BackgroundMechanical Thrombectomy (MT) is standard of care for eligible patients with Acute Ischemic Stroke (AIS) due to large vessel occlusion (LVO). With increasing use of MT, clinicians are more likely to encounter seizures, a potential complication of AIS treated with MT. Tracking future trends in the burden of post-stroke seizure associated with MT will require baseline pre-approval benchmark estimates of its frequency and outcomes. MethodsAll patients with AIS who underwent MT (International Classification of Diseases, Ninth Revision, Clinical Modification; ICD-9-CM procedure code: 39.74) were identified from the National Inpatient Sample (NIS) 2006-2014, using appropriate ICD-9-CM codes. We identified a subset of patients with seizures using ICD-9-CM secondary discharge diagnoses codes 780.3x and 345.x. We computed the rate of seizures overall and across pre-specified demographic, clinical, and healthcare system-related variables. Finally, we assessed the independent association of mortality with seizures using a multivariable logistic regression model. ResultsOf 30137 (weighted) patients with AIS who underwent MT, 1,363 (4.5%) had seizures. Patients who had seizures were younger, privately insured, or Medicaid beneficiaries, and frequently died in the hospital. There were no statistically significant differences between the seizures and no-seizures groups by race, sex, IV thrombolysis with recombinant tissue plasminogen activator, length of stay, and the number of medical comorbidities. However, patients who underwent MT and developed seizures had 75% higher odds of in-hospital mortality (adjusted OR 95% CI 1.75; 1.22-2.49). ConclusionIn this nationwide sample, prior to the 2015 AHA/ASA guidelines update supporting MT use, seizures occurred in one of twenty patients with AIS treated with MT, and occurrence of seizure was independently associated with a nearly two-fold increase in the odds of in-hospitality death.