Surgical Treatment of Long-Term Epilepsy Associated with Cerebral Tumors of Glioneuronal Origin

Refractory or drug-resistant epilepsies may be associated with a subgroup of glial and glioneural primary neoplasms with indolent behavior described by Luyken et al. (2003) as LEATs “Long-term epilepsy associated tumors”. The clear majority of tumors included in this definition are gangliogliomas and DNETS (neuromeloplastic neuroepithelial tumors). Focal epilepsy is the most frequent clinical manifestation of these tumors and there is an association between LEATs and focal cortical dysplasias. The surgical treatment of these lesions has the possibility of offering a satisfactory result in the control of seizures, reducing the use of antiepileptic drugs and their side effects, implying in improvement of quality of life of these patients. This study aims to describe the results of a cohort of patients submitted to surgical treatment in a Brazilian hospital, under the philosophy of epilepsy surgery, of LEATs in order to evaluate the general effectiveness of surgical procedure in the control of seizures according to Engel’s classification, to analyze the relationship between the results in epilepsy control according to the surgical technique used, time interval between onset of seizures and surgical treatment, and histological findings. Retrospective analysis of medical records and imaging of patients with epilepsy who met the criteria for defining LEATs submitted to surgical treatment in the period from 2002 to 2016. Thirty-three patients were included in the study, the majority being male (51.5%). The mean age at onset of seizures was 13 years and the mean time interval between the onset of seizures and the surgical treatment was 10 years. The vast majority of patients had focal seizures as first symptom, evolving with generalized seizures (78.8%). The lesions were located mainly in the temporal lobe (60.6%), followed by the parietal lobe (21.2%). Lesionectomy was performed in 69.7% of cases and extended resection in 30.3%. Only 9.1% of the tumors presented associated cortical dysplasia. Ganglioglioma represented the most common histological subtype (63.4%), followed by pilocytic astrocytoma (9.1%) and anaplastic xantoastrocytoma (9.1%). According to Engel’s criteria, 90.1% of patients were free of disabling seizures in the first year after surgery (Engel I). The surgical treatment of LEATS is very effective, in our cohort 90.1% of patients classified as Engel I, and safe. Thus, early surgical treatment of these lesions should be indicated.