Global and focal cerebral perfusion after aneurysmal subarachnoid hemorrhage in relation with delayed cerebral ischemia

Abstract

Introduction The pathogenesis of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) is unclear. We assessed whether DCI relates to focal or global cerebral perfusion on admission and on follow-up imaging. Materials and methods Twenty-seven SAH patients underwent computed tomography (CT) perfusion (CTP) on admission and at clinical deterioration or 1 week after admission in clinically stable patients. We compared global and focal (least perfused territory) perfusion in patients with DCI (n=12), clinically stable patients (n=7), and patients with non-DCI-related deterioration (n=8). Results Global cerebral blood flow (CBF) increased on follow-up: 29% (95% confidence interval (CI) 15% to 43%) in patients with DCI, 12% (95%CI −1% to 25%) in stable patients, and 20% (95%CI 4% to 36%) in patients with non-DCI-related deterioration. Focal CBF decreased in patients with DCI, (−23%; 95%CI −58% to 12%) but increased in patients with non-DCI-related deterioration (23%; 95%CI −26% to 55%) and stable patients (7%; 95%CI −30% to 45%). On follow-up, global CBF was lower in patients with DCI (70.0 ml per 100 g/min) than in clinically stable patients (81.6; difference 11.6; 95%CI 0.8 to 22.5 ml per 100 g/min) but comparable to patients with non-DCI-related deterioration (67.6; difference −2.4; 95%CI −11.9 to 7.2 ml per 100 g/min). Focal CBF was lower in patients with DCI (30.7) than in clinically stable patients (53.6; difference 22.9; 95%CI 5.1 to 40.6 ml per 100 g/min) and patients with non-DCI-related deterioration (46.6; difference 15.9; 95%CI −2.6 to 28.4 ml per 100 g/min) Conclusion Our results suggest that DCI is more likely a focal than a global process.

Predictors of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Cardiac Focus

“…Although the mean age for DCI subjects in this study (53 years) was lower than the mean age for DCI subjects in some studies (59 years) [17, 18], it was similar to mean age for DCI subjects (54 years) and overall SAH population (52 years) in other studies [9], and we saw no between-group difference. We did not find a relationship between DCI and other demographic characteristics (Table 2) which is consistent with the literature [8, 13].…”

CT Perfusion and Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

“…Eight of the nine studies using quantitative assessments reported mean perfusion values [6][7][8][10][11][12]15,16 and one gave the lowest values in predefined regions of interest (ROIs). 17 In six studies, all ROIs were used in the analyses, 7,10,12,[15][16][17] whereas two other studies only used the ROIs with lowest CBF or CBV and highest MTT or TTP. 6,8 Of these last two studies, we obtained additional information on the mean values of all ROIs together and included these values in the quantitative analyses.…”

“…6,11,17 CT Perfusion and Prediction of Delayed Cerebral Ischemia Four studies with 153 patients investigated the relationship between perfusion on admission and later development of DCI. 7,8,10,13 Three studies determined CBF, CBV, MTT, and TTP quantitatively (Table 2, Figure 2). 7,8,10 Cerebral blood flow, CBV, MTT, and TTP on admission did not differ between patients who later developed DCI and those who did not develop DCI.…”

Evaluating CT Perfusion Using Outcome Measures of Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage

“…Perfusion deficits are described as focal regions of reduced CBF and/or prolonged MTT. However, global perfusion abnormalities have also been observed in patients with DCI [14]. Few studies in the literature have evaluated CTP using DCI defined as clinical deterioration.…”