Tardive dyskinesia: review and update.

Tardive dyskinesia is an extrapyramidal syndrome associated with the chronic administration of major neuroleptic agents. The pathogenesis of the disorder appears to relate to chronic striatal dopaminergic receptor site blockade; the pathophysiology of tardive dyskinesia appears to relate to the resultant denervation hypersensitivity. Agents that deplete the brain of dopamine are the mainstay of therapy for tardive dyskinesia. Cholinergic agents that potentially modulate the balance between dopamine and acetycholine in the striatum offer possible additional therapeutic options. Clearly, resumption of neuroleptic therapy is treatment with the presumed pathogenic agent and is to be avoided whenever possible.