Seizures in WHO grade 2 glioma: semiology and significance

Background: WHO Grade 2 gliomas are a group of highly epileptogenic brain tumours. Seizures occur in the majority of patients and often at an early stage. How exactly these seizures are generated, their characteristics and their optimal management are not well understood. In addition, we also consider how experiencing seizures may inform tumour course and prognosis and how this may influence management. We review the existing literature before presenting a series of original research studies in an attempt to better understand this interplay and its clinical consequences.
Methods: Retrospective observational studies were performed on a patient cohort attending a low-grade glioma clinic at a large regional neurosciences hospital. Statistical methods employed predominantly included survival modelling with Kaplan-Meier plots and Cox-proportional hazard models as well as regression modelling.
Results: We demonstrate several novel relationships between gliomas and the seizures they generate in a clinical patient cohort. Experiencing predominantly motor seizures improved overall survival, despite controlling for known prognostic factors. Tumour laterality (left hemisphere) is also shown to significantly increase the risk of seizure generalisation, as is male sex. We show that levetiracetam is an effective first choice antiseizure medication in this patient population, though it does not appear to modulate MGMTp methylation, at least in grade 2 glioma.
Conclusions: We demonstrate that a complex relationship exists between grade 2 gliomas and the seizures they generate influencing their course and treatment. We outline further research directions via which an even greater understanding of these dynamics may be possible and allow advances in patient care.