Abstract
While poor-grade subarachnoid hemorrhage (SAH) is generally associated with high mortality and morbidity, some patients make an unexpected dramatic recovery. To estimate prognosis for severe SAH, we assessed cerebral blood circulation by computed tomography perfusion (CTP) imaging on admission. CTP studies were performed for 25 of 49 SAH patients with World Federation of Neurosurgical Societies (WFNS) Grade V between March 2006 and July 2008. Four patients were excluded due to rerupture of aneurysm after CTP images were obtained. We measured cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in the cerebral cortex or basal ganglia. Outcomes were assessed using the modified Rankin Scale (mRS), and patients were classified into 3 groups (n＝7 each): Group A, mRS 0-3; Group B, mRS 4, 5; and Group C, mRS 6. All patients of Groups A and B underwent surgery, while 6 patients in Group C with mydriasis on admission were treated conservatively. CBF of the cerebral cortex was significantly lower in Group C than in Groups A or B. No significant differences were seen in CBV among the 3 groups. MTTs of cerebral cortex were significantly longer in Group C than in Groups A or B, with a cutoff value of 6.6 s. CTP is a potential modality for poor-grade SAH, in that discrimination between “false” and “true” Grade V patients could be made rapidly and less invasively.
