Changes in Cerebral Hemodynamics in Patients with Multiple Sclerosis

Cerebral hemodynamics changes are common in patients with multiple sclerosis (MS), with reduced cerebral vasomotor reactivity (CVR) compared with healthy controls, according to study results published in Multiple Sclerosis and Related Disorders.

The pathogenesis of MS is not clearly understood and while it is considered to be an autoimmune inflammatory disease, studies suggested changes in cerebral vasculature may have a role in the disease. The goal of the current study was to assess for changes in cerebral hemodynamics in patients with MS.

The study enrolled 80 patients with MS, including 48 patients (mean age 40.4 years, 35 women) with relapsing-remitting MS (RRMS) and 32 patients (mean age 52.1 years, 22 women) with secondary-progressive MS (SPMS). In addition, a control group included a similar number of healthy volunteers, matched by age and sex.  Continuous wave and color flow B-mode Doppler ultrasound of neck vessels and transcranial Doppler were completed in all study subjects to assess steno-occlusive disease and cerebral hemodynamics. Breath-holding index (BHI) was used to measure CVR to hypercapnia.

The researchers reported that BHI values were lower in healthy controls compared to those in patients with MS: 1.15±0.11 in healthy controls, 0.87±0.18 in patients with RRMS, and 0.51±0.20 in those with SPMS (P<.001). Patients with SPMS had significantly lower BHI values compared to those of patients with RRMS.

Statistical analysis showed a weak correlation between BHI and age, and a moderate correlation between BHI and Expanded Disability Status Scale score. Analysis also revealed that the secondary-progressive form of MS was an independent predictor of lower BHI values (adjusted β =-.37; 95% CI, -.50 to -.23; P<.001).

Furthermore, the data showed that CVR was reduced in patients with MS when compared with controls.

Acknowledging several limitations, the researchers recognized their inability to explore underlying mechanisms due to the single center and cross-sectional design of the study.

“The contribute of vascular abnormalities remains elusive, and studies exploring the relationships between cerebral hemodynamics, functional impairment, disease course and therapeutic response may reasonably allow to improve the understanding of MS pathophysiology and translate in implications for clinical practice,” wrote the researchers.

Reference

Lattanzi S, Acciari MC, Danni M, et al. Cerebral hemodynamics in patients with multiple sclerosis [published online June 15, 2020]. Mult Scler Relat Disord. doi: 10.1016/j.msard.2020.102309.