Document Detail


Basilar vasospasm diagnosis: investigation of a modified "Lindegaard Index" based on imaging studies and blood velocity measurements of the basilar artery.
MedLine Citation:
PMID:  11779892     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND AND PURPOSE: Numerous studies have shown that cerebral vasospasm is one of the leading causes of death and neurological disability after subarachnoid hemorrhage. Most of these studies, however, have focused on anterior circulation vessels. Since the introduction of the transcranial Doppler (TCD), increasing attention has been given to basilar artery (BA) vasospasm, especially in traumatic subarachnoid hemorrhage. As shown for the anterior circulation, however, the significance of elevated flow velocities (FVs) in the posterior vessels may be ambiguous, so vasospasm may not be reliably differentiated from hyperemia. The purpose of the present study was to evaluate the potential additional value of an intracranial/extracranial FV ratio in the posterior circulation to cope with this shortcoming of the TCD in the diagnosis of BA vasospasm. METHODS: FV in the extracranial vertebral artery (VA) was measured in 20 healthy volunteers. Normative values of an intracranial/extracranial VA FV ratio (IVA/EVA) and a BA/extracranial VA FV ratio (BA/EVA) were calculated. Thirty-four patients with subarachnoid hemorrhage were then evaluated with TCD and CT angiography (CTA). The value of the IVA/EVA and BA/EVA ratios in the diagnosis and assessment of vertebrobasilar vasospasm was investigated. RESULTS: The extracranial VA could be insonated in all subjects at depths ranging from 45 to 55 mm. The average FV for the extracranial VA was 26 cm/s. The ratios between intracranial and extracranial VA FVs were 1.6 on both sides, whereas the ratio between the BA FVs and the mean extracranial VA FVs was slightly higher at 1.7. Fourteen patients (41.2%) had CTA evidence of BA vasospasm. Vasospasm was severe in 7 patients, moderate in 1, and mild in the remaining. An FV threshold of 80 cm/s was indicative of BA vasospasm in 92.8% with 3 false-positive results that could be related to vertebrobasilar hyperemia. Comparative analysis between CTA and TCD findings showed that BA/EVA was >2 in all patients with BA vasospasm (100% sensitivity) and < 2 in all but 1 patient without BA vasospasm (95% specificity). Furthermore, the BA/EVA ratio showed a close correlation with BA diameter (r=-0.8139, P<0.0001) and was >3 in all patients with severe vasospasm. CONCLUSIONS: The results of the present study showed that the BA/EVA ratio may contribute to an improved discrimination between BA vasospasm and vertebrobasilar hyperemia and enhance the accuracy and reliability of TCD in the diagnosis of BA vasospasm. Our data further suggest that the BA/EVA ratio may provide an approximation of vasospasm severity and help in identifying patients who are likely to suffer from hemodynamically significant vasospasm.
Authors:
Jean F Soustiel; Venyamin Shik; Reuven Shreiber; Yonit Tavor; Dorith Goldsher
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article    
Journal Detail:
Title:  Stroke; a journal of cerebral circulation     Volume:  33     ISSN:  1524-4628     ISO Abbreviation:  Stroke     Publication Date:  2002 Jan 
Date Detail:
Created Date:  2002-01-07     Completed Date:  2002-02-01     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0235266     Medline TA:  Stroke     Country:  United States    
Other Details:
Languages:  eng     Pagination:  72-7     Citation Subset:  IM    
Affiliation:
Department of Neurosurgery, Rambam Medical Center, Bruce Rappaport Faculty of Medicine, The Technion, Israel Institute of Technology, Haifa, Israel. j_soustiel@rambam.health.gov.il
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MeSH Terms
Descriptor/Qualifier:
Adolescent
Adult
Aged
Basilar Artery / physiopathology,  radiography,  ultrasonography*
Blood Flow Velocity
Brain / blood supply
Cerebral Angiography
Cerebrovascular Circulation
Diagnosis, Differential
Female
Humans
Hyperemia / diagnosis
Male
Middle Aged
Subarachnoid Hemorrhage / complications
Tomography, X-Ray Computed
Ultrasonography, Doppler, Transcranial / methods*
Vasospasm, Intracranial / etiology,  physiopathology,  radiography,  ultrasonography*
Vertebral Artery / physiopathology,  radiography,  ultrasonography
Comments/Corrections
Comment In:
Stroke. 2002 Jan;33(1):78   [PMID:  11813696 ]
Stroke. 2002 Jul;33(7):1746-7; author reply 1746-7   [PMID:  12105343 ]

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