There appears to be no link between chronic cerebrospinal venous insufficiency and multiple sclerosis (MS), according to new research published in CMAJ (Canadian Medical Association Journal).

In 2009, Dr. Paolo Zamboni postulated that chronic cerebrospinal venous insufficiency is a cause of MS, an inflammatory disease of the central nervous system that affects people in northern climates in particular. Published evidence has not been able to find a link to MS, and no one has been able replicate his findings. Several recent studies have shown an association between ultrasound-diagnosed chronic cerebrospinal venous insufficiency and MS but results vary widely.

Using ultrasound technology and magnetic resonance venography, researchers undertook a study to explore the validity of the theory that chronic cerebrospinal venous insufficiency and MS are linked. They enrolled 120 patients with MS and 60 healthy controls. A high percentage of patients (58%) and controls (63%) met one or more proposed ultrasound criteria that would help diagnose chronic cerebrospinal venous insufficiency although there were no differences seen between groups.

"We detected no link between chronic cerebrospinal venous insufficiency and multiple sclerosis," writes Dr. Fiona Costello, departments of Clinical Neurosciences and Surgery, University of Calgary, Calgary, Alberta, with coauthors.

They cite concerns over the diagnosis of chronic cerebrospinal venous insufficiency.

"We also identified several methodologic concerns that challenge the validity of the criteria used to define chronic cerebrospinal venous insufficiency, and in turn we dispute the authenticity of this diagnosis."