dystonia
Pronunciation: dis-TOH-nee-ah
Involuntary muscle contractions causing abnormal postures or repetitive movements, often occurring as an adverse effect of antipsychotic medications.
Full Definition
Dystonia is a neurological disorder characterized by sustained or intermittent involuntary muscle contractions that result in abnormal postures, repetitive movements, or both. In psychopharmacology, acute dystonia is a common extrapyramidal side effect of antipsychotic medications, particularly high-potency first-generation agents. It typically affects the head, neck, and face, manifesting as oculogyric crisis (forced upward eye deviation), torticollis (neck twisting), or facial grimacing. Acute dystonic reactions usually occur within hours to days of medication initiation or dose increase, and are more common in young males. These reactions respond rapidly to anticholinergic medications such as benztropine or diphenhydramine. Chronic dystonia can also occur with long-term antipsychotic use.
Usage
Usage note: Distinguish from dyskinesia (abnormal involuntary movements) and other 'dys-' terms in medical writing.
In Context
- "The patient experienced acute dystonia within six hours of receiving haloperidol in the emergency department." — Clinical incident report
- "Prophylactic anticholinergic agents may prevent dystonia in high-risk patients starting antipsychotics." — Treatment protocol