Cortical deficits in multiple sclerosis on the basis of subcortical lesions

Patients suffering fron multiple sclerosis have a high frequency of cogniti ve deficits usually attributable to demyelination and axonal loss in the su bcortical white matter. Neurologic abnormalities referable to cortical func tion ore uncommon but have been described. The present study describes thre e patients with clinically definite MS with deficits in cognitive function referable to cortical location. Two of the patients underwent positron emis sion tomography and showed profound cortical hypometabolism adjacent to sub cortical white matter lesions seen on MRI. This paper points out that neuro logic deficits referable to cortical sites may be caused by subcortical whi te matter lesions and that cognitive dysfunction in patients with MS may pr ogress rapidly in the absence of motoria deficits or other evidence of clin ical deterioration.