Neurologic complications of drugs. Tardive dyskinesias, neuroleptic malignant syndrome, and cocaine-related syndromes.

Drugs, either self-administered or prescribed by physicians, can result in substantial neurologic disability in psychiatric patients. It is clear that the use of neuroleptic agents to treat psychiatric illness may result in a variety of tardive movement disorders. Most commonly, these take the form of orobuccal dyskinesias, but choreic movements of the trunk and extremities, dystonic postures, myoclonus, tics, parkinsonism, and akathisic syndromes also may occur. The choreic tardive syndromes are thought to occur more commonly in the elderly female population, but tardive variants may affect a different population. The neuroleptic malignant syndrome carries a significant mortality and remains a diagnostic and therapeutic challenge. Early detection and vigorous treatment reduces the morbidity and mortality from this condition. Stroke, seizures, and various movement disorders may complicate the illicit use of cocaine and complicate the rehabilitation of those patients dependent on its use. The unsatisfactory treatment of tardive syndromes, neuroleptic malignant syndrome, and cocaine-induced neurologic disease underscores our incomplete understanding of the neurochemistry of dopamine, the function of newly discovered dopamine receptors, and the role they play in maintaining normal emotional and motoric function. For now, awareness of the varied neurologic syndromes related to neurotransmitter-modulating agents should provide the impetus for careful use of these agents and for the continued development of improved drugs for the treatment of psychiatric disease.