A dyskinesia is an abnormal involuntary movement that involves a muscle or muscle group. It usually affects the muscles of the mouth and face, but the hands, legs and truck may also be affected. They are considered an extrapyramidal symptom, often referred to as EPS.
Dyskinesias are often a side effect of medication, most commonly from antipsychotic medications. Tardive dyskinesias refer to dyskinesias that begin after prolonged use of antipsychotic medications. The newer, atypical antipsychotic medications appear to be less likely to cause tardive dyskinesia than older, conventional antipsychotics.
In dementia, antipsychotic medications are often used for severe behavioral disturbances like agitation and aggression. Some studies show that elderly people may be especially vulnerable to tardive dyskinesia.
