BACKGROUND: Spreading depolarization describes a near-complete electrical discharge with altered local cerebral blood flow. It is described in association with acute and chronic diseases like hemorrhagic stroke or migraine. Moyamoya vasculopathy is a chronic, progressive cerebrovascular disorder leading to cerebral hypoperfusion, hemodynamically insufficient basal collateralization, and increased cortical microvascularization. METHODS: In a prospective case series, we monitored for spontaneous spreading depolarization activity by using intraoperative laser speckle imaging for real-time visualization and measurement of cortical perfusion and cerebrovascular reserve capacity during cerebral revascularization in 4 consecutive patients with moyamoya. RESULTS: Spontaneous spreading depolarization occurrence was documented in a patient with moyamoya before bypass grafting. Interestingly, this patient also exhibited a marked preoperative increase in angiographic collateral vessel formation. CONCLUSIONS: The spontaneous occurrence of SDs in moyamoya vasculopathy could potentially provide an explanation for localized cortical infarction and increased cortical microvascular density in these patients.

Aneurysmal subarachnoid hemorrhage (aSAH) has a high complications burden, with in-hospital mortality as the most devastating outcome. We aimed to develop and validate a risk score for early prediction of in-hospital mortality after aSAH. Data from 2 university hospitals were pooled (n = 1070), with cohorts for score construction (n = 886) and external validation (n = 184). Several parameters assessable at admission were collected. Independent predictors of in-hospital mortality were used as mortality score components. Diagnostic accuracy of the novel score was compared to the Hunt and Hess Age, Intraventricular Hemorrhage, Rebleed and World Federation of Neurosurgical Societies (WFNS) scores. Overall rate of in-hospital mortality was 19% and 14.7% in construction and validation cohorts, respectively. The novel risk score (aSAH mortality score: 0-12 points) included patients' age (≤55 years: 0 points, 56-70 years: 1 point, >70 years: 2 points), aneurysm rebleeding (2 points), WFNS grade (grade I-II: 0 points, grade III-IV: 2 points, grade V: 5 points), and Hijdra sum score (≤10: 0 points, 11-20: 1 point, 21-30: 2 points, >30: 3 points). In-hospital mortality rates ranged 0.6% (0 points) to 100% (12 points) in the construction cohort, and 0% (0 points) to 60% (10 points) in the validation cohort. In the receiver operating characteristic analysis, the aneurysmal subarachnoid hemorrhage mortality score (area under the curve [AUC]: 0.829 and 0.824 in the construction and validation cohorts, respectively) was superior to the Hunt and Hess Age, Intraventricular Hemorrhage, Rebleed (AUC: 0.811 and 0.813) and WFNS scores (AUC: 0.768 and 0.795). Risk of in-hospital mortality after aSAH can be predicted with high accuracy using baseline characteristics. The novel risk score showed best diagnostic performance in the construction and validation cohorts and can aid in early prognostication and treatment decisions.

Background: The clinical utility of risk scores predicting shunt dependency after aneurysmal subarachnoid hemorrhage (aSAH) remains limited due to scarce validation data. This multicenter pooled analysis aimed to assess the predictive accuracy of existing post-aSAH shunt risk scores. Methods: Consecutive aSAH cases treated at two German university hospitals from January 2010 to July 2023 were pooled into a validation cohort. Total scores for the CHESS, CHESS-Huckman, and SDASH risk models were calculated, and their diagnostic performance was compared using receiver operating characteristic (ROC) curve analysis. Results: A total of 813 patients were included, of whom 215 (26.4%) required ventriculoperitoneal shunt placement within a median time of 29 days post-aSAH. All three risk scores were significantly associated with shunt dependency. ROC analysis showed that the CHESS-Huckman score had the highest predictive accuracy (AUC: 0.792, 95% CI: 0.761–0.824), followed by the SDASH (AUC: 0.782, 95% CI: 0.750–0.814) and CHESS (AUC: 0.780, 95% CI: 0.748–0.812) scores. Pairwise comparisons of AUCs were not statistically significant. All three scores showed good overall calibration, with CHESS–Huckman performing best, as confirmed by calibration intercepts and slopes, Brier scores, and decile-based analysis. Higher CHESS–Huckman scores correlated with earlier shunt placement, whereas delayed shunting (>30 days after aSAH) was most common in patients with moderate CHESS–Huckman scores (7–8 points), occurring in 47.4% of cases compared to 41.4% and 33.3% in patients scoring 0–6 and 9–10 points, respectively. Conclusions: This multicenter analysis validated existing risk scores for predicting shunt dependency after aSAH, with the CHESS–Huckman score demonstrating the nominally highest diagnostic accuracy. Integrating these risk scores into clinical practice could enhance early identification of patients requiring shunting, potentially reducing external ventricular drain weaning time, shortening hospital stays, and lowering the risk of cerebrospinal fluid infections.

BACKGROUND AND IMPORTANCE: This case highlights the effectiveness of endovascular balloon dilatation (percutaneous transluminal angioplasty (PTA)) for treating vasospasm in a radial artery (RA) bypass graft from the internal carotid artery to the M2 branch of the middle cerebral artery in a patient with severe subarachnoid hemorrhage. CLINICAL PRESENTATION: A 69-year-old woman with severe subarachnoid hemorrhage due to a ruptured giant aneurysm in the ophthalmic segment of the right internal carotid artery underwent an extracranial-intracranial high-flow bypass with a RA graft, followed by trapping of the aneurysm. During her intensive care unit stay, vasospasms developed primarily in the intracranial radial graft and M2 branches. These spasms showed only minimal improvement after standard care and intra-arterial vasospasmolysis with nimodipine. Thus, after systemic anticoagulation, balloon PTA was performed, treating both the intracranial and extracranial sections of the graft, including areas near the anastomosis. The procedure was complication-free, with immediate morphological success and significant improvement in perfusion to the middle cerebral artery territory. CONCLUSION: Endovascular balloon PTA should be considered a rescue measure for vasospasm in extracranial-intracranial bypasses, particularly with RA grafts post-SAH. Owing to its muscular structure, the RA graft is especially prone to spasm, potentially compromising graft patency. When pharmacological treatments fail, balloon PTA offers a targeted intervention to restore vessel caliber, stabilizing blood flow and preventing ischemic complications, thus supporting the bypass's long-term success.