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Prevalence, sensitivity, and specificity of chronic cerebrospinal venous insufficiency in MS.

PREVALENCE, SENSITIVITY, AND SPECIFICITY OF CHRONIC CEREBROSPINAL VENOUS INSUFFICIENCY IN MS To the Editor: We read with interest the article by Zivadinov et al.,1 who now state that their findings do not support chronic cerebrospinal venous insufficiency (CCSVI) as a primary causative contributor in the development of multiple sclerosis (MS), as previously proposed.2 However, by analyzing the prevalence of CCSVI in pediatric patients with MS (5/10, 50%), it is possible that the prevalence of CCSVI in this population is more than doubled with respect to adult healthy controls (37/163, 22.7%). This finding indicates that CCSVI can be considered a neglected susceptibility factor for MS development as MS in children is 4 times higher than in the adult population without MS (odds ratio 4.4, 95% confidence interval [CI] 1.2 to 16; p 0.0293, 2-sided Fisher exact test).1 We recommend more caution before drawing conclusions reported in the article.