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

In contrast to juvenile rigid form of Huntington's disease (HD) in which myoclonus is often seen, only 5 patients with myoclonus complicating adult HD have been reported. We herein described an adult HD patient who suffered from severe action myoclonus leading to physical disability. To our knowledge, this is the first case report in Japan. The patient, a 32-year-old female with a family history of chorea, developed choreiform movements and mental changes since the age of 24. Subsequently her motor disability has been aggravated by distinctively different involuntary movements characterized by sudden, violent, continuous muscular contractions of four extremities on any attempts at movement. Examination revealed moderate dementia and chorea complicated by frequent myoclonic jerks involving upper and lower extremities in posture or during movement. A head CT scan and MRI revealed caudate atrophy. The myoclonus, as recorded by surface electromyography over the right arm consisted of 40-60 msec-synchronous semirhythmic bursts. The cortical component of SEP was enlarged and C reflex was also observed. Clonazepam (4 mg a day) was instituted with a pronounced reduction in myoclonus and a return to her previous level of daily life activity. Although myoclonic jerks are often recognized in juvenile patients with rigid form of HD, they have been considered to exert a minor influence on physical disability. By contrast, our present observation and review of literature suggest that myoclonus may lead to severe motor impairment in adult HD.
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PMID:[Action myoclonus in adult Huntington's disease]. 129 Nov 67

Myoclonus, defined as shock-like involuntary movement, may be physiological or caused by a very wide variety of hereditary and acquired conditions. Because myoclonus can originate from different disorders and lesions affecting quite varied levels of the central and peripheral nervous systems, it represents from many points of view a diagnostic challenge. Moreover, new entities have been recently individualized, such as cortical tremor, which deserve renewed attention. The aim of this review is to propose a rationale for a diagnostic approach based on clinical and electrophysiological grounds. In this setting, we successively address 1) the clinical features allowing a positive diagnosis of myoclonus; 2) the clinical clues to the etiology; 3) the relevance of the clinical context to the diagnosis; and 4) the contribution of neurophysiology. Differentiating myoclonus from tics, spasm, chorea and dystonia can be difficult, and a careful reappraisal of clinical features allowing precise identification is presented. Moreover, the topographical distribution of myoclonus, the temporal pattern of muscle recruitment, the condition of occurrence and the rhythm of the event, may provide clinical clues relevant to the diagnosis. Myoclonus without associated epilepsy, myoclonus with epilepsy, myoclonus with encephalopathy, parkinsonism and/or dementia represent overlapping clinical categories, although they remain useful for the diagnostic approach. Using electrophysiology (including back-averaging EEG, MEG, SEP, C-reflex studies) to determine the origin of myoclonus may not allow us to focus on the underlying condition. Indeed, in many instances, the myoclonus is cortical in origin, but the pathology is found elsewhere.
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PMID:[Myoclonus in the adult: diagnostic approach]. 1128 Oct 67