Restricted Brain Blood Flow May Be Symptom of Multiple Sclerosis, Not Cause
Chronic cerebrospinal venous insufficiency is a chronic problem where blood from the brain and spine has trouble getting back to the heart. Researchers have noted that patients with multiple sclerosis are more likely to have CCSVI, but that the condition may actually be a result of the disease and not a cause.
CCSVI Restricts Blood Flow From Brain, Causing Cell Damage
At the University of Buffalo, Robert Zivadinov MD PhD, an associate professor of neurology and president of the International Society for Neurovascular Disease, and colleagues investigated a group of participants in the Combined Transcranial and Extracranial Venous Doppler Evaluation (CTEVD) study which began in April 2009. The study group consisted of 289 MS patients, 21 patients with clinically isolated syndrome or CIS (a first neurologic episode caused by inflammation/demyelination of the central nervous system), 26 patients with other neurological diseases, and 163 healthy controls.
Zivadinov and his team had previously found CCSVI to be strongly associated with MS, but could not conclude if restricted blood outflow caused MS to occur or if CCSVI was another symptom of the disease.
All patients underwent transcranial (inside the brain) and extracranial (outside the cranium) echo-Doppler scans of the head and neck. Persons were considered CCSVI-positive if they met two or more of five venous hemodynamic criteria.
The results showed that 62.5% of MS patients had positive CCSVI and 42.1% of patients with SCI had the condition. The highest prevalence was seen in those with relapsing primary-progressive MS followed by non-relapsing secondary progressive MS. “The higher prevalence of CCSVI in progressive MS patients suggests that CCSVI may be a consequence, rather than a cause, of MS,” says Bianca Weinstock-Guttman, MD, co-principal investigator of the study and UB professor of neurology.
But the team also noted that 45.8% of patients with other neurological diseases also had CCSVI as well as 25.5% of the healthy controls. Blood that remains in the brain too long creates a delay in deoxygenated blood leaving the head, a condition called “slowed perfusion.” This can cause hypoxia, or a lack of oxygen in the brain which can damage cells. It can also lead to iron deposits in the brain tissue.
Further research is planned for the relationship between CCSVI and multiple sclerosis, as well as other neurological conditions. The Zivadinov study was published in a recent edition of the journal Neurology, a publication of the American Academy of Neurology.
Wednesday, May 25, 2011 is World MS Day which was originally launched in May 2009 to raise awareness about MS and to strengthen the network of people living with MS across the world. Tools and resources are available at worldmsday.org, including a Guide to Advocacy from the Multiple Sclerosis International Federation.