Clinical relationship of extrapyramidal symptoms and tardive dyskinesia.
The author reviews the relationship between extrapyramidal syndromes (EPS) such as dystonia, akathisia and parkinsonism, and tardive dyskinesia (TD), characterized clinically by late-onset repetitive movements. While the pathophysiological mechanisms are unclear, neuroleptic-induced EPS have been shown to be associated with a higher risk of TD. The appearance of EPS, however, has not been shown to predict the occurrence of TD. It has been hypothesized that dopamine hypofunction resulting in EPS may lead to the development of dopamine receptor supersensitivity, thereby increasing the TD risk. If this theory can be validated in the clinical setting, atypical neuroleptics (for example, clozapine, risperidone) with a lower EPS liability may result in a lower incidence of TD.
Andrew
H G
HG
Community and Mental Health Services Division, Ministry of Health, Province of Manitoba.
D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001480:Basal Ganglia Diseases / Q000139:chemically induced* / Q000175:diagnosis; D004409:Dyskinesia, Drug-Induced / Q000175:diagnosis*; D006801:Humans; D009460:Neurologic Examination / Q000187:drug effects; D011954:Receptors, Dopamine / Q000187:drug effects; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents; D011954:Receptors, Dopamine