Real Dictionary

athetosis in American English
a muscular disorder characterized by continuous, slow, twisting motions of the hands, feet, etc., as in cerebral palsy
noun: a condition, chiefly in children, of slow, involuntary, wormlike movements of the fingers, toes, hands, and feet, usually resulting from a brain lesion

athetosis in British English
noun: a condition characterized by uncontrolled rhythmic writhing movement, esp of fingers, hands, head, and tongue, caused by cerebral lesion