Antipsychotic drug with least extra pyramidal side effect is:

Extrapyramidal motor disturbances ) are intimately linked to the antipsychotic effect, but are more prominent in the high potency compounds and least in thioridazine, clozapine and other atypical antipsychotics. A predominance of lower frequency waves occurs in EEG and arousal response is dampened. However, no consistent effect on sleep architecture has been noted. The disturbed sleep pattern in a psychotic is normalize Ref: KD Tripati 8th ed.