Ischemia of the internal capsule due to mild head injury in a child.

We encountered an instructive case of repetitive reversible severe neurological deficit due to ischemia of the internal capsule after mild head injury. A 1-year-old boy fell and hit his head on the floor without losing consciousness. Intermittent episodes of left hemiparesis lasting from 30 s to 30 min developed 4 h later. Magnetic resonance (MR) imaging revealed acute infarction in the left internal capsule and corona radiata on diffusion-weighted imaging, and no microbleeding on susceptibility-weighted imaging. MR angiography of the intracranial and cervical vessels showed no obstruction of the large cerebral arteries. Motor impairment began to improve the next day with conservative therapy. Neurological deficit gradually resolved over the course of 1 month. This tiny lesion of the internal capsule and corona radiata may have represented a small infarction caused by mechanical vasospasm of the perforating vessels branching from the middle cerebral artery after minor injury. Even mild head injuries may cause infarction of the internal capsule, although minor head injuries are common accidents in childhood and usually do not result in severe complications. Copyright (c) 2007 S. Karger AG, Basel.