AUTHOR=Hamou Hussam , Alzaiyani Mohammed , Rossmann Tobias , Pjontek Rastislav , Kremer Benedikt , Zaytoun Hasan , Ridwan Hani , Clusmann Hans , Hoellig Anke , Veldeman Michael 

TITLE=Seizure after surgical treatment of chronic subdural hematoma—Associated factors and effect on outcome

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.977329

DOI=10.3389/fneur.2022.977329

ISSN=1664-2295

ABSTRACT=INTRODUCTION
Chronic subdural hematoma (cSDH) is becoming more prevalent due to population aging and increasing use of antithrombotic drugs. Postoperative seizure in cSDH negatively effects outcome and no consensus exists to date regarding prophylactic anti-epileptic drug (AED) treatment. The objective of this study was to evaluate predisposing and triggering factors associated with postoperative epileptic seizure in cSDH patients. 
METHODS
All patients, surgically treated for cSDH in a single tertiary care center between 2015 and 2019 were considered for inclusion. Relevant patient- and hematoma-specific characteristics were retrospectively extracted from hospital records. Paroxysmal events categorized by the treating physician as suspected postoperative seizure were noted. Clinical outcome was extracted from the last available follow-up visit and classified according to the Glasgow outcome scale (GOS). 
RESULTS
Of the included 349 patients, 54 (15.5%) developed suspected postoperative epileptic complications in form of early seizure (≤ 7 days) in 11 patients (3.2%) and late seizure (> 7 days) in 43 patients (12.3%). In logistic regression analysis, solely depressed brain volume (supratentorial volume (ml) not filled with re-expanded brain) was independently associated with postoperative seizure (OR 1.006, 95%CI 1.001 to 1.011; p = 0.034). Occurrence of postoperative seizure (OR 6.210, 95%CI 2.704 to 14.258; p < 0.001) and preoperative Markwalder grading (OR 2.919, 95%CI 1.538 to 5.543; p = 0.001) were independently associated with unfavorable (GOS1–3) outcome. 
CONCLUSION
Larger postoperative depressed brain volume constituted the only factor independently associated with suspected postoperative seizure and could help identify a subgroup of patients with higher susceptibility to epileptic events. No formal recommendation can be made regarding the prophylactic use of anti-epileptic drugs, based on our data. Nevertheless, the relative safety of new generation AEDs and the detrimental effect of postoperative seizure on outcome may justify its use in a selected patient population.