Somatotopy within the Internal Capsule Illustrated by Diffusion Tensor Tractography

Abstract

within the right MCA territory on T 2 -weighted images ( fig. 1 c). Diffusion tensor imaging demonstrated fiber discontinuation within the posteromedial part of the posterior limb of the right internal capsule, when fibers passing through the anterolateral part were relatively spared ( fig. 1 g–j). A 65-year-old man, known for active cigarette smoking, suddenly developed, shortly after awakening, a left paresis of the face, arm and leg associated with hypoesthesia and hemineglect. CT perfusion and angiography scans revealed a right internal carotid artery occlusion ( fig. 1 a) with a large penumbra within the right middle cerebral artery (MCA) territory and a definitive infarct within the posterior limb of the internal capsule ( fig. 1 d– f). Rt-PA intravenous injection was initiated at 80 min from symptom onset. Clinical evolution was characterized by recovery of hypoesthesia, hemineglect and face and arm strength. An MRI obtained at day 34 after stroke onset confirmed the restricted right capsular infarct and revealed an almost complete rescue of the penumbra Received: March 31, 2009 Accepted: May 11, 2009 Published online: August 7, 2009