Glioblastoma induced seizures: the mechanisms involved

Glioblastoma multiforme is the most malignant and invasive primary brain tumor in adults. The disease has a poor prognosis with a survival rate of 14-16 months post diagnosis. Depending on the tumor location in the brain, a wide range of signs and symptoms may appear in the patient. One of the most common of which is recurrent hard to control seizures. Despite the high prevalence of tumor-induced seizures, the mechanisms involved in its occurrence are yet to be fully identified. However, it has been shown that glutamate and GABA are probably the major contributing factors. Increasing extracellular glutamate levels due to changes in the expression of ion transporters and the conversion of GABA to a stimulatory mediator are some of the mechanisms involved in the development of these seizures. In addition, factors such as the complex pathophysiology of the disease, its associated-seizures, drug interactions, resistance to treatment and tumor recurrence have made glioblastoma management a major challenge. In this article, the common clinical symptoms of this disease and in particular tumor-associated seizures are reviewed. The mechanisms thought to be responsible for the development of the tumor-induced seizures are then discussed.