Focal asterixis caused by a small putaminal hemorrhage.

Unilateral asterixis and mild pure motor hemiparesis contralateral to a small putaminal hemorrhage were observed in a 74-year-old hypertensive man. The motor deficit proved to be rapidly reversible, but the focal asterixis remained for some time as the only sign of the intracranial hemorrhage. This case suggests that altered striopallidal inhibitory input to the thalamus probably disturbed the circuit subserving the maintenance of postural tone.