State-related cyclical dyskinesias in manic-depressive illness.

Cyclical dyskinesias in two rapidly cycling manic-depressive patients recurred during depression and disappeared during mania. One case is reviewed in detail including findings of a 2-year follow-up. Spinal fluid biochemical data are presented and discussed. The finding of a reversible neurological alteration associated with changes in clinical state is of interest in relationship to the mechanisms underlying tardive dyskinesia and also provides evidence of a biological dysfunction in manic-depressive illness.