[Tardive dyskinesia--diagnosis and treatment]

Tardive dyskinesia is defined as a syndrome consisting of abnormal, stereotypical involuntary movements usually of choreoathetoid type, principally affected the mouth, face, limbs and trunk, which occurs relatively late in the course of neuroleptic drug treatment and in the etiology of which the drug treatment is a necessary factor. Presently, the prevalence of tardive dyskinesia in the hospitalized patients in psychiatric hospitals in Japan is estimated to be 20-30%. Epidemiology, possible pathophysiology and symptomatology of tardive dyskinesia are briefly described. Differential diagnosis between this syndrome and other involuntary movements such as psychotic mannerism, senile orofacial dyskinesia, rabbit's syndrome, Pisa syndrome or Meige's syndrome is discussed. Several drugs to suppress involuntary movements of tardive dyskinesia are described. However, there appears to be no consistently reliable therapies for patients who develop the tardive dyskinesia. Treatment for this syndrome, other than neuroleptic withdrawal, are still uncertain.