ATHETOSIS, the medical term for certain slow, purposeless movements of the hands and feet. The fingers are separately flexed and extended, abducted and adducted in an entirely irreg ular way. The hands as a whole are also moved, and the arms, toes and feet may be affected. The condition is usually due to some lesion of the brain which has caused hemiplegia, and is especially common in childhood. It is occasionally due to injury of the brain during birth. Athetosis never develops where there is no recovery of voluntary power. The movements are one-sided and may or may not continue during sleep. They cannot be arrested for more than a moment by will power, and are aggravated by voluntary movements. The prognosis is unsatisfactory, as the condition usually continues unchanged for years, though improve ment occasionally occurs in slight cases, or even complete re covery.