Introduction: Seizures are a common and potentially devastating manifestation of intracranial metastatic disease. Characterizing the seizure rate and determining which primary cancers may be associated with an increased seizure rate allows for better management of patients with intracranial metastasis through prevention of seizures.
Methods: Relevant publications were identified through electronic searches of PubMed and Embase databases using search terms related to brain metastasis and seizure. Google Scholar results were used to supplement the study. Studies published between January 2000 and July 2014 with thirty or more consecutive adult patients with brain metastasis from all primary cancers were included. The overall seizure rate was calculated by summating the data. Differences between observed and expected seizure rates between primary tumour sites were examined using the chi-square statistic and adjusted standardized residuals.
Results: A systematic search produced 18 studies relevant for this review, with a total study population of 2012 adult patients with confirmed brain metastasis. Of the 2012 patients, 14.6% (n=294) had seizures. There was a significant association between primary tumour site and seizure rates. The seizure rate in patients with primary melanoma tumours was significantly greater than for all other primary cancer types (z = 2.7; p=.006). The seizure rate in patients with primary prostate tumours was significantly lower than for all other primary cancer types (z = -2.6; p=.008).
Conclusions: Patients with intracranial metastasis demonstrate an appreciable seizure rate. Seizure rates appear to be greater in certain primary tumours, such as melanoma. Antiepileptic drugs and avoidance of medications that lower seizure threshold may be important to consider in managing patients with intracranial metastasis.
Patient Care: The goal of managing patients is to improve their quality of life. Seizures pose a significant medical risk to, and have considerable emotional and psychological impact on, patients. In understanding the association between seizure and intracranial metastasis, we hope to identify strategies and interventions that reduce the morbidity associated with seizures. Our study provides support for treating seizures prophylactically in patients with intracranial metastasis. In understanding how likely these patients will suffer from seizure, we can begin to stratify which patients will benefit from intervention and what strategy will be sufficient. Late stage cancer is associated with a large burden of disease, results from this study aim to guide management of these patients in order to reduce some of the burden.
Learning Objectives: By the conclusion of this session, participants should be able to 1) Appreciate the association between intracranial metastasis of different primary cancers and seizure, 2) Discuss the impact that seizures have on these patients, 3) Identify possible interventions to manage and prevent seizures in patients with intracranial metastasis