Cerebral hemodynamics in patients with multiple sclerosis

Background and Purpose: Multiple sclerosis (MS) is a demyelinating disease of the central nervous system. Although the currently predominant view is that of an autoimmune inflammatory condition, changes in brain vasculature can occur and contribute to pathophysiology. The aim of this study was to evaluate cerebral hemodynamics in patients with MS and explore its relationship with disease status. Methods: Patients with MS and age- and sex- matched healthy controls were recruited. All participants underwent assessment of cerebral hemodynamics through transcranial Doppler ultrasonography. Cerebral vasomotor reactivity (CVR) to hypercapnia was measured by the breath-holding index (BHI). Results: A total of 80 patients with MS and 80 healthy controls were recruited. BHI values obtained in healthy controls, relapsing-remitting (RR)-MS and secondary progressive (SP)-MS patients were 1.15±0.11, 0.87±0.18 and 0.51±0.20, respectively (p<0.001). Group-wise, patients showed decreased CVR in comparison to controls and BHI values were significantly lower in SP-MS than in RR-MS patients. At linear regression analysis, the disease form was significantly associated with cerebral hemodynamics being the SP phenotype an independent predictor of lower BHI values [β=-0.36, 95% confidence interval (CI): -0.44 to -0.27, p<0.001; adjusted β=-0.37, 95% CI: -0.50 to -0.23, p<0.001). Conclusions: Cerebrovascular hemodynamic insufficiency in MS may be secondary to the downstream effects of neuro-inflammatory cascades.