Callosal tissue loss parallels subtle decline in psychomotor speed. A longitudinal quantitative MRI study. The LADIS Study

► Corpus callosum atrophy has been cross-sectionally related to cognitive impairment. ► Longitudinal cognitive decline and corpus callosum tissue loss were investigated. ► Corpus callosum tissue loss determined subtle decline in psychomotor speed. ► This association was independent of white matter lesions and global brain atrophy.