Snapshot A 67-year-old woman presents to the emergency department by her daughter due to an observed seizure-like event. The daughter states that this is the first time she has ever had a seizure. The daughter also reports that for the past few weeks she has had progressively worsening diffuse headaches, which are more severe in the morning, and accompanied by nausea. Medical history is significant for breast cancer. On physical exam, there is right-sided weakness in both upper and lower extremities. A head CT was obtained which showed hyperdense lesions with surrounding vasogenic edema. Introduction Most common intracranial malignancy in adults most commonly carcinomas such as lung breast kidney colorectal melanomas In children, most common sources are sarcomas neuroblastomas germ cell tumors Epidemiology > 50% of all intracranial tumors etiology Pathogenesis hematogenous spread (most commonly) usually found at gray-white matter junction Presentation Highly variable clinical presentation must be suspected in patients with a history of malignancy who present with neurologic symptoms or behavioral abnormalities Symptoms headache morning headache is highly suggestive although it is uncommon nausea and vomiting cognitive dysfunction e.g., personality changes and altered mental status seizure of new onset stroke patients with malignancy are at risk of being hypercoagulable may hemorrhage into the metastasis tumor may compress artery Physical exam focal neurologic deficit e.g., hemiparesis location dependent papilledema imaging Contrast-enhanced MRI preferred for diagnosing brain metastasis features suggestive of metastasis multiple lesions lesions at grey-white matter junction vasogenic edema large when compared to lesion size studies Brain biopsy when diagnosis is unclear Differential Primary brain tumor Intracranial abscess Progressive multifocal leukoencephalopathy (PML) Cerebral infarction or hemorrhage Treatment Increased intracranial pressure dexamethasone Seizures phenytoin Radiation therapy Surgery stereotactic radiosurgery surgical resection neurosurgical resection is the standard for a single or limited number of metastases in a surgically accessible location Prognosis If untreated, the median survival from solid tumors of brain metastases is ~ 1-2 months