[Frontiers in Bioscience 14, 1730-1744, January 1, 2009]

Cognition in multiple sclerosis: a review of neuropsychological and fMRI research

Helen M. Genova1, James F. Sumowski1, Nancy Chiaravalloti1,2, Gerald T. Voelbel1,2, John DeLuca1,2

1Kessler Medical Rehabilitation Research and Education Center, 300 Executive Drive, Suite 10, West Orange, NJ 07052, 2University of Medicine and Dentistry of New Jersey - New Jersey Medical School, Department of Physical Medicine and Rehabilitation, 30 Bergen Street, Newark, NJ 07101


1. Abstract
2. Introduction
3. Cognitive Dysfunction in MS
3.1. Processing speed
3.2. Working memory
3.3. Executive functioning
3.4. Interaction between processing speed and higher-order cognition
3.5. Visual perception
3.6. Episodic memory functioning
3.7. Lifestyle, fatigue, psychological functioning
4. Investigation of cognitive impairment in MS using neuroimaging
4.1. Functional MRI and cognition in MS
4.1.1. Working memory
4.1.2. Executive functioning
4.1.3. Processing speed
4.1.4. Learning and memory
4.1.5. Attention
4.2. Potential explanations for activation pattern differences in MS
4.2.1. Brain reorganization and compensation
4.2.2. Task effort
4.2.3. Cognitive fatigue
4.2.4. Decreased activation in MS
5. Conclusions and future directions for research on cognitive impairment in MS
6. References


Multiple Sclerosis (MS) is a disease of the central nervous system affecting millions of people worldwide. In addition to the disabling physical symptoms of MS, roughly 65% of individuals with MS also experience significant cognitive dysfunction, especially in the domains of learning/memory, processing speed (PS) and working memory (WM). The purpose of this review is to examine major topics in research on cognitive dysfunction, as well as review recent functional magnetic resonance imaging (fMRI) studies focusing on cognitive dysfunction in MS. Additionally, directions for future research are discussed.