To review the pathophysiology of Neuromyelitis Optica Spectrum Disorders (NMOSD) and discuss its distribution pattern. To illustrate the main imaging findings of NMOSD, highlighting its main differences from Multiple Sclerosis (MS).

Neuromyelitis Optica spectrum disorder was first reported by Dr. Eugène Devic in the 19th century,who named it Neuromyelitis Optica. It is an inflammatory disease affecting the central nervous system (CNS), with a preference for optic nerves and spinal cord. The disease-specific autoantibody to aquaporin-4 (AQP4-Ab) damages astrocyte food processes in areas of the increased blood-brain barrier and plays a central role in the diagnosis. Bilateral and recurrent posterior optic neuritis typically occurs. Early on its knowledge, NMOSD had been thought to involve only the optic...

Pathophysiologicalconsiderations NMOSD is immunopathologically distinct of other demyelinating diseases because it has a target: AQP4. Aquaporin-4 is a protein molecule, part of a transmembrane water channel, that plays a role in water/sodium homeostasis, cardiovascular regulation, feeding, and energy homeostasis, immunomodulation, vomiting. It is expressed in the spinal cord, optic nerve, hypothalamus, periventricular areas, brainstem, and area postrema, and in basal cells of the olfactory epithelium as well. Autoantibodies cause complement activation, cellular damage, demyelination, and necrosis, leading to blood-brain barrier disruption. Lesions occur predominantlywhere these...

Neuromyelitis Optica Spectrum Disorders represent a severe morbid entity, with suggestive imaging findings and a defined list of differential diagnosis, including multiple sclerosis. Prompt suspicion is of utmost importance and must be recalled by the radiology resident, in order to improve diagnostic accuracy.

·MRI characteristics of neuromyelitis optica spectrum disorder. An international update Ho Jin Kim et al.Neurology®2015;84:1165–1173 (1) ·Differential diagnosis of neuromyelitis optica spectrum disorders. Sung-Min Kim, Seong-Joon Kim, Haeng Jin Lee, Hiroshi Kuroda, Jacqueline Palace and Kazuo Fujihara.Ther Adv Neurol Disord2017, Vol. 10(7) 265–289 . DOI:10.1177/ 1756285617709723
(2) ·Neuromyelitis Optica Spectrum Disorders: Spectrum of MR Imaging Findings and Their Differential DiagnosisBruna Garbugio Dutra, MD
Antônio José da Rocha, MD, PhD Renato Hoffmann Nunes, MD Antônio Carlos Martins Maia Júnior, MD,PhD.RadioGraphics 2018;38:169–193. Doi: 10.1148/rg.2018170141.(3) ·Brain Abnormalities in...