Document Detail


Cerebrovascular reserve in patients with carotid occlusive disease assessed by stable xenon-enhanced ct cerebral blood flow and transcranial Doppler.
MedLine Citation:
PMID:  11486110     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND AND PURPOSE: Cerebrovascular reserve (CVR) by both transcranial Doppler ultrasonography (TCD) and quantitative cerebral blood flow (CBF) can identify subgroups of patients at increased risk for stroke. A direct comparison of CVR measurements obtained with both technologies in patients with cerebrovascular occlusive disease is lacking. METHODS: CVRs before and after acetazolamide administration (1 g IV) were measured by TCD insonation of the middle cerebral artery (MCA) and CBF obtained with stable xenon CT (Xe/CT) in 38 patients with carotid occlusive disease. Sensitivity/specificity calculations were based on 2 Xe/CT MCA values: an average over 4 levels and the level with the lowest percent change in CBF. Compromised CVR was defined as no reactivity or a decrease in reactivity. RESULTS: Using the analysis of the systolic TCD, we found that velocity changes compared with the average Xe/CT MCA CVR showed a sensitivity of 33%, specificity of 90.6%, positive predictive value of 54.5%, and negative predictive value of 80%. The sensitivity of TCD compared with the lowest Xe/CT CBF CVR was 35.5%, specificity and positive predictive values were 100%, and negative predictive value was 66.7%. The index of validity was between 72% and 76%. CONCLUSIONS: TCD is much less sensitive than Xe/CT CBF in identifying patients with compromised CVR. This may be a result of the inability of TCD to identify patients with compromised reserves when their MCA blood flow comes from collateral sources. The lack of correlation between TCD and Xe/CT CBF for identifying patients with compromised CVR should be considered when stroke risk assessments are made by TCD.
Authors:
R R Pindzola; J R Balzer; E M Nemoto; S Goldstein; H Yonas
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Stroke; a journal of cerebral circulation     Volume:  32     ISSN:  1524-4628     ISO Abbreviation:  Stroke     Publication Date:  2001 Aug 
Date Detail:
Created Date:  2001-08-03     Completed Date:  2001-08-30     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0235266     Medline TA:  Stroke     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1811-7     Citation Subset:  IM    
Affiliation:
Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA. pindzola@neuronet.pitt.edu
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MeSH Terms
Descriptor/Qualifier:
Acetazolamide / diagnostic use
Aged
Aged, 80 and over
Blood Flow Velocity
Brain / blood supply,  physiopathology,  radiography
Carotid Artery Diseases / diagnosis*,  physiopathology
Cerebrovascular Circulation*
Female
Humans
Male
Middle Aged
Middle Cerebral Artery / physiopathology,  ultrasonography
Predictive Value of Tests
Reproducibility of Results
Sensitivity and Specificity
Tomography, X-Ray Computed* / methods
Ultrasonography, Doppler, Transcranial*
Vasodilator Agents / diagnostic use
Xenon / diagnostic use*
Grant Support
ID/Acronym/Agency:
1-K01 HL-03851-01/HL/NHLBI NIH HHS; R03 HS09021-01/HS/AHRQ HHS
Chemical
Reg. No./Substance:
0/Vasodilator Agents; 59-66-5/Acetazolamide; 7440-63-3/Xenon

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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