Neuromyelitis optica spectrum disorders (NMOSDs) are autoimmune disorders of astrocytic water channels associated with the highly specific serum biomarker, aquaporin-4 (AQP-4) IgG.1 Aquaporin-4 has high expression in the circumventricular organs and spinal cord. The area postrema (AP), located in the dorsal medulla, is the chemosensitive vomiting center and has high AQP-4 expression.2 The AP syndrome with unexplained hiccups, nausea, and vomiting is one of the core clinical characteristics in the 2015 diagnostic criteria for NMOSDs and may occur concurrently with a myelitis episode.1 Prior studies have suggested spinal cord lesions extending to the AP are specific for NMOSDs.3 However, in our clinical practice, we have encountered numerous non-NMOSD long myelopathies extending to the region of the AP. In this study, we evaluated whether longitudinally extensive cervical cord lesions extending to or accompanied by AP/dorsal medulla lesions on magnetic resonance imaging (MRI) are specific for NMOSDs.
Dubey D, Pittock SJ, Krecke KN, Flanagan EP. Association of Extension of Cervical Cord Lesion and Area Postrema Syndrome With Neuromyelitis Optica Spectrum Disorder. JAMA Neurol. 2017;74(3):359-361. doi:10.1001/jamaneurol.2016.5441