Optic Neuritis as the Presenting Feature of Neuromyelitis Optica (NMO): Diagnosis and Management

Since its description in 1894 by Eugene Devic, many had considered neuromyelitis optica (NMO) to be a “variant” of multiple sclerosis (MS). Clinical and MRI differences between MS and NMO along with the landmark discovery of highly specific anti-aquaporin 4 (AQP4) antibodies in 2004 indicated that NMO is a distinct disease marked by severe demyelination of the central nervous system (CNS) with particular predilection for the optic nerves, spinal cord, and area postrema in the medulla. Over the last 13 years, there has been a plethora of research and clinical interest in NMO facilitating improved awareness among physicians. Despite this, controversies on how to best diagnosis and treat NMO persist. This chapter will discuss the current evidence-based understanding of optic neuritis as the presenting feature of NMO while highlighting a few actively debated differences in its clinical care throughout the world.