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

Acrylamide, widely employed as a vinyl monomer in the polymer industry, is a potent neurotoxin to man and to animals. The cumulative effect of prolonged, low-level exposure to acrylamide monomer is the insidious development of a progressive peripheral neuropathy. Sensory symptoms begin in the hands and feet (numbness, pins and needles), certain reflexes are lost and, with severe exposure, muscle weakness and atrophy occur in the extremities. The peripheral neuropathy may be supplemented by symptoms indicative of central nervous system damage (ataxia, tremor, somnolence and mental changes). The neuropathologic basis for this clinical picture has been determined in cats. Here, chronic acrylamide intoxication produces selective peripheral and central nerve fiber degeneration. Degeneration first occurs in the extremities of long and large nerve fibers which later undergo a progressive, seriate proximal axonal degeneration known as dying-back. Especially vulnerable are sensory axons supplying Pacinian corpuscles and muscle spindles in the hindfoot toepads, while adjacent motor nerve axons die back later. Distal central nerve fiber degeneration is seen in the medulla and the cerebellum. The neurotoxic property of acrylamide is of practical concern in two areas. One major problem is the protection of factory workers engaged in the manufacture of acrylamide. A sensitive test of neurologic function in these individuals, i.e., touch sensation, based on the experimental observation of the exquisite vulnerability of Pacinian corpuscles in acrylamide intoxicated cats, is presently under consideration. The second area for concern is the exposure of the populace to minute amounts of neurotoxic acrylamide monomer which contaminate acrylamide polymers currently deployed in the environment. Federal restrictions on the maximum permitted exposure to acrylamide, based on a largely clinical study of acrylamide neurotoxicity conducted ten years ago, may require a re-evaluation in the light of recent advances which have pinpointed the initial sites of nerve fiber degeneration.
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PMID:Nervous system degeneration produced by acrylamide monomer. 17 76

Eosinophils contain a substance that is neurotoxic when injected intracerebrally or intrathecally into laboratory animals-an effect known as the "Gordon phenomenon." We found neurotoxic activity in eosinophils from three patients with eosinophilic syndromes by injecting cell preparations into rabbits and guinea pigs. These animals developed a syndrome of muscular rigidity and ataxia, progressing to severe paralysis. No neurotoxic activity was found in preparations of polymorphonuclear or mononuclear leukocytes from normal donors. Examination of the brains of affected animals confirmed widespread loss of Purkinje cells, as described by earlier investigators. A new finding was severe spongy change occurring in the white matter of the cerebellum, brainstem, and spinal cord. Electron microscopic examination showed that vacuoles formed within the myelin sheaths of axons by separation of lamellae. Associated axonal degeneration was common and was also seen occasionally in peripheral nerves. Gray matter in the cerebral hemispheres and spinal cord was normal. This eosinophil-derived neurotoxin was partially purified by ultracentrifugation of sonicated eosinophils and fractionation of the supernate by gel filtration. Fractions with neurotoxic activity eluted at a position consistent with a molecular weight of approximately 15,000. The neurotoxic activity of this material withstood lyophilization and dialysis but was destroyed by heating to 90 degrees C. Injection of eosinophil-derived neurotoxin into laboratory animals may provide a useful short-term experimental model for study of mechanisms of damage to myelinated nerve fibers. The clinical significance of the Gordon phenomenon has yet to be established.
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PMID:Neurotoxicity of human eosinophils. 28 29

Two female patients aged 30 and 40 years with the Charlevoix-Saguenay ataxia were studied. Both had absent sensory action potentials in upper and lower extremities but, unlike typical cases of Friedreich's ataxia, they displayed a marked slowing of motor conduction velocities. Sural nerve biopsies taken from calf and ankle revealed a severe loss of large myelinated axons contrasting with a normal myelinated fiber density. Evidence for active axonal degeneration was scarce, with no indication of axonal regeneration. Teased myelinated fibers revealed an increased variability of internodal length but no evidence for myelin breakdown. These findings support, as a primary defect, a developmental abnormality of peripheral nerve, namely a lack of maturation of large myelinated axons and possibly a faulty myelination of nerve fibers. We think it is unlikely to represent a progressive axonal atrophic or dystrophic process, as suggested in Friedreich's ataxia.
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PMID:The neuropathy of Charlevoix-Saguenay ataxia: an electrophysiological and pathological study. 48 11

During the course of investigating a 10-year-old boy because of progressive deterioration of intellectual functioning, ataxia, and hemiplegia, an absence of serum hexosaminidase activity was noted. A skin biopsy examined by electron microscopy showed axonal accumulations of dense osmiophilic deposits. Because of the patient's age at onset and the slowly progressive nature of his ilness, we are reporting an atypical juvenile case of Sandhoff disease.
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PMID:Progressive cerebellar ataxia, spasticity, psychomotor retardation, and hexosaminidase deficiency in a 10-year-old child: juvenile Sandhoff disease. 55 67

The paper describes the clinical and morphological features of a congenital neurological disease affecting two in-bred litter-mate kittens. The principal neurological features were ataxia and dysmetria. In one of the kittens light microscopy revealed widespread vacuolation of white and grey matter of the brain and spinal cord. Electron microscopy revealved intra-myelinic vacuolation and some expansion of the extracellular space. Neuronal, axonal and glial changes were not seen, nor was there evidence of myelin breakdown. The entity is compared with congenital brain oedema of calves and spongy degeneration of the CNS in man.
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PMID:Spongy degeneration of the central nervous system in kittens. 93 80

We describe the histomorphometric changes in the superficial peroneal nerve biopsy from 13 patients with xeroderma pigmentosum (XP). The mean age at time of biopsy was 15 yr (range 2.5-24 yr). The clinical examination was normal in the two youngest patients and showed absence of the deep tendon reflexes, with choreo-athetosis in ten patients. In addition, in the three oldest patients there were cerebellar signs, ataxia and Babinski signs. The nerve biopsy showed an age-dependent decrease of myelinated fibres, which was mild in the youngest and severe in the oldest patients. This was associated with rare acute axonal degeneration, sparse axonal regeneration, rare axonal atrophy and few onion bulb formations. These findings suggest a neuropathic process. This neuronal degeneration seems to be a progressive and stereotyped phenomenon in XP.
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PMID:Age-dependent axonal loss in nerve biopsy of patients with xeroderma pigmentosum. 130 Jan 84

The serine/cysteine hydrolase inhibitor phenylmethylsulfonyl fluoride (PMSF) markedly intensifies the clinical expression of organophosphorus-induced delayed neurotoxicity (OPIDN) in adult chickens when administered after organophosphate exposure. In this study, we have examined the ability of PMSF post-treatment to affect sensitivity to OPIDN in developing animals at ages normally showing resistance. Chickens (35, 49 or 70 days of age) were treated with diisopropylphosphorofluoridate (DFP, 2 mg/kg, sc) and then treated four hours later with PMSF (90 mg/kg, sc) or vehicle only and examined for clinical signs of ataxia and incoordination. Chickens treated with DFP alone showed a marked age-related increase in the severity of motor deficits. Birds treated with DFP followed by PMSF showed more extensive clinical deficits relative to those treated with DFP only, but relatively similar degrees of motor dysfunction among the age groups. Cervical spinal cord samples processed by the Fink-Heimer degeneration method indicated that PMSF post-treatment induced more extensive axonal degeneration in all age groups relative to treatment with DFP only. As the DFP treatment alone caused greater than or equal to 90% inhibition of neurotoxic esterase activity (NTE, the putative molecular target site for OPIDN), interaction with NTE by PMSF does not appear to be involved in potentiation. We hypothesize that PMSF potentiates OPIDN through impairment of a physiological process which normally imparts resistance to young animals and which regresses during development.
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PMID:Phenylmethylsulfonyl fluoride alters sensitivity to organophosphorus-induced delayed neurotoxicity in developing animals. 143 55

We investigated motor function and pain sensation in the gracile axonal dystrophy (GAD) mutant mouse, using the tail-flick test and the rotarod test. GAD (gad/gad) and normal sib mice (gad/+ or +/+) were used between 5 and 11 weeks of age, during which time the behavioral signs of GAD mice shifted from sensory ataxia (about 4 to 8 weeks of age) to paresis (after about 9 weeks of age). In the tail-flick test, significant shortening of latency was observed at 6 and 8 weeks of age in female GAD mice, in comparison with normal female mice. This may be related to dysfunction or degeneration of axons in the fasiculus gracilis, whose collaterals are thought to control the transmission of nociceptive information. In the rotarod test, a cumulative chi 2 test showed significant reduction in the performance times of GAD mice beginning at 5 and 6 weeks of age in males and females, respectively, indicating that the rotarod test can detect the development of motor incoordination as early as these ages. The performance times of GAD mice dropped sharply from 9 weeks of age onwards, and this is believed to reflect the progression of paresis. The rotarod test therefore appears to be a good method of quantifying behavioral changes in GAD mice and to be applicable both to objective selection of GAD mice before 8 weeks of age and to evaluation of drugs to treat ataxia or paresis.
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PMID:Behavioral study on the gracile axonal dystrophy (GAD) mutant mouse. 145 62

We report on a 5 1/2 year-old boy with chronic progressive polyneuropathy, ataxia, and pyramidal signs. His hair was not curled. Sural nerve biopsy disclosed many axons enlarged by accumulation of 10-nm neurofilaments and a marked variability in the number of myelinated fibers as well as in the amount of axonal enlargements among different fascicles. These findings and the electrophysiological data were consistent with a giant axonal polyneuropathy with a multifocal fiber loss.
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PMID:Giant axonal neuropathy: report on a case with focal fiber loss. 162 11


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