Withdrawal of antiepileptic drugs in glioma patients after long-term seizure freedom: design of a prospective observational study

BACKGROUND Epilepsy is common in patients with a glioma. Antiepileptic drugs (AEDs) are the mainstay of epilepsy treatment, but may cause side effects and may negatively impact neurocognitive functioning and quality of life. Besides antiepileptic drugs, anti-tumour treatment, which currently consists of surgery, radiotherapy and/or chemotherapy, may contribute to seizure control as well. In glioma patients with seizure freedom after anti-tumour therapy the question emerges whether AEDs should be continued, particularly in the case where anti-tumour treatment has been successful. We propose to explore the possibility of AED withdrawal in glioma patients with long-term seizure freedom after anti-tumour therapy and without signs of tumour progression. METHODS/DESIGN We initiate a prospective, observational study exploring the decision-making process on the withdrawal or continuation of AEDs in low-grade and anaplastic glioma patients with stable disease and prolonged seizure freedom after anti-tumour treatment, and the effects of AED withdrawal or continuation on seizure freedom. We recruit participants through the outpatient clinics of three tertiary referral centers for brain tumour patients in The Netherlands. The patient and the treating physician make a shared decision to either withdraw or continue AED treatment. Over a one-year period, we aim to include 100 glioma patients. We expect approximately half of the participants to be willing to withdraw AEDs. The primary outcome measures are: 1) the outcome of the shared-decision making on AED withdrawal or continuation, and decision related arguments, and 2) seizure freedom at 12 months and 24 months of follow-up. We will also evaluate seizure type and frequency in case of seizure recurrence, as well as neurological symptoms, adverse effects related to AED treatment or withdrawal, other anti-tumour treatments and tumour progression. DISCUSSION This study addresses two issues that are currently unexplored. First, it will explore the willingness to withdraw AEDs in glioma patients, and second, it will assess the risk of seizure recurrence in case AEDs are withdrawn in this specific patient population. This study aims to contribute to a more tailored AED treatment, and prevent unnecessary and potentially harmful use of AEDs in glioma patients.