GLIA/ASTROCYTES | Tumor-Induced Epilepsy and Epileptogenic Potential of Brain Tumor Treatment

Abstract

Brain tumors are often accompanied by epileptic seizures. In fact, a seizure is often the first telling sign of brain neoplasm. But it is not only the tumor that can change CNS excitability. The chemotherapeutic treatment of tumors may also carry with it epileptogenic potential – or may dampen excitability, depending on which drug is used. Radiotherapy, likewise, can have an influence on seizure genesis, either aggravating or reducing the epileptogenic tendency. The mechanisms underlying these apparent excitability changes have long been of interest, not least because epileptic seizures decrease quality of life and encumber management in brain tumor patients. Only rather recently, however, have studies begun to dissect the relevant pathophysiological processes and identified factors responsible for network and cellular excitability changes in the tumor patients. The issue of tumor-induced epileptogenesis is far from resolved, and we have only begun to understand therapy-associated alterations in brain excitability. This article attempts to summarize the current hypotheses for tumor-associated epilepsy, with emphasis on recent discoveries in this field. Further, it will also address findings, both clinical and experimental, on tumor therapy-associated neuronal excitability changes. Finally, it will offer a brief outlook on future challenges in the field.