Predictors for Surgical Outcome in Patients with Tumor-Associated Epilepsy

This study aimed to evaluate possible predictors for postoperative outcome in patients with tumor-associated epilepsy.
In this study, patients with tumor-associated epilepsy who were candidates for epilepsy surgery were included. After required presurgical evaluations, they underwent surgical resection of the tumor. Patients were followed 24-57 months after the surgery and were divided to two groups of seizure-free and not-seizure-free. Demographic data, medical history, seizure characteristics and tumor features were compared between the two groups to find possible predictors.
Findings: Thirty-five patients (17 men and 18 women) with the mean age of 22.8 years (8 to 45 years) were enrolled this study. Most of the patients had temporal lobe tumors (68.0%) followed by frontal and parietal lobe tumors. Ganglioglioma was seen in 62.9% of the patients, followed by astrocytoma and dysembryoplastic neuroepithelial tumour (DNET). We found a non-significant positive correlation between better surgical outcome and being male, younger age at epilepsy onset, longer duration of epilepsy, more seizure frequency, tumors in right hemisphere, tumor type of ganglioglioma, and seizures with secondary generalization. Furthermore, we found that history of head trauma, infection of centeral nervous system (CNS), febrile convulsion, natural vaginal delivery, familial history of epilepsy, tumors in temporal lobe, having auras, developing more seizure types and ipsilateral temporal spikes on preoperative electroencephalogram (EEG) were associated with worst surgical outcome (P > 0.05 for all).
In this study, we found no statistically significant predicting factor for surgical outcome; however, we found that being male, smaller ages at seizure onset, longer duration of epilepsy, higher seizure frequency before surgery, involvement of right hemisphere, ganglioglioma, and secondary generalization are more seen in patients with better surgical outcome while history of head trauma, CNS infection, family history of epilepsy, temporal lobe tumors, presence of aura, having multiple types of seizures, and epileptic discharges from temporal lobe in preoperative EEG were seen more in patients with poor outcome. Studies with larger sample sizes are suggested to confirm these findings.