Cognitive impairment in multiple sclerosis

Hirofumi Ochi

Department of Geriatric Medicine and Neurology, Ehime University Graduate School of Medicine

Cognitive impairment may occur in up to 70% of all patients with multiple sclerosis (MS). Although MS can affect various sites within the central nervous system, specific pattern of cognitive deficits tends to be seen, especially earlier in the disease. These deficits include problems with attention, information processing speed, and working memory. This constellation of deficits can occur with any disease course, and minimal correlation has been found between physical disability and cognitive impairment. Many studies have shown that cognitive impairment correlates with brain lesion volume, as well as brain atrophy. In addition, there are promising neuroimaging indicators that may be useful to identify patients at risk for cognitive impairment, such as diffusion tensor imaging, magnetization transfer ratio, and N-acetyl aspartate levels. Cognitive impairment is associated with adverse effects on quality of life, employment status, social activities, and so on. Today, there are three avenues of treatment;disease modifying therapy, symptomatic treatments, and cognitive rehabilitation. Unfortunately, data linking therapeutic interventions are limited. A better understanding of cognitive function and its correlation with disease mechanisms will provide a new comprehensive therapeutic strategy for cognitive impairment in MS.

Address correspondence to Dr. Hirofumi Ochi, Department of Geriatric Medicine and Neurology, Ehime University Graduate School of Medicine (454 Shitsukawa, Toon, Ehime 791-0295, Japan)