Structural brain indices and executive functioning in multiple sclerosis: A review

Multiple sclerosis (MS) is a neurological disease characterized by lesion-induced white matter deterioration. Brain atrophy and damage to normal appearing white matter (NAWM) and normal appearing gray matter (NAGM) have also been identified as consequences of MS. Neuroimaging has played an integral role in investigating the effects of white and gray matter damage across the three primary clinical phenotypes of the disease - primary progressive (PPMS), relapsing remitting (RRMS), and secondary progressive (SPMS) MS. Both conventional (e.g., T1-weighted imaged) and nonconventional (e.g., diffusion tensor imaging) neuroimaging methods have yielded important information regarding the structural integrity of the brain during the course of the disease. Moreover, it has provided the opportunity to explore the relationship between structural brain indices and cognitive functioning, such as executive functioning, in MS. In this paper, we provide a brief overview of executive functioning in MS, a general review of how structural damage presents in MS by way of sclerotic lesions, atrophy, and microstructural white matter damage, and, finally, how structural brain damage relates to executive dysfunction.