, and neurotrophic factors. Several of these trials have shown modest effects in slowing the disease course. None, however, have yielded marked benefit in arresting disease progression. The most significant effect in abating disease progression has been our use and understanding of aggressive symptomatic therapy to reduce disability, enhance quality of life, and improve prognosis.

Julien, J. P. (2001). "Amyotrophic lateral sclerosis. unfolding the toxicity of the misfolded." Cell 104(4): 581-91.

Karitzky, J. and A. C. Ludolph (2001). "Imaging and neurochemical markers for diagnosis and disease progression in ALS." J Neurol Sci 191(1-2): 35-41.

          Based on the development of a transgenic animal model, an increasing number of experimental strategies have revealed the potential to modify the selective degeneration of motor neurons, a feature unique to motor neuron diseases such as amyotrophic lateral sclerosis (ALS). The translation of this success into therapeutic effects in human diseases is a challenge of the future. For this purpose, tools must be developed which serve as diagnostic and surrogate markers for diagnosis and disease progression. Currently, to understand the pathogenesis of the spinal cord disease, the focus remains on more traditional electrodiagnostic techniques. For the characterization of the involvement of brain structures, imaging techniques are increasingly explored. This review focuses on the use of imaging techniques as surrogate markers for the involvement of the brain in motor neuron disorders, but also tries to point out that the final goal will be the development of cheap biochemical markers for the screening of populations at risk.

Kato, S., K. Nakashima, et al. (2001). "Formation of advanced glycation end-product-modified superoxide dismutase-1 (SOD1) is one of the mechanisms responsible for inclusions common to familial amyotrophic lateral sclerosis patients with SOD1 gene mutation, and transgenic mice expressing human SOD1 gene mutation." Neuropathology 21(1): 67-81.

          Neuronal Lewy body-like hyaline inclusions (LBHI) and astrocytic hyaline inclusions (Ast-HI) are morphological hallmarks of certain familial amyotrophic lateral sclerosis (FALS) patients with superoxide dismutase-1 (SOD1) gene mutations, and transgenic mice expressing the human SOD1 gene mutation. The ultrastructure of inclusions in both diseases is identical: the essential common constituents are granule-coated fibrils approximately 15-25nm in diameter and granular materials. Detailed immunohistochemical analyses have shown that the essential common protein of the inclusions in both diseases is an SOD1 protein. This finding, together with the immunoelectron microscopy finding that the abnormal granule-coated fibrils comprising the inclusions are positive for SOD1, indicates that these granule-coated fibrils containing SOD1 are important evidence for mutant SOD1-linked disease in human and mouse. For immunoelectron microscopy, the granule-coated fibrils are modified by advanced glycation endproducts (AGE) such as N(epsilon)-carboxymethyl lysine, pyrraline and pentosidine (Maillard reaction). Based on the fact that AGE themselves are insoluble molecules with direct cytotoxic effects, the granule-coated fibrils and granular materials are not digested by the lysosomal and ubiquitin systems. The neurons and astrocytes of the normal individuals and non-transgenic mice show no significant immunoreactivity for AGE. Considered with the mutant-SOD1 aggregation toxicity, a portion of the SOD1 comprising both types of the inclusion is modified by the AGE, and the formation of the AGE-modified SOD1 (probably AGE-modified mutant SOD1) is one of the mechanisms responsible for the aggregation (i.e. granule-coated fibril formation).

Kurosawa, K. (2001). "[Amyotrophic lateral sclerosis]." Ryoikibetsu Shokogun Shirizu(33): 178-80.

Kwiecinski, H. (2001). "[Symptomatic treatment and palliative care of ALS]." Neurol Neurochir Pol 35(1 Suppl): 51-9.

          Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, affecting upper and lower motor neurons, which eventually progresses to respiratory deterioration and death in most of the patients. Only one drug, riluzole, has been approved for the treatment of ALS. The drug has a benefit, prolonging life by 3-6 months, but the disease progresses inexorably, with no better quality of life. The fundamental role of medicine is sometimes to cure, but always to bring comfort. In current situation, ALS patients need adequate palliative care more than anything else. Prognosis and treatment options should be discussed with the patient and the relatives, but full information about the prognosis may deprive the patient of hope. However, disclosure of the prognosis is necessary to obtain informed consent for management decisions such as tracheostomy and artificial ventilation. Nasal positive-pressure ventilation (BiPAP) is an alternative to tracheostomy, at least for some patients without advanced bulbar impairment. Nutritional status in patients who cannot swallow can be efficiently improved by a percutaneous endoscopic gastrostomy. (PEG).

Le Forestier, N., T. Maisonobe, et al. (2001). "Does primary lateral sclerosis exist? A study of 20 patients and a review of the literature." Brain 124(Pt 10): 1989-99.

          The question of whether primary lateral sclerosis (PLS) is a nosological entity distinct from amyotrophic lateral sclerosis (ALS) has been the subject of controversy since it was first described in the nineteenth century. PLS has been defined as a rare, non-hereditary disease characterized by progressive spinobulbar spasticity, related to the selective loss of precentral pyramidal neurones, with secondary pyramidal tract degeneration and preservation of anterior horn motor neurones. In the recent clinical literature, the frontier between ALS and neurodegenerative disease remains poorly defined. We studied 20 patients with a diagnosis of PLS. We carried out a variety of tests in order to determine the presence of a more diffuse neurodegenerative process. We also performed a longitudinal electrophysiological evaluation. Our clinical, electrophysiological and pathological investigations provide evidence that the disease has a heterogeneous clinical presentation and that degeneration is not restricted to the central motor system.

Leger, J. M. and F. Salachas (2001). "Diagnosis of motor neuropathy." Eur J Neurol 8(3): 201-8.

          Motor neuropathy is a clinical entity which leads to consideration of a wide spectrum of peripheral nerve disorders. Firstly, it may be distinguished from other causes of peripheral motor involvement such as muscle diseases and disorders of the neuromuscular junction. Secondly, it may be discussed in two different forms: acute and chronic. Acute chronic neuropathies are mainly observed in Guillain-Barre syndrome, in which electrophysiological studies allow us to recognize the classical demyelinating form and the axonal form. The other causes of acute motor neuropathy are mainly poliomyelitis and porphyrias. Chronic motor neuropathies are mainly observed in motor neuron diseases, mainly amyotrophic lateral sclerosis, but also Kennedy's disease and other lower motor neuron diseases which may be inherited or acquired. The other causes are multifocal motor neuropathy and the predominantly motor forms of chronic inflammatory demyelinating polyneuropathy. The characterization of these different types of chronic neuropathy is of major importance because of the therapeutic consequences which may lead to the proposal of specific treatments.

Link, C. D. (2001). "Transgenic invertebrate models of age-associated neurodegenerative diseases." Mech Ageing Dev 122(14): 1639-49.

          Transgenic Drosophila melanogaster and Caenorhabditis elegans strains have been engineered to express human proteins associated with neurodegenerative diseases. These model systems include transgenic animals expressing beta-amyloid peptide (Alzheimer's disease), polyglutamine repeat proteins (Huntington's disease, Spinocerebellar ataxia), and alpha-synuclein (Parkinson's disease). In most of these invertebrate models, some aspects of the human diseases are reproduced. Although expression of all these proteins in transgenic mice has been instructive, the invertebrate models offer experimental advantages (e.g. forward genetic screens) that can potentially address some of the outstanding questions regarding the cellular processes underlying these diseases. This review considers what has been learned from these invertebrate models, and speculates what further insight may be gained from them.

Ludolph, A. C., A. Sperfeld, et al. (2001). "[Tauopathies--a new class of neurodegenerative diseases]." Nervenarzt 72(2): 78-85.

          Recently it was shown by several research groups that mutations in the gene encoding for the tau protein associated with microtubuli on chromosome 17 caused a distinct form of dementia named frontotemporal dementia and parkinsonism (FTDP-17). This disease includes familial asymmetrical frontal and, in the further course, frontotemporal dementia, parkinsonism, which is often initially sensitive to levodopa, signs of upper motor neuron degeneration, and, less commonly, amyotrophy. Tau is an intracellular protein of the cytoskeleton, which is responsible for the arrangement and stabilization of microtubuli. The discovery of mutations in the tau gene causing a distinct neurodegenerative disease in humans has firmly established the importance of the tau gene for neurodegenerative processes, not only in tauopathies but also in other degenerative disorders with tau pathology, such as corticobasal degeneration, supranuclear progressive paralysis, amyotropic lateral sclerosis, parkinsonism-dementia complex of Guam, and Alzheimer's disease. Our experience with patients suffering from PTDP-17 shows that its phenotype varies more than was described in the first consensus conferences. In the future, it will be important to designate the diagnostic gold standard not by clinical description, but etiologic classification.

Macmillan-Crow, L. A. and D. L. Cruthirds (2001). "Invited review: manganese superoxide dismutase in disease." Free Radic Res 34(4): 325-36.

          Manganese superoxide dismutase (MnSOD) is essential for life as dramatically illustrated by the neonatal lethality of mice that are deficient in MnSOD. In addition, mice expressing only 50% of the normal compliment of MnSOD demonstrate increased susceptibility to oxidative stress and severe mitochondrial dysfunction resulting from elevation of reactive oxygen species. Thus, it is important to know the status of both MnSOD protein levels and activity in order to assess its role as an important regulator of cell biology. Numerous studies have shown that MnSOD can be induced to protect against pro-oxidant insults resulting from cytokine treatment, ultraviolet light, irradiation, certain tumors, amyotrophic lateral sclerosis, and ischemia/reperfusion. In addition, overexpression of MnSOD has been shown to protect against pro-apoptotic stimuli as well as ischemic damage. Conversely, several studies have reported declines in MnSOD activity during diseases including cancer, aging, progeria, asthma, and transplant rejection. The precise biochemical/molecular mechanisms involved with this loss in activity are not well understood. Certainly, MnSOD gene expression or other defects could play a role in such inactivation. However, based on recent findings regarding the susceptibility of MnSOD to oxidative inactivation, it is equally likely that post-translational modification of MnSOD may account for the loss of activity. Our laboratory has recently demonstrated that MnSOD is tyrosine nitrated and inactivated during human kidney allograft rejection and human pancreatic ductal adenocarcinoma. We have determined that peroxynitrite (ONOO- ) is the only known biological oxidant competent to inactivate enzymatic activity, to nitrate critical tyrosine residues, and to induce dityrosine formation in MnSOD. Tyrosine nitration and inactivation of MnSOD would lead to increased levels of superoxide and concomitant increases in ONOO- within the mitochondria which, could lead to tyrosine nitration/oxidation of key mitochondrial proteins and ultimately mitochondrial dysfunction and cell death. This article assesses the important role of MnSOD activity in various pathological states in light of this potentially lethal positive feedback cycle involving oxidative inactivation.

Maimone, D., R. Dominici, et al. (2001). "Pharmacogenomics of neurodegenerative diseases." Eur J Pharmacol 413(1): 11-29.

          Current knowledge of sporadic degenerative disorders suggests that, despite their multifactorial etiopathogenesis, genetics plays a primary role in orchestrating the pathological events, and even dramatically changes the disease phenotype from patient to patient. Genes may act as susceptibility factors, increasing the risk of disease development, or may operate as regulatory factors, modulating the magnitude and severity of pathogenic processes or the response to drug treatment. The goal of pharmacogenomics is the application of this knowledge to elaborate more specific and effective treatments and to tailor therapies to individual patients according to their genetic profile. Here, we outline the leading theories on the etiopathogenesis of neurodegenerative diseases, including amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer disease, and we review the potential role of genetic variations, such as gene mutations and polymorphisms, in each context. We also suggest potential targets for new therapeutic approaches and variability factors for current treatments based on genotype features. Finally, we propose a few options of preventive therapeutic interventions in patients with a high genetic risk of disease.

Martin, L. J. (2001). "Neuronal cell death in nervous system development, disease, and injury (Review)." Int J Mol Med 7(5): 455-78.

          Neuronal death is normal during nervous system development but is abnormal in brain and spinal cord disease and injury. Apoptosis and necrosis are types of cell death. They are generally considered to be distinct forms of cell death. The re-emergence of apoptosis may contribute to the neuronal degeneration in chronic neurodegenerative disease, such as amyotrophic lateral sclerosis and Alzheimer's disease, and in neurological injury such as cerebral ischemia and trauma. There is also mounting evidence supporting an apoptosis-necrosis cell death continuum. In this continuum, neuronal death can result from varying contributions of coexisting apoptotic and necrotic mechanisms; thus, some of the distinctions between apoptosis and necrosis are becoming blurred. Cell culture and animal model systems are revealing the mechanisms of cell death. Necrosis can result from acute oxidative stress. Apoptosis can be induced by cell surface receptor engagement, growth factor withdrawal, and DNA damage. Several families of proteins and specific biochemical signal-transduction pathways regulate cell death. Cell death signaling can involve plasma membrane death receptors, mitochondrial death proteins, proteases, kinases, and transcription factors. Players in the cell death and cell survival orchestra include Fas receptor, Bcl-2 and Bax (and their homologues), cytochrome c, caspases, p53, and extracellular signal-regulated protein kinases. Some forms of cell death require gene activation, RNA synthesis, and protein synthesis, whereas others forms are transcriptionally-translationally-independent and are driven by posttranslational mechanisms such as protein phosphorylation and protein translocation. A better understanding of the molecular mechanisms of neuronal cell death in nervous system development, injury and disease can lead to new therapeutic approaches for the prevention of neurodegeneration and neurological disabilities and will expand the field of cell death biology.

Martin-Rendon, E., M. Azzouz, et al. (2001). "Lentiviral vectors for the treatment of neurodegenerative diseases." Curr Opin Mol Ther 3(5): 476-81.

          A number of potential gene therapy applications in the adult nervous system include neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. During the last five years, lentiviral vectors have developed into extremely efficient gene transfer vehicles to the nervous system, revealing a wide range of possibilities for the treatment or such disorders. This review describes the most important and recent advances in the development of lentiviral vectors as well as the demonstration of proof-of-principle in animal models of human neurodegenerative diseases.

Meininger, V. (2001). "Clinical trials: the past, a lesson for the future." Amyotroph Lateral Scler Other Motor Neuron Disord 2 Suppl 1: S15-8.

          Numerous drugs have been tested in amyotrophic lateral sclerosis with the expectation both that they will treat patients and improve our understanding of some of the basic mechanisms of the disease. Most of these trials were considered to be negative. Careful analysis of the trials does not allow us to clearly discard any of the tested drugs, or any of the suspected mechanisms. Expectations for the future are that: a) we need to be realistic about what to expect; b) we have to define clearly our end-points; c) we have to calculate the expected power before the trials, not after; and d) we have to improve our understanding of the pharmacology.

Miller, R. G. (2001). "Examining the evidence about treatment in ALS/MND." Amyotroph Lateral Scler Other Motor Neuron Disord 2(1): 3-7.

          The application of evidence-based medicine to the treatment of patients with amyotrophic lateral sclerosis (ALS) is just beginning. A small number of systematic reviews analyzing the pertinent evidence, grading the methodology and formulating recommendations to guide clinical decision-making have begun to appear. The American Academy of Neurology practice parameters for informing the patient and managing nutritional and respiratory issues and palliative care are discussed. In addition, the first systematic review in the field of ALS/MND from the Cochrane collaboration concerns riluzole treatment and this meta-analysis is also described. Some of the most important recommendations that have the potential to significantly prolong survival and enhance quality of life are the early institution of percutaneous endoscopic gastrostomy for patients with significant dysphagia, and the initiation of non-invasive positive pressure ventilation for patients with symptoms of early respiratory insufficiency. Assertive treatment of pain and dyspnea are also strongly recommended for patients with ALS. The North American ALS patient database, ALS C.A.R.E., is also described as a methodology for measuring clinical outcomes, and some early results are presented. The evidence on riluzole indicates effectiveness in prolonging survival with a good safety profile.

Miller, R. G., J. D. Mitchell, et al. (2001). "Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND)." Cochrane Database Syst Rev(4): CD001447.

          BACKGROUND: Riluzole has been approved for treatment of patients with amyotrophic lateral sclerosis (ALS) in some countries but not others. Questions persist about its clinical utility because of high cost, modest efficacy and concern over adverse effects. OBJECTIVES: To examine the efficacy of riluzole in prolonging survival, and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival. SEARCH STRATEGY: Search of the Cochrane Neuromuscular Disease Group Register for randomized trials and enquiry from authors of trials and other experts in the field. The most recent search was conducted in June 1999. SELECTION CRITERIA: Types of studies: randomized trials Types of participants: adults with a diagnosis of ALS Types of interventions: treatment with riluzole or placebo Types of outcome measures: Primary: per cent mortality at 12 months with riluzole 100 mg Secondary: per cent mortality as a function of time with 100 mg and with all doses of riluzole, scales of neurologic function, quality of life, muscle strength and adverse events. DATA COLLECTION AND ANALYSIS: We identified two randomized trials. Each reviewer graded them for methodological quality. Data extraction was performed by a single reviewer and checked by the other two. We obtained some missing data from investigators. We performed meta-analyses with RevMan software using a fixed effects model. MAIN RESULTS: The two eligible trials included a total of 794 riluzole treated patients and 320 placebo treated patients. The methodological quality was acceptable and the trials were easily comparable. There were significant differences between the riluzole and placebo groups of both trials, in terms of the primary outcome measure, which was per cent mortality at 12 months with the 100 mg dose of riluzole. The odds ratio for the combined studies was 0.57 (95%CI 0.41 to 0.80) at 12 months. In the secondary outcome measures, there was a survival advantage with riluzole 100 mg at six, nine, 12 and 15 months, but not at three or 18 months. Pooled data from the 50, 100 and 200mg dose groups in the larger trial showed a lower per cent mortality with riluzole compared to placebo only at 12 months (odds ratio (OR) 0.64, 95% CI 0.47 to 0.88). There was no beneficial effect on bulbar function, or muscle strength. There were scant data on quality of life, but patients treated with riluzole remained in a more moderately affected health state significantly longer than placebo-treated patients (weighted mean difference (WMD) 35.5 days, 95% CI 5.9 to 65.0). A threefold increase in serum alanine transferase was more frequent in riluzole treated patients than controls (WMD 2.65, 95% CI 1.51 to 4.65). REVIEWER'S CONCLUSIONS: Riluzole 100 mg per day appears to be modestly effective in prolonging survival for patients with ALS.

Mitsumoto, H. (2001). "Clinical trials: present and future." Amyotroph Lateral Scler Other Motor Neuron Disord 2 Suppl 1: S10-4.

          The past decade has seen a major expansion of clinical trials in amyotrophic lateral sclerosis (ALS). However, the perfectly-designed ALS trial remains elusive. Attempts to track the progression of the disease are affected by continual improvements in the care of patients. Comparing the effectiveness of different drugs is difficult because different primary endpoints are used in different studies. We also need to decide how much benefit we are aiming to achieve when studying a new treatment. The interpretation of animal models has also proved problematic, with results not being replicated in human studies. Moreover, promising phase I/II trial results have often not been confirmed by phase III studies. Our patients, meanwhile, are anxious to try any medication that may help. The ALS research community has learned a great deal from past trials and this will be greatly beneficial when evaluating the novel and combination therapies currently being developed. Effort must also be directed towards the search for objective markers for ALS.

Munch, C. and A. C. Ludolph (2001). "Pharmacological treatment of ALS." Neurol Neurochir Pol 35(1 Suppl): 41-50.

          Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease resulting from chronic and selective loss of motor neurons in the brain and spinal cord. In 1993, the etiology of ALS has been clarified for a small sub-group of patients with an autosomal-dominant form of this disease. About 10 percent of familial ALS patients have been associated with more than 50 mutations of the gene of the Cu/Zn superoxide dismutase (SOD1). Mutations in the SOD1 gene account for 1 percent of all ALS patients and have therefore limited epidemological and clinical relevance; however, they are of fundamental importance for the understanding of the ALS pathogenesis, and the development of neuroprotective strategies. In two double-blind and placebo-controlled studies the membrane stabilisator riluzole has been shown to be the first neuroprotective compound with a significant effect on survival of ALS patients. The neuroprotective approach reduced therapeutic nihilism in ALS and is a first step in the treatment of this devastating disease.

Munsat, T. L. (2001). "Slowing down ALS--is this good or bad?" Amyotroph Lateral Scler Other Motor Neuron Disord 2 Suppl 1: S19-22.

          The availability of a drug that provides modest relief in ALS without altering its inevitable progression and end, has posed new ethical and economic problems for patients, caregivers and physicians. Early evidence suggests that riluzole does provide a short additional quality of life and economic benefit for patient and society. However, there is a clear need for additional therapies, even if the benefit is minor.

Newbery, H. J. and C. M. Abbott (2001). "Of mice, men and motor neurons." Trends Genet 17(10): S2-6.

          The use of mouse models has been of particular importance in studying the pathogenesis of amyotrophic lateral sclerosis. Here, we describe both transgenic and classical mutants for which the genetic lesion is known. We draw attention, wherever possible, to pathological factors common to multiple models.

Nobile-Orazio, E., M. Carpo, et al. (2001). "Are there immunologically treatable motor neuron diseases?" Amyotroph Lateral Scler Other Motor Neuron Disord 2 Suppl 1: S23-30.

          Several studies have addressed the issue of a possible immunological involvement in the pathogenesis of amyotrophic lateral sclerosis (ALS) or motor neuron disease (MND), particularly when the disease was associated with cancer, lymphoma or other monoclonal gammopathies or with the presence of serum antibodies to neural antigens. The hypothesis of the existence of immunologically treatable MND was reinforced by the occasional report of MND patients responding to immune or cytostatic therapies and by the identification among those with a purely lower motor neuron syndrome (LMNS) of a motor neuropathy, presently known as multifocal motor neuropathy (MMN), which almost invariably responded to immune therapies. These observations have led to several attempts to treat patients with MND or LMNS, either idiopathic or associated with the above mentioned conditions, with a number of immune or cytostatic therapies. The aim of this review is to verify whether the available data provide enough evidence to support the concept of dysimmune MND and to justify the use in these patients of potentially harmful immune cytostatic therapies.

Opstelten, F. W. and A. J. Boon (2001). "[Suspected amyotrophic lateral sclerosis? Don't forget diagnostic imaging of the spine]." Ned Tijdschr Geneeskd 145(11): 505-9.

          Two patients, men aged 35 and 72 years, had progressive muscle weakness, lower motor neuron signs in all extremities and upper motor neuron signs in the legs. There were no major sensory signs on examination. The clinical picture very much resembled amyotrophic lateral sclerosis (ALS), although there were never brain stem signs. Myelopathy and polyradiculopathies caused by a tandem cervical and lumbar spinal stenosis explained the clinical picture. Cervical MRI and lumbar CT confirmed this diagnosis. Laminectomy was done, after which both patients remained with unchanged symptoms. Tandem spinal stenosis should be part of the differential diagnosis of ALS. Imaging of the spine is necessary to confirm this diagnosis, and in the absence of bulbar signs always necessary prior to the diagnosis of ALS.

Orrell, R. W. and D. A. Figlewicz (2001). "Clinical implications of the genetics of ALS and other motor neuron diseases." Neurology 57(1): 9-17.

          Genetic mutations have been identified in the major motor neuron diseases, including ALS, spinal muscular atrophy, bulbospinal muscular atrophy (Kennedy's disease), the hereditary spastic paraplegias, and rarer conditions such as GM2 gangliosidosis (hexosaminidase A deficiency). These include mutations in the SOD1 gene, deletions of the telomeric copy of the SMN gene, expansions of the trinucleotide repeat region in the first exon of the androgen receptor gene, other rare mutations, and diseases where linkage has been established but the gene not identified. Identification of one of these genetic abnormalities will allow specific diagnosis in patients. Because cure is not yet available, presymptomatic testing is seldom indicated; in such cases, careful counseling is appropriate.

Orth, M. and A. H. Schapira (2001). "Mitochondria and degenerative disorders." Am J Med Genet 106(1): 27-36.

          In mammalian cells, mitochondria provide energy from aerobic metabolism. They play an important regulatory role in apoptosis, produce and detoxify free radicals, and serve as a cellular calcium buffer. Neurodegenerative disorders involving mitochondria can be divided into those caused by oxidative phosphorylation (OXPHOS) abnormalities either due to mitochondrial DNA (mtDNA) abnormalities, e.g., chronic external ophthalmoplegia, or due to nuclear mutations of OXPHOS proteins, e.g., complex I and II associated with Leigh syndrome. There are diseases caused by nuclear genes encoding non-OXPHOS mitochondrial proteins, such as frataxin in Friedreich ataxia (which is likely to play an important role in mitochondrial-cytosolic iron cycling), paraplegin (possibly a mitochondrial ATP-dependent zinc metalloprotease of the AAA-ATPases in hereditary spastic paraparesis), and possibly Wilson disease protein (an abnormal copper transporting ATP-dependent P-type ATPase associated with Wilson disease). Huntingon disease is an example of diseases with OXPHOS defects associated with mutations of nuclear genes encoding non-mitochondrial proteins such as huntingtin. There are also disorders with evidence of mitochondrial involvement that cannot as yet be assigned. These include Parkinson disease (where a complex I defect is described and free radicals are generated from dopamine metabolism), amyotrophic lateral sclerosis, and Alzheimer disease, where there is evidence to suggest mitochondrial involvement perhaps secondary to other abnormalities.

Portet, F., J. Touchon, et al. (2001). "[Amyotrophic lateral sclerosis and cognitive disorders: review and analysis of the literature]." Rev Neurol (Paris) 157(2): 139-50.

          In the last ten years, the syndromic nature of amyotrophic lateral sclerosis (ALS) has become more accepted. Together with upper and lower motor neuron signs, sensory or cognitive impairment are not uncommon. The frequency of a multidegenerative profile in ALS with SOD1 mutations is also an argument for this. We reviewed the literature about:

Racek, J., V. Holecek, et al. (2001). "[Free radicals in immunology and infectious diseases]." Epidemiol Mikrobiol Imunol 50(2): 87-91.

          Free radicals contribute significantly in modification of immune processes and inflammatory reactions. They are produced by activated phagocytes which use them for killing microorganisms. Free radicals facilitate production of cytokines, which are important as modifiers of inflammatory reactions. Formation of free radicals is influenced by antioxidants which can thus modify the intensity of inflammatory reaction and immune response. The authors describe in detail the contribution of free radicals in etiology and pathogenesis of autoimmune diseases including rheumatoid arthritis, multiple sclerosis or amyotrophic lateral sclerosis. The role of free radicals and modifying influence of antioxidants in viral, bacterial, parasitic and mycotic diseases is described in the second part of the review. Finally, influence of free radicals and antioxidants on immunity changes in patients with malignant tumours, during aging and physical exercise is discussed.

Rideout, H. J. and L. Stefanis (2001). "Caspase inhibition: a potential therapeutic strategy in neurological diseases." Histol Histopathol 16(3): 895-908.

          Caspases are intracellular proteases t