Prognostic implications of epilepsy in glioblastomas

The role of seizures and antiepileptic treatments associated with glioblastoma is a current topic of discussion. The objective of this study is to characterize and establish implications of epilepsy associated with glioblastoma.

We retrospectively analyzed the medical history, focused on epileptic features of 134 histologically diagnosed glioblastoma over a period of 4 years.

The sample group had an average age of 56 years and 66% were male. Complete tumor resection was performed in 66% and 64.2% received further radio-oncologic treatment. The average survival rate was 12.4 months and 11.5% survived to 5 years. Epileptic seizures were the presentation symptom in 27% of cases and 51% suffered seizures during the disease, 26% become drug-resistant. Focal evolving to a bilateral convulsive seizures were the most frequent type. Epileptic seizures at presentation independently predicted longer survival (p<0.001). Furthermore, a history of epilepsy or seizures during disease improved survival. Late onset seizures, recurrences or status epilepticus during the course of the disease indicated tumor progression or the final stages of life. Prophylactic antiepileptic drugs did not prevent seizures. Similarly, there was no difference in survival between patients who did not use antiepileptic drugs and those using valproate or levetiracetam. Patients under 60 years, full oncologic treatment and secondary glioblastomas were factors that improved survival (p<0.001).

Previous history of epilepsy or the onset of seizures as a presentation symptom in glioblastomas predict longer survival. Half of patients have seizures during the course of the disease. Antiepileptic drugs alone do not increase survival in glioblastoma patients.