Between 30% and 50% of patients with brain tumors first present with a seizure, 
and up to 30% more will develop seizures later. Therefore, optimal management of 
these patients requires a rational approach to the use of antiseizure 
medications. Based on current evidence, prophylactic prescription of long-term 
antiepileptic drugs (AEDs) in patients with brain tumors in patients who did not 
present with seizures is not justified. Because of the high risk of recurrence, 
however, AED treatment should be strongly considered after a single seizure 
considered to be due to a tumor. Because of the lack of well-controlled 
randomized trials, the decision on which AED provides the best risk-benefit 
ratio in the individual patient is based mostly on physician's judgment rather 
than sound scientific evidence. In patients who may require chemotherapy, a 
non-enzyme-inducing AED is preferred for initial treatment to minimize the risk 
of drug interactions that impact adversely on the outcome of anticancer 
chemotherapy. Several retrospective studies in seizure patients with 
glioblastoma treated with chemotherapy have provided evidence for a moderately 
improved survival with the use of valproic acid, possibly due to inhibition of 
histone deacetylase. However, valproic acid may also increase the hematologic 
toxicity of antineoplastic drugs, presumably by inhibiting their metabolism, and 
may independently impair hemostasis, which is of some concern for patients who 
require surgical intervention. Among newer generation AEDs, levetiracetam has a 
number of advantageous features, including availability of a parenteral 
formulation, but other agents such as gabapentin, lamotrigine, oxcarbazepine, 
topiramate, and zonisamide may also be considered. Potentially more effective 
treatments targeting specific mechanisms of epileptogenesis and ictogenesis are 
being investigated. Resection of the tumor, radiation therapy, or chemotherapy 
can bring refractory seizures under control or prolong the duration of seizure 
freedom, an effect that does not appear to be necessarily related to removal or 
shrinkage of the tumor mass. In patients with a successfully treated tumor and 
an overall good prognosis for long-term survival, gradual discontinuation of 
AEDs may be considered.