Nonneuroleptic etiologies of extrapyramidal symptoms

Antipsychotic or neuroleptic medications are known to produce various extrapyramidal symptoms as common side effects. Extrapyramidal symptoms may present clinically as acute dystonic reactions, tardive dyskinesia, akinesia, Parkinsonism, akathisia, and neuroleptic malignant syndrome. Dopamine blockade or depletion in the basal ganglia produces these symptoms. Not as widely known or understood is that extrapyramidal symptoms can also occur as side effects from a variety of nonantipsychotic agents, namely certain antidepressants, antiemetics, lithium, and, rarely, some anticonvulsants and oral contraceptive agents. These symptoms mimic the naturally occurring, idiopathic pathologies of the extrapyramidal system and basal ganglia disease. Clinicians must be able to recognize these symptoms as side effects, distinguish extrapyramidal symptoms from psychiatric symptoms and, assess the possible nonantipsychotic causes of extrapyramidal symptoms, particularly in nonpsychiatric settings.