http://www.biomedcentral.com/content/pd ... 7-12-9.pdf
In the last 5 years, numerous cross-sectional and longitudinal studies established that GM damage is a better predictor of physical disability and cognitive impairment than WM damage.  Most studies examining this argument used novel imaging techniques that can indirectly assess the extent of GM damage, the most important being a measurement of GM atrophy. [2,5] Therefore, monitoring the evolution of GM damage by various imaging techniques is becoming an important marker in predicting the future disease course and response to therapy in MS patients. A number of current clinical trials examine the effects of immunomodulatory treatments on slowing down GM damage over time.
In conclusion, the review papers by Lucchinetti and Popescu,  Walker and colleagues,  Hulst and colleagues  and Horakova and colleagues  represent a comprehensive update on the role and significance of GM damage in MS. They also raise a number of important new questions and outline comprehensive approaches to address those questions in years to come.