Abstract 254: Imaging Findings of Stroke Following Treatment of Ruptured Cerebral Aneurysm Increases Risk of Postoperative Delirium
Authors: Qudah Abdullah M. Al , Doheim Mohamed F. , Suresh Varshapriya , Lavu Diti Vinuthna , Sivaguru Sreeja , Shhadeh Adham , Alkalbani Leen , Sultany Abdullah , Kakamyradov Guvanch , Thirumala Parthasarathy D. 
Published: March 2024

Introduction
Delirium is an acute cognitive or perceptual disturbance that is associated with prolonged hospital and ICU length of stay, therefore, extending recovery time. According to a recent study, approximately one in five patients undergoing intracranial procedures are vulnerable to postoperative delirium within the first three days of surgery.1‐4 Retrospective cohort studies found a link between postoperative delirium and intraoperative hypotension, indicating reduced cerebral blood flow.5 ICSS‐ MRI study (International Carotid Stenting Study Magnetic Resonance Imaging Study), indicated that patients with periprocedural hemodynamic depression had decreased cerebral blood flow and increased the risk of new lesions in imaging.6 Ruptured intracerebral aneurysms are associated with higher morbidity and mortality than unruptured ones. This is secondary to delayed postoperative cerebral ischemia and infarction caused by vasospasm.7 Clinical indicators like delirium can play a role in evaluating for delayed cerebral ischemia and infarction leading to timely management of vasospasms.5,8,9 Our study aimed to assess the association between imaging findings of stroke and delirium in patients who underwent treatment for ruptured aneurysms.

Methods
We reviewed the medical records of 167 patients with ruptured intracranial aneurysms between 2015‐2019. We included all the patients who had a postoperative delirium assessment, neurological assessments, and MRI/CT scans for evaluation of cerebral ischemia. Patients were divided into 2 groups, one group with delirium and the other without delirium. Delirium was assessed by using the ICD9/10 codes and The Intensive Care Delirium Screening Checklist (ICDSC).10

Results
A total of 167 patients presented with ruptured aneurysm and the incidence of delirium was 38.3% (64 patients). Patients with delirium had a median age of 57 (50.0‐65.8) compared to a median age of 55 (44.0‐64.0) in patients without delirium. Additional risk factors (delirium vs no delirium) included a history of stroke (17.5%/7.8%), smoking (30.1% vs 40.6%), female gender (63.1% vs 71.9%), preop‐benzodiazepines (26.2% vs 23.4%), intraoperative hypotension (78.6% vs 85.9%), and history of alcohol abuse (9.7% vs 9.4%). None of these factors reached statistical significance between patients with and without Delirium (p‐value >0.05). A new neurological deficit was noted in 17 (26.6%) patients with delirium compared to 12 (11.7%) patients without delirium (p‐value, 0.01). 24/29 (82.8%) patients with new neurological deficits had imaging finding suggesting acute ischemic changes (p‐value, <0.001). 30/64 (49.9%) patients with delirium had imaging findings associated with acute ischemic changes on imaging (p‐value, 0.001). After adjusting for confounders such as age, preop benzodiazepines, history of drug abuse, and history of stroke. Patients with delirium had imaging findings suggestive of acute ischemic changes of stroke ORadj 2.46 (CI 95%, 1.12 – 5.36, p‐value 0.02), while patients with new neurological deficit did not ORadj 1.66 (CI 95%, 0.62 – 4.41, p‐value 0.31).

Conclusion
Our findings suggest that delirium might be one of the manifestations associated with imaging changes indicating acute silent ischemic strokes. Delirium might be one of the manifestations postoperatively for delayed cerebral ischemia as noted on imaging, this highlights the importance of timely identification and management of patients with delirium.