Significance of chronic epilepsy in glial tumors

Abstract

Objective：The aim of this study is to compare the frequency of postoperative epilepsies of patients with chronic as opposed to recent onset epilepsy due to glial tumors in the frontal or temporal lobe with the hypothesis that patients with chronic epilepsy do worse.

Methods : We compared the clinical and diagnostic characteristics of the patients(n=73) who had seizures preoperatively to those of the patients(n=153) who did not. Among those who have had seizures preoperatively, we compared those(n=32, chronic seizure group) who had seizures a year or more prior to surgery to those(n=41, acute seizure group) who had seizures within a year prior to surgery.

Results : Among the various factors, the frequency of benign pathology and favorable neurological state were higher in seizure group than in non-seizure group(p<0.05). Complex partial seizure and low-grade tumors were frequent in chronic seizure group, whereas simple partial seizure and high-grade tumors were frequent in acute seizure group. Seizure-free rate was significantly higher in acute seizure group than in chronic one(p<0.05). Also, the difference of seizure control rate between surgical strategies were statistically significant(p<0.05).

Conclusion : This study indicates that preoperative seizure durations and frequencies have a close relationship with the frequency of postoperative epilepsy of glial tumors. A longer lapse may allow the formation of epileptogenic foci, leading to chronic epilepsy, and eventually having a negative effect on the prognosis of the patients. Factors including histopathological characteristics of the tumor, its location, seizure duration/frequency, and semiology should be taken account of deciding on surgical strategies.