AQP4 and narcolepsy: The characteristic brain lesions of NMOSD typically occur in areas abundant in AQP-4, including the periependymal regions surrounding the lateral ventricles, and the cerebral aqueduct.[7] These lesions are the anterior border of the thalamus, hypothalamus, and midbrain.[7] NMOSD frequently invades the area postrema and nucleus tractus solitarius, the dorsal medulla oblongata adjacent to the fourth ventricle.[7] When periependymal lesions surrounding the lateral ventricles are affected in NMOSD, SIADH, symptoms such as narcolepsy, and changes in body temperature can occur.