CORPUS-CALLOSUM ATROPHY IN AMYOTROPHIC-LATERAL-SCLEROSIS

Recent studies have suggested widespread involvement of the cerebral r egions other than the primary motor cortex in amyotrophic lateral scle rosis. To investigate atrophy of the corpus callosum as a measure of c erebral pathology, we studied 25 right-handed patients with sporadic a myotrophic lateral sclerosis using magnetic resonance imaging. Five pa tients had cognitive decline or emotional and personality changes. The ratios of mid-sagittal corpus callosum areas to the midline internal skull surface area on T1-weighted images were analysed. Compared with 25 age- and sex-matched right-handed control subjects, the patients ha d significantly decreased callosal/skull area ratio, with anterior pre dominance of the degree of atrophy. The patients with cognitive declin e or psychiatric symptoms had substantial atrophy of the anterior four th of the corpus callosum. These findings suggest that atrophy of the corpus callosum, especially in the anterior half, is present in amyotr ophic lateral sclerosis, and that severe atrophy in the anterior fourt h is associated with cognitive decline and psychiatric symptoms. Callo sal atrophy may reflect the widespread distribution of pathological ch anges in the cerebral cortex, which are accentuated in the frontal cor tex.