Efficacy of antiseizure prophylaxis in chronic subdural hematoma: a cohort study on routinely collected health data

OBJECTIVE: Chronic subdural hematoma (CSDH) is a common neurosurgical condition that can result in significant morbidity. The incidence of epileptic events associated with CSDH reported in the literature varies considerably and could potentially increase morbidity and mortality rates. The effectiveness of antiepileptic prophylaxis for this indication remains unclear. The primary objective of this study was to assess the relevance of anticonvulsant prophylaxis in reducing seizure events in patients with CSDH. METHODS: All consecutive cases of CSDH from January 1, 2005, to May 30, 2014, at the Hopital de l'Enfant-Jesus in Quebec City were retrospectively reviewed. Sociodemographic data, antiepileptic prophylaxis use, incidence of ictal events, and clinical and radiological outcome data were collected. Univariate analyses were done to measure the effect of antiepileptic prophylaxis on ictal events and to identify potential confounding factors. Multivariate logistic regression was performed to evaluate factors associated with epileptic events. RESULTS: Antiepileptic prophylaxis was administered in 28% of the patients, and seizures occurred in 11%. Univariate analyses showed an increase in the incidence of ictal events in patients receiving prophylaxis (OR 5.92). Four factors were identified as being associated with seizures: septations inside the hematoma, membranectomy, antiepileptic prophylaxis, and a new deficit postoperatively. Antiepileptic prophylaxis was not associated with seizures in multivariate analyses. CONCLUSIONS: Antiepileptic prophylaxis does not seem to be effective in preventing seizures in patients with CSDH. However, due to the design of this study, it is difficult to conclude definitively about the usefulness of this prophylactic therapy that is widely prescribed for this condition.