Revisiting the WFNS Score: Native Computed Tomography Imaging Improves Identification of Patients With "False Poor Grade" Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND AND OBJECTIVES: In patients suffering from aneurysmal subarachnoid hemorrhage (aSAH), the optimal time to determine the World Federation of Neurosurgical Societies (WFNS) score remains controversial because of possible confounding factors. Goals of this study were (1) to analyze the most sensitive timepoint to determine the WFNS score in patients with aSAH and (2) to evaluate the impact of initial native computed tomography (CT) imaging on reducing the mismatch of "false poor grade" patients. METHODS: We retrospectively analyzed daily WFNS scores from admission until day 7 in 535 aSAH patients and evaluated their predictive value for the modified Rankin Scale at discharge and 6 months postbleeding. Patients with an initial WFNS score of IV-V who showed improvement to a WFNS score of I-II within the first 7 days (even short-term) were defined as "false poor grade" patients. We tried to identify the "false poor grade" patients using parameters of the initial native CT imaging. RESULTS: Later determination of the WFNS score (day 1 vs 7; pseudo-R 2 = 0.13 vs 0.21) increasingly improved its predictive value for neurological outcome at discharge ( P < .001). We identified 39 "false poor grade" patients who had significantly better outcomes than "real poor grade" patients (N = 220) (modified Rankin Scale-discharge: 0-2, 56% vs 1%, P < .001; 3-5: 41% vs 56%, P = .12; 6: 3% vs 43%, P < .001). "False poor grade" patients differed significantly in initial CT parameters. A predictive model called "initial CT WFNS" ( ICT WFNS) was developed, incorporating SEBES, Hijdra score, and LeRoux score (sensitivity = 0.95, specificity = 0.84, accuracy = 0.859, F1 = 0.673). ICT WFNS scores of ≤4.6 classified patients as "false poor grade." CONCLUSION: The initial WFNS score may misclassify a subgroup of patients with aSAH as poor grade, which can be avoided by later determination of the WFNS score, at days 3-4 losing its usefulness. Alternatively, the initial WFNS score can be improved in its predictive value, especially in poor-grade patients, using criteria from the initial native CT imaging, such as the Hijdra, LeRoux, and Subarachnoid Hemorrhage Early Brain Edema score, combined in the ICT WFNS score with even higher predictive power.

Clinical Outcome Prediction of Early Brain Injury in Aneurysmal Subarachnoid Hemorrhage: the SHELTER-Score.

BACKGROUND: Despite intensive research on preventing and treating vasospasm and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage (aSAH), mortality and morbidity rates remain high. Early brain injury (EBI) has emerged as possibly the major significant factor in aSAH pathophysiology, emphasizing the need to investigate EBI-associated clinical events for improved patient management and decision-making. This study aimed to identify early clinical and radiological events within 72 h after aSAH to develop a conclusive predictive EBI score for clinical practice. METHODS: This retrospective analysis included 561 consecutive patients with aSAH admitted to our neurovascular center between 01/2014 and 09/2022. Fourteen potential predictors occurring within the initial 72 h after hemorrhage were analyzed. The modified Rankin Scale (mRS) score at 6 months, discretized to three levels (0-2, favorable; 3-5, poor; 6, dead), was used as the outcome variable. Univariate ordinal regression ranked predictors by significance, and forward selection with McFadden's pseudo-R2 determined the optimal set of predictors for multivariate proportional odds logistic regression. Collinear parameters were excluded, and fivefold cross-validation was used to avoid overfitting. RESULTS: The analysis resulted in the Subarachnoid Hemorrhage Associated Early Brain Injury Outcome Prediction score (SHELTER-score), comprising seven clinical and radiological events: age (0-4 points), World Federation of Neurosurgical Societies (0-2.5 points), cardiopulmonary resuscitation (CPR) (2 points), mydriasis (1-2 points), midline shift (0.5-1 points), early deterioration (1 point), and early ischemic lesion (2 points). McFadden's pseudo-R2 = 0.339, area under the curve for death or disability 0.899 and 0.877 for death. A SHELTER-score below 5 indicated a favorable outcome (mRS 0-2), 5-6.5 predicted a poor outcome (mRS 3-5), and ≥ 7 correlated with death (mRS 6) at 6 months. CONCLUSIONS: The novel SHELTER-score, incorporating seven clinical and radiological features of EBI, demonstrated strong predictive performance in determining clinical outcomes. This scoring system serves as a valuable tool for neurointensivists to identify patients with poor outcomes and guide treatment decisions, reflecting the great impact of EBI on the overall outcome of patients with aSAH.

Evaluation of MTT Heterogeneity of Perfusion CT Imaging in the Early Brain Injury Phase: An Insight into aSAH Pathopysiology.

The concept of early brain injury (EBI) is based on the assumption of a global reduction in brain perfusion following aneurysmal subarachnoid hemorrhage (aSAH). However, the heterogeneity of computed tomography perfusion (CTP) imaging in EBI has not yet been investigated. In contrast, increased mean transit time (MTT) heterogeneity, a possible marker of microvascular perfusion heterogeneity, in the delayed cerebral ischemia (DCI) phase has recently been associated with a poor neurological outcome after aSAH. Therefore, in this study, we investigated whether the heterogeneity of early CTP imaging in the EBI phase is an independent predictor of the neurological outcome after aSAH. We retrospectively analyzed the heterogeneity of the MTT using the coefficient of variation (cvMTT) in early CTP scans (within 24 h after ictus) of 124 aSAH patients. Both linear and logistic regression were used to model the mRS outcome, which were treated as numerical and dichotomized values, respectively. Linear regression was used to investigate the linear dependency between the variables. No significant difference in cvMTT between the patients with and those without EVD could be observed (p = 0.69). We found no correlation between cvMTT in early CTP imaging and initial modified Fisher (p = 0.07) and WFNS grades (p = 0.23). The cvMTT in early perfusion imaging did not correlate significantly with the 6-month mRS for the entire study population (p = 0.15) or for any of the subgroups (without EVD: p = 0.21; with EVD: p = 0.3). In conclusion, microvascular perfusion heterogeneity, assessed by the heterogeneity of MTT in early CTP imaging, does not appear to be an independent predictor of the neurological outcome 6 months after aSAH.

Blood Pressure Affects the Early CT Perfusion Imaging in Patients with aSAH Reflecting Early Disturbed Autoregulation.

BACKGROUND: Early computed tomography perfusion (CTP) is frequently used to predict delayed cerebral ischemia following aneurysmatic subarachnoid hemorrhage (aSAH). However, the influence of blood pressure on CTP is currently controversial (HIMALAIA trial), which differs from our clinical observations. Therefore, we aimed to investigate the influence of blood pressure on early CTP imaging in patients with aSAH. METHODS: We retrospectively analyzed the mean transit time (MTT) of early CTP imaging within 24 h after bleeding prior to aneurysm occlusion with respect to blood pressure shortly before or after the examination in 134 patients. We correlated the cerebral blood flow with the cerebral perfusion pressure in the case of patients with intracranial pressure measurement. We performed a subgroup analysis of good-grade (World Federation of Neurosurgical Societies [WFNS] I-III), poor-grade (WFNS IV-V), and solely WFNS grade V aSAH patients. RESULTS: Mean arterial pressure (MAP) significantly correlated inversely with the mean MTT in early CTP imaging (R = - 0.18, 95% confidence interval [CI] - 0.34 to - 0.01, p = 0.042). Lower mean blood pressure was significantly associated with a higher mean MTT. Subgroup analysis revealed an increasing inverse correlation when comparing WFNS I-III (R = - 0.08, 95% CI - 0.31 to 0.16, p = 0.53) patients with WFNS IV-V (R = - 0.2, 95% CI - 0.42 to 0.05, p = 0.12) patients, without reaching statistical significance. However, if only patients with WFNS V are considered, a significant and even stronger correlation between MAP and MTT (R = - 0.4, 95% CI - 0.65 to 0.07, p = 0.02) is observed. In patients with intracranial pressure monitoring, a stronger dependency of cerebral blood flow on cerebral perfusion pressure is observed for poor-grade patients compared with good-grade patients. CONCLUSIONS: The inverse correlation between MAP and MTT in early CTP imaging, increasing with the severity of aSAH, suggests an increasing disturbance of cerebral autoregulation with the severity of early brain injury. Our results emphasize the importance of maintaining physiological blood pressure values in the early phase of aSAH and preventing hypotension, especially in patients with poor-grade aSAH.

Asymmetry of P1 and vertebral arteries is not related to basilar tip aneurysm development or rupture.

OBJECTIVE: Lately, morphological parameters of the surrounding vasculature aside from aneurysm size, specific for the aneurysm location, e.g., posterior cerebral artery angle for basilar artery tip aneurysms, could be identified to correlate with the risk of rupture. We examined further image-based morphological parameters of the aneurysm surrounding vasculature that could correlate with the growth or the risk of rupture of basilar artery tip aneurysms. METHODS: Data from 83 patients with basilar tip aneurysms (27 not ruptured; 56 ruptured) and 100 control patients were assessed (50 without aneurysms and 50 with aneurysms of the anterior circle of Willis). Anatomical parameters of the aneurysms were assessed and analyzed, as well as of the surrounding vasculature, namely the asymmetry of P1 and the vertebral arteries. RESULTS: Patients with basilar tip aneurysm showed no significant increase in P1 or vertebral artery asymmetry compared with the control patients or patients with aneurysms of the anterior circulation, neither was there a significant difference in asymmetry between cases with ruptured and unruptured aneurysms. Furthermore, we observed no significant correlations between P1 asymmetry and the aneurysm size or number of lobuli in the aneurysms. CONCLUSION: We observed no significant difference in aneurysm size, rupture, or lobulation associated with P1 or vertebral artery (surrounding vasculature) asymmetry. Therefore, the asymmetry of the surrounding vessels does not seem to be a promising morphological parameter for the evaluation of probability of rupture and growth in basilar tip aneurysms in future studies.