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)

The patient was 56-year-old female, who suffered from ataxia and then fell into coma on the next day after she had moved from the sea level to an altitude of 4,200 m. After she was brought to lower altitude, consciousness recovered within several hours. For about 2 days thereafter, disorientation was observed, and she was diagnosed as AMS (acute mountain sickness). Only insomnia continued in chronic stage. The results of X-ray computed tomography (CT) on 25th day after the onset of the disease revealed no abnormal finding except the slightly increasing uptake of contrast material. Symmetrical low density regions were seen in bilateral basal ganglia after one year, and the globus pallidus lesions were confirmed by magnetic resonance imaging. In the past, cerebral edema has been reported in most cases of AMS, and the neurotic symptoms of AMS have been attributed to cerebral edema, while the essential condition of this disease is not yet elucidated. In the present case, the globus pallidus lesions could be identified through the following-up of the central nervous system by X-ray CT and MRI as the first attempt for the case of AMS. There has been no report of globus pallidus lesions in the cases of AMS. Whereas low oxygen partial pressure is the primary cause of AMS, and it is highly probable that the disorders in globus pallidus as reported in the cases of carbon monoxide poisoning, anesthetic accident, etc. are related to the occurrence of AMS.
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PMID:[A case of acute mountain sickness with bilateral lesion of pallidum]. 222 57

With the great progress in the imaging technique of cerebro-cerebellar perfusion and metabolism, it has been revealed that supratentorial cerebrovascular disorders often cause some reduction of contralateral cerebellar blood flow and metabolism. The phenomenon, termed crossed cerebellar diaschisis (CCD), is interpreted to be brought about by transneuronal deactivation of cerebellum via the corticopontocerebellar pathway and usually not to accompanied by limb-incoordination. We have experienced 2 cases presenting ataxia clinically and CCD in positron emission tomography (PET) which are thought to be caused by the interruption of two distinctive neural pathways, the corticopontocerebellar and cerebellorubrothalamic pathways. Case 1 was a 34-year-old housewife with cerebral infarction which magnetic resonance imaging disclosed in the left parietal cortex and subcortical white matter. She showed mild right-sided hemiataxia featured by dysarthria, hypermetria, dysrhythmia, decomposition, dysdiadochokinesis and rebound phenomenon. Cheirooral syndrome, a hand-pronation sign and defects of combined sensation were present on the right but not accompanied by any disturbances of deep sensation. PET with 15O-labeled CO2 and O2 demonstrated the left frontoparietooccipital and contralateral cerebellar hypoperfusion and hypometabolism. Case 2 was a 69-year-old female suffering from aftereffects of old thalamic hemorrhage. Neurological examination revealed moderate degree of right-sided hemiataxia suggesting a cerebellar type of dysfunction like in case 1. Muscle power and sensory system were well-preserved. Brain CT revealed a small and restricted low density area in the left posterolateral thalamus indicating destruction of the Vim nucleus. PET study confirmed reduced blood flow and oxygen metabolism in the left thalamus and contralateral cerebellar hemisphere.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Clinical and etiological study of crossed cerebellar diaschisis. Report of two cases]. 261

"Energy metabolism" is deranged in a wide variety of disorders of the nervous system. This term refers rather loosely to the pathways responsible for the utilization of the major substrates of brain. Primary disorders of energy metabolism are those in which the primary insult affects the cellular machinery required for energy metabolism. A typical example would be a defect in a gene coding for a mitochondrial protein. Biochemically, defects which appear to be hereditary and which lead to disease of the central nervous system have been described in each of the pathways of energy metabolism: glycogenolysis (the break-down of glycogen to glucose); glycolysis (the break down of glucose to pyruvate and lactate); the pyruvate dehydrogenase complex (which oxidizes pyruvate to enter the Krebs tricarboxylic acid cycle); the tricarboxylic acid cycle itself (which completes the oxidation of carbohydrates and other substrates to carbon dioxide); electron transport (which carries out their oxidation to water); the pentose phosphate pathway (an alternate pathway for glucose oxidation); and several "minor" mitochondrial pathways. Clinically, the spectrum of syndromes associated with primary disorders of energy metabolism is wide. Common manifestations include psychomotor retardation, with associated lactic acidosis and/or hypoglycemia. The laboratory abnormalities may be intermittent. Syndromes which have been culled out include congenital lactic acidosis, Leigh disease, intermittent ataxia, Kearns-Sayre-Shy syndrome (KSS), myoclonus epilepsy with ragged red fibers (MERRF), and mitochondrial myopathy-encephalopathy-lactic acidosis-stroke (MELAS). As with other families of inborn errors, both clinical and biochemical heterogeneity occur. Patients with apparently similar clinical syndromes can turn out to have different inborn errors, and patients with abnormalities of the same gene product can have clinically distinguishable syndromes. Secondary disorders are those in which the derangements of energy metabolism are presumably secondary to some other insult but may still be important for the cellular pathophysiology. These include the metabolic encephalopathies and probably a number of well-known neurodegenerative disorders. In the hereditary ataxias, abnormalities of mitochondrial markers are common but do not correlate consistently with the disorders as conventionally classified; a new classification into axonal ataxias, multiple system degenerations, and ataxic encephalopathies may be easier to relate to the pathophysiology.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Energy metabolism in disorders of the nervous system. 297 43

The effects of administration of one of four opiates (pethidine 1 mg/kg bodyweight (bwt), morphine 0.1 mg/kg bwt, methadone 0.1 mg/kg bwt, and butorphanol 0.05 mg/kg bwt) given intravenously to horses and ponies already sedated with detomidine (10 micrograms/kg bwt) were investigated. Behavioural, cardiovascular and respiratory effects of the combinations were compared with those occurring with detomidine alone. Addition of the opiate increased the apparent sedation and decreased the response of the animal to external stimuli. At doses used, butorphanol produced the most reliable response. Side effects seen were increased ataxia (greatest following methadone and butorphanol) and excitement (usually muzzle tremors and muscle twitching). Following pethidine, generalised excitement was sometimes seen. Marked cardiovascular changes occurred in the first few minutes after morphine or pethidine injection, but within 5 mins cardiovascular changes were minimal. Following morphine or pethidine there was a significant increase in arterial carbon dioxide tension. Fourteen clinical cases were successfully sedated using detomidine/butorphanol combinations.
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PMID:Combined use of detomidine with opiates in the horse. 318 Nov 17

Cynomolgus macaque monkeys received head-only exposure to 0, 100, 200, 500, 1000, 2000, 3000, and 4500 ppm toluene for 50 min while simultaneously tested for delayed matching-to-sample behavior, a test of cognitive functions. Response time increased and accuracy of matching decreased at 2000 ppm or more of toluene, indicating an attentional deficit but not specific memory effects. Behavioral indices exhibited monotonic concentration-related changes. Expired carbon dioxide (CO2), the most sensitive index, displayed an inverted U-shaped concentration-effect curve, which increased at 100 ppm (the TLV) and decreased at 4500 ppm toluene. Changes in expired CO2 provide new evidence of physiological changes at very low levels of toluene. These changes may indicate combined behavioral, respiratory, sensory, and metabolic effects. No behavioral measure exhibited either cumulative effects or tolerance to 4500 ppm during two 3-day exposures. However, both response time and expired CO2 exhibited an acute, within-session tolerance. The results indicate that brief inhalation exposure to toluene impairs cognitive and motor abilities at concentrations below those causing overt signs, such as ataxia and intention tremoring.
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PMID:Effects of toluene inhalation on behavior and expired carbon dioxide in macaque monkeys. 392 33

The presentation and treatment of a central hypoventilation syndrome in a boy with pyruvate dehydrogenase complex (PDHC) deficiency are reported. Dephosphorylated PDHC was assayed in disrupted fibroblasts after pretreatment with dichloroacetate, a pyruvate dehydrogenase kinase inhibitor. Maximal specific activity of activated patient PDHC was 10% to 30% of control values. Patient PDHC activity was not increased by alterations in concentrations of pyruvate or cofactors (thiamine pyrophosphate [TPP], coenzyme A [CoA], oxidized form of nicotinamide adenine dinucleotide [NAD+]). Clinically, normalization of plasma lactate by a high-lipid diet did not prevent slowly progressive neurologic decline. The patient manifested intermittent ataxia, episodic profound weakness, moderate psychomotor retardation, ophthalmoplegia, and retinal pigment epithelial changes. A true central hypoventilation syndrome was documented on the basis of rigorous radiologic, electrophysiologic, and pulmonary function criteria. Theophylline, progesterone, and ritalin neither altered ventilatory response to CO2 nor permitted weaning from the ventilator. In contrast, peripheral chemoreceptor stimulants (intravenous doxapram; oral almitrine) effected an acute doubling of minute ventilation with appropriate decreases in PaCO2. However, a positive response to long-term therapy with almitrine could not be unequivocally shown. It was concluded that measurement of disrupted fibroblast PDHC following dichloroacetate activation constitutes an accurate assay for PDHC deficiency. PDHC deficiency must be considered in the differential diagnosis of the central hypoventilation syndrome; this appears to be the first report of such an association. Finally, a therapeutic trial of a peripheral chemoreceptor agonist is warranted in the management of central hypoventilation syndrome.
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PMID:Central hypoventilation syndrome in pyruvate dehydrogenase complex deficiency. 643 1

Subacute necrotizing encephalomyelopathy (Leigh's syndrome) is a rare neurodegenerative disease in the adult. The precise metabolic defect is unknown, but abnormalities of a mitochondrial enzyme system related to cytochrome-c oxidase or pyruvate dehydrogenase are described. The clinical picture usually consists of an altered breathing pattern, oculomotor paralysis, other signs of cranial nerve dysfunction, ataxia, myoclonic jerks, nystagmus, generalized seizures, optic atrophy and demyelinating peripheral neuropathy. Hypopnea leads to CO2-retention with consecutive loss of consciousness demanding mechanical ventilation. Respiratory failure is the most frequent cause of death. Here we describe two patients with adult onset Leigh's syndrome and we discuss the longterm treatment strategies including vitamin B1 and CPAP mask.
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PMID:[Adult Leigh syndrome. A rare differential diagnosis of central respiratory insufficiency]. 771 56

Seven adult mares were used to determine the analgesic, CNS, and cardiopulmonary effects of detomidine hydrochloride solution after epidural or subarachnoid administration, using both regimens in random sequence. At least 1 week elapsed between experiments. A 17-gauge Huber point (Tuohy) directional needle was used to place a catheter with stylet into either the epidural space at the first coccygeal interspace or the subarachnoid space at the lumbosacral intervertebral junction. Catheters were advanced so that the tips lay at the caudal sacral (S5 to S4) epidural space or at the midsacral (S3 to S2) subarachnoid space. Position of the catheter was confirmed radiographically. A 1% solution of detomidine HCl was injected into the epidural catheter at a dosage of 60 micrograms/kg of body weight, and was expanded to a 10-ml volume with sterile water to induce selective caudal epidural analgesia (CEA). A dose of 30 micrograms of detomidine HCl/kg expanded to a 3-ml volume with spinal fluid was injected into the subarachnoid catheter to induce caudal subarachnoid analgesia (CSA). Analgesia was determined by lack of sensory perception to electrical stimulation (avoidance threshold > 40 V, 0.5-ms duration) at the perineal dermatomes and no response to superficial and deep muscular pinprick stimulation at the pelvic limb and lumbar and thoracic dermatomes. Maximal CEA and CSA extended from the coccyx to spinal cord segments T15 and T14 at 10 to 25 minutes after epidural and subarachnoid drug administrations in 2 mares. Analgesia at the perineal area lasted longer after epidural than after subarachnoid administration (142.8 +/- 28.8 minutes vs 127.1 +/- 27.7 minutes). All mares remained standing. Both CEA and CSA induced marked sedation, moderate ataxia, minimal cardiopulmonary depression, increased frequency of second-degree atrioventricular heart block, and renal diuresis. All treatments resulted in significantly (P < 0.05) decreased heart rate, respiratory rate, systemic arterial blood pressure, PCV, and plasma total solids concentration. To the contrary, arterial carbon dioxide tension, plasma bicarbonate, and standard base excess concentrations were significantly (P < 0.05) increased. Arterial oxygen tension, pH, and rectal temperature did not change significantly from baseline values. Results indicate that use of detomidine for CEA and CSA in mares probably induces local spinal and CNS effects, marked sedation, moderate ataxia, mild cardiopulmonary depression, and renal diuresis.
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PMID:Caudal analgesia induced by epidural or subarachnoid administration of detomidine hydrochloride solution in mares. 806 16

Vertigo related to acidosis in Meniere's disease has been reported. This study was undertaken to ascertain whether acidosis has any effect on vertigo. Since patients with Meniere's disease usually show unilateral vestibular dysfunction, unilateral intratympanic injection of streptomycin sulfate (SM) was used to induce unilateral vestibular dysfunction in rabbits. Intratympanic SM injections induced vestibular destruction and elicited severe spontaneous nystagmus and ataxia. Then symptoms of acute vestibular upset gradually subsided and eventually disappeared completely. Three weeks after SM injections, in compensated rabbits, NH4Cl injection or CO2 inhalation was used to induce acidosis. Intravenous NH4Cl injection or CO2 inhalation induced nystagmus and ataxia again. In normal rabbits, no nystagmus was induced by NH4Cl injection or by CO2 inhalation. These results suggest that acidosis might be a cause of recurrence of vertigo in patients with unilateral vestibular dysfunction.
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PMID:Effect of experimental acidosis on nystagmus in rabbits. 820 92

Methyl tertiary-butyl ether (MTBE) is an oxygenate that is added to gasoline to boost octane and enhance combustion, thereby reducing carbon monoxide and hydrocarbon tailpipe emissions. The acute and subchronic neurotoxicity of MTBE were evaluated in rats using a functional observation battery (FOB), measures of motor activity (MA) and a neuropathological evaluation. In the acute study, rats were exposed once to 0, 800, 4000 or 8000 ppm MTBE by inhalation for 6 h and then evaluated three times over a 24-h period. In the FOB evaluations, treatment-related effects were seen at the 1-h session immediately following exposure and were indicative of transient central nervous system (CNS) depression. Effects were most apparent in the high-dose group (8000 ppm) but were also evident to a lesser extent in the mid-dose (4000 ppm) group. Labored respiration, ataxia, duck-walk gait and decreases in muscle tone, hind-limb grip strength and treadmill performance were the most frequently noted findings. No significant effects were observed in the FOB when testing was conducted at 6 h and 24 h post-exposure. The pattern of motor activity measured in the different dose groups following exposure was also in keeping with a reversible CNS-depressant effect of MTBE. In the subchronic study, rats were exposed to 0, 800, 4000 or 8000 ppm MTBE for 6 h a day, 5 days per week, for 13 weeks. No persistent or cumulative effects on neurobehavioral function were found. Body weights and absolute brain weights were reduced in the 8000 ppm group, however there were no differences among groups when brain weight was expressed relative to body weight. No histopathological changes were noted in the brains or peripheral nervous tissues of MTBE-exposed animals. In summary, MTBE produced signs of acute reversible CNS depression following exposure to 8000 ppm and, to a lesser extent, to 4000 ppm vapor. The no-observed-adverse-effect level for these effects was 800 ppm in the present study. No persistent or cumulative neurotoxic effects were observed following exposure to MTBE at concentrations up to 8000 ppm for 13 weeks.
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PMID:Neurotoxicological evaluation of methyl tertiary-butyl ether in rats. 917 28


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