Epilepsy and gliomas: incidence and treatment in 119 patients

One hundred and nineteen consecutive patients affected by supratentorial gliomas were studied in order to determine the incidence of seizure at diagnosis, the occurrence of subsequent seizures and the efficacy of anticonvulsant treatment. The overall incidence of seizures as presentation symptom was 52% (62 patients). Preoperative seizures were present in 83% of patients affected by low-grade astrocytoma, in 46% of patients affected by anaplastic astrocytoma and in 36% of patients affected by glioblastoma. Postoperative epilepsy refractory to anticonvulsant treatment significantly related to low-grade histology and presence of preoperative seizures occurred in 48% of patients. Adverse effects associated with anticonvulsants were observed in 33.8% of patients treated with phenobarbital, 14.3% in the group treated with carbamazepine and 12% of patients treated with vigabatrin. We conclude that anticonvulsant treatment in patients affected by gliomas is often ineffective and prophylactic treatment should be discontinued after 6 months in patients preoperative seizures free. In patients with high risk of seizures antiepileptic drugs with good efficacy and lower incidence of adverse effects than phenobarbital are indicated.