Functional imaging during covert auditory attention in multiple sclerosis

Recent literature suggests that the brain in multiple sclerosis (MS) undergoes reorganization that subserves the performance of visual and motor tasks. We identified sites of cerebral activity in 16 MS patients while performing a covert attention (CA) task, presented in the auditory modality. Positron emission tomography (PET) revealed activation of rostral/dorsal anterior cingulate cortex (ACC) in normal subjects studied previously. Activity in this region was not significant in MS patients, but there was a large region of activity in superior temporal cortex. Decreased activation of frontal attentional networks and greater activity in sensory/perceptual cortical areas (auditory association cortex) suggests a reduction of transmission along white matter tracts connecting these regions. This study demonstrates cingulate hypoactivity and cerebral reorganization during auditory attention in MS.