Vitamin B nutrition in the Nigerian tropical ataxic neuropathy.

Assessment of nutritional status of vitamin B components by plasma or blood levels indicated riboflavin deficiency and possibly thiamine deficiency in Nigerian patients who suffered from tropical ataxic neuropathy and neurologically normal Nigerians who subsisted on predominant cassava diet. Serum levels of folate, niacin, pyridoxine and panthothenic acid were normal. Vitamin deficiencies probably are minor factors, if any, in the pathogenesis of tropical ataxic neuropathy in Nigerians.     

Controlled trial of hydroxocobalamin and riboflavine in Nigerian ataxic neuropathy

The results are presented of a double-blind therapeutic trial of hydroxocobalamin and riboflavine in Nigerian patients suffering from a degenerative neuropathy. Although no benefit from either vitamin was demonstrated, this may reflect the inadequacy of the dosages used. The results are discussed in relation to the hypothesis that dietary cyanide and cyanogens are responsible, at least in part, for the occurrence of this disease in a malnourished population.     

Biochemical studies in Tanzanian patients with ataxic tropical neuropathy

Data on thiocyanate and vitamin B₁₂ concentrations in plasma from Tanzanian patients with ataxic tropical neuropathy are presented and support the hypothesis that, as in Nigeria, the condition may result from chronic exposure to cyanide or cyanogens from a diet including large amounts of cassava.     

Controlled trial of combinations of hydroxocobalamincystine and riboflavine-cystine, in Nigerian ataxic neuropathy

Chronic cyanide intoxication of dietary origin and riboflavine deficiency are believed to be major aetiological factors in Nigerian tropical ataxic neuropathy. The results are presented of a double-blind controlled therapeutic trial of combinations of large doses of hydroxocobalamin and cystine as cyanide binding agents together with riboflavine or placebos in Nigerian patients suffering from the tropical ataxic neuropathy. No clinical benefit was demonstrable with any of the treatments.     

Incidence of endemic ataxic polyneuropathy and its relation to exposure to cyanide in a Nigerian community

BACKGROUND: The occurrence of ataxic polyneuropathy in an endemic area in south west Nigeria has been attributed to exposure to cyanide from cassava foods. However, it has been shown that the prevalence of ataxic polyneuropathy is not high in several communities in the tropics where exposure to cyanide from cassava foods is high. OBJECTIVES: To determine the incidence of ataxic polyneuropathy in an endemic community, and to compare the intake of cassava foods, exposure to cyanide, and levels of thiols in cases and controls. METHODS: A cohort of 3167 healthy subjects aged 10 years and over in Ososa, Nigeria, was followed for two years, screened, and examined neurologically. Ataxic polyneuropathy was diagnosed if sensory polyneuropathy and sensory gait ataxia were both present. Controls were selected randomly within 10 year age groups of subjects who screened negative. Intake of cassava foods, exposure to cyanide, concentrations of thiols (glutathione, cysteine, and gamma glutamylcysteine) in plasma, and visual evoked potentials were measured. RESULTS: Person-years of follow up were 6246 for 1469 male and 1698 female subjects in the cohort. The incidence of ataxic polyneuropathy was 64 per 10,000 person-years (31 for male and 93 for female subjects). Multivariate odd ratios were 0.78 (95% CI 0.23 to 2.61) for intake of the commonest cassava food, and 1.64 (0.56 to 5.09) for concentration of thiocyanate in plasma. The concentration of thiols was less than the reference limits in two controls, but in none of the cases. The latency of P100 was prolonged in 20 cases (69%) compared with 14 controls (42%) (p<0.05). CONCLUSIONS: The incidence of ataxic polyneuropathy is high in Ososa, Nigeria, but the intake of cassava foods, exposure to cyanide, and levels of thiols, are not related to the occurrence. These findings do not suggest that cyanide is the cause of endemic ataxic polyneuropathy.     

Chronic idiopathic ataxic neuropathy

Fifteen patients with chronic sensory ataxia caused by a large-fiber sensory neuropathy were studied and followed up for a period of 17.4 years (range, 4 to 41). When first seen, they had distal paresthesias and sensory ataxia of slow onset and progression, areflexia, normal strength, and a profound loss of proprioceptive and kinesthetic sensation extending up to the most proximal joints. Needle electromyogram and motor-nerve conduction velocity findings were normal in most of the patients and sensory potentials were absent in all. Nerve biopsy showed severe loss of the large myelinated fibers. Nine patients had a serum monoclonal or polyclonal gammopathy (3 with IgM kappa, 1 with IgA kappa, and 5 with a polyclonal increase of IgG, IgA, or IgM), and 8 had elevated cerebrospinal fluid gamma globulin levels in spite of low normal total cerebrospinal fluid protein levels. No circulating antibodies to ganglionic neurons were found. Therapy with immunosuppressants or plasmapheresis was unsuccessful. All patients are disabled and their conditions have continued to worsen without signs of malignancy or systemic illness during a mean follow-up period of 17.4 years. Chronic idiopathic ataxic neuropathy is a proprioceptive neuropathy, clinically indistinguishable from the one associated with carcinoma or pyridoxine abuse due to involvement of the dorsal root ganglia, and could represent a distinct form of an indolent, slowly progressive sensory neuronopathy (ganglionopathy). Although immunopathological mechanisms may play a role, especially in patients with an associated paraproteinemia, the resistance of such patients to therapy, the progressive course, and the resemblance of this disorder to other toxic neuronopathies associated with pyridoxine abuse or doxorubicin administration suggest a possible toxic etiopathogenesis.     

Chronic idiopathic ataxic neuropathy: neuropathology of a case

Summary A case of chronic, sporadic, slowly progressive, purely sensory, ataxic neuropathy is reported. In previously published similar cases only muscle and nerve biopsies have been available for study. In the present case the patient died of an unrelated illness 39 years after onset of the neuropathy. A full neuropathological study was performed. The disease process was limited to the dorsal root ganglia and their central and peripheral processes. Large myelinated fibers were preferentially involved. Involvement of the dorsal root ganglia has also been reported in certain toxic ganglioneuropathies and in the sensory neuropathy associated with carcinoma. The long duration and insidious development set the present case apart from those conditions. An inflammatory component was lacking. Except for a microscopic focus of adenocarcinoma of the prostate no malignancy was present. The etiology of chronic idiopathic ataxic neuropathy is unknown, but it is likely that the dorsal root ganglion is the main target for the disease process in most if not all cases.Supported by the Veterans Administration Medical Research Program     

Antidisialosyl antibodies in chronic idiopathic ataxic neuropathy

Antidisialosyl antibodies were found in two out of 13 patients with chronic idiopathic ataxic neuropathy (CIAN) and not in 32 patients with different sensory neuropathies of known cause. This finding confirms the association of antidisialosyl antibodies and CIAN regardless of the absence of the M band. These antibodies may have pathogenic relevance; however, larger series are needed to establish their clinical significance.     

Chronic ataxic neuropathy initially diagnosed as ataxic variant of guillain barré syndrome

Aquadynia is a rare phenomenon of water‐induced pain through presumed neural mechanisms. We describe two women in whom bathing was regularly followed by pain in the lower limbs, as a unique symptom (case 1) and, respectively, in the clinical context of an axonal polyneuropathy (case 2). Case 1: A 71‐year‐old woman complained, by age 69, of pruritus and pinprick‐like pain in the extremities that lasted about 20 minutes following bathing. Neurological examination and electroneurography were negative, as well as investigations for systemic diseases. Quantitative sensory testing (QST) showed abnormal cold‐pain sensation. Treatment with gabapentin was not effective. Case 2: A 69‐year‐old woman affected with HCV‐related cryoglobulinemia had numbness and aquadynia in the distal lower limbs and restless legs syndrome, in the last few months. Neurological examination showed absent ankle jerks, and decreased touch and vibration sense in the feet. Electroneurography demonstrated an axonal neuropathy. Aquadynia likely represents a manifestation of small fiber neuropathy. It is unclear whether it has to be viewed as a primary sensory phenomenon similar to allodynia, or a type of noradrenergic pain primarily due to autonomic dysfunction. Alteration of QST in case 1, and the association with obvious features of sensory neuropathy in case 2, may favour the sensory hypothesis.     

Chronic ataxic neuropathy mimicking dorsal midbrain syndrome

We describe the clinical course, with special attention to the disturbance of eye movements, of a 29-year-old man with chronic ataxic neuropathy with ophthalmoplegia, IgM paraprotein, cold agglutinins and anti-GD1b disialosyl antibodies (CANOMAD). Using the magnetic search coil technique, we documented convergence during upward saccades and other features suggestive of dorsal midbrain syndrome. Thus, in common with Miller Fisher syndrome, CANOMAD may present with clinical findings implicating involvement of the central nervous system, which contains ganglioside antigens to anti-GD1b antibodies.     

Sensory conduction study in chronic sensory ataxic neuropathy.

Sensory conduction was studied in six patients with chronic sensory ataxic neuropathy of an idiopathic type and associated with Sjögren's syndrome. Motor nerve conduction velocities were normal in most cases, but sensory nerve potentials could not be evoked in a routine peripheral nerve conduction study. Cortical and cervical somatosensory evoked potentials (SEPs) and evoked potentials from Erb's point were barely recorded by median nerve stimulation at the wrist. When the median nerve was stimulated at more proximal points, clear potentials were recorded from Erb's point, but cortical SEPs were still hardly elicited. Thus the sensory nerves are centrally and peripherally involved in this condition, and the involvement is more prominent in the distal portion in the peripheral nerve. These findings suggest that central-peripheral distal axonopathy is a process involved in this illness and that the dorsal root ganglia may be primarily involved, in accord with previous pathological studies.     

Sensory ataxic neuropathy and esophageal achalasia in a patient with Sjogren's syndrome

We describe a patient who developed an ataxic sensory syndrome associated with xerophthalmia and progressive dysphagia with regurgitation. Electrophysiological findings were consistent with an axonal sensory neuropathy, and superficial peroneal nerve biopsy showed a reduction in number of myelinated fibers with epineurial inflammation. Rheumatoid factor, anti-SSA/SSB and antinuclear antibodies were positive and a diagnosis of Sjogren's syndrome was made. An endoscopic investigation revealed esophageal achalasia. We suggest that there may be a common autoimmune mechanism directed to different targets on the basis of this rare association.     

Acute ataxic neuropathy: a clinical, electrophysiological and morphological study

Sensory ataxia as the chief manifestation of acute neuropathy is rather rare. Of the 224 cases of acute polyneuropathy seen over 6 years (1984-1990) only 10 patients (M:F 3:7) had disabling ataxia as the presenting feature. Their ages ranged from 14-61 years. Antecedent febrile illness was present in 6 patients and the peak deficit evolved over 2-25 days. Severe ataxia, paresthesia, distal areflexia and predominant joint sense loss were common to all, motor weakness was either absent or insignificant. CSF was acellular and revealed elevated protein in 3 subjects. All patients had electrophysiological evidence of severe sensory neuropathy with mild or no motor neuropathy. Sural nerve biopsy in one patient showed loss of large, as well as small, diameter myelinated fibres, secondary demyelination, but no evidence of inflammation. At follow up marginal to moderate improvement in ataxia was noted in only 5 patients. Absence of ophthalmoplegia and motor weakness, poor prognosis and characteristic electrophysiological and histopathological observations suggest that acute ataxic neuropathy may be a distinct entity.     

Pyridoxine-induced sensory ataxic neuronopathy and neuropathy: revisited

High dose pyridoxine is neurotoxic. Previous case reports were sparse and little is known about the clinical and electrodiagnostic findings. Three patients with pyridoxine-induced sensory ataxic neuropathy were studied and a review of the involved literature was performed. Three patients, aged 80, 83 and 83 years old, presented with sensory ataxia for 3–8 months. Examination showed signs of polyneuropathy and sensory ataxia. Six hundred milligrams of pyridoxine was consumed each day for 3–10 years, in the form of vitamin B1-6-12 combination tablet. Investigations for other causes of neuropathy were unremarkable. Blood levels of vitamin B6 were markedly elevated at 104.6, 81.4 and 66.9 times of upper normal limits. Electrodiagnostic tests showed symmetric axonal sensory polyneuropathy in two patients. Two years after vitamin discontinuation, all patients showed no significant improvement in the neuropathy and gait. In conclusion, consumption of high dose pyridoxine can cause sensory neuronopathy and axonal sensorimotor polyneuropathy, leading to sensory ataxia which may not be reversible.     

Balance exercise in patients with chronic sensory ataxic neuropathy: a pilot study

Although exercise therapy is considered part of the treatment of neuropathic patients, and somatosensory input is essential for motor learning, performance and neural plasticity, rehabilitation of patients with sensory ataxia has received little attention so far. The aim of this prospective pilot study was to explore the short‐ and medium‐term efficacy of a 3‐week intensive balance and treadmill exercise program in chronic ataxic neuropathy patients; 20 consecutive patients with leg overall disability sum score (ODSS‐leg) ≥2, absent/mild motor signs, clinical and therapeutic stability ≥4 months were enrolled. Evaluations were done at baseline, at the end of treatment and at 3‐ and 6‐month follow‐up. Outcome measurements included: ODSS‐leg, Berg balance scale, 6‐min walk distance, and the functional independence measure (FIM) scale. The short‐form‐36 health status scale (SF‐36) was used to measure health‐related quality of life (HRQoL). ODSS‐leg improved significantly compared with baseline, 3 weeks, 3 months (primary outcome), and 6 months follow‐up. A significant improvement in all functional secondary outcome measurements and in some SF‐36 subscales was also observed. This pilot study suggests that balance exercise is safe and well tolerated and might be effective in ameliorating disability and HRQoL in patients with chronic peripheral sensory ataxia.     

Two cases of ataxic sensory neuropathy associated with silicosis

Two patients of ataxic sensory neuropathy associated with silicosis were studied. Case 1 is a 53-year-old (in 1979) man who was a stonecutter for 40 years and diagnosed as silicosis in 1973. Case 2 is a 64-year-old (in 1984) man who was a glasscutter for 30 years and had been treated for silicosis from 1980 to 1982. Both patients developed dysesthesias in the hands, feet and face asymmetrically and gait ataxia over a few months. Vibratory and joint position senses were profoundly diminished but were accompanied by only mildly decreased pain and temperature sensations. Their muscle power was almost unchanged. Both had absent muscle power was almost unchanged. Both had absent muscle stretch reflexes. Sensory nerve conduction velocities were absent and motor nerve studies were almost normal. Nerve biopsy in case 2 showed a severe loss of large myelinaed fibers, and no inflammatory infiltrates and onion bulb formations. Although these findings suggested the carcinomatous neuropathy, we could not find any malignancy. Both patients had elevated polyclonal gamma-globulin levels and rheumatoid factors and, in case 2 an increase of IgG in serum. Cerebrospinal fluid showed an albumino-cytogenic dissociation and steroid therapy was successful in both patients. Case 1 died of pneumonia in 1989. Though an autopsy was not performed, his condition had continued to improve without signs of malignancy during 10 years. The condition of case 2 has also continued to improve, although ataxias remain.(ABSTRACT TRUNCATED AT 250 WORDS)