Background: In multiple sclerosis (MS), insufficient blood supply might worsen energy deficiency of the brain tissue. Thus, cerebrovascular reactivity (CVR), which is the capacity of cerebral circulation to match blood supply to metabolic demand, might be important in MS pathology.
Objectives: The objective of this study was to investigate the relationship of CVR to disease activity and neuroimaging markers of disease progression in patients with MS.
Material and methods: In 43 patients with relapsing remitting MS (RRMS) in clinical remission, 30 patients with a relapse of MS and 30 healthy controls, we measured CVR with transcranial Doppler as a relative change in flow velocity after breath-holding (breath-holding index) and voluntary hyperventilation (hyperventilation index). All patients in remission underwent brain magnetic resonance imaging at baseline and 33 underwent repeated imaging after 12 months, with various brain volume measurements taken.
Results: Cerebrovascular reactivity indices did not differ between patients in remission, patients with a relapse and controls. In patients in remission, CVR did not differ between those with or without contrast-enhancing lesions. In patients with a relapse, glucocorticoids significantly reduced both CVR indices. Cerebrovascular reactivity was not related to brain volume, white matter lesion volume, percent brain volume change, and the change in total white matter lesion volume.
Conclusions: In RRMS, CVR appeared normal and unrelated to disease activity. There was no substantial association of CVR to brain atrophy and accumulation of white matter lesions.
Keywords: brain atrophy; cerebral blood flow; cerebrovascular reactivity; multiple sclerosis; transcranial Doppler ultrasonography.