Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0751354 (Action myoclonus)
 18 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Action myoclonus secondary to posthypoxic encephalopathy is being seen increasingly with improved resuscitation techniques. A case report describes 5 specific physical and occupational therapeutic techniques for achieving independence in ambulation, transfers and self-care: (1) analysis and segmentation of complex motions into small steps; (2) controlled progression of training; (3) voluntary cessation of abnormal activity (pacing); (4) progressive densensitization to external stimuli; and (5) quantification of progress. Literature review suggests that posthypoxic action myoclonus is secondary to a loss of inhibitory synapses in the brainstem reticular formation due to low serotonin levels. The proposed therapeutic effect of clonazepam, the drug used in this patient, is decreased serotinin degredation. L-5-hydroxytryptamine, an investigative drug, is also therapeutic, for it stimulates increased serotonin production.
 ...
PMID:Action myoclonus following acute cerebral anoxia. 42 May 69

Action myoclonus, reviewed in this chapter, is the term applied to arrhythmic muscular jerking induced by voluntary movement. It is made worse by attempts at precise or coordinated movement (intention myoclonus) and may also be provoked by certain sensory stimuli. The effective stimuli for action myoclonus is probably feedback from muscle afferents, although it may be initiated by corollary discharge from motor cortex to reticular formation before or at the onset of voluntary movement. The condition is usually associated with diffuse neuronal disease such as post-hypoxic encephalopathy, uremia, and the various forms of PME, although action myoclonus may be limited to one limb in some cases of focal cerebral damage. It is caused by hyperexcitability of the sensorimotor cortex (cortical reflex myoclonus) or reticular formation (reticular reflex myoclonus), or both. No consistent pathological change has been reported in autopsied cases of action myoclonus. The underlying disorder appears to be a loss of inhibitory mechanisms involving serotonin and possibly GABA as transmitter agents. The term PME is used for the association of myoclonus with degenerative changes in the nervous system which are commonly diffuse but may predominate in certain systems. There may or may not be associated tonic-clonic seizures, other manifestations of epilepsy, or dementia. Those cases of PME associated with Lafora inclusion bodies and cerebral storage diseases can be distinguished from the system degenerations. Systems which may be involved in the latter group include cerebellodentatorubral, pyramidal, extrapyramidal, optic, auditory, posterior columns and gracile and cuneate nuclei, spinocerebellar pathways, motor neurons of cranial nerves and anterior horns, and muscle fibers. Confronted with this diversity of pathological change, it seems unnecessary to make any clinical distinction between Ramsay Hunt syndrome and Unverricht-Lundborg syndrome (Baltic myoclonus) because cerebellar signs are found in patients described under both headings. Additional systems may be involved in individuals or families who are otherwise typical. All three names could well be joined in an eponymous title (Unverricht-Lundborg-Hunt disease) or the condition simply known as the systems degeneration type of PME, as Halliday (43) suggested. The cause of the condition (or spectrum of conditions) is at present unknown. Action myoclonus usually responds to sodium valproate or clonazepam, and some individuals, particularly those with posthypoxic myoclonus, improve with the administration of serotonin precursors.
 ...
PMID:Action myoclonus, Ramsay Hunt syndrome, and other cerebellar myoclonic syndromes. 308 Aug 51