Author Affiliations: The Sandra and Malcolm Berman Brain & Spine Institute and Adult Hydrocephalus Center, Sinai Hospital of Baltimore (Dr Williams) and Division of Neuroimmunology and Neuroinfectious Diseases, Department of Neurology, Johns Hopkins University School of Medicine (Dr Venkatesan), Baltimore, Maryland.
Multiple sclerosis (MS) is a chronic neurodegenerative disorder of unknown cause. Inflammation, demyelination, and neuroaxonal dysfunction contribute to its pathogenesis. It has long been recognized that MS lesions tend to be perivenular, which raises the possibility of a vascular cause. The vascular hypothesis for MS has recently received increased attention owing to a series of studies by Zamboni and colleagues.1- 3 Using cerebrovascular and cervicovascular ultrasonography, they report evidence of chronic cerebrospinal venous insufficiency (CCSVI) in all patients with MS but in no control subjects. They hypothesize that CCSVI results in cerebral venous hypertension, which in turn disrupts the blood-brain barrier and causes or contributes to inflammation that incites MS. Multiple efforts to replicate these results have been unsuccessful. In the largest CCSVI study to date,4 an evaluation of 499 subjects in which echo-color Doppler raters were blinded, a higher frequency of CCSVI was found in patients with MS (56%) than in healthy control subjects (23%), although the prevalence was far lower than that reported by Zamboni et al. The prevalence of CCSVI was also high in patients with other neurologic disorders (46%), suggesting that the venous changes were not specific for MS. In addition, the prevalence was higher in progressive forms of MS than in relapsing forms, suggesting that CCSVI is unlikely to be an initiating factor in MS pathogenesis.
Williams MA, Venkatesan A. No Endovascular Innovation Without Evaluation in Chronic Cerebrospinal Venous InsufficiencyA Call for the IDEAL Model. Arch Neurol. 2011;68(12):1510-1512. doi:10.1001/archneurol.2011.1555