Assessing cerebrovascular reactivity by the pattern of response to progressive hypercapnia.

摘要: Cerebral blood flow responds to a carbon dioxide challenge, and is often assessed as cerebrovascular reactivity, assuming linear response over limited stimulus range or sigmoidal wider range. However, these assumed patterns may not necessarily apply regions with pathophysiology. Deviations from responses are hypothesised result upstream limitations causing competition for between downstream regions, particularly vasodilatory stimulation; preferentially distributed more reactive vessels. Under conditions, fitting fairly describe the relationship flow. To assess of their prevalence survey healthy control subjects patients disease was conducted. We used ramp challenge hypo- hypercapnia stimulus, magnetic resonance imaging measure responses. categorized BOLD into four types based on signs slopes in hypercapnic ranges, color coded mapped them onto respective anatomical scans. suggest that type maps complement reactivity by providing better indication actual patterns. Hum Brain Mapp, 2017. © 2017 Wiley Periodicals, Inc.