A variety of signs and symptoms—including muscular rigidity, tremors, drooling, shuffling gait (parkinsonism), restlessness (akathisia), unusual involuntary postures (dystonia), motor inertia (akinesia), and many other neurological disturbances—resulting from dysfunction of the extrapyramidal system. This syndrome may occur as a reversible side effect of certain conventional antipsychotic drugs, particularly phenothiazines.
Any of several degenerative nervous system diseases that involve the extrapyramidal system and the basal ganglion of the brain. The symptoms include tremors, chorea, athetosis, and dystonia. Parkinsonism is an extrapyramidal syndrome.