[Interferon beta1-a IM once weekly does not modify general psychological function in the first months after therapy in patients with relapsing-remitting multiple sclerosis]. / L'interféron beta1-a IM ne modifie pas le fonctionnement psychologique global de patients atteints de sclérose en plaques rémittente pendant les premiers mois de traitement.

INTRODUCTION: Psychological troubles are common in multiple sclerosis but their underlying etiology is still controversial. METHODS: The objective of this open, non comparative, multicenter study was to assess changes in global psychological functioning in new multiple sclerosis patients during the first 3 months of treatment with intramuscular interferon beta-1a once weekly (Avonex). This functioning was rated every 4 weeks with the GAF (Global Assessment Functioning) scale. Depression measured on MADRS (Montgomery & Asberg Depression Rating Scale), clinical global impression (CGI) on patients'psychological status and clinical as well as biological tolerance were also assessed every 4 weeks. RESULTS: Five hundred and ninety-nine patients (71.4 percent women), aged 39.4 years were included. No clinically significant difference in mean GAF score between baseline and the end of the first 3 months of interferon beta-1a IM treatment (main evaluation outcome) was found. Similar results were obtained on MADRS scale. CONCLUSION: No clinically significant alteration of global psychological functioning, including symptoms of depression, was observed during the first 3 months of treatment with interferon beta-1a IM.

Xaliproden (SR57746A) induces 5-HT1A receptor-mediated MAP kinase activation in PC12 cells.

Neurotrophic growth factors are involved in cell survival. However, natural growth factors have a very limited therapeutic use because of their short half-life. In the present study, we investigated the mechanism of action of a non-peptidic neurotrophic drug, Xaliproden, a potential molecule for the treatment of motoneuron diseases, since the transduction pathways of this synthetic 5-HT1A agonist are very poorly understood. Xaliproden does not activate the Trk receptor but causes a rapid increase in the activities of the ERK1 and ERK2 isoforms of MAP kinase, which then rapidly decrease to the basal level. We demonstrate that isoforms of the SHC adapter protein are phosphorylated independently of each other and are probably not the source of the Xaliproden-induced MAP kinases activation. The inhibitor of Ras farnesylation, FPT-1, and the protein kinase C inhibitors, GF 109203X and chelerythrine, inhibited the Xaliproden-induced MAP kinase activation, suggesting p21Ras and PKC involvement. Moreover, the observations that the 5-HT1A antagonist, pindobind, and pertussis toxin abolished the Xaliproden-induced ERK stimulation suggested that Xaliproden activates the MAP kinase pathways by stimulating the G protein-coupled receptor, 5-HT1A. These results demonstrate clearly that the non-peptidic compound, Xaliproden, exerts its neurotrophic effects through a mechanism of action differing from that of neurotrophins. These findings suggest that this compound does not involve MAPK activation by TrkA receptor stimulation but acts by MAP kinase pathway by a pertussis toxin-sensitive mechanism involving 5-HT1A receptors, p21 Ras and MEK-1 and by PKC and Akt pathways.

MAPK activation via 5-hydroxytryptamine 1A receptor is involved in the neuroprotective effects of xaliproden.

Motoneurons require neurotrophic factors for their survival and their differentiation. Xaliproden (SR57746A) is a synthetic compound that exhibits in vivo and in vitro neurotrophic effects in several experimental studies. Here we demonstrate that neuroprotective effects of Xaliproden on motoneuron cultures are mediated by the activation of the mitogen activated protein kinase pathway. It is inhibited by PD98059, a selective and irreversible inhibitor of MEK1. The activation of this pathway seems to involve two different proteins, the protein kinase C and the Ras. Indeed, we show that Xaliproden is able to activate the MAP kinases ERK1/2 and PKC in motoneurons. In addition, the use of a 5-hydroxytryptamine 1A receptor antagonist, Pindobind and pertussis toxin, inhibits the effect of Xaliproden on motoneuron survival, suggesting the involvement of this G-protein coupled receptor. Morever, 8-OH-DPAT, an agonist of 5-hydroxytryptamine 1A receptor, increases the survival of mouse motoneurons but not by the same extent as BDNF or xaliproden. Since 8-OH-DPAT does not act synergistically with Xaliproden, it is likely that their neuroprotective properties involve a similar pathway. Taken together, these results indicate that neuroprotective effects of Xaliproden on mouse motoneurons are dependent on the mitogen-activated protein kinase activation via 5-hydroxytryptamine 1A receptor.

[Acute relapse in Charcot-Marie-Tooth 1B neuropathy: can protein P0 behave like an autoantigen?]. / Aggravation aiguë régressive d'une maladie de Charcot-Marie-Tooth de type 1B: la Protéine P0 peut-elle agir comme un auto-antigène?

INTRODUCTION: The natural history of Charcot-Marie-Tooth neuropathy is marked by accentuated motor and sensitive deficits suggestive of acute polyradiculoneuritis or, more generally, chronic inflammatory demyelinizing polyneuropathy. OBSERVATION: A 41-year-old woman, with Charcot-Marie-Tooth (CMT) 1B neuropathy associated with a P0 gene mutation, developed several episodes of ataxia which resolved after intravenous administration of IgG or corticosteroids. CONCLUSION: The sudden increase of a motor or sensitive deficit in this patient with CMT type I led to two hypotheses: chance association between an inherited and an inflammatory neuropathy, or a dysimmune inflammatory reaction, the mutated protein acting like an autoantigen. These two hypotheses are discussed.

Quantification of neurotrophin mRNA expression in PMN mouse: modulation by xaliproden.

Compounds possessing neurotrophic properties may represent a possible treatment for neurodegenerative disorders such as amyotrophic lateral sclerosis. Xaliproden (SR57746A), an orally-active non-peptide compound, which has been found to exhibit neurotrophic effects in vitro and in vivo, increased the lifespan and delayed the progression of the motor neuron degeneration in PMN mice. We have used a quantitative reverse transcription/polymerase chain reaction amplification technique to study the regulation of neurotrophin mRNA and trk mRNA expression in PMN mice. NGF and NT-3 mRNA are downregulated in PMN mice. These deficiencies can be overcome by a treatment with xaliproden. Such an effect could contribute to neurotrophic effects of xaliproden in vivo and in vitro.

Homozygosity mapping of Marinesco-Sjögren syndrome to 5q31.

Marinesco-Sjögren syndrome (MSS), first described in 1931, is an autosomal recessive condition characterised by somatic and mental retardation, congenital cataracts and cerebellar ataxia. Progressive myopathy was later reported to be also a cardinal sign of MSS, with myopathic changes on muscle biopsies. Hypergonadotrophic hypogonadism and skeletal deformities related to pronounced hypotonia were also reported. The major differential diagnosis of MSS is the syndrome defined by congenital cataracts, facial dysmorphism and peripheral neuropathy (CCFDN), which is localised to 18qter. Using homozygosity mapping strategy in two large consanguineous families of Turkish and Norwegian origin, respectively, we have identified the MSS locus on chromosome 5q31. LOD score calculation, including the consanguinity loops, gave a maximum value of 2.9 and 5.6 at theta=0 for the Turkish and the Norwegian families, respectively, indicating linkage between the disease and the D5S1995-D5S436 haplotype spanning a 9.3 cM interval. Patients of the two families presented with the strict clinical features of MSS. On the other hand, the study of two smaller French and Italian families, initially diagnosed as presenting an atypical MS syndrome, clearly excluded linkage from both the MSS locus on 5q31 and the CCFDN locus in 18qter. Patients of the two excluded families had all MSS features (but the myopathic changes) plus peripheral neuropathy and optic atrophy, and various combinations of microcornea, hearing impairment, seizures, Type I diabetes, cerebral atrophy and leucoencephalopathy, indicating that only the pure MSS syndrome is a homogeneous genetic entity.

[Siderosis of the brain and spinal cord. Report of two cases]. / Sidérose cérébrale et médullaire. A propos de deux observations.

Two cases of superficial siderosis of the brain and spinal cord with cochleovestibular and cerebellar symptoms are diagnosed on brain and spinal MRI scans. Low signal intensity lines are noted on the surface of the brainstem, cerebellum, spinal cord and within the interhemispheric and sylvian fissures. In one case, no brain or vascular malformation is identified; in the second case, two cavernous angiomas are noted on the MRI study. 3D CISS may visualize thickening of the cochleovestibular nerve.

[Lyme borreliosis]. / La maladie de Lyme.

Lyme disease is a multisystemic disease caused by a spirochete, Borrelia Burgdorferi that is transmitted by ticks. A clinical diagnosis is easy when a tick bite is followed 3 weeks later by erythema migrans, than by involvement of nervous system, joints or heart. In case of neuroborreliosis, serological tests, performed in blood and cerebro-spinal fluid, support the diagnosis and patients recover rapidly with antibacterial treatments. However an accurate diagnosis remains sometimes problematic, especially distinction between a coincidental positive serologic test and a nervous system Lyme borreliosis which require antibiotics. Furthermore, the role of autoimmunity in the pathophysiology of late Lyme disease, antibiotic choice in early disease, duration of treatment, and utility of vaccination are discussed.

Phenotypic variability of aprataxin gene mutations.

The clinical and genetic features of three non-Portuguese and non-Japanese patients with aprataxin gene mutations are reported. Patient 1 came from Italy and presented with typical ataxia with ocular motor apraxia (OMA). She was homozygous for the W279X nonsense mutation, which is associated with the Portuguese founding haplotype. Patients 2 and 3 were French siblings and did not present with either OMA or hypoalbuminemia. They were compound heterozygous for the nonsense W279X mutation and a missense K197Q mutation.

Kennedy's Disease Initially Manifesting as an Endocrine Disorder.

Spinal and bulbar muscular atrophy (SBMA, or Kennedy's disease) is an X-linked, late-onset neuro-endocrine disorder characterized by degeneration of motor neurons in the spinal cord and brainstem and partial androgen insensitivity. We describe the case of a 59-year-old man who presented with diabetes mellitus, hypercholesterolemia, testicular atrophy, gynecomastia, and elevated serum creatine kinase (CK) levels. He did not have a familial history of motor neuron disease or neuromuscular symptoms or physical signs. Electromyographic (EMG) examination showed evidence of widespread denervation in muscles of different segmental innervation. Genetic studies found an abnormal 43 CAG repeat in the androgen receptor gene, leading to the diagnosis of SBMA. This report highlights the fact that SBMA can present with a pure endocrine phenotype and an absence of neuromuscular complaints or physical signs.

[Prion diseases]. / Les maladies du prion.

Creutzfeldt-Jakob disease, kuru, Gerstmann Sträussler Scheinker syndrome and fatal familial insomnia in humans, as well as scrapie and bovine spongiform encephalopathy, in animals, are fatal disorders of the central nervous system that are part of the group of transmissible spongiform encephalopathies, (TSE) or prion diseases. Neuronal intracellular spongiosis and the accumulation of abnormal, protease resistant prion protein in the nervous central system characterize TSE. The conformational change of a host protein, prion protein, into a pathological isoform is the key pathogenetic event in TSE. Despite their relative rarity, prion diseases have a great impact on the scientific community and society in general. There are two major reasons: first, the heretical hypothesis of a disease transmitted by an "infectious protein" in the absence of nucleic acid, the basis of the conformational transmissibility concept; second, the panic originated from the appearance of new variant Creutzfeldt-Jakob disease and the evidence linking it to the exposure of humans to bovine spongiform encephalopathy via food contaminated by affected bovine tissue. Novel therapeutic approaches are examined.

Selective changes in mitochondria respiratory properties in oxidative or glycolytic muscle fibers isolated from G93AhumanSOD1 transgenic mice.

Cases of familial amyotrophic lateral sclerosis (FALS) are associated with mutations in cytosolic copper, zinc superoxide dismutase (SOD1). Total SOD activity and functional mitochondrial properties were studied in muscles and nervous tissues of control and transgenic mice mimicking the disease. It was found that total SOD activity was lower in nervous tissues than in muscles in both transgenic and control mice. In addition SOD activity increased during progression of disease in muscle but not in nervous tissue of transgenic mice. Maximal oxygen consumption and apparent Km for ADP were decreased in mitochondria from transgenic soleus (an oxidative muscle). However there was no difference between control and transgenic mice in respiratory parameters of mitochondria in the EDL muscle (a glycolytic muscle). These findings indicate that oxidative stress due to SOD1 mutations could alter energy metabolism in FALS mice, thereby affecting primarily oxidative muscle of the limbs, independently of motoneuron loss.

Normal innervation and differentiation of X-linked myotubular myopathy muscle cells in a nerve-muscle coculture system.

To study the pathogenesis of X-linked recessive myotubular myopathy (XLMTM), we used a nerve-muscle coculture system which allows the reconstitution of functional motor units in vitro after coupling of human skeletal muscle cells with embryonic rat spinal cord explants. We used three skeletal muscle cell lines derived from subjects with known mutations in the MTM1 gene (two from embryonic tissues, associated with mutations predicted to give a severe phenotype, and one from a neonate still alive at 3 years 6 months and exhibiting a mild phenotype). We compared these three XLMTM muscle cell cultures with control cultures giving special attention to behaviour of living cocultures (formation of the myofibres, contractile activity, survival), expression of muscular markers (desmin, dystrophin, alpha-actinin, troponin-T, myosin heavy chain isoforms), and nerve-muscle interactions (expression and aggregation of the nicotinic acetylcholine receptors). We were unable to reproduce any 'myotubular' phenotype since XLMTM muscle cells behaved like normal cells with regard to all the investigated parameters. Our results suggest that XLMTM muscle might be intrinsically normal and emphasize the possible involvement of the myotubularin-deficient motor neurons in the development of the disease.

[Isolated neurologic disorders disclosing Biermer's disease in young subjects]. / Troubles neurologiques isolés révélant une maladie de Biermer chez le sujet jeune.

INTRODUCTION: In young subjects, the discovery of a cobalamine deficiency (Biermer's disease) at the time of neuropsychiatric disorders even of isolated MRI anomalies is a rare event (less than 0.01%). EXEGESIS: We report two observations of cobalamine deficiency, in patients 30 and 37 years old, revealed by acroparesthesia and spontaneous hypersignal in the T2 sequence of MRI and by a peripheral sensitive neuropathy respectively. CONCLUSION: The neuropsychiatric demonstrations of pernicious anemia are polymorphic with, sometimes, isolated spinothalamic attacks. The MRI can contribute to the diagnosis but more often leads to an erroneous diagnosis. Our observations are of special interest because symptoms occurred apart from supplementation of folates and recovered ad integrum with an early treatment by vitamin B12.

A case of multiple sclerosis triggered by organic solvents.

The neurotoxicity of organic solvents has long been recognized. Some are used as anesthetic agents, others in various industries. Their acute effect has been well documented since the nineteenth century, but more recently they have become notorious as the cause of addiction to glue sniffing. They may alter the immune system by causing lymphopenia, impairing phagocytosis and decreasing the level of serum complement, as well as altering the impermeability of the blood-brain barrier and leading to the appearance of white matter lesions in the brain. The following case study explores the possible role of organic solvents in the pathogenesis of multiple sclerosis.

Pyridoxine-induced neuropathy in rats: a sensory neuropathy that responds to 4-methylcatechol.

Sensory neuropathies are frequently associated with diabetes or with antimitotic treatments in humans suffering from cancer, and are in this case the most important limitation to the use of antimitotic drugs. For this reason, there is a need to establish and validate animal models of sensory neuropathies that could be routinely used, together with the already known models, for studying and evaluating the effects of putative neuroprotective compounds. In the present study, we prove by behavioral and electromyographical analyses that (a) it is possible to induce a nonlethal, exclusively sensory, reversible neuropathy by intoxicating rats with large amounts of pyridoxine, using a new schedule of intoxication; (b) 4-methylcatechol, a drug known to induce nerve growth factor synthesis, improves the clinical status of pyridoxine-intoxicated animals, shortens the duration of the disease, and restores the morphological integrity of the sensory fibers. Owing to its mode of installation and its clinical features, we propose that this model be used as an additional model for preclinical studies of neuroprotective drugs.

The frissonnant mutant mouse, a model of dopamino-sensitive, inherited motor syndrome.

The frissonnant (fri) mutation is an autosomic recessive mutation which spontaneously appeared in the stock of C3H mice. fri mutant mice have locomotor instability and rapid tremor. Since tremor ceases when mutant mice have sleep or are anaesthetized, and because of their obvious stereotyped motor behavior, these mice could represent an inherited Parkinsonian syndrome. We show here that the fri/fri mouse fulfills two out of the three criteria required to validate an experimental model of human disease, that is isomorphism, homology and predictivity. Indeed, fri/fri mice present an important motor deficit accompanying visible tremor and stereotypies. They display some memory deficits as in human Parkinson's desease. l-Dopa and apomorphine (dopaminergic agonists), ropinirole (selective D2 agonist), and selegiline (an monoamino-oxidase B [MAO-B] inhibitor) improve their clinical status. However, neither anatomopathological evidence of nigrostriatal lesion, nor decrease in tyrosine hydroxylase production could be seen.

On the possible role of muscle in the pathogenesis of spinal muscular atrophy.

Spinal muscular atrophy (SMA) is a common human inherited disease characterized by degeneration of motoneurons and muscular atrophy. SMA results from deletions or mutations of the SMN (survival motor neuron) gene. A nerve-muscle coculture model, consisting of human muscle cells innervated by rat embryonic spinal cord explants, was used to study the pathogenesis of SMA. Previous studies have shown that myotubes formed by fusion of satellite muscle cells from patients with SMA I or SMA II (but not SMA III) underwent a characteristic degeneration 1-3 weeks after innervation. To correlate this cellular study with a molecular approach, we used reverse transcriptase-polymerase chain reaction (RT-PCR), and showed that SMN mRNAs were expressed throughout the fusion of normal satellite muscle cells with two peaks, the first appearing prior to the onset of fusion and the second one or two days before innervation. When satellite muscle cells from patients with SMA I or II were used, only the first peak was observed. Because in these cases the SMN telomeric gene (SMNtel) is deleted, it was concluded that the contribution of SMNtel-dependent mRNAs to the second peak is predominant in normal myogenesis and involved in maturation of myotubes. In addition, diseased satellite muscle cells did not fuse at the same rate as normal satellite muscle cells. Studies on myf-5, a muscle specific transcription factor family, showed that its expression was impaired during the fusion of satellite muscle cells from patients with SMA I or II compared with normal satellite muscle cells. Taken together, these observations suggest that (a) there is a muscle specific expression pattern of SMN, and (b) SMN probably plays a crucial role in maintenance of a functional motor unit, by allowing muscle cells to correctly differentiate and to allow motoneuron survival.

[Inherited human prion diseases]. / Les maladies humaines familiales à prions.

Familial prion diseases (familial Creutzfeldt-Jakob disease: Gerstmann-Sträussler-Scheinker disease, Fatal familial insomnia) are rare, but are also at present one of the most fascinating chapters of Neurology because of their double transmissibility. They are hereditary diseases of adults with a dominant autosomal transmission and an almost complete penetrance. They result most often of a point mutation of the gene of PrP with a consequent change in its primary sequence and conformation. Does the mutated PrP acquire a novel function or lose a still unknown function? At present there is no answer tho these question. The mutated PrP may sometimes be transmitted from man to animals. All PrP point mutations appear to have a noxious effect on neurons, but only some of them are transmissible. How mutated PrP acquires or does not acquire transmissibility may represent a fundamental progress in our understanding of prion diseases.