Brain Hemodynamic Changes Associated with Chronic Cerebrospinal Venous Insufficiency Are Not Specific to Multiple Sclerosis and Do Not Increase Its Severity

Abstract

To investigate the relationship between chronic cerebrospinal venous insufficiency (CCSVI) and cerebral hemodynamic parameters and to disclose any possible involvement in the pathophysiology of multiple sclerosis (MS). The study was approved by the institutional review board, and written informed consent was obtained from all participants. The diagnosis of CCSVI was assigned by using specific color Doppler ultrasonographic criteria. Cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time were assessed with dynamic susceptibility contrast material-enhanced magnetic resonance imaging in normal-appearing white matter (NAWM) in 39 patients with MS. Of these, 25 had CCSVI and 14 did not. Twenty-six healthy control subjects were also evaluated, and of these, 14 had CCSVI and 12 did not. Two-way analysis of variance testing was used for statistical analysis, with Bonferroni correction for multiple comparisons. Correlation analysis was performed by calculating Spearman coefficients. Individuals with CCSVI showed cerebral hemodynamic anomalies, such as decreased CBF and CBV, as compared with individuals without CCSVI, without any delay in mean transit time. No significant interaction between MS and CCSVI was found for any hemodynamic parameters. Furthermore, no correlations were found between CBV and CBF values in NAWM or for severity of disability in patients with MS. The MS group showed prolonged mean transit time in the periventricular NAWM, as compared with the control group, and positive correlation was found between mean transit time values and disability scales in patients with MS. The data support a role of CCSVI in cerebral hemodynamic changes, such as a decrease of CBV and CBF, regardless of the presence of MS. CCSVI had no effect on neurologic function and disability progression in patients with MS.