HEMODYNAMICALLY SIGNIFICANT CEREBRAL VASOSPASM AND OUTCOME AFTER HEAD-INJURY - A PROSPECTIVE-STUDY

Citation
Jh. Lee et al., HEMODYNAMICALLY SIGNIFICANT CEREBRAL VASOSPASM AND OUTCOME AFTER HEAD-INJURY - A PROSPECTIVE-STUDY, Journal of neurosurgery, 87(2), 1997, pp. 221-233
Citations number
53
Categorie Soggetti
Neurosciences,"Clinical Neurology",Surgery
Journal title
ISSN journal
00223085
Volume
87
Issue
2
Year of publication
1997
Pages
221 - 233
Database
ISI
SICI code
0022-3085(1997)87:2<221:HSCVAO>2.0.ZU;2-1
Abstract
The authors prospectively investigated cerebral hemodynamic changes in 152 patients with head injuries to clarify the relationship between c erebral vasospasm and outcome. They also sought to determine the most clinically meaningful criteria for diagnosing cerebral vasospasm. Pati ents with varying degrees of moderate-to-severe head injury were monit ored using transcranial Doppler (TCD) ultrasonography and intravenous Xe-133-cerebral blood flow (CBF) measurements. Outcome was determined at 6 months. Using TCD ultrasonography, mean flow Velocities were dete rmined for the middle cerebral artery (V-MCA, 149 patients) and basila r artery (V-BA, 126 patients). Recordings of the mean extracranial int ernal carotid artery Velocity (VEC-ICA) were also performed to determi ne the hemispheric ratio (V-MCA/VBC-ICA 147 patients). Cerebral blood flow measurements were obtained in 91 patients. Concurrent TCD and CBF data from 85 patients were used to calculate a ''spasm index'' (the V -MCA or V-BA respectively, divided by the hemispheric or global CBF). The authors investigated the clinical significance of elevated flow ve locity, hemispheric ratio, and spasm index. Patients diagnosed as havi ng MCA or BA vasospasm on the basis of TCD-derived criteria alone had a significantly worse outcome than patients without vasospasm. When CB F was considered hemodynamically significant vasospasm, as defined by an elevated spasm index, was even more strongly associated with poor o utcome. Stepwise logistic regression analysis confirmed that hemodynam ically significant vasospasm was a significant predictor of poor outco me, independent of the effects of admission Glasgow Coma Scale score a nd age. On the basis of the results of this study, the authors suggest that the important factor impacting on outcome is not vasospasm per s e, but hemodynamically significant vasospasm with low CBF. These findi ngs show that Vasospasm is a pathophysiologically important posttrauma tic secondary insult, which is best diagnosed by the combined use of T CD and CBF measurements.