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.
Tardive dyskinesia
Muscular dystonia
Akathas i a
Malignant neurolept syndrome