Emerging Advances in the Management of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Narrative Review

Background/Objectives: Aneurysmal subarachnoid hemorrhage (aSAH) remains a life-threatening cerebrovascular event with high rates of mortality and long-term morbidity. Among its complications, delayed cerebral ischemia (DCI) is a major contributor to poor clinical outcomes. Although cerebral vasospasm has traditionally been considered the primary mechanism underlying DCI, recent studies have revealed the multifactorial nature of this condition. This review aims to provide a comprehensive overview of the pathophysiology, preventive strategies, and current treatment options for DCI following aSAH. Methods: A narrative literature review was conducted using the PubMed database to identify peer-reviewed articles relevant to the prevention and treatment of DCI following aSAH. The search strategy employed the following terms: (“Subarachnoid Hemorrhage” [MeSH]) AND “Delayed Cerebral Ischemia” AND (“Prevention and Control” [Subheading] OR “Secondary Prevention” [MeSH]). This search strategy was designed to capture studies addressing both pharmacological and non-pharmacological preventive measures for DCI. Results: A comprehensive PubMed search identified a total of 113 relevant articles. Among these, 40 publications primarily addressed pharmacological interventions, while 22 focused on neuromonitoring techniques. An additional 20 articles explored the pathophysiological mechanisms underlying DCI, and 15 involved preclinical studies utilizing animal models. The remaining 16 articles encompassed diverse topics, including prophylactic endovascular therapies, newly proposed definitions of DCI, treatment algorithm development, functional outcome analyses, and entries in clinical trial registries. Emerging evidence highlights that vasospasm alone does not account for all cases of DCI. Pharmacological approaches such as nimodipine, clazosentan, and fasudil have shown varying degrees of efficacy. Circulatory management and removal of subarachnoid hematoma via CSF drainage or thrombolytics may reduce DCI risk, although their impact on long-term neurological outcomes remains controversial. Endovascular therapy and adjunctive agents such as cilostazol or anticoagulants have demonstrated potential but require further validation through large-scale trials. Conclusions: Effective DCI prevention and treatment require a multimodal approach targeting diverse pathological mechanisms beyond vasospasm. Improved risk stratification, early detection, and individualized therapy are essential for advancing the management of patients with aSAH.