[The electrophysiological approach to tardive dyskinesias].
Electrological study of TD is of value on two counts: it facilitates diagnosis in cases where the origin of the dyskinesia is not known, it enables objective monitoring of therapeutic studies. TD electromyographic recordings are highly specific. The recording shows: either, continuous activity of irregular amplitude corresponding to that which is called "tardive dystonia" in a clinical context, or, discontinuous irregular activity sometimes grouped into bursts of activity of relatively long duration, with a rhythm of 0.5 to 2 Hz during the temporal sequences, which are of variable duration. This type of activity is the same as that found in movements induced by L-dopa (L-dopa IM). In both cases, these involuntary movements only occur after several months' or years' treatment. They predominate in the oro-facial region. However, reactions to various pharmacological agents are not identical. While activity is decreased by neuroleptics and increased by L-dopa, anticholinergics have no effect on L-dopa IM whereas they exacerbate TD. GABA decreases TD but is ineffective against L-dopa IM. The reaction of these movements to L-dopa and neuroleptics, suggests that both reflect hypersensitivity to dopamine. Their different reactions to GABA lead one to suppose that GABA modulation of the dopaminergic system is defective in TD.
Rondot
P
P
Centre Hospitalier Sainte-Anne, Service de Neurologie, Paris.
D003937:Diagnosis, Differential; D015259:Dopamine Agents / Q000627:therapeutic use; D004409:Dyskinesia, Drug-Induced / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D004576:Electromyography; D006801:Humans; D009069:Movement Disorders / Q000209:etiology / Q000503:physiopathology; D010276:Parasympatholytics / Q000627:therapeutic use; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives / Q000627:therapeutic use
D015259:Dopamine Agents; D010276:Parasympatholytics; C017985:progabide; D005680:gamma-Aminobutyric Acid
Approche électrologique des dyskinésies tardives.