Which statement best describes the scope of extrapyramidal symptoms (EPS)?

• A. Acute dystonia, akathisia, parkinsonism, and tardive dyskinesia are all EPS.
• B. EPS only include tremor.
• C. EPS are unrelated to antipsychotic use.
• D. EPS only occur in high-dose clozapine.

Answer: (D)

Extrapyramidal symptoms represent a group of drug-induced movement disorders caused mainly by blocking dopamine D2 receptors in the nigrostriatal pathway, a common effect of many antipsychotics. This spectrum includes acute dystonia (sudden, sustained muscle contractions), akathisia (a subjective inner restlessness with observable motor activity), parkinsonism (rigidity, slowed movements, tremor), and tardive dyskinesia (involuntary movements that often emerge after long-term use). Because of that, EPS is not just tremor; tremor can be part of parkinsonism, but the full range encompasses the four major categories. EPS are linked to antipsychotic use, not unrelated to it, and they are not exclusive to high-dose clozapine—clozapine has relatively low risk of EPS compared with many other antipsychotics. The statement that most accurately describes the scope is that these four conditions together constitute the common spectrum of EPS.