Outcomes After Surgical Resection of Cerebral Cavernous Malformations Stratified by Preoperative Seizure History: A Propensity-adjusted Analysis

Introduction: Cerebral cavernous malformations (CCMs) are the most epileptogenic cerebrovascular disease. Though most CCM-related seizures are initially medically managed with antiepileptic drugs (AEDs), neurosurgical intervention may be indicated for patients with drug-resistant breakthrough seizures or patients with hemorrhage-induced first-time seizures. We compared clinical and seizure outcomes after surgical resection of CCMs in patients stratified by varying preoperative seizure histories.

Methods: A retrospective cohort of patients with CCMs was identified from January 2010 through June 2016 at a large-volume cerebrovascular center. Firth’s logistic regression was used to perform a multivariate propensity score adjustment, constructed from demographics, comorbidities, and malformation size. Primary outcomes included prevalence of postoperative seizures and changes in postoperative AED usage. Modified Rankin scale (mRS), length of hospital stay, and post-operative complications were used as secondary outcomes. Standardized mean differences (SMD) were used to quantify effect size for significant associations (p < 0.05).

Results: A total of 203 patients with CCMs were treated during the study period. Four groups were stratified - patients with seizure history with breakthrough seizure (36) and without (10), and patients without seizure history with first-time seizure (46) and without (91). Groups 1 and 2, with seizure history, were associated with increased pre-operative and post-operative AED usage (p < 0.001), and had higher rates of weaning off AEDs (16.7% and 10%, respectively). On multivariate analysis, groups without seizure history had lower odds of developing post-operative seizures on discharge (OR = 0.15, p = 0.025). Trends in discharge and follow-up mRS ≤ 2 were also observed for the same comparison (OR = 5.1, 6.1, p = 0.068, 0.083, respectively).

Conclusion : Our analysis, the largest to date, reinforces that CCM patients without prior seizure history receive more immediate neurosurgical intervention, preventing them from becoming AED-resistant and increasing chances of remaining seizure-free post-operatively.