[Tardive dyskinesia--review of clinic, pathogenesis, prevention and treatment of a late neuroleptic side effect].

Tardive dyskinesia (t.d.) is a disorder of the extrapyramidal motor system occurring as a late harmful side-effect long-term therapy with neuroleptic drugs. Prevalence rates, for a variety of causes not easily obtainable, are apparently rising and, according to new studies that also take into account borderline or doubtful cases, may reach 30% for both hospitalized and non-hospitalized chronically schizophrenic patients. Very pronounced forms and complications of tardive dyskinesia are rare. Tardive dyskinesia does not present as a single well defined disorder; rather, several types of t.d. may be distinguished either clinically with regard to localisation, manifestation and the course of the disease, or pharmacologically with regard to susceptibility to provocation or therapy. Reversibility remains the most important practical criterion for differentiation. In addition to long-term treatment with neuroleptics old age, and an ill-defined "individual disposition" are of particular importance in the multiconditional model of t.d.. In terms of pathophysiology t.d. is conceived to be a hypersensitivity of postsynaptic-dopamine-receptors of the nigrostriatal pathways. While therapeutic guidelines may be derived from this model, an effective and generally accepted therapeutic regimen for t.d. does not exist. Therefore, prevention or, secondarily, early diagnosis must receive proper emphasis and attention.