Overview Snapshot A 56-year-old female is brought to the emergency department by her daughter due to new-onset abnormal movements suggestive of a seizure. While the patient is being managed, the physician learns that the patient is being treated for lung cancer. Head CT was obtained after the patient was stabilized. Introduction Structure tight junctions between nonfenestrated capillary endothelial cells also consists of astrocytic foot processes, pericytes, basement membrane irradiation, malignancy, infection can disrupt the blood-brain barrier (BBB) infarction destroys tight junctions → vasogenic edema login to view 1 more bullet Function control entry of substances into the brain substances cross via diffusion, ion channels, and selective transport proteins login to view 6 more bullets certain areas of the CNS lack a BBB posterior pituitary (neurohypophysis) login to view 1 more bullet area postrema login to view 1 more bullet organum vasculosum lamina terminalis (OVLT) login to view 1 more bullet