Cerebral vasomotor responsiveness during 100% oxygen inhalation in cerebral ischemia.
Cerebral vasoconstrictor responsiveness to 100% oxygen inhalation was measured in 149 subjects, including normal healthy volunteers and those with risk factors for cerebral arteriosclerosis (N = 87). Test results were compared among patients with hemispheric stroke and vertebrobasilar insufficiency (N = 62) with the 133Xe inhalation method. Normal volunteers without risk factors (N = 49), aged 25 to 86 years, showed symmetrical vasoconstriction. Asymptomatic subjects with risk factors (N = 38) and those with vertebrobasilar insufficiency (N = 25) had decreased hemispheric gray matter flow (Fg) values during rest, but vasoconstrictor responsiveness to 100% oxygen inhalation was not significantly reduced. In patients with acute hemispheric infarction, regional vasoconstrictor responsiveness to 100% oxygen inhalation was lost and/or paradoxically reversed; in patients with chronic hemispheric infarction, it was decreased. Testing vasomotor responses during hyperoxia is safe, clinically helpful, and demonstrates impaired vasomotor reactivity in infarcted regions.
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D001921:Brain / Q000503:physiopathology*; D002545:Brain Ischemia / Q000503:physiopathology / Q000628:therapy; D002544:Cerebral Infarction / Q000503:physiopathology / Q000628:therapy; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage* / Q000097:blood; D014661:Vasoconstriction
D010100:Oxygen