Introduction: Seizures are a well-described complication of aneurysmal subarachnoid hemorrhage (SAH). There is conflicting evidence of the impact of seizures on patient outcomes, prophylactic use of anti-epileptics, and timing of initiating continuous electroencephalography (EEG) for early seizure detection.

Methods: An IRB-approved retrospective chart review was conducted on patients presenting with aneurysmal SAH at our institution between July 2012 and December 2017.

Results: 215 patients [135 Females (62.5%), 80 Males (37.5%)] were included. 125 (58.3%) had anterior and 21 (9.7%) posterior circulation aneurysms. 69 (31.9%) patients had angio-negative SAH. 106 patients had EVD placed on admission for hydrocephalus and poor clinical exam (HH3 or above). 24 (11.1%) patients had seizure activity (Prior to arrival or on admission: 13, 1-3 days: 4, 4-10 days: 2, >10 days: 5). 20 patients (83.3%) with seizures had either Fisher grade 3 or 4 and were Hunt Hess 3 or higher (p<.0005). In eight instances, EEG was able to identify electrographic seizure activity when overt clinical seizures were not witnessed. Three patients (1.39%) developed non-convulsive status epilepticus, on days 5, 31 and 45, respectively. Seizures were independently associated with longer length of stay (p<0.001). In Hunt and Hess score 3 or above, 51 out of 93 (54.8%) were started on AEDs (p <0.0005), and 49 of 93 (52.6%) had EEGs (p<0.0005).

Conclusions: In our series, 11.1% patients had overt seizure activity most commonly at the time of ictus or on arrival to the hospital. Majority of patients with seizures had a higher Fisher grade (3 or 4) and Hunt Hess score (3 or higher), and had hydrocephalus on admission. Higher Hunt Hess (3 or higher) and Fisher score (3 and 4) were associated with higher utilization of AEDs and EEG monitoring. Longer length of hospital stay was associated with seizure activity.

Patient Care: Better understanding of patient predictive factors will allow surgeons and critical care physicians to treat epileptic seizures and the accompanying metabolic and local ischemic changes more effectively in this critically ill patient population. The appropriate utilization of EEG (spot vs video) and the impact of AEDs will also improve allocation of resources and minimize unnecessary use of these diagnostic and treatment modalities.

Learning Objectives: By the conclusion of this session, participants should be able to: 1. Understand the incidence of seizures in aneurysmal subarachnoid hemorrhage (aSAH) 2. Describe the patient predictive factors associated with seizures 3. Understand the utility of electroencephalography and anti-epileptic drugs in treatment of patients with aSAH 4. Understand the short and long term impact of epileptic activity in this patient population

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