High T2 signal in primary lateral sclerosis supports the topographic distribution of fibers in the corpus callosum: Assessing disease in the primary motor segment

Abstract

PLS is a disease of the UMN, distinguished from ALS in prognosis and absence of LMN signs. We present, to our knowledge, the first conventional MR imaging visualization of the callosal motor segment, a concept previously supported by primate models, electrophysiologic studies, and postmortem examinations. Modification of the Witelson topographic scheme of the CC is supported by MR tractography. On the basis of 2 cases of PLS, we present conventional imaging confirmation of the revised topographic scheme of fiber distribution across the CC. Copyright © 2011 by the American Society of Neuroradiology.