Executive function in multiple sclerosis. The role of frontal lobe pathology.

Deficits in executive function and the relationship to frontal lesion load as detected on MRI were investigated in 42 multiple sclerosis patients. A battery of neuropsychological test examining executive skills including computerized tests of planning and spatial working memory was administered to all subjects. Performance on these tests was impaired in the patient group when compared with a group of matched controls, but not all executive skills were affected to the same extent. Although a number of executive test scores correlated with the severity of frontal lesion load, it was difficult to disentangle the specific contribution of frontal lobe pathology to the impairment on executive tasks. This study highlights the difficulties in attempting to attribute specific cognitive abnormalities to focal brain pathology in the presence of widespread disease such as in multiple sclerosis.