Although hemorrhage in the setting of tPA administration might imply that the etiology is treatment related, it is important to consider the differential of nontraumatic intracranial hemorrhage, which includes hypertension, amyloid angiopathy, vascular malformations, and hemorrhagic metastases (refer to Chaps. 2, 5, 16, 20, 29, 30, and 32). Hypertensive hemorrhages are typically parenchymal hemorrhages, commonly striatocapsular and thalamic. Amyloid angiopathy is common in older patients and often presents with lobar hemorrhage. Patients with bleeding secondary to a vascular malformation often present at a younger age, and an enhancing underlying lesion is eventually evident. Hemorrhage associated with the presence of enhancement may also occur secondary to a hemorrhagic neoplastic process, such as metastasis.