Causal Hypothesis for Multiple Sclerosis Challenged
New research fails to support cerebrospinal venous insufficiency theory
THURSDAY, Aug. 5 (HealthDay News) -- An emerging hypothesis suggests that the demyelination of cerebral veins that characterizes multiple sclerosis (MS) may be caused by chronic cerebrospinal venous insufficiency (CCSVI), but research published in the August issue of the Annals of Neurology does not concur with the hypothesis.
Peter Sundström, M.D., of Umea University in Sweden, and colleagues assessed blood flow in the internal carotid arteries, vertebral arteries, and internal jugular veins (IJV) in 21 patients with MS and 20 healthy controls to test the vascular MS hypothesis. They found no significant differences between patients and controls in either total IJV blood flow or the amount of cerebral blood flow returning. They concluded that they were not able to reproduce findings in support of the CCSVI hypothesis.
Florian Doepp, M.D., of Humboldt University in Berlin, and colleagues analyzed extracranial venous blood volume flow, cross-sectional areas, IJV and vertebral vein (VV) flow, and CCSVI criteria in 56 patients with MS and 20 controls. They found blood flow direction in IJVs and VVs normal in all but one subject (an MS patient), and no IJV stenosis in any subject.
"Our results challenge the hypothesis that cerebral venous congestion plays a significant role in the pathogenesis of MS. Future studies should elucidate the difference between patients and healthy subjects in blood volume flow regulation," Doepp and colleagues conclude.
One author of the second study has received speaking honoraria from pharmaceutical companies.