LESIONS IN THE LEFT ARCUATE FASCICULUS REGION AND DEPRESSIVE SYMPTOMSIN MULTIPLE-SCLEROSIS

Depression is a common mood disturbance in multiple sclerosis (MS) pat ients. Epidemiologic data suggest a causative relationship between dep ressive symptoms and cerebral demyelination, although a specific lesio n site responsible for depressed mood has not been identified. Given t hat depression in neurologic disease is closely related to frontal and temporal lobe damage, we focused our study on investigating the exten t to which lesions in the white matter connecting both cerebral lobes may account for depressive symptoms in MS. Forty-five patients were as sessed using the Beck Depression Inventory and an MRI protocol conceiv ed to quantify lesions separately in the basal, medial, and lateral fr ontotemporal white matter. The presence of lesions in the left suprain sular white matter, the region that mainly includes the arcuate fascic ulus, was specifically associated with depressive symptoms, accounting for a significant 17% of the depression score variance. Although a mu ltifactorial origin is suspected for depression in MS, this finding gi ves support to the existence of a direct negative effect of demyelinat ion on mood.