Unilateral Asterixis

Abstract

To the Editor.— The unilateral asterixis has been described in patients with focal brain lesion in midbrain, thalamus, and parietal region.^1-5 We describe here a case of unilateral asterixis in a patient with discrete infarction in the internal capsule. A 71-year-old, right-handed, hypertensive man was admitted because of sudden onset of slurred speech. Significant neurologic findings were dysarthria and marked right central facial weakness. There was minimal drift of the right upper extremity. With both hands outstretched and dorsiflexed, there was asterixis in the right hand only. Computed tomographic scan showed a discrete ischemic lesion in the genu of the left internal capsule (Figure). His liver and renal function tests showed no abnormalities and there was no evidence of any other metabolic disturbances or exposure to medications, such as phenytoin or valproate sodium. Unilateral asterixis was described by Young et al⁵ in eight patients who underwent stereotactic ventrolateral