Seizures are a common and potentially devastating complication of both primary and metastatic brain tumors . Such seizures are focal in origin and may either remain focal or secondarily generalize. The diagnosis of a seizure disorder is usually made clinically.
The epidemiology and treatment of seizures, prophylactic use of antiepileptic drugs (AEDs), and complications of therapy in patients with brain tumors will be reviewed here. The clinical manifestations of brain tumors and the general management of seizures are discussed elsewhere. (See "Clinical presentation and diagnosis of brain tumors", section on 'Clinical manifestations' and "Overview of the management of epilepsy in adults".)
Seizures are a relatively common problem in patients with brain tumors. Seizures may be the initial manifestation of a brain tumor or may occur during the course of disease. (See "Clinical presentation and diagnosis of brain tumors", section on 'Seizures'.)
Factors that influence the incidence of seizures include tumor-type and location:
●Among patients with primary brain tumors, seizures are less common with high-grade compared with low-grade gliomas . As an example, the prevalence rates of epilepsy in a series of 1028 patients with primary brain tumors were 49, 69, and 85 percent among patients with glioblastoma (GBM), anaplastic glioma, and low-grade glioma, respectively . However, in one carefully studied series of 75 high-grade gliomas, seizures were present at diagnosis in 35 (52 percent), but occurred at some time during the course of the disease in 60 (80 percent) . Dysregulation of adenosine kinase in the peritumoral region of astrocytic brain tumors has been postulated to play a role in tumor-related epileptogenesis .