MMA Embolization Is Associated With a Decreased Risk of Post-Operative Seizures in Patients With Chronic SDH.

Introduction: Clinical seizure are a widely recognized complication of chronic SDH (cSDH), with a reported incidence of 2.6-23%. Risk factors for post-operative seizure have been identified previously as larger SDH, placement of a drain, early recurrence, low GCS, mixed density hematomas, and open craniotomy with membranectomy. However, there have been no studies examining post-operative seizure risk factors in the era of middle meningeal artery embolization (MMAe).

Methods: We conducted a bi-institutional retrospective review of all cases of cSDH treated by craniotomy, MMAe or a combined approach from 2017-2021 at BIDMC and DHMC using ICD9 codes and an institutional prospective database. 219 cases were analyzed, and patient, hematoma, and procedural characteristics were extracted for review. Univariate analysis was used to compare seizure outcomes between the three cohorts. Multivariate logistic regression was then performed to identify factors that were independently associated with post-operative seizure.

Results: The overall rate of post-operative seizure was 9.2% (20 patients); there was a rate of 19.4% in patients with craniotomy alone, 11.1% in patients who had craniotomy followed by MMAe, and 5% in patients treated by MMAe alone. On univariate analysis, patients treated with craniotomy had a significantly greater chance of post-operative seizure compared to those treated with MMAe alone (p=0.0463). There was no significant difference in post-operative seizure between patients treated with craniotomy + MMAe vs. patients treated with MMAe alone (p=0.1304). However, on multivariate analysis, craniotomy was not independently associated with post-operative seizure (OR 1.609 95%CI 0.4424-5.595). Adjusting for co-variates, midline shift remained the only significant predictor of post-operative seizures (OR 1.145 95%CI 1.028-1.282).

Conclusion : Patients with cSDH treated with craniotomy alone have a significantly higher rate of seizure compared to patients who have craniotomy + MMAe, or MMAe alone. Adjusting for co-variates, craniotomy was not independently associated with post-operative seizures, however this is likely confounded by selection bias.