Risk of seizure and its clinical implication in the patients with cerebral metastasis from lung cancer

Background: The prevalence, risk factors, and clinical implication of seizure development were investigated in patients with metastatic brain tumors. Methods: Medical records and radiological findings were analyzed retrospectively in 258 patients with brain metastasis from lung cancer who underwent Gamma Knife radiosurgery (GKS) between January 2008 and December 2009. Results: During the follow-up period 32 patients (12.4 %) experienced seizure episodes. Coexistence of leptomeningeal seeding was a significant risk factor related to development of seizure (p < 0.001). Prophylactic use of anticonvulsants was not correlated with reduction of seizure incidence (p = 0.818). Continued use of anticonvulsants was necessary in nine of the 258 patients (3.5 %) because of recurrent seizures. Imaging studies performed immediately after seizure attacks in the patients with known metastatic brain lesions revealed tumor progression or complications related to treatment in 35 of 42 episodes of seizure (77.8 %). Conclusions: Patients with metastatic lesions have a substantial risk of developing seizure. Seizure in known metastatic brain tumor patients are usually related to disease progression or complications of treatment. Follow-up imaging should be considered for each seizure episode and adequate multimodal treatment needs to be added to antiepileptic medication.