Document Detail


Predicting delayed ischemic deficits after aneurysmal subarachnoid hemorrhage using a transient hyperemic response test of cerebral autoregulation.
MedLine Citation:
PMID:  11014420     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: To assess whether the development of delayed ischemic deficits (DIDs) after aneurysmal subarachnoid hemorrhage can be predicted using transcranial Doppler ultrasonography and the transient hyperemic response test (THRT). METHODS: An increase in the middle cerebral artery peak flow velocity (FV) of more than 9% of baseline values after 5 to 9 seconds of carotid artery compression was defined as a normal THRT result, indicating good autoregulatory reserve. The transcranial Doppler criteria for vasospasm were a FV of more than 120 cm/s and a Lindegaard ratio of more than 3. Twenty patients with no immediate postoperative neurological deficits were studied. The FVs at all of the major cerebral arteries were measured daily after surgery, and the THRT results were assessed bilaterally. RESULTS: Five of six patients with abnormal THRT results in the first examination after surgery (primary THRT impairment) developed DIDs; none of the remaining patients developed DIDs (Fisher exact test, P = 0.0004). All five patients with DIDs initially exhibited low FVs but all subsequently developed increases in FVs to values of more than 150 cm/s and four exhibited FVs of more than 200 cm/s. The time of onset of DIDs corresponded to the time of onset of moderate vasospasm (FV > 150 cm/s). None of the patients with initially normal THRT results developed DIDs, although four patients did exhibit late (secondary) THRT impairment, which was associated with FVs of more than 120 cm/s. CONCLUSION: When the effects of primarily impaired (after surgery) autoregulation are magnified by vasospasm, the risk of DIDs seems to be very high. Vasospasm alone does not seem to cause DIDs. The development of DIDs could therefore be predicted using the THRT for patients after aneurysm clipping.
Authors:
J M Lam; P Smielewski; M Czosnyka; J D Pickard; P J Kirkpatrick
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Neurosurgery     Volume:  47     ISSN:  0148-396X     ISO Abbreviation:  Neurosurgery     Publication Date:  2000 Oct 
Date Detail:
Created Date:  2001-01-08     Completed Date:  2001-01-25     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  7802914     Medline TA:  Neurosurgery     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  819-25; discussions 825-6     Citation Subset:  IM    
Affiliation:
Wolfson Brain Imaging Centre, and Academic Neurosurgical Unit, Addenbrooke's Hospital, Cambridge, England.
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MeSH Terms
Descriptor/Qualifier:
Adult
Aged
Blood Flow Velocity
Brain Ischemia / etiology*,  physiopathology*,  radiography
Cerebrovascular Circulation
Female
Homeostasis
Humans
Hyperemia / physiopathology
Intracranial Aneurysm / complications*,  physiopathology*
Male
Middle Aged
Prognosis
Subarachnoid Hemorrhage / complications*,  physiopathology*
Time Factors
Tomography, X-Ray Computed
Vasospasm, Intracranial / etiology

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


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