Risk Factors for Preoperative Seizures and Loss of Seizure Control in Patients Undergoing Surgery for Metastatic Brain Tumors

OBJECTIVE: Metastatic brain tumors are the most common brain tumors in adults. Patients with metastatic brain tumors have poor prognoses with median survival of 6e12 months. Seizures are a major presenting symptom and cause of morbidity and mortality. In this article, risk factors for the onset of preoperative seizures and postoperative seizure control are examined. METHODS: Adult patients who underwent resection of one or more brain metastases at a single institution between 1998 and 2011 were reviewed retrospectively. RESULTS: Of 565 patients, 114 (20.2%) patients presented with seizures. Factors independently associated with preoperative seizures were preoperative headaches (P=0.044), cognitive deficits (P=0.031), more than 2 intracranial metastatic tumors (P=0.013), temporal lobe location (P=0.031), occipital lobe location (P=0.010), and bone involvement by tumor (P=0.029). Factors independently associated with loss of seizure control after surgical resection were preoperative seizures (P=0.001), temporal lobe location (P=0.037), lack of postoperative chemotherapy (P=0.010), subtotal resection of tumor (P=0.022), and local recurrence (P=0.027). At last follow-up, the majority of patients (93.8%) were seizurefree. Thirty patients (5.30%) in total had loss of seizure control, and only 8 patients (1.41%) who did not have preoperative seizures presented with new-onset seizures after surgical resection of their metastases. CONCLUSIONS: The brain is a common site for metastases from numerous primary cancers, such as breast and lung. The identification of factors associated with onset of preoperative seizures as well as seizure control postoperatively could aid management strategies for patients with metastatic brain tumors. Patients with preoperative seizures who underwent resection tended to have good seizure control after surgery.