title: Effect of internal carotid artery occlusion on middle cerebral artery blood flow at rest and in response to hypercapnia.
abstract: In patients with symptomatic cerebrovascular disease the rise in middle cerebral artery (MCA) blood-flow velocity in response to hypercapnia, recorded with a pulsed transcranial doppler velocimeter, was significantly less in MCAs above a totally occluded carotid artery than in MCAs above a patent carotid. These findings support the existence of compensatory cerebral vasodilatation above a carotid occlusion and suggest that transient ischaemic attacks in patients with carotid occlusion may be flow-related rather than embolic phenomena. These patients may therefore benefit from extracranial-intracranial surgical revascularisation. The method presented is non-invasive and therefore ideally suited for use as a screening test or in follow-up studies.
authors.forename: C C
authors.initials: CC
authors.lastname: Bishop
authors.forename: S
authors.initials: S
authors.lastname: Powell
authors.forename: M
authors.initials: M
authors.lastname: Insall
authors.forename: D
authors.initials: D
authors.lastname: Rutt
authors.forename: N L
authors.initials: NL
authors.lastname: Browse
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D002245:Carbon Dioxide / Q000097:blood*; D002340:Carotid Artery Diseases / Q000503:physiopathology*; D002343:Carotid Artery, Internal; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000503:physiopathology*; D006801:Humans; D002546:Ischemic Attack, Transient / Q000503:physiopathology; D008875:Middle Aged; D014463:Ultrasonography
chemical_list: D002245:Carbon Dioxide