Multiple Sclerosis: White Matter versus Gray Matter Involvement (The Cause of Disability in MS)

The classic view of multiple sclerosis (MS) as a chronic, inflammatory-demyelinating condition affecting solely the white matter (WM) of the central nervous system (CNS) has been challenged by the demonstration, from pathologic and magnetic resonance imaging (MRI) studies, of an extensive and diffuse involvement of the gray matter (GM). This observation has driven the application of modern MR technology and methods of analysis to quantify the extent and distribution of damage to the different compartments of the CNS, with the ultimate goal of improving our understanding of the factors associated with the accumulation of clinical disability and cognitive impairment in these patients.