Unilateral hand flapping as warning sign of stroke

Excerpt

A 74-year-old man presented with transient (10 min lasting) right hemiplegia and aphasia, followed by isolated right hand asterixis (with normal muscle strength and proprioception) lasting for 5 days (Video). Diffusion-weighted imaging was normal, MR angiography showed left internal carotid occlusion, and perfusion-weighted imaging (PWI) revealed middle cerebral artery hypoperfusion (Fig. 1). Electroencephalography (EEG) showed no epileptic discharges, and negative myoclonus was confirmed by electromyography (EMG) (Fig. 1). Somatosensory-evoked potentials were strictly normal. Despite combined intravenous heparin and anti-platelet therapy, right hemiparesis due to brain infarction occurred 5 days after the initial symptoms. Unilateral asterixis has been reported in different focal brain lesions including the thalamus, the internal capsule, the brainstem, primary motor cortex, and the parietal cortex [1, 2]. The exact pathophysiology of asterixis is unknown. An imbalance between excitatory and inhibitory systems in the central nervous system has been proposed as a possible underlying mechanism. In our patient, unilateral asterixis was a warning sign of stroke.

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