September 2, 2009

One of the newer, more interesting hypotheses about the pathology of MS is that the damage seen in MS stems from blockages (narrowing or twisting) in veins draining blood from the central nervous system. These blockages result in poor drainage and even reversal of blood flow direction, which could lead to inflammation, increased iron deposition, and eventually blood-brain barrier damage and lesions. A proponent of this hypothesis, Dr. Paolo Zamboni, has previously published results using Doppler sonogram technology showing that this reflux is prevalent in people with MS and specific to MS. Since then, he has taken the next step of performing surgical procedures in 75 people with RRMS, SPMS, or PPMS. These procedures included either balloon angioplasty (inflating up a tiny balloon inside the vein to open it back up) or stenting (inserting a tiny tube inside the vein to hold it open). In the year following the procedure, relapse rates and clinical test scores in the group overall were improved compared with those from before the procedure. Those subjects who had relapses following the procedure were also found to have had renarrowing of their treated veins. No follow-up MRIs were performed to evaluate whether this procedure reduced the formation of new or enlarging lesions, however.

These are preliminary results only so it's too soon to say exactly how CCVSI (chronic cerebrospinal venous insufficiency) is involved in MS and how/whether these types of treatments should be used in MS. An international meeting will be held in Italy next week to discuss this topic further, including a presentation by a doctor at Stanford (Michael Dake) who has recently treated some MS patients using these procedures. It is interesting to think that opening narrowed veins could lead to significant improvements for people with MS. It also raises the question of why cerebral veins are narrowed in people with MS in the first place and whether that could also be addressed.

Women get MS more often than men, and this gap in MS risk seems to be widening according to recent studies. Once someone has MS, does their gender also affect how their disease evolves? A few studies have examined whether MRI findings are different in men with MS compared with women, and a review of these studies concludes that in general, gender does not greatly affect MRI characteristics such as lesion load and atrophy.

This review included ten studies that had analyzed MRI findings such as lesion number, lesion volume, atrophy and atrophy progression. Many of the studies were smaller, single-center investigations while others analyzed data from multi-center studies or large databases such as the Sylvia Lawry Center clinical trials database. Some of the single-center studies included in the review did find that women had more Gd-enhancing lesions than men or that men had more T1 hypointense lesions. However, larger studies did not see these differences. Another study found that men with MS had lower gray matter volumes than women, but this has not yet been confirmed by separate investigations. The reviewers conclude that while gender differences in MRI may still exist, so far no major distinctions have been discovered and confirmed. They also note that differences may exist in spinal MRIs as well as in PPMS (for which the gender gap in risk is much less than in RRMS), since these areas have not been explored as thoroughly as brain MRIs for people with RRMS.