Effects of electroacupuncture on patients with chronic urinary retention caused by a lower motor neuron lesion: An exploratory pilot study

Chronic urinary retention (CUR) is defined as a non-painful bladder that remains palpable or percussible after the patient has passed urine. Acupuncture may decrease PVR and improve bladder function in patients with neurogenic CUR. The aim of this study was to preliminarily observe the effectiveness of electroacupuncture (EA) for patients with CUR caused by a lower motor neuron lesion and to provide some therapeutic data for further study.This study was a pilot study of 30 patients with CUR caused by a lower motor neuron lesion. Patients were treated with EA for 12 weeks with 36 sessions of EA.Responders were defined as participants with a decline in postvoid residual urine (PVR) volume after spontaneous urination of ≥50% from baseline. The proportion of responders, change in PVR volume from baseline after spontaneous urination, and the proportion of patients with severe difficulty with urination, who required assistance with bladder emptying and with stool retention, were measured at weeks 4, 8, and 12.Thirty patients were included in this study, and 23 completed 12 weeks of treatment. The proportion of responders at weeks 4, 8, and 12 was 6.67%, 28%, and 43.48%, respectively. Decrease in PVR volume, compared with baseline, was significant at all asessment timepoints. The proportion of patients with severe difficulty with urination, who required assistance with bladder emptying and with stool retention, decreased after treatment.EA is a potential treatment for improving bladder function in patients with CUR caused by a lower motor neuron lesion.

Stress-related over-enhancement of the hypothalamic-pituitary-adrenal axis causes experimental neurolathyrism in rats

Neurolathyrism is a motor neuron disease that is caused by the overconsumption of grass peas (Lathyrus sativus L.) under stressful conditions. The neuro-excitatory β-N-oxalyl-L-α,β-diaminopropionic acid present in grass peas was proposed the causative agent of spastic paraparesis of the legs. Historical reports of neurolathyrism epidemics, studies of neurolathyrism animal models, and in vitro studies on the mechanism of β-N-oxalyl-L-α,β-diaminopropionic acid toxicity support the hypothesis that stress increases susceptibility to neurolathyrism. To elucidate the role of stress in neurolathyrism-induced motor dysfunction, we focused on the hypothalamic-pituitary-adrenal axis in a rodent model of neurolathyrism. Our results implicated increased glucocorticoid and neuroinflammation in the motor dysfunction (paraparesis) exhibited by the stress loaded rat models of neurolathyrism.

Myasthenia gravis seronegative for acetylcholine receptor antibodies in South Korea: Autoantibody profiles and clinical features

Acquired myasthenia gravis (MG) is a prototype autoimmune disease of the neuromuscular junction, caused in most patients by autoantibodies to the muscle nicotinic acetylcholine receptor (AChR). There seem to be ethnic and regional differences in the frequency and clinical features of MG seronegative for the AChR antibody. This study aimed to describe the autoantibody profiles and clinical features of Korean patients with generalized MG seronegative for the AChR antibody. A total of 62 patients with a high index of clinical suspicion of seronegative generalized MG were identified from 18 centers, and we examined their sera for antibodies to clustered AChR, muscle-specific tyrosine kinase (MuSK), and low-density lipoprotein receptor-related protein 4 (LRP4) by cell-based assays (CBA) and to MuSK by radioimmunoprecipitation assay (RIPA). We also included 8 patients with ocular MG, 3 with Lambert-Eaton myasthenic syndrome, 5 with motor neuron disease, and 9 with other diagnoses as comparators for the serological testing. Antibodies were identified in 25/62 (40.3%) patients: 7 had antibodies to clustered AChR, 17 to MuSK, and 2 to LRP4. Three patients were double seropositive: 1 for MuSK and LRP4, and 2 for MuSK and clustered AChR. The patients with MuSK antibodies were mostly female (88.2%) and characterized by predominantly bulbar involvement (70%) and frequent myasthenic crises (58.3%). The patients with antibodies to clustered AChR, including 2 with ocular MG, tended to have a mild phenotype and good prognosis.

Sensory Neuronopathy Revealing Severe Vitamin B12 Deficiency in a Patient with Anorexia Nervosa: An Often-Forgotten Reversible Cause

Vitamin B12 (B12) deficiency is known to be associated with various neurological manifestations. Although central manifestations such as dementia or subacute combined degeneration are the most classic, neurological manifestations also include sensory neuropathies. However, B12 deficiency is still rarely integrated as a potential cause of sensory neuronopathy. Moreover, as many medical conditions can falsely normalize serum B12 levels even in the context of a real B12 deficiency, some cases may easily remain underdiagnosed. We report the illustrating case of an anorexic patient with sensory neuronopathy and consistently normal serum B12 levels. After all classical causes of sensory neuronopathy were ruled out, her clinical and electrophysiological conditions first worsened after folate administration, but finally improved dramatically after B12 administration. B12 deficiency should be systematically part of the etiologic workup of sensory neuronopathy, especially in a high risk context such as anorexia nervosa.

Serum neurofilament light chain protein is a measure of disease intensity in frontotemporal dementia

OBJECTIVE

To investigate serum neurofilament light chain (NfL) concentrations in frontotemporal dementia (FTD) and to see whether they are associated with the severity of disease.

METHODS

Serum samples were collected from 74 participants (34 with behavioral variant FTD [bvFTD], 3 with FTD and motor neuron disease and 37 with primary progressive aphasia [PPA]) and 28 healthy controls. Twenty-four of the FTD participants carried a pathogenic mutation in C9orf72 (9), microtubule-associated protein tau (MAPT; 11), or progranulin (GRN; 4). Serum NfL concentrations were determined with the NF-Light kit transferred onto the single-molecule array platform and compared between FTD and healthy controls and between the FTD clinical and genetic subtypes. We also assessed the relationship between NfL concentrations and measures of cognition and brain volume.

RESULTS

Serum NfL concentrations were higher in patients with FTD overall (mean 77.9 pg/mL [SD 51.3 pg/mL]) than controls (19.6 pg/mL [SD 8.2 pg/mL]; p < 0.001). Concentrations were also significantly higher in bvFTD (57.8 pg/mL [SD 33.1 pg/mL]) and both the semantic and nonfluent variants of PPA (95.9 and 82.5 pg/mL [SD 33.0 and 33.8 pg/mL], respectively) compared with controls and in semantic variant PPA compared with logopenic variant PPA. Concentrations were significantly higher than controls in both the C9orf72 and MAPT subgroups (79.2 and 40.5 pg/mL [SD 48.2 and 20.9 pg/mL], respectively) with a trend to a higher level in the GRN subgroup (138.5 pg/mL [SD 103.3 pg/mL). However, there was variability within all groups. Serum concentrations correlated particularly with frontal lobe atrophy rate (r = 0.53, p = 0.003).

CONCLUSIONS

Increased serum NfL concentrations are seen in FTD but show wide variability within each clinical and genetic group. Higher concentrations may reflect the intensity of the disease in FTD and are associated with more rapid atrophy of the frontal lobes.

Lower serum levels of selenium, copper, and zinc are related to neuromotor impairments in children with konzo

We assessed the relationship between key trace elements and neurocognitive and motor impairments observed in konzo, a motor neuron disease associated with cassava cyanogenic exposure in nutritionally challenged African children. Serum concentrations of iron, copper, zinc, selenium, and neurotoxic lead, mercury, manganese, cadmium, and cobalt were measured in 123 konzo children (mean age 8.53 years) and 87 non-konzo children (mean age 9.07 years) using inductively coupled plasma mass spectrometry (ICPMS). Concentrations of trace elements were compared and related to performance scores on the Kaufman Assessment Battery for Children, 2nd edition (KABC-II) for cognition and Bruininks-Oseretsky Test, 2nd edition (BOT-2) for motor proficiency. Children with konzo had low levels of selenium, copper, and zinc relative to controls. Selenium concentration significantly correlated with serum 8,12-iso-iPF2α-VI isoprostane (Spearman r=0.75, p<0.01) and BOT-2 scores (r=0.31, p=0.00) in children with konzo. Elemental deficiency was not associated with poor cognition. Mean (SD) urinary level of thiocyanate was 388.03 (221.75) μmol/l in non-konzo compared to 518.59 (354.19) μmol/l in konzo children (p<0.01). Motor deficits associated with konzo may possibly be driven by the combined effects of cyanide toxicity and Se deficiency on prooxidant mechanisms. Strategies to prevent konzo may include dietary supplementation with trace elements, preferentially, those with antioxidant and cyanide-scavenging properties.

Autoantibodies to neurofascin-186 and gliomedin in multifocal motor neuropathy

We tested autoantibodies to neurofascin-186 (NF186) and gliomedin in sera from patients with multifocal motor neuropathy (MMN, n=53) and chronic inflammatory demyelinating polyneuropathy (CIDP, n=95) by ELISA. IgG antibodies to NF186 or gliomedin were found in 62% of MMN and 1% of CIDP sera, and IgM antibodies to the same antigens in 12% of MMN and 1% of CIDP sera. These autoantibodies activated complement. Ten percent of the MMN sera without IgM anti-GM1 reactivity had anti-NF186 antibodies. Because NF186 and gliomedin play a crucial role for salutatory conduction, the autoantibodies may contribute to produce motor nerve conduction block and muscle weakness in MMN.

Spontaneous degenerative polioencephalomyelopathy in feeder pigs--a new motor neuron disease?

A central nervous disorder occurred spontaneously in a herd of feeder pigs characterized by muscle fasciculations, convulsions, squealing, and acute death in numerous animals. Histopathology revealed a degenerative poliomyeloencephalopathy of brain stem and spinal cord consisting of neuronal hypertrophy, chromatolysis, neuronophagia, and satellitosis associated with Wallerian degeneration of ventral rootlets and neurogenic muscle atrophy of limb musculature. The sudden onset of clinical signs and the pattern of morphological findings were suggestive of intoxication. Though parathion was found in two animals, serum acetylcholine esterase activity and morphological findings were not compatible with an organophosphate poisoning. A hereditary disorder was excluded by genetic analysis. Summarized findings in the present cases are reminiscent of changes observed in ruminants suffering from patulin poisoning, a neuromycotoxicosis caused by Aspergillus clavatus. However, toxicological and microbiological investigations failed to identify the cause of this unusual and so far not described disease in pigs. Morphologically, lesion distribution and alterations of motor neurons resemble changes observed in equine motor neuron disease, spinal muscular atrophy of certain canine breeds, and amyotrophic lateral sclerosis (Lou Gehrig's disease) in man. Therefore, the term spontaneous porcine motor neuron disease (SPMND) is proposed for this new and unique entitiy.

Motor unit number estimate as a predictor of motor dysfunction in an animal model of type 1 diabetes

Peripheral neuropathy is a common complication of diabetes that leads to severe morbidity. In this study, we investigated the sensitivity of motor unit number estimate (MUNE) to detect early motor axon dysfunction in streptozotocin (STZ)-treated mice. We compared the findings with in vitro changes in the morphology and electrophysiology of the neuromuscular junction. Adult Thy1-YFP and Swiss Webster mice were made diabetic following three interdaily intraperitoneal STZ injections. Splay testing and rotarod performance assessed motor activity for 6 wk. Electromyography was carried out in the same time course, and compound muscle action potential (CMAP) amplitude, latency, and MUNE were estimated. Two-electrode voltage clamp was used to calculate quantal content (QC) of evoked transmitter release. We found that an early reduction in MUNE was evident before a detectable decline of motor activity. CMAP amplitude was not altered. MUNE decrease accompanied a drop of end-plate current amplitude and QC. We also observed small axonal loss, sprouting of nerve endings, and fragmentation of acetylcholine receptor clusters at the motor end plate. Our results suggest an early remodeling of motor units through the course of diabetic neuropathy, which can be readily detected by the MUNE technique. The early detection of MUNE anomalies is significant because it suggests that molecular changes associated with pathology and leading to neurodegeneration might already be occurring at this stage. Therefore, trials of interventions to prevent motor axon dysfunction in diabetic neuropathy should be administered at early stages of the disorder.

Peripheral neuropathies associated with monoclonal gammopathies of undetermined significance

Monoclonal gammopathies (MGs) or plasma cell dyscrasias (PCDs) are hematologic disorders that may affect peripheral nerves. An MG is a proliferation of a single clone of neoplastic or nonneoplastic plasma that usually secretes a monoclonal protein (M-protein) serum or urine. If a diagnosis of monoclonal gammopathy of undetermined significance (MGUS) is established, a sudden increase in M-protein levels can indicate malignant transformation of a benign PCD. Roughly 50% of MGUS neuropathies are associated with an IgM gammopathy and the remaining 50% with IgG- and IgA-MGUS-associated neuropathies. MGUS is the most common of the PCDs associated with neurologic disorders, which are easily approached clinically by classifying them as IgM or non-IgM types.

Change in blood antioxidant status of horses moved from a stable following diagnosis of equine motor neuron disease

The antioxidant status of 10 horses living in stable 1 where 2 cases of equine motor neuron disease had previously been diagnosed was assessed before and 9 weeks after moving to another stable. Duration of residence in stable 1, subsequent moving, or both, significantly affected several parameters of the antioxidant status.

Absence of paraneoplastic antineuronal antibodies in sera of 145 patients with motor neuron disease

BACKGROUND

Well characterised antineuronal antibodies (ANAbs) have been shown to be highly specific markers of neurological syndromes with a paraneoplastic aetiology. Previous reports indicate that pure motor neuron disease (MND) is rarely of paraneoplastic origin.

OBJECTIVE

To screen systematically for the prevalence of well characterised paraneoplastic ANAbs in a large collective of patients with pure MND.

METHODS

In a cohort of 145 patients with MND, the frequency of ANAbs was estimated by ELISA, employing recombinant antigens (HuD, Yo, Ri, CV2/CRMP5, Ma2 and amphiphysin).

RESULTS

None of the sera revealed high antineuronal antigen reactivity. Very low reactivity was detected in only five sera, in all probability representing background activity.

CONCLUSION

According to these data, routine analysis for ANAbs in patients with isolated MND is not mandatory.

Vitamin E deficiency and risk of equine motor neuron disease

BACKGROUND

Equine motor neuron disease (EMND) is a spontaneous neurologic disorder of adult horses which results from the degeneration of motor neurons in the spinal cord and brain stem. Clinical manifestations, pathological findings, and epidemiologic attributes resemble those of human motor neuron disease (MND). As in MND the etiology of the disease is not known. We evaluated the predisposition role of vitamin E deficiency on the risk of EMND.

METHODS

Eleven horses at risk of EMND were identified and enrolled in a field trial at different times. The horses were maintained on a diet deficient in vitamin E and monitored periodically for levels of antioxidants--alpha-tocopherols, vitamins A, C, beta-carotene, glutathione peroxidase (GSH-Px), and erythrocytic superoxide dismutase (SOD1). In addition to the self-control another parallel control group was included. Survival analysis was used to assess the probability of developing EMND past a specific period of time.

RESULTS

There was large variability in the levels of vitamins A and C, beta-carotene, GSH-Px, and SOD1. Plasma vitamin E levels dropped significantly over time. Ten horses developed EMND within 44 months of enrollment. The median time to develop EMND was 38.5 months. None of the controls developed EMND.

CONCLUSION

The study elucidated the role of vitamin E deficiency on the risk of EMND. Reproducing this disease in a natural animal model for the first time will enable us to carry out studies to test specific hypotheses regarding the mechanism by which the disease occurs.

Comparison of the growth hormone, IGF-1 and insulin in cerebrospinal fluid and serum between patients with motor neuron disease and healthy controls

Neurotrophic effects of the growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin on the central nervous system have become more apparent in the past decade. In this study, we measured serum and cerebrospinal fluid (CSF) concentrations of GH, IGF-1 and insulin in 35 patients with motor neuron disease (MND) [24 patients with definite amyotrophic lateral sclerosis (ALS) and 11 patients with progressive bulbar palsy] and in 40 healthy controls. Levels of serum concentrations of GH and IGF-1 did not significantly differ between the MND patient group and the healthy controls, while the level of insulin was significantly decreased (P = 0.0033) in the MND patient group. However, levels of all three examined parameters in CSF were significantly lower in the MND group than in the healthy controls with the statistical significance for IGF-1 and insulin of P < 0.001. This finding has not been reported previously, and further investigations into its association with ALS should establish whether it can be used as an early marker of the disease, or whether it merely represents a consequence of ALS development.

Utility of serum Campylobacter specific antibodies in determining prior Campylobacter infection in neurological disease

Campylobacter jejuni has been implicated in the pathogenesis of Guillain-Barre syndrome (GBS); however, little information exists on the utility of Campylobacter serology in determining recent infection in the patient population. C. jejuni specific antibodies (CAs) were measured in 420 blood donors (controls), 99 patients with recent C. jejuni infection, 34 patients with central nervous system disorders (neurology controls), and 44 patients with peripheral nervous system (PNS) disorders: 18 with GBS, 12 with MND and 14 with chronic inflammatory neuropathies. Elevated CA titres consistent with recent C. jejuni infection were found in six of the 44 patients with PNS disorders (three with GBS, two with neuropathy, and one with MND, only one of whom had a history of recent C. jejuni infection), compared with two of 454 controls (p = 0.00001). Therefore, we conclude that CAs are often raised in patients with PNS disorders who do not have a history of recent C. jejuni gastroenteritis, so Campylobacter serology may be an unreliable marker of recent infection in this patient group.

Total antioxidant capacity of cerebrospinal fluid is decreased in patients with motor neuron disease

Oxidative stress has been associated with motor neuron disease (MND). The human body has several antioxidant defense systems to repair the damage caused by oxidative stress. The activity of these systems is thought to be reduced in neurodegenerative diseases, which may increase the level of oxidative damage and be a contributing factor to motor neuron death. In the present study, we compared the total antioxidant capacity (TAC) of human serum and cerebrospinal fluid (CSF) of MND patients with that of a control group including patients with migraine, tension headache and psychiatric disorders. Within-subject serum and CSF TAC were strongly correlated (r=0.639; p=0.000), and CSF TAC was significantly lower in MND patients as compared to controls after adjustment for known influencing factors (112.7 micromol Fe/L+/-11.7 versus 135.2 micromol Fe/L+/-19.7; p=0.012). No differences in serum or CSF TAC were observed among the clinical forms of MND considered in this work. In conclusion, the CSF TAC was strongly correlated with serum TAC, and a decrease in CSF TAC was demonstrated in MND patients compared to controls that was not independent from serum antioxidants, this translating in a systemic (but prevailing in the CNS) oxidative damage in this pathology.

Anti-tissue transglutaminase IgA antibodies in peripheral neuropathy and motor neuronopathy

OBJECTIVES

The aim of the study was to investigate the occurence of anti-tissue transglutaminase antibodies (tTGA) in peripheral nerve disorders, and to correlate them with neurophysiologic findings and anti-glycolipid antibodies.

MATERIALS AND METHODS

We examined tTGA immunoglobulin-A serum level from 220 patients with polyneuropathy (acute inflammatory: n=90; chronic inflammatory: n=56; non-inflammatory: n=74) and 110 with motor neuron disease (MND).

RESULTS

Seven of the 330 neurologic patients (2.1%, six with polyneuropathy and one with MND) were positive for tTGA. Sixty-one of the 330 neurologic patients (18.4%) had slightly increased tTGA values compared with healthy controls. Increased tTGA values were associated with greater impairment of neurophysiologic findings, but not with the presence of anti-glycolipid antibodies.

CONCLUSIONS

We found a high prevalence of tTGA reactivity in patients with peripheral nerve disorders or MND. However, we were unable to demonstrate an increased risk of celiac disease in these diseases.

Horses on pasture may be affected by equine motor neuron disease

REASONS FOR PERFORMING STUDY

Equine motor neuron disease (EMND) was diagnosed in 3 horses maintained on lush, grass-based pasture. This contrasted with North American studies which identified limited or no access to green herbage as an important risk factor for EMND.

HYPOTHESIS

Grazing horses that have an apparently adequate intake of pasture herbage to meet normal equine vitamin E requirements can develop EMND.

METHODS

Owners of 32 European horses diagnosed with EMND completed a questionnaire regarding intrinsic, managemental, nutritional and environmental factors that could potentially be risk factors for EMND, and also regarding clinical signs, treatments and case outcome. Plasma/serum vitamin E data for these horses were supplied by the veterinarians. No control population was studied.

RESULTS

Thirteen of 32 horses (termed the 'grazing' group) had part- or full-time access to grass-based pasture at the onset of EMND (median duration at pasture 12 h/day, range 3-24 h). Five of these horses were at pasture for at least 235 h/day at the onset of EMND, 2 of which were at pasture for at least 23.5 h/day throughout the year. Despite grazing, all these horses had a low vitamin E status. The remaining 19 horses resembled those cases reported from North America, in that they had no or limited access to pasture.

CONCLUSIONS AND POTENTIAL RELEVANCE

A diagnosis of EMND should not be discounted on the basis that a horse has access, even full-time, to lush grass-based pasture. Inadequate vitamin E intake was probably not the sole cause of either the EMND or the low vitamin E status in the grazing horses; the latter was probably the result of abnormal bioavailability or excessive utilisation of vitamin E.

Cerebrospinal fluid insulin-like growth factor-1, insulin growth factor binding protein-2 or nitric oxide are not increased in MS or ALS

OBJECTIVES

Many studies have shown that nitric oxide (NO) and growth factors including insulin growth factors (IGFs) may be involved in the pathogenesis of multiple sclerosis (MS) and neurodegenerative diseases. Our previous studies suggested a relationship between cerebrospinal fluid (CSF) NO metabolites (nitrates and nitrites, NN(x)) and IGF-1 in patients with progressive encephalopathy, hypsarrhythmia and optic atrophy syndrome.

MATERIAL AND METHODS

We examined CSF concentrations of NN(x), IGF-1 and IGF binding protein-2 (IGFBP-2) in 25 controls, 14 patients with MS and 14 patients with amyotrophic lateralis sclerosis (ALS).

RESULTS

There were no significant differences in CSF levels of NN(x), IGF-1 or IGFBP-2 between the groups. CSF IGFBP-2 concentrations correlated significantly with age in controls, which may reflect age-related changes in the blood-brain barrier function.

CONCLUSION

Upregulation of the production of NO and IGF-1 in the brain or spinal cord does not influence CSF levels of these molecules in MS or ALS.

Serum IgM anti-GM1 ganglioside antibodies in lower motor neuron syndromes

Lower motor neuron syndromes (LMNS) are heterogenous conditions, which include patients with progressive lower motor neuron disease (LMND) and cases with the clinical phenotype of motor neuropathy (MN). The aim of this study was to estimate the IgM anti-GM1 ganglioside antibodies titer and the ratio of the light chains in order to define the presence of autoimmunity process in particular cases with LMNS. Twenty-eight patients were diagnosed with LMND and 15 patients were diagnosed with MN (10 patients with multifocal motor neuropathy with conduction block, five patients with MN without conduction block). Total of 103 patients with classical amyotrophic lateral sclerosis (ALS) and 50 healthy, age-matched persons were also tested. The IgM anti-GM1 ganglioside titer and the ratio of lambda/kappa light chains in serum were determined using the ELISA technique. High titer of IgM anti-GM1 antibodies were detected in serum of 46% LMND patients, 80% of MN patients, and 18% of the classical ALS cases. An elevated ratio of lambda/kappa light chains appeared in 18% of LMND patients, and in 67% of the MN cases. The lambda/kappa light chains ratio was normal in all ALS patients. The presence of elevated titer of IgM anti-GM1 ganglioside antibodies and the changed ratio of the light chains supports the presence of autoimmune process in LMNS and may provide clues for their management.

[Effects of serum from a patient with acute motor axonal neuropathy on spinal motor neurons cultured in vitro]

The effect of serum from a patient with acute motor axonal neuropathy (AMAN) on cultured motor neurons was studied. The ventral spinal ventral tissue was isolated from embryonic rats and digested into dissociated cell suspension for culture in vitro. The cultured cells were stained with SMI-32, a non-phosphorylated neurofilment marker monoclonal antibody to identify motor neurons. The 6 days' cultured cells were exposed to the AMAN patient serum in a concentration of 25%, and to the normal human serum as the control. Positive PennerO:19 Campylobacter jejuni lipopolysaccharide antibody in the AMAN serum used in this experiment had been testified. The serum-cultured motor neurons were observed morphologically and also stained by Guillery Shirra and Webster method. With this staining, degenerated nerve fibers were brown-black and normal nerve fibers were brown-yellow. At the 9th h after the AMAN serum exposure, the axon degenerated and was stained brown-black due to increased silver-phile property. At the 12th h, the neuron soma began to swell and nuclear deviation with silver granules depositing in the cytoplasm. At last, the neurons began to die from the 16th h of the exposure. However, the control motor neurons did not show these alterations in the same period of culture. The serum of AMAN patient may be toxic to the neurite of motor neuron and thus cause axon degeneration, then soma alterations and death followed. It is suggested that Campylobacter jejuni lipopolysaccharide antibody may play an important role in this process without the participation of macrophages and complements.

[Nocturnal oxymetry in patients with amyotrophic lateral sclerosis: role in predicting survival]

Death is the most important end point along the course of amyotrophic lateral sclerosis (ALS). It is commonly attributed to a respiratory failure in relation with a restrictive respiratory disorder. However, in clinical practice, it is frequent to observe that death has not direct relation with the values of the respiratory function, at least measured with vital capacity. It is also frequent that relatives report sudden death during nocturnal sleep. All these features raised the question of the possible relation between death and nocturnal oxymetry in ALS patients. In a prospective study, we studied 69 ALS patients. We recorded demographic data, clinical parameters as manual muscle testing and functional scales, various parameters of oxymetry measured by pulse oxymetry recorded during night, slow vital capacity and survival time. There is a strong correlation between survival time measured by Kaplan Meier curves and log rank and the mean nocturnal saturation. We determined 93 mmHg as a threshold value. Below this threshold, mean survival time was 7.5+/-1.6 months and above it was equal to 18.5+/-1.5; relative risk was 3.31. These data confirm the importance of nocturnal oxymetry on survival in ALS patients both in clinical practice and in view of therapeutic trials.

Venous serum chloride and bicarbonate measurements in the evaluation of respiratory function in motor neuron disease

Respiratory failure, with or without pneumonia, is the usual cause of death in patients with motor neuron disease (MND). Forced vital capacity (FVC) is often used to monitor respiratory function in MND and is, in part, predictive of survival time. However, such volitional tests are unreliable in many patients, especially later in the disease, and access to hospital laboratories can also be a problem for some disabled patients. We assessed the use of domiciliary venous serum chloride and bicarbonate measurements in evaluating respiratory function in MND. Newly-diagnosed MND patients (n=23) were followed-up at home every 3 months for up to 15 months. Respiratory symptoms were measured using a questionnaire, and FVC was documented. Venous serum chloride and bicarbonate were also measured. One patient had symptoms of airway obstruction disease, and was excluded from the analysis. Ten patients developed abnormally low chloride (mean 95, range 88-97, reference interval 98-107 mmol/l) and an abnormally high bicarbonate (mean 33, range 31-37, reference interval 22-30 mmol/l) during follow-up, of whom eight died within the next 5 (mean 2.2, range 0.5-5) months; two were still alive at the end of the study but had developed respiratory symptoms. Twelve patients had normal chloride and bicarbonate during follow-up: all were still alive at 15 months, all had a FVC of >50% predicted, and only one had respiratory symptoms at their last assessment. Raised bicarbonate and low chloride were associated with the presence of respiratory symptoms suggesting respiratory muscle weakness. Venous serum chloride and bicarbonate potentially can provide useful information about respiratory status and prognosis in MND patients.

Unaltered cytochrome oxidase, glutamate dehydrogenase and glutaminase activities in platelets from patients with sporadic amyotrophic lateral sclerosis--a study of potential pathogenetic mechanisms in neurodegenerative diseases

Sporadic Amyotrophic Lateral Sclerosis (SALS) is a fatal neurologic disease characterized by degeneration of motor neurons in the spinal cord, brainstem and cortex. While familial cases of ALS exist, the sporadic form accounts for the majority of adult-onset cases. It has been hypothesized that the neurodegenerative mechanisms underlying SALS might arise from glutamate-mediated excitotoxicity and mitochondrial dysfunction. Studies on autopsied SALS spinal cord and brain have reported decreased cytochrome oxidase activity, decreased astrocytic glutamate-transporter protein, and alterations of glutamate levels and glutamate metabolizing enzyme activities. We conjectured that if alterations in glutamate metabolism and cytochrome oxidase activity occur in the SALS central nervous system these alterations may also be manifested in peripheral tissues such as platelets in living SALS patients. In this study we compared the activities of cytochrome oxidase, citrate synthase, glutamate dehydrogenase and glutaminase in platelets from SALS and control subjects. We found that there were no differences in any of the enzyme activities measured between the two groups. Our data argue against generalized ubiquitous biochemical alterations of these enzymes in SALS patients.

Blood levels of toxic and essential metals in motor neuron disease

Toxic and essential metals have been implicated in the pathogenesis of sporadic motor neuron disease (SMND), but attempts to measure blood levels of these metals have led to contradictory results. We, therefore, measured blood levels of various metals using paired SMND/controls. In 20 subjects with SMND (15 males, five females, mean age 56.8 years) and 20 partner controls (15 females, five males, mean age 55.0 years) cadmium, lead, mercury, copper, zinc and selenium levels were measured in blood, plasma and red cells with inductively coupled plasma mass spectrometry and manganese levels with atomic absorption spectrophotometry. Results were analysed using non-parametric tests. Hypo-osmotic red blood cellfragility was estimated in six SMND/control pairs to see if hemolysis could account for increased metal levels. The plasma cadmium level was significantly raised in SMND cases (P = 0.005), but with considerable overlap between SMND and controls. No other metal levels were significantly different, though plasma lead in SMND had a tendency to be higher than controls. No difference in red cell fragility was found between groups. In conclusion, plasma levels of cadmium were raised in this SMND group, but the biological significance of this is uncertain. The measurement of metals in the blood of SMND cases seems unwarrranted for routine diagnostic testing.

Intravenous immunoglobulin therapy in multifocal motor neuropathy: a double-blind, placebo-controlled study

We conducted a double-blind, placebo-controlled, study of 19 patients fulfilling eligibility criteria for multifocal motor neuropathy with persistent conduction block. They were enrolled and divided into two groups: those who had never been treated previously with intravenous immunoglobulins (IVIg) (Group 1: 10 patients) and those who presented recurrent symptoms after previously successful treatment with IVIg (Group 2: nine patients). They were randomized prospectively to receive either IVIg or placebo at a dose of 500 mg/kg/day for 5 consecutive days, once a month for 3 months. At month 4, patients found to be responders remained on the same treatment for the 3 following months, while non-responders were switched to the alternative study drug for the 3 following months. Clinical assessment was conducted with the MRC score in 28 muscles and a self-evaluation scale (five daily motor activities scored from 0 to 5). In Group 1, nine patients completed the study, of whom initially four received IVIg and five placebo; four patients responded to IVIg (two at months 4 and 7, and a further two at month 7 after switching treatment at month 4), two patients responded to placebo at months 4 and 7, and three patients did not respond to either treatment. In Group 2, nine patients completed the study. Five patients first received IVIg and all responded at months 4 and 7. Four patients first received placebo and none responded at month 4; all were then switched to IVIg and three responded at month 7. When the 18 patients were considered together, seven out of the nine patients who received IVIg first were responders at month 4, compared with two of the nine patients who received placebo first, a difference that was statistically significant (P = 0.03). On the other hand, there was no significant difference in MRC score but a significant difference in the self-evaluation score, at month 4, between IVIg patients and placebo patients. Electrophysiological studies did not show significant differences at month 4 in motor parameters between IVIg patients and placebo patients. IgM anti-GM1 titres did not change significantly in patients treated with IVIg compared with those who received placebo, between baseline, month 4 and month 7. However, of five patients who had significantly high anti-GM1 titres (>3200) at baseline, four responded to IVIg. This trial confirms that IVIg is a promising therapeutic option for multifocal motor neuropathy.

Matrix metalloproteinase-9 is elevated in serum of patients with amyotrophic lateral sclerosis

Matrix metalloproteinase-9 (MMP-9) and its specific inhibitor, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), were analysed by enzyme-linked immunosorbent assay (ELISA) and by zymography in serum and cerebrospinal fluid (CSF) of patients with amyotrophic lateral sclerosis (ALS). In contrast to patients with inflammatory diseases, MMP-9 levels were not elevated in CSF of ALS patients. In serum, however, compared to healthy donors, MMP-9 was significantly (p = 0.0003) increased up to levels as high as those of viral meningoencephalitis (VM) or bacterial meningitis (BM) patients. MMP-9 levels remained elevated during long-term observation of ALS patients. In the absence of an inflammatory response, the results indicate that the increase of MMP-9 in serum of ALS patients might be caused by upregulation of MMP-9 in denervated muscles or in degenerating peripheral nerves following motor neurone loss.

Serum markers of type I collagen synthesis and degradation in amyotrophic lateral sclerosis

Collagen abnormalities in the skin and spinal cord have been reported in amyotrophic lateral sclerosis (ALS) patients. Serum carboxyterminal propeptide of type I procollagen (PICP) and the carboxyterminal cross-linked telopeptide of type I collagen (ICTP) reflect type I collagen synthesis and degradation, respectively. However, there has been no study concerning PICP or ICTP in ALS. We studied collagen contents of the skin and measured serum levels of PICP and ICTP in patients with ALS and control subjects. Serum PICP levels were significantly lower in ALS patients than in controls. Serum ICTP levels were significantly higher in ALS patients than in controls, and there was an appreciable positive correlation between serum ICTP levels and the duration of illness in ALS patients. In ALS patients, the collagen content of the skin was significantly smaller than in controls and indicated a progressive decrease in relation to illness. In addition, there was a significant negative correlation between serum ICTP concentrations and the collagen content of the skin in ALS patients. These data suggest that increased ICTP levels and decreased serum PICP levels may reflect unique changes in the skin, with a predominance of degradation compared to the synthesis of type I collagen in ALS.

Detection of reverse transcriptase activity in the serum of patients with motor neurone disease

The recognition that both human and murine retroviruses can cause motor neurone disease-like syndromes has raised the possibility that a retrovirus may be involved in the aetiology of motor neurone disease. This possibility was explored by looking for evidence of reverse transcriptase in the serum of motor neurone disease patients. Sera from 56 patients with motor neurone disease and 58 controls were tested by the product-enhanced reverse transcriptase assay, a technique that is approximately a million fold more sensitive than conventional reverse transcriptase assays and capable of detecting very low numbers of retroviral particles. Cell-free reverse transcriptase activity was detected in the serum of 33 of the 56 motor neurone disease patients (59%) but in only 3 of the controls (P < 0.00001). The reverse transcriptase activity was detectable in the presence of a large excess of an effective inhibitor of human cellular DNA polymerases and was therefore tentatively considered to be compatible with a retroviral origin. The reverse transcriptase activity, however, was not found to be due to the presence of known human exogenous retroviruses including HIV-1, HIV-2, HTLV-I, HTLV-II, HRV-5 or human foamy virus, as assessed by PCR-based assays. Further investigations will be required to determine the source of the reverse transcriptase activity observed in these motor neurone disease patient sera.

Chronic motor axonal neuropathy associated with antibodies monospecific for N-acetylgalactosaminyl GD1a

We report on three patients with chronic motor neuropathy who had elevated titers of immunoglobulin (Ig)G antibodies against N-acetylgalactosaminyl GD1a (GalNAc-GD1a) and normal titers of antibodies against other gangliosides. Presenting with progressive muscular atrophy, fasciculations, and no sensory deficits, the patients had been diagnosed to have motor neuron disease. Electrodiagnostic features were predominantly axonal. Two patients clinically improved after intravenous Ig infusion and cyclophosphamide therapy. Increased titers of IgM antibodies to GalNAc-GD1a were also found in two of 15 patients with multifocal motor neuropathy with conduction block but were associated with concomitant rise of anti-GM1 antibodies. These three cases represent a chronic motor axonal neuropathy in which antibody testing for a minor ganglioside was helpful for instituting therapy.

Lower motor neuron syndrome associated with anti-GM1 antibodies

It has been recently recognized that increased titers of serum anti-GM1 antibodies may be associated with motoneurone diseases or with multiple motor neuropathy with or without conduction block and also with chronic sensorimotor neuropathy and Guillain-Barré syndrome. Santoro et al. were the first to note that anti-GM1 antibodies were able to bind to the nodes of Ranvier of the sural nerve of a patient with clinical signs and symptoms mostly resembling amyotrophic lateral sclerosis who also showed, in nerve conduction studies, multifocal motor nerve fibers conduction block and serum IGM anti-GM1 antibodies. The two patients presented in this report had asymetrical motor neurone disease with signs and symptoms of lower motoneurone involvement, and other signs, in the first patient, which suggested the existence of upper motoneurone damage. Besides, the second patient also had clinical sensory impairment in the lower limbs. Electrophysiologically, none of them had nerve conduction block but both showed inexcitable median and sural nerve sensory fibers. Both had high titers of anti-GM1. A sural biopsy of both patients showed immunoglobulins into the sensory fibers. However, we do not know whether the anti-GM1 antibodies bind to a cross-reactive glycolipid other than the GM1 itself. In any case, it seems that the presence of anti-GM1 antibodies might be a marker signalling a potentially treatable immune disorder which may have signs of lower and upper motor neurone disease and, also, clinical and electrophysiological evidences of peripheral sensory involvement.

Blood glutamate levels in patients with motor neuron disease

This study was undertaken to evaluate the role of excitatory amino acid glutamate (Glu) in the pathophysiology of motor neuron disease (MND). It was observed that blood Glu levels were significantly higher in MND patients with respect to healthy controls. The data indicate that Glu homeostasis is altered in the patients with MND.

Multifocal motor neuropathy: serum IgM binding to a GM1 ganglioside-containing lipid mixture but not to GM1 alone

IgM anti-GM1 antibodies are associated with motor neuropathy syndromes, including multifocal motor neuropathy (MMN). We compared the ability of serum IgM from patients with multifocal motor neuropathy to bind to GM1 ganglioside alone and to GM1 as a component of a lipid mixture that also contained galactocerebroside and cholesterol (GGC). Our results showed that high-titer selective serum IgM binding to GGC has strong specificity for MMN. Further, over 40% more serums from patients with MMN have high-titer serum IgM binding to GGC than to GM1 alone. The specific composition and structure of the lipid mixture altered the ability of serum IgM to bind to GM1 ganglioside. Substitutions of other lipids for galactocerebroside or cholesterol could completely inhibit the antibody binding. We conclude that serum IgM anti-GGC autoantibodies have specificity for MMN and their binding is strongly influenced by the lipid environment of GM1 ganglioside.

Tremor associated with benign IgM paraproteinaemic neuropathy

The clinical and neurophysiological features of six patients with action tremor of the upper limbs associated with IgM paraproteinaemic neuropathy are described. Symptomatic tremor was confined to the upper limbs and was broadly symmetrical. The frequency of associated rhythmic muscle activity ranged from 2.8 to 5.5 Hz in abductor pollicis brevis and from 3.7 to 5.5 Hz in the forearm flexor muscles. Magnetic brain stimulation, somatosensory evoked potentials (SEPs) and stretch reflex studies did not provide evidence for delayed conduction within central pathways. There was marked slowing of the maximum motor conduction velocities in peripheral nerves. Forearm stretch reflexes were present but their latencies were prolonged. Somatosensory evoked potentials were obtained in the majority of patients, but were delayed. Wrist tremor could be modulated by mechanical perturbations or median nerve electrical shocks. Simple voluntary wrist movements were of normal duration and peak velocity, but the kinematic profile was asymmetric. Each movement was associated with a triphasic EMG pattern in agonist-antagonist-agonist muscles but the durations of the bursts were prolonged and the onset of the second agonist was delayed. These results support the hypothesis that distorted, mistimed peripheral inputs reach a central processor (probably the cerebellum) which although intact is misled into producing tremor in certain parts of the body.

The anti-oligosaccharide antibodies present in sera from patients with motor neuron disease and neuropathy recognize the N-glycolylneuraminic acid containing gangliotetrahexosyl oligosaccharide

We found that serum antibodies present in the serum of patients with motor neuron disease and neuropathy, which were previously shown to react with the oligosaccharide chain of ganglioside GM1(Neu5Ac), can be recognized and titred using the N-glycolylneuraminic acid containing monosialo-gangliotetrahexosylceramide, GM1(Neu5Gc), which is not a component of normal human cells. The antibody-antigen reaction was abolished by immunoabsorption with the free oligosaccharide chain. This result, together with the knowledge that these antibodies recognize several glycoconjugates, supports the conviction that these antibodies are non-specific for a gangliosidic structure.

Multifocal motor neuropathy human sera block distal motor nerve conduction in mice

Multifocal motor neuropathy (MMN) is associated with serum autoantibodies to gangliosides, but their pathogenic role is uncertain. We have used a novel approach to study the effects of serum and plasma from 8 patients with this syndrome, 6 of whom were anti-GM1 positive. The nerve stimulus required to evoke muscle contraction and endplate potentials (EPPs) was measured in the mouse phrenic nerve-diaphragm preparation during 4 to 6 hours of direct application (plasma at 1:1 or serum 1:2 dilution) and following intraperitoneal injection of plasma (1 ml/day) for 1 to 5 days ("passive transfer"). Direct application of MMN serum or plasma produced a progressive increase in stimulus threshold, followed by complete block of nerve-evoked muscle contraction in 3 cases, and an associated decline to about 50% of the EPP amplitude followed by sudden loss of EPPs. These effects were complement independent. Even with complete block of nerve-evoked EPPs, miniature EPP (MEPP) frequency could be increased by raising external K+ to depolarize the nerve terminal directly. Passive transfer of 1 ml of MMN plasma (n = 5) for 3 days caused similar but less marked changes. These results demonstrate that serum factors in MMN can block nerve conduction at distal motor nerves.

CSF and plasma amino acid levels in motor neuron disease: elevation of CSF glutamate in a subset of patients

Fasting plasma and/or CSF amino acid levels have been measured in a group of 37 patients with motor neurone disease (MND) and in 35 neurological control patients undergoing lumbar puncture prior to myelography. There were no significant differences in the plasma levels of 22 amino acids between the two groups. In CSF, there was a significant elevation of the glutamate level in the MND patients (P = 0.008). However, the MND group were heterogeneous with regard to CSF glutamate: 19/31 (61%) had levels within the normal range; eight (26%) had levels more than twice the upper limit of normal (> or = 10 mumol/l) and five (16%) had levels more than seven times normal (> or = 30 mumol/l). In a subset of seven MND patients there was a significant inverse correlation (rs = -0.775, P < 0.03) between CSF glutamate levels in life and the density of pre-synaptic glutamate re-uptake sites in the lumbar spinal cord measured in a post-mortem autoradiographic study. A possible interpretation of these findings is that an abnormality of glutamate transport may underlie the increase in CSF glutamate. The identification of a subgroup of MND patients with high CSF glutamate levels may be important in evaluating the clinical response to antiglutamate therapeutic agents.

Motor neuron disease and monoclonal gammopathy

In a study to determine the prevalence of monoclonal gammopathy (MG) among patients with motor neuron disease (MND), 6 out of 56 (10.7%) were found to have a monoclonal paraprotein. Of these 6 patients, 4 had an IgG and 2 had an IgA paraprotein. The clinical syndromes consisted of amyotrophic lateral sclerosis in 2 patients, lower motor neuron syndrome with preserved reflexes in at least one limb in 3 patients, and motor neuropathy with multifocal conduction block in 1 patient. The presence of gammopathy appears to correlate with the absence of marked upper motor neuron involvement and with elevated CSF protein concentration. An underlying malignant disorder was ruled out in all 6 patients, and they were considered to have MG of undetermined significance (MGUS). In a control group of 121 age-matched patients with other neuroimmunological disorders, 5 patients (4.13%) had MG. Four of these had gammopathy associated with malignant myeloma, and 1 had MGUS. These results support previous reports of increased prevalence of MGUS in patients with MND and suggest that an autoimmune mechanism may play a role in the disease.

Plasma lysosomal enzyme levels in patients with motor neuron disease

beta-Hexosaminidase and acid-alpha-mannosidase were estimated in 17 adult patients with motor neuron disease. Normal plasma levels of beta-hexosaminidase ((A+B) and A) were found in all patients studied. Plasma acid alpha-mannosidase levels were normal in all but two patients with the spinal muscular atrophy type of the disorder. In addition, altered biochemical properties of acid alpha-mannosidase (i.e. Km, thermal stability) were found in the low-activity cases.

Monoclonal IgM antibodies to GM1 and asialo-GM1 in chronic neuropathies cross-react with Campylobacter jejuni lipopolysaccharides

We tested monoclonal IgM anti-GM1 and asialo-GM1 antibodies from 6 patients with chronic motor neuropathies for binding to lipopolysaccharides (LPS) from three stains of Campylobacter jejuni. Four of the 6 patients showed strong reactivity with LPS from at least one of the three C. jejuni strains tested as shown by enzyme-linked immunosorbent assay or western blot. Preabsorption with GM1 or asialo-GM1, or blocking with cholera toxin, prevented antibody binding to LPS. These studies indicate that human anti-GM1 or anti-asialo-GM1 antibodies cross-react with LPS from certain strains of C. jejuni, and that bacterial LPS might provide antigenic stimuli for the activation of B cells expressing anti-GM1 antibodies.

Konzo in the Central African Republic

We identified a new focus of konzo, an upper motor neuron disease, in a part of western Central African Republic. Interviews and high serum levels of thiocyanate indicate that cyanide exposure from insufficiently processed cassava may cause konzo. Abrupt onset, nonprogressive course, and seronegativity to HTLV-I clearly differentiate konzo from HTLV-I-associated myelopathy in tropical countries.

The clinical and diagnostic role of anti-GM1 antibody testing

There is increasing evidence that multifocal motor neuropathy (MMN) and some lower motor neuron (LMN) syndromes are immune-mediated and treatable. The frequent occurrence of high titers of anti-GM1 antibodies in these motor neuropathies raised hopes that serum testing would provide useful diagnostic information. Unfortunately, in routine practice, simple quantification of IgM binding to GM1 ganglioside has proved to be a test with poor sensitivity and specificity. We have found that much greater sensitivity and specificity for MMN and LMN syndromes can be obtained by determining serum antibody binding to panels of antigens, such as GM1, histone H3, and NP-9. These results suggest that combined measurement of serum antibody binding to GM1 and other antigens can provide tests that are useful in the diagnosis and management of motor neuropathy syndromes.

Anti-GM1/GD1b M-proteins damage human spinal cord neurons co-cultured with muscle

IgM M-proteins in some motor neuron disease (MND) patients bind immunologically to shared determinants on gangliosides GM1 and GD1b. Since patients with these M-proteins have improved with immunotherapy the antibodies may be important in the pathogenesis of MND. To study how the M-proteins might damage motor neurons, we established co-cultures of human neurons from spinal cord explants and human myotubes. Antibodies from patient but not control serum bound to the cultured neurons. Neurons in co-cultures degenerated after incubation with patient but not control serum. These results demonstrate that anti-GM1 antibodies can bind to and destroy spinal cord neurons that are cultured with muscle. Nerve-muscle co-cultures can serve as a system to examine effects of anti-GM1/GD1b M-proteins on motor neurons.

Immunofixation superior to plasma agarose electrophoresis in detecting small M-components in patients with polyneuropathy

Monoclonal immunoglobulins (M-components) in blood are found in some patients with polyneuropathy and are thought to be of pathogenetic importance, especially if the M-component is of IgM isotype. As the finding of an M-component may indicate a treatable polyneuropathy, the potential of the method to uncover an M-component is of importance. Cellulose acetate or agarose electrophoresis used in routine practice may miss small M-components covered by other proteins. We therefore applied the uncovering and specific method of immunofixation in comparison with agarose electrophoresis on patients investigated for polyneuropathy. Of 83 consecutive patients, 5 had M-components. Two of these 5 patients, one with an axonal polyneuropathy and the other with a lower motor neuron syndrome, had extra bands on agarose electrophoresis, verified as IgG M-components by immunofixation. In the 3 additional patients an M-component was uncovered only by immunofixation, not seen in the agarose electrophoresis of plasma; 2 of them were of IgM isotype and one was of IgG isotype. These 3 patients were diagnosed as having a demyelinating (i.e., possibly immune-mediated) polyneuropathy by means of neurophysiology and in one by means of nerve biopsy. A 6th patient had 2 small bands in the gamma region on the agarose electrophoresis, verified as oligoclonal bands of IgG isotype by immunofixation but was not judged as an M-component. Three out of the 83 patients, were judged as having motor neuron diseases. All remaining 80 were found to have polyneuropathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal glycine metabolism in motor neurone disease: studies on plasma and cerebrospinal fluid

Plasma amino acid levels were measured following oral glycine loading in 43 patients with motor neurone disease (MND), eight normal subjects and 18 neurological disease controls with wasting or spasticity from a variety of other causes. Levels at baseline and 1.5 h after loading did not differ, but at 4 h, plasma glycine levels in MND patients remained significantly higher than in normal and neurological controls (P < 0.013). Cerebrospinal fluid glycine levels, which were maximal at 2.5 h, were also significantly higher in MND patients than neurological controls (P < 0.04). These observations suggest a defect of glycine 'housekeeping' in the central nervous system in MND which may be relevant to the pathogenesis of the disease.