title: Differentiating hemodynamic compromise by the OEF response to acetazolamide in occlusive vascular disease.
abstract: Identification of increased stroke risk in a population of symptomatic patients with occlusive vascular disease (OVD) is presently accomplished by measurement of oxygen extraction fraction (OEF) or cerebrovascular reserve (CVR). However, many regions identified by compromised CVR are not identified by OEF. Our aim was to determine whether the response of OEF to acetazolamide, namely, oxygen extraction fraction response (OEFR) would identify those hemispheres in hemodynamic compromise with normal OEF. Nine patients symptomatic with transient ischemic attacks and strokes, and with occlusive vascular disease were studied. Anatomical MRI scans and T2-weighted images were used to identify and grade subcortical white matter infarcts. PET cerebral blood flow (CBF) and OEF were measured after acetazolamide. The relationship between CVR and oxygen extraction fraction response (OEFR) showed that positive OEFR occurred after acetazolamide despite normal baseline OEF values. The two hemispheres with positive OEFR were also associated with severe (> 3 cm) subcortical white matter infarcts. We found that the OEFR was highly correlated with CVR and identified hemispheres that were hemodynamically compromised despite normal baseline OEF.
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Nemoto
authors.forename: Howard
authors.initials: H
authors.lastname: Yonas
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kuwabara
authors.forename: Ronda
authors.initials: R
authors.lastname: Pindzola
authors.forename: Donald
authors.initials: D
authors.lastname: Sashin
authors.forename: Yuefang
authors.initials: Y
authors.lastname: Chang
authors.forename: Tudor
authors.initials: T
authors.lastname: Jovin
authors.forename: James
authors.initials: J
authors.lastname: Gebel
authors.forename: Maxim D
authors.initials: MD
authors.lastname: Hammer
authors.forename: Lawrence
authors.initials: L
authors.lastname: Wechsler
mesh_terms: D000086:Acetazolamide / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D001157:Arterial Occlusive Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D049268:Positron-Emission Tomography; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000503:physiopathology
chemical_list: D000086:Acetazolamide; D010100:Oxygen