Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat pups were injected intracisternally (i.c.) or intraperitoneally (i.p.) with 5,7-dihydroxytryptamine (5,7-DHT) or saline and challenged 2 and 14 weeks later with the 5-HT precursor 5-hydroxytryptophan (5-HTP), which evokes behavioral supersensitivity in adult rats, 5,7-DHT induced transient postinjection convulsions in rats injected i.c. but not i.p. Rats with either type of 5,7-DHT lesions displayed supersensitive behavioral responses to 5-HTP. However, rats lesioned by i.p. injections exhibited significantly greater shaking behavior (+1445%) in response to 5-HTP than their i.c. counterparts, who instead showed more forepaw myoclonus (+250%) and head weaving (+270%), the core features of the 5-HT syndrome. Differences in 5-HT syndrome behaviors were already present 2 weeks after lesioning, whereas the difference in shaking behavior was not. After 14 weeks, 5-HT was selectively depleted (-43 to -92%) in hippocampus, spinal cord, and frontal cortex, and differences between i.c. and i.p. 5,7-DHT routes were insignificant except in frontal cortex. Brainstem 5-HT concentrations were significantly increased (+35%) after i.p. 5,7-DHT injections in contrast to reduction (-89%) after i.c. 5,7-DHT; 5-hydroxyindole acetic acid/5-hydroxytryptamine (5-HIAA/5-HT) ratios were decreased (-20%) with either route. These data suggest that brainstem 5-HT hyperinnervation following i.p. 5,7-DHT injection modifies the functional consequences of injury in abating the 5-HT syndrome, but does not result in complete recovery since shaking behavior is enhanced. Loss of presynaptically mediated autoregulation or receptor dysregulation may play a major role in behavioral supersensitivity induced by 5-HTP in rats with 5,7-DHT lesions. To the extent that the 5-HT syndrome is mediated by 5-HT1A receptors and shaking behavior by 5-HT2 sites, differential responses to injury of 5-HT1A and 5-HT2 receptors may contribute to these behavioral differences.
 ...
PMID:Brainstem serotonergic hyperinnervation modifies behavioral supersensitivity to 5-hydroxytryptophan in the rat. 258 10

REM sleep is the most antiepileptic state in the sleep-wake cycle for human generalized epilepsy, yet the neural mechanism is unknown. This study verified the antiepileptic properties of REM sleep in feline generalized epilepsy and also isolated the responsible factors. Conclusions are based on 20 cats evaluated for generalized EEG and motor seizure susceptibility before and after dissociation of specific REM sleep components. Bilateral electrolytic lesions of the medial-lateral pontine tegmentum created a syndrome of REM sleep without atonia. Systemic atropine created a syndrome of REM sleep without thalamocortical EEG desynchronization. Identical results were obtained in two seizure models, systemic penicillin epilepsy and electroconvulsive shock. (1) Normal REM sleep retarded the spread of EEG seizure discharges and had even more potent anticonvulsant effects. (2) Selective loss of 'sleep paralysis' (skeletal muscle atonia) during REM abolished REM sleep protection against myoclonus and convulsions without affecting generalized EEG paroxysms. (3) Conversely, selective loss of thalamocortical EEG desychronization abolished REM sleep protection against generalized EEG seizures without affecting clinical motor accompaniment. These results suggest that the descending brainstem pathways which mediate lower motor neuron inhibition also protect against generalized motor seizures during REM sleep. Protection against spread of EEG paroxysms is governed by a separate mechanism, presumably the ascending brainstem pathways mediating intense thalamocortical EEG desynchronization during REM sleep.
 ...
PMID:Mechanisms of seizure suppression during rapid-eye-movement (REM) sleep in cats. 259 45

A 44-year-old man suffered from repeated impairment of consciousness associated with flapping tremor, myoclonus and generalized convulsions, and died in coma 6 months after admission. He had had a psychosomatically underdeveloped childhood, with a propensity for legumes without a family history of the same or a record of consanguinity. On admission, he had disturbed consciousness and emaciation without other physical abnormalities. The EEG revealed diffuse slow waves with occasional appearance of triphasic waves. A high level of serum citrulline (534.7 nmol/ml) was recognized and the assay of urea cycle enzymes in the liver demonstrated decreased argininosuccinate synthetase (ASS) activity (0.062 U/g liver, 7.4% of that in normal liver), although no kinetic abnormality was found. Accordingly he was diagnosed as having type II citrullinemia. In addition, this case could be classified as cluster type of localization of the ASS in the liver by immunohistochemical study. There were characteristic findings concerning his clinical picture and laboratory data, such as a significant correlation between the grade of disturbed consciousness and arterial blood gas pH (r = 0.61, p less than 0.01). However, the blood ammonia level did not always correlate with the severity of disturbed consciousness. Oral treatment with sodium citrate and sodium benzoate was very effective, though transiently, for disturbed consciousness in this case. Pathological findings of the autopsied liver were fatty change and fibrosis. Neuropathologically, characteristic findings were brain edema with cerebellar tonsilar herniation, laminar necrosis with spongy formation in cerebral cortex, and Alzheimer type II glia. The relationship between citrullinemia and other hepatic encephalopathy was also discussed.
 ...
PMID:[An autopsied case of type II citrullinemia--transient effectiveness with either citrate or benzoate to the consciousness disturbance]. 269 30

A case of familial juvenile Alzheimer's disease with apallic state at the relatively early stage and various neurological features was reported. A 33-year-old woman showed a progressive dementia followed by apallic state at the relatively early stage, and died of cardiac failure at the age of 45. Neurological examination disclosed chorea, myoclonus, rigidity, pyramidal sign, and generalized convulsion. Neuropathologically, extensive senile changes such as senile plaques, neurofibrillary tangles, and granurovascular degenerations were observed in the brain, chiefly in the cerebral cortex and limbic system. The present case was characterized by a severe neuronal loss in the subcortical gray matter such as the caudate nucleus, dentate nucleus, substantia nigra, and thalamus as well as a marked myelin loss and axonal damages in the cerebral white matter. This case suggested a combination of multisystemic degeneration and a primary degeneration of the cerebral white matter. The additional peculiar aspects in this case were the senile plaques and amyloid angiopathy in the cerebellar cortex, and the senile plaques and grumose degeneration in the cerebellar dentate nucleus. In the clinicopathological standpoint, the apallic state in this case could be attributed to a severe degeneration of the cerebral white matter in addition to the cerebral cortical deterioration. Furthermore, the occurrence of chorea and myclonus might be contributed to the severe degeneration of the caudate nucleus and to the degeneration of the dentate nucleus, particularly to the grumose degeneration, respectively.
 ...
PMID:[A case of familial juvenile Alzheimer's disease with apallic state at the relatively early stage and various neurological features--a clinicopathological study]. 279 15

A case of an infant suffering from progressive lethargy, sparse scalp hair, autistic-like behavior, myoclonias, and drug-resistant generalized seizures is reported. Laboratory investigations revealed, in the absence of metabolic acidosis, an increased urinary excretion of 2-ketoglutaric acid and a small peak of 3-hydroxyisovaleric acid. The serum biotinidase activity was 0.15 nmol min-1 ml-1 (normal range 5.2 +/- 0.9) in the propositus and 0.310 and 0.420 in her father and mother, respectively. The interictal EEG showed multifocal abnormalities; numerous seizures were recorded, with the pattern of true tonic-clonic fits, exceptional in infancy. Also myoclonias, auditory myoclonus, and repetitive startles were documented. Because of dramatic improvement of all symptoms and signs after starting biotin (5 mg twice daily), the authors suggest a therapeutical trial in all drug-resistant infantile seizures.
 ...
PMID:Biotin-responsive infantile encephalopathy: EEG-polygraphic study of a case. 279 32

An autopsy case of familial juvenile Alzheimer's disease with extensive involvement of the subcortical gray and white matters is reported. A 33-year-old woman showed a progressive dementia and died of cardiac failure at the age of 45. Neurological examination disclosed choreatic movements, myoclonus, rigidity, and generalized convulsion. Gross inspection of the brain showed a diffuse cerebral atrophy and marked degenerations of both the subcortical gray and white matters. Microscopically, numerous and extensive argyrophilic changes such as senile plaques, neurofibrillary tangles, and granulovacuolar degenerations were observed in the brain. The present case was characterized by a severe neuronal loss in the basal ganglia, substantia nigra, dentate nucleus, and thalamus as well as a marked myelin loss and axonal damage in the cerebral white matter. This case suggested a combination of multisystemic degeneration and primary degeneration of the cerebral white matter. The pathological similarity of this case to Creutzfeldt-Jakob disease and Pick's disease is discussed.
 ...
PMID:An autopsy case of familial juvenile Alzheimer's disease with extensive involvement of the subcortical gray and white matters. 292 95

The effects of some biologically active metabolites of tryptophan on the high pressure neurological syndrome (HPNS) were studied. Kynurenic acid, quinolinic acid, 5-hydroxytryptophan, kynurenine and 3-hydroxyanthranilic acid, at doses within the physiological range, were administered exogenously to rats prior to exposure to increased pressure and any effects on the tremor, myoclonus and convulsion end points of the high pressure neurological syndrome were observed. Quinolinic acid (25 and 50 mg/kg) and kynurenine (50 mg/kg) reduced the onset pressure for tremor, but not myoclonus or convulsions. Kynurenic acid (100 mg/kg) increased tremor onset pressure; 5-hydroxytryptophan (20 mg/kg) slightly increased onset pressure for tremor but decreased that for myoclonus. 3-Hydroxyanthranilic acid (20 mg/kg) had no significant effect on any of the motor signs of the syndrome. These data provide further support for the idea that the motor events seen in the high pressure neurological syndrome are not produced by a single mechanism. Differences between the responses to related metabolites suggest that the precise balance between compounds such as kynurenic acid and quinolinic acid may be important in the appearance of the high pressure neurological syndrome.
 ...
PMID:The effects of kynurenic acid, quinolinic acid and other metabolites of tryptophan on the development of the high pressure neurological syndrome in the rat. 292 79

An autopsy case of a 66 year-old woman is reported. She developed personality change and psychotic symptoms at the age of 58. She began to show gait disturbance and forgetfullness at the age of 60. She was admitted to Okayama University Hospital at the age of 61, when she showed personality change, dementia, cerebellar sings and chorea like involuntary movement. The illness progressed slowly and she died of septicemia at the age of 66. At autopsy brain weighed 990 g. Macroscopically, the atrophy of the brain stem was severe, and the cerebellum was slightly atrophic. Microscopically, the globus pallidus was almost intact, but the degeneration involved dentate nuclei, their projections, red nucleus and the subthalamic nuclei, so this case was considered to be a case of pseudo-Huntington form of dentatorubropallidoluysian atrophy, proposed by Hirayama. The most striking feature of this case was marked atrophy of the brain stem and her intense familial history. Investigation of her familial history revealed that there were 18 affected cases in 5 successive generations. Their onset of the disease varied from the age of 10 to 60 years old. Cases of juvenile onset showed myoclonus and convulsion as the initial symptoms, and convulsion as the initial symptoms, and those of presenile onset showed dementia, cerebellar ataxia and chorea like involuntary movement. And in some of these cases it was proved by NMR-CT that their brain stem were small. We discussed the meaning of the atrophy of the brain stem in these cases and the difference of the symptoms between the cases of juvenile onset and the cases of presenile onset.
 ...
PMID:[An autopsy case of dentatorubropallidoluysian atrophy showing marked atrophy of the brain stem]. 296 93

Sodium valproate, nipecotic acid, diaminobutyric acid (DABA) and beta-alanine are drugs which enhance transmission mediated by gamma-aminobutyric acid (GABA) by a variety of mechanisms. They were used to study the role of GABA in the high pressure neurological syndrome (HPNS) in the rat. Sodium valproate, nipecotic acid and DABA reduced the increase in slow waves seen in the electroencephalogram (EEG) of control rats at pressures above 10-20 ATA; however, only sodium valproate had a beneficial effect on the behavioural signs of the high pressure neurological syndrome (tremor, myoclonus and convulsions). Sodium valproate is also thought to decrease neurotransmission produced by excitatory amino acids; thus, these results suggest that GABA is not one of the major neurotransmitters involved in all aspects of the high pressure neurological syndrome and that changes in excitatory neurotransmission may affect the behavioural signs.
 ...
PMID:Gamma-aminobutyric acid and the high pressure neurological syndrome. 309 Apr 69

An epidemic of bismuth (Bi)-related neurotoxicity in France remains poorly understood, partly because no satisfactory animal model exists. We have now characterized such a model. Single or multiple intraperitoneal injections of Bi subnitrate into female mice produced neurologic signs (myoclonus, ataxia, tremors, convulsions) and blood (1.2 micrograms/g) and brain (8.4 micrograms/g) Bi levels like those in human cases. Hydrocephalus and axonal swellings in spinal cord were the major neuropathologic lesions.
 ...
PMID:Characterization of a murine model for human bismuth encephalopathy. 324 42


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>