Abstracts

Rationale: Epilepsy is common in patients with brain tumor and can substantially affect daily life, even if the tumor is under control. Its negative impact on quality of life could not be negligible, due to its unpredictability and psychological influence leading to loss of own body control. Treatment with antiepileptic drugs (AEDs) is clearly indicated for patients with preoperative tumor-related seizures. Moreover, surgical treatment itself is also associated with a high risk of postoperative seizures. Approximately, one-third of patients have seizures after resection. Despite the increasing awareness of the difficulties in controlling seizures, clinical studies on epilepsy with tumors and effects of anti-seizure therapy are limited. The goal of this retrospective cohort study was to delineate the frequency of seizures and the effect of AEDs in tumor cases. Methods: Between April 2008 and March 2011, 254 surgeries of supratentorial brain tumor have been undergone in our department. The clinical profiles, i.e., histological diagnosis, anti-tumor treatment, seizure type and frequency, applied AEDs, seizure control and tolerability of AEDs, were retrospectively analyzed. Results: We here reported results from 220 patients (113 males and 107 females: aged 8-83 years, mean 53), excluding patients with medically intractable epilepsy. 55 patients (25%) were not perioperatively treated with any AEDs. Besides them, 95 cases were treated as monotherapy with zonisamide, 17 with valproic acid, 12 with carbamazepine, 12 with phenytoin, 2 each with clobazam or gabapentine. The remaining 25 patients were treated with various combinations of multiple AEDs. While 75% of 165 treated patients eventually achieved seizure control within 6 months after surgery, only 2 patients (4%) of 55 non-treated patients developed seizures during that period. These pathological findings result in glioblastoma multiforme and meningioma. Initial AEDs were eventually changed in 63 cases (38% of the patients treated with AEDs), due to adverse or insufficient effects. Especially, the group of patients treated with multiple AEDs showed highest incidence of recurrent seizures within 6 months (52%) and 12 months (60%) after operation. Conclusions: Generally, prophylactic use of AEDs is not recommended, and potential interactions between antiepileptic and chemotherapeutic agents are documented for the use of enzyme-inducing AEDs. However, routine use of AED in tumor cases still remains the prevailing practice pattern. Optimal AEDs would be applied preoperatively to control tumor-related seizures, provided that fewer side effects, lesser neuropsychological effects, and little interaction to adjunctive chemotherapeutic agents are warranted.