Athetosis. slow, writhing, continuous, uncontrollable movement of the arms and legs

An athetosis is a series of involuntary movements of the limbs, typically affecting the distal parts of the limbs.

Athetosis is mainly due to lesions or damages in putamen. Patients might have involuntary, purposeless and worm-like movements (especially of the distal parts of their limbs)

Many patients with Lesch-Nyhan will never learn to walk. By the end of the first year, writhing motions (athetosis), and spasmodic movements of the limbs and facial muscles (chorea) are clear evidence of defective motor development