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Query: UMLS:C0008489 (chorea)
 2,102 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cerebellar hypoplasia is common to a variety of congenital disorders. Both stable conditions and progressive (degenerative) disorders may cause cerebellar hypoplasia. Pontocerebellar hypoplasia (PCH) is distinct from cerebellar hypoplasias in general, because the ventral pons is affected. Reviewing both clinical and neuropathological evidence, two specific neurogenetic entities are delineated. It is proposed to call these, respectively, type 1 (PCH-1) and type 2 (PCH-2). In type 1 the hallmark is the presence of spinal anterior horn degeneration similar to Werdnig-Hoffmann disease. Presentation in the neonatal period is characterized by respiratory insufficiency, frequent congenital contractures, and a combination of central and peripheral motor signs. Patients die early, usually before 1 year of age. In type 2 the hallmark is the presence of chorea/dystonia, which is often severe, while spinal anterior horn pathology is absent. Patients have microcephaly and severely impaired mental and motor development. They frequently die during childhood. Neuronal degeneration in both types of PCH is non-specific. Reactive changes in the degenerated parts appear more extensive in type 1. Examples of both types are given. Differentiation of the two types appears straightforward and possible by clinical means. Carbohydrate-deficient glycoprotein syndrome, one other cause of (ponto)cerebellar hypoplasia, should be excluded in all cases of PCH by appropriate means.
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PMID:Pontocerebellar hypoplasias. An overview of a group of inherited neurodegenerative disorders with fetal onset. 814 99

We report a homozygous case of spinocerebellar ataxia type 17 with 48 glutamines. The age of the patient at disease onset was not lower than those of heterozygotes with the same CAG-repeat sizes, but the clinical manifestations were rapidly progressive dementia and chorea. Neuronal loss was relatively restricted and most prominent in the Purkinje cell layer and striatum; however, intranuclear neuronal polyglutamine accumulation was widespread, with a high frequency in the cerebral cortex and striatum.
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PMID:SCA17 homozygote showing Huntington's disease-like phenotype. 1523 16

Chorea is a basal-ganglia (BG) related hyperkinetic movement disorder characterized by irregular continuous involuntary movements. Chorea and related hyperbehavioral disorders may be induced in behaving primates by local microinjections of the GABA(A) antagonist bicuculline to the globus pallidus externus (GPe). We performed multielectrode extracellular recordings in the GPe and in the globus pallidus internus (GPi) before, during, and after bicuculline microinjections. Bicuculline led to an increase in the firing rate and a change in the firing pattern of GPe neurons. Two types of abnormal neuronal firing patterns were detected in GPe neurons close to the bicuculline microinjection site: continuous high-frequency activity and bistable activity, in which neurons transitioned between high-frequency and complete cessation of firing. Neuronal activity remained uncorrelated within and between the GPe and the GPi, with no evidence for propagation of the focal GPe abnormal activity downstream to the GPi. Despite reduction in the information capacity of bicuculline-affected GPe neurons, the ability to encode behavioral events was maintained. We found similar responses of GPe neurons to bicuculline in vitro in the rat, suggesting a basic cellular mechanism underlying these abnormal firing patterns. These results demonstrate that chorea is associated with focal neuronal changes that are not complemented by global changes in the BG nuclei. This suggests a mechanism of stochastic phasic alteration of BG control leading to the chaotic nature of chorea. Thus rather than imposing a globalized state of cortical excitability, chorea might be associated with changes in internal information processing within the BG.
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PMID:Bicuculline-induced chorea manifests in focal rather than globalized abnormalities in the activation of the external and internal globus pallidus. 2059 18