Seizures in oligodendroglial tumors

Abstract

Epilepsy develops in more than 70-90% of oligodendroglial tumors and represents a favorable indicator for long-term survival if present as the first clinical sign. Presence of IDH1 mutation is frequently associated with seizures in oligodendrogliomas, next to alterations of glutamate and GABA metabolism in the origin of glioma-associated epilepsy. Treatment by surgery or radiotherapy results in seizure freedom in about two-thirds of patients, and chemotherapy to a seizure reduction in about 50%. Symptomatic anticonvulsive therapy with levetiracetam and valproic acid as monotherapy are both evidence-based drugs for the partial epilepsies, and their effective use in brain tumors is supported by a large amount of additional data. Pharmacoresistance against anticonvulsants is more prevalent among oligodendrogliomas, occurring in about 40% despite polytherapy with two anticonvulsants or more. Toxic signs of anticonvulsants in brain tumors involve cognition, bone marrow and skin. Previous neurosurgery, radiation therapy or chemotherapy add to the risks of cognitive dysfunction.

Prediction of the recurrence risk in patients with epilepsy after the withdrawal of antiepileptic drugs

“…Studies in patients with glioma-induced epilepsy have also shown that the etiology plays an important role in withdrawal success or failure [54][55][56]. Kerkhof et al [24] evaluated the recurrence rate after AED withdrawal in 71 patients with histologically confirmed lowgrade or anaplastic (grades II-III) glioma who were seizure-free for at least 1 year after antitumor treatments, including surgery, radiotherapy, and chemotherapy.…”

Valproic Acid: A Promising Therapeutic Agent in Glioma Treatment

“…Currently, more and more anti-epilepsy drugs (AEDs), including VPA, phenobarbital, carbamazepine, clonazepam, levetiracetam, lamotrigine, topiramate, and oxcarbazepine, have been concerned in studying tumors of CNS. Among these AEDs, VPA and levetiracetam exhibits superiority in the clinical application of brain tumor-related epilepsy (BTE), due to their sensitization of TMZ through MGMT-dependent or MGMTindependent mechanisms (92,93). In addition, levetiracetam and VPA would be beneficial to verbal memory and cognitive function via downregulating excitatory amino acid transporter-2 expression (94,95).…”

Seizure in Indonesian Glioma Patients: Associated Risk Factors and Impact on Survival

“…Our study showed higher OR compared with that study, indicating that glioma patients with oligodendroglioma histology were almost five times more likely to have seizures. This can be explained by the fact that oligodendrogliomas more often involve the cortex; therefore, they are more likely to cause seizures compared with astrocytomas, which tend to be situated in the white matter (Kerkhof et al, 2015;Rudà et al, 2012).…”