March 10, 2004
Boston Cure Project
Although MS is traditionally thought of as a white matter disease, a new study in the journal "Brain" adds to the growing body of evidence concerning the importance of gray matter damage in MS. (Gray matter is the outer part of the brain, or cortex, where thought processing takes place. It contains less myelin than white matter which is why it appears gray in color.) A team of researchers from the UK performed MRIs on 58 people presenting with clinically isolated syndrome (CIS), a single MS-like symptom that often is the first clinical sign of MS. They performed follow-up MRIs on all subjects after three years and determined which subjects had been diagnosed with definite MS in that time and which ones had not. They then compared changes between the baseline and year 3 MRIs in the MS and non-MS groups.
One of the most important differences between the two groups was the degree of gray matter atrophy. The MS subjects lost on average around 3% of their gray matter, compared with 1% for the non-MS subjects. Interestingly, there was no major difference in white matter volume changes between the two groups -- in fact, white matter volume increased slightly in both groups. That doesn't necessarily mean that there was no white matter tissue loss in the MS group because inflammation in the white matter, with infiltration of cells and fluid, may have compensated for any loss of brain tissue.
Further analysis showed little correlation between gray matter atrophy
and lesion volume. This study provides more evidence that gray matter damage
is important early on in MS, may occur independently of white matter effects,
and therefore should be analyzed separately in studies assessing treatment
efficacy, disease mechanisms, disability, and so on.
Copyright © 2004, Boston Cure Project