Brainstem hypoperfusion in severe symptomatic vasospasm following aneurysmal subarachnoid hemorrhage: role of basilar artery vasospasm.
BACKGROUND
The hemodynamic effects of vertebrobasilar vasospasm are ill defined. The purpose of this study was to determine the effects of basilar artery (BA) vasospasm on brainstem (BS) perfusion.


METHODS
Forty-five patients with delayed ischemic neurological deficits (DIND) following aneurysmal subarachnoid hemorrhage (SAH) underwent cerebral angiography prior to decision-making concerning endovascular treatment. BA diameter was compared with baseline angiogram. Regional brainstem (BS) cerebral blood flow (CBF) was qualitatively estimated by (99m)Tc ethyl cysteinate dimer single photon emission computed tomography (ECD-SPECT).


RESULTS
Delayed BS hypoperfusion was found in 22 (48.9%) of 45 patients and BA narrowing of more than 20% was found in 23 (51.1%). Seventeen of 23 (73.9%) patients with BA narrowing of more than 20% experienced BS hypoperfusion compared to 6 of 22 (27.3%) patients with minimal or no narrowing (p = 0.0072). Patients with severe and moderate BS hypoperfusion had higher degree of BA narrowing compared to patients with normal BS perfusion and mild BS hypoperfusion (p < 0.001). The three-month outcome of patients n-22) with BS hypoperfusion was significantly worse compared to patients (n-23) with unimpaired (p = 0.0377, odd ratio for poor outcome 4, 1.15-13.9 95% confidence interval).


CONCLUSIONS
These findings suggest that the incidence of BA vasospasm in patients with severe symptomatic vasospasm is high and patients with significant BA vasospasm are at higher risk to experience BS ischemia. Further studies should be done to evaluate the effects of endovascular therapy on BS perfusion and the impact of BS ischemia on morbidity and mortality of patients with severe symptomatic vasospasm.
Sviri
G E
GE
Department of Neurosurgery, Rambam (Maimonides Medical Center), Haifa, Israel. sviri@u.washington.edu
Britz
G W
GW
Lewis
D H
DH
Ghodke
B
B
Mesiwala
A H
AH
Haynor
D H
DH
Newell
D W
DW
D000328:Adult; D000368:Aged; D001488:Basilar Artery / Q000503:physiopathology; D001933:Brain Stem / Q000098:blood supply / Q000503:physiopathology; D020526:Brain Stem Infarctions / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000503:physiopathology; D013346:Subarachnoid Space / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D014715:Vertebrobasilar Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology