Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A neurological disorder developed after prolonged exposure to nitrous oxide in 15 patients, all but 1 of whom were dentists. 13 patients had abused nitrous oxide to some extent for periods ranging from 3 months to several years, but 2 patients were exposed to nitrous oxide only professionally, by working in poorly ventilated surgeries. Symptoms included early sensory complaints, Lhermitte sign, loss of balance, leg weakness, gait ataxia, impotence, and sphincter disturbances. Neurological examination showed sensorimotor polyneuropathy, often combined with signs of involvement of the posterior and lateral columns of the spinal cord. Electrodiagnostic tests pointed to an axonal polyneuropathy, but other laboratory results were normal, including examination of the spinal fluid. The neurological picture is similar to that of subacute combined degeneration of the spinal cord, and it is possible that nitrous oxide interferes with the action of vitamin B12 in the nervous system.
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PMID:Myeloneuropathy after prolonged exposure to nitrous oxide. 8 36

We reviewed 153 episodes of cobalamin deficiency involving the nervous system that occurred in 143 patients seen over a recent 17-year period at 2 New York City hospitals. Pernicious anemia was the most common underlying cause of the deficiency. Neurologic complaints, most commonly paresthesias or ataxia, were the first symptoms of Cbl deficiency in most episodes. The median duration of symptoms before diagnosis and treatment with vitamin B12 was 4 months, although long delays in diagnosis occurred in some patients. Diminished vibratory sensation and proprioception in the lower extremities were the most common objective findings. A wide variety of neurologic symptoms and signs were encountered, however, including ataxia, loss of cutaneous sensation, muscle weakness, diminished or hyperactive reflexes, spasticity, urinary or fecal incontinence, orthostatic hypotension, loss of vision, dementia, psychoses, and disturbances of mood. Multiple neurologic syndromes were often seen in a single patient. In 42 (27.4%) of the 153 episodes, the hematocrit was normal, and in 31 (23.0%), the mean corpuscular volume was normal. Neutropenia and thrombocytopenia were unusual even in anemic patients. In nonanemic patients in whom diagnosis was delayed, neurologic progression frequently occurred although the hematocrit remained normal. In 27 episodes, the serum cobalamin concentration was only moderately decreased (in the range of 100-200 pg/ml) and in 2 the serum level was normal. Neurologic impairment, as assessed by a quantitative severity score, was judged to be mild in 99 episodes, moderate in 39 and severe in 15. Severity of neurologic dysfunction before treatment was clearly related to the duration of symptoms prior to diagnosis. In addition, the hematocrit correlated significantly with severity, independent of the longer duration of symptoms in nonanemic patients. Four patients experienced transient neurologic exacerbations soon after beginning treatment with cyanocobalamin, with subsequent recovery. Followup evaluation was adequate to assess the neurologic response to vitamin B12 therapy in 121 episodes. All patients responded, and in 57 (47.1%), recovery was complete, with no remaining symptoms or findings on examination. The severity score was reduced by 50% or greater after treatment in 91% of the episodes. Residual long-term moderate or severe neurologic disability was noted following only 7 (6.3%) episodes. The extent of neurologic involvement after treatment was strongly related to that before therapy as well as to the duration of symptoms. The percent improvement over baseline neurologic status after treatment was inversely related to duration of symptoms and hematocrit. Some evidence of response was always seen during the first 3 months of treatment.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Neurologic aspects of cobalamin deficiency. 164 56

We report on 7 patients (2 women, 5 men) with chronic renal failure, who developed under a high dosage of the new diuretic muzolimine (range 240 to 1440 mg per day) fatal neuromyeloencephalopathy. Clinical neurophysiological and neuroradiological findings and finally neuropathological studies in 2 patients resembled those found in vitamin-B12-deficiency-syndrome with a predominant affection of the spinal posterior column and the corticospinal tracts. The first neurological symptoms like paraesthesia, severe hyperpathia of the legs and mild to heavy spinal ataxia occurred after an average time of treatment of 78 days and a mean dosage of 52 g. The most progressive neurological deficits like severe tetraspastic paresis, were seen only in the nondialytic renal insufficient group (3 patients), while the others had a more benign course of the disease. This lead to the hypothesis of a partially dialysable toxic metabolite of muzolimine. After a follow-up of more than 2 1/2 years no significant recovery was seen in these cases.
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PMID:Muzolimine-induced severe neuromyeloencephalopathy: report of seven cases. 184 34

Vitamin B12 malabsorption in the ileum has been postulated as the underlying cause of the Imerslund-Grasbeck syndrome comprising megaloblastic anemia, proteinuria, and multiple neurological abnormalities. A young Saudi child with spasticity, truncal ataxia, cerebral atrophy, megaloblastic anaemia and proteinuria is described. Replacement therapy with parenteral vitamin B12 resulted in the complete resolution of his neurological findings and brain atrophy.
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PMID:Reversal of severe neurological abnormalities after vitamin B12 replacement in the Imerslund-Grasbeck syndrome. 194 Sep 89

Detailed electrophysiological studies were performed in 4 patients with myeloneuropathy induced by abuse of nitrous oxide for 1 to 4 years. All presented with paresthesias, weakness, and Lhermitte's phenomena, and exhibited signs of sensorimotor polyneuropathy, ataxia, and arreflexia. Two had subnormal serum vitamin B12 levels. Baseline electrophysiologic testing revealed reduced motor unit potentials, prolonged F wave latencies, absent H reflexes, denervation potentials, and delays in motor and sensory conduction. Three had peripheral and nuchal delay after median nerve stimulation. All were reevaluated after 3 to 12 months' abstinence and treatment with vitamin B12, and all showed substantial clinical improvement. Parallel improvement in electrophysiologic findings occurred, but residual minor conduction delays, loss of H reflexes, electromyographic evidence of denervation, or abnormalities of posterior tibial SEP were noted. These findings confirm the reversibility of myeloneuropathy of nitrous oxide abuse and describe the profile of electrophysiologic recovery in subjects who abstain from further neurotoxic exposure.
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PMID:Reversible myeloneuropathy of nitrous oxide abuse: serial electrophysiological studies. 199 94

Sibling cases of familial vitamin E deficiency accompanied by ataxia, polyneuropathy and mental retardation were reported. Case 1 was a 37-year-old male who developed progressive gait disturbance, deformity of the feet and head tremor from childhood, after normal delivery and development of early childhood. On physical examination, he had cataract, high arched palate and pes cavus. Neurological examination revealed mental retardation (WAIS 68), scanning speech, muscular atrophy of the face and extremities with predominance in the lower limbs, absent Achilles tendon reflex, disturbance of superficial and deep sensation predominant in distal limbs, and marked gait ataxia. Ataxia was both cerebellar and sensory in nature. Laboratory data of the blood showed no significant abnormalities including blood glucose and vitamin B12 except a markedly low level of serum vitamin E. The brain CT scan revealed severe cerebellar atrophy and marked dilatation of the cisterna magna and the subarachnoid space around the cerebellum. Motor nerve conduction velocity in the leg was decreased. Biopsy specimen from the quadriceps muscle showed neurogenic atrophy. Sural nerve biopsy revealed decrease in large myelinated fibers with axonal degeneration and regeneration. Oral administration of alpha-tocopherol acetate, 600 mg per day, diminished ataxia significantly. Based on lysosomal enzyme activity in leukocytes, clinical and laboratory examination, lipidosis or spinocerebellar degeneration was excluded. Chronic lipid malabsorption or beta lipoprotein deficiency which can cause decrease in vitamin E absorption, was not recognized. On oral loading with 2 g of alpha-tocopherol acetate, the decrease rate of serum vitamin E was normal. Consequently the low vitamin E was considered to have resulted from selective impairment of vitamin E absorption.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Familial idiopathic vitamin E deficiency associated with cerebellar atrophy]. 226 7

Pigs were treated with N2O which is known to impair vitamin B12 function in vivo. Such pigs demonstrated an inability to gain weight, progressive ataxia, and spinal neuropathy. The ataxia was totally and the neuropathy partially preventable by dietary methionine supplementation. Methionine synthase activity was inhibited in both the liver and brain. There was a marked elevation of S-adenosylhomocysteine in the neural tissues and a concomitant failure of S-adenosylmethionine to rise and thus maintain the methylation ratio, except when supplementary dietary methionine was added. In contrast, the methylation ratio in the rat was affected to a lesser extent. The neuropathy, it is suggested, is caused by raised S-adenosylhomocysteine levels in neural tissue; as a result, the methylation ratio is inverted and S-adenosylmethionine-dependent methylation reactions are inhibited.
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PMID:Methylation deficiency causes vitamin B12-associated neuropathy in the pig. 318 71

Dementia--a syndrome of acquired intellectual deterioration--is an etiologically non-specific condition which is permanent, progressive, or reversible. In the evaluation of demented patients, a careful exposure history will determine the possible role of drugs, metals, or toxins. The physical examination may reveal focal deficits in cases of intracranial mass lesions and spasticity or ataxia of the lower limbs if hydrocephalus is present. Coexistance of dementia and peripheral neuropathy usually indicates a toxic or metabolic disorder. Asterixis, myoclonus, and postural tremor are common in toxic-metabolic dementias, while resting tremor, choreoathetosis, and rigidity occur in progressive extrapyramidal disorders. EEG is focally abnormal in cases of cerebral mass lesions and exhibits generalized slowing in toxic-metabolic encephalopathies. CT will aid in the identification of hydrocephalus, subdural hematomas, and intracranial mass lesions. A thorough laboratory evaluation including complete blood count, erythrocyte sedimentation rate, electrolytes, blood urea nitrogen and blood sugar, liver and thyroid tests, calcium and phosphorus levels, B12 and folate levels, serum copper and ceruloplasmin, VDRL, chest X-ray, electrocardiogram, and lumbar puncture may demonstrate treatable disorders that are adversely affecting intellectual function. Elderly individuals are particularly susceptible to the effects of toxic or metabolic disorders, and a mild dementia might be exaggerated by relatively minor fluctuations in metabolic status. Treatable causes of dementia should be considered in all demented patients.
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PMID:[Treatable dementia syndromes]. 358 48

After four months of excessive nitrous oxide (N2O) exposure, a dentist had myeloneuropathy with spastic paraparesis, Lhermitte's sign, sensory shading, loss of position and vibration sense, ataxia, and impotence. Macrocytosis, hypersegmented neutrophils, and a reduced vitamin B12 level were associated with normal findings on gastric analysis and Schilling test. Complete hematologic and neurologic recovery followed N2O avoidance and vitamin therapy for six months.
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PMID:Myeloneuropathy and macrocytosis associated with nitrous oxide abuse. 630 15

Dementia, a syndrome of acquired intellectual deterioration, is an etiologically nonspecific condition that can be permanent or reversible. When evaluating demented patients, a careful exposure history will determine the possible role of drugs, metals, or toxins. Physical examination may reveal focal deficits in cases of intracranial mass lesions and spasticity or ataxia of the lower limbs if hydrocephalus is present. Coexistence of dementia and a peripheral neuropathy usually indicates the existence of a toxic or metabolic disorder. Depressed mood, sleep disturbance, anorexia, impotence, constipation, and psychomotor retardation indicate the presence of a depressive syndrome. Asterixis, myoclonus, and postural tremor are common in toxic-metabolic dementias, whereas resting tremor, choreoathetosis, or rigidity occur in progressive extrapyramidal disorder. EEG is focally abnormal in cases of cerebral mass lesions and shows generalized slowing in toxic-metabolic encephalopathies. CT will aid in the identification of hydrocephalus, subdural hematomas, and intracranial mass lesions. A thorough laboratory evaluation including complete blood count, erythrocyte sedimentation rate, electrolytes, blood urea nitrogen and blood sugar, liver and thyroid function tests, serum calcium and phosphorus levels, B12 and folate levels, serum copper and ceruloplasmin, VDRL, chest X-ray, electrocardiogram, and lumbar puncture may demonstrate treatable disorders that are adversely affecting intellectual function. Elderly individuals are particularly susceptible to the effects of toxic or metabolic disorders, and a mild dementia may be exaggerated by relatively minor fluctuations in metabolic status. Treatable causes of dementia should be sought in all demented patients.
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PMID:Treatable dementias. 635 58


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