A patient of schizophrenia treated for 5 years developed perioral movements. Likely diagnosis is -

Perioral movement after antipsychotic therapy occurs in two syndromes:- Tardive dyskinesia → Facial muscles (perioral muscles) show involuntary movement. Rabbit syndrome → Perioral tremor. Perioral muscles are also involved in acute dystonia, but there is a spasm of muscles (not movement) and it occurs within a week after initiation of the drug.