Factors Affecting Development of Epilepsy and Postoperative Recurrence of Epilepsy in Primary Brain Tumor

ABSTRACT

BACKGROUND: A small but significant proportion of patients with brain tumors continued to have seizures postoperatively. All of them could not be explained simply by the failure to adequately resect the tumor mass. We investigated factors influencing seizure recurrence in primary brain tumors. METHODS: We analyzed 435 patients treated with tumor surgery and examined the differences between epileptic seizure group (ESG) and non-epileptic seizure group (NESG). Among ESG, we selected 99 patients confirmed by pathology. We divided patients into chronic epileptic seizure group (CESG; duration of seizure attack >or=1 year) and acute epileptic seizure group (AESG; < 1 year). We also investigated the differences between two groups. RESULTS: Of 435 patients, 104 were ESG and 331 NESG. Among various factors, male, favorable neurological state, fronto-temporal lobe origin, astrocytoma, oligodendroglioma were statistically significant in ESG compared with NESG (p<0.05). Of 99 patients, 43 were CESG and 56 AESG. Among various factors, seizure recurrence rate without residual tumor or tumor recurrences was significantly higher in CESG than in AESG (p<0.05). On the other hand, the laboratory abnormalities, and the rate of residual tumor or tumor recurrences on follow-up MRI were significantly higher in AESG than in CESG (p<0.05). CONCLUSIONS: Among many factors, sex, neurological state, location and pathology of tumors were significantly related to seizure attacks in brain tumor. There were the differences of epileptogenesis between AESG and CESG. We suggest that patients with brain tumor and chronic epilepsy have to be investigated with extensive work-up including invasive electrophyosiologic studies.