Cerebral blood flow dependency on systemic arterial circulation in progressive multiple sclerosis

Area of Science:

• Neurology
• Vascular Biology
• Medical Imaging

Background:

• Multiple sclerosis (MS) involves neuroinflammation and neurodegeneration, impacting brain function.
• Cerebral blood flow (CBF) regulation is crucial for maintaining brain health, and its impairment is implicated in MS.
• Understanding the relationship between systemic circulation and brain perfusion is vital for MS patient management.

Purpose of the Study:

• To investigate the association between systemic arterial blood flow (SABF) and cerebral perfusion parameters in patients with MS.
• To explore potential differences in this relationship between clinically isolated syndrome/relapsing-remitting MS and progressive MS (PMS).

Main Methods:

• 118 MS patients (75 CIS/RRMS, 43 PMS) underwent MRI with DSC-PWI for cerebral perfusion (MTT, TTP) and Doppler ultrasound for SABF.
• Measures included normal-appearing whole brain (NAWB) and gray matter (GM) perfusion.
• Covariates included whole brain volume (WBV) and body mass index (BMI).

Main Results:

• Higher SABF correlated with reduced mean transit time (MTT) and time-to-peak (TTP) in both NAWB and GM across the MS cohort.
• These associations were particularly strong in progressive MS (PMS) patients.
• SABF was a significant predictor of TTP in PMS, and lower SABF quartiles showed significantly lower MTT and TTP.

Conclusions:

• A direct relationship exists between SABF and cerebral blood flow in PMS, suggesting potential cerebrovascular reactivity failure.
• Cerebral blood flow in PMS appears increasingly dependent on SABF, possibly influenced by blood pressure.
• Neurovascular unit dysfunction may contribute to MS pathophysiology and clinical disability.