Finding NMO: The Evolving Diagnostic Criteria of Neuromyelitis Optica

Abstract

Neuromyelitis optica (NMO) is an autoimmune demyelinating disorder of the central nervous system (CNS) with predilection for the optic nerves and spinal cord. Since its emergence in the medical literature in the late 1800's, the diagnostic criteria for NMO has slowly evolved from the simultaneous presentation of neurologic and ophthalmic signs to a relapsing or monophasic CNS disorder defined by clinical, neuroimaging, and laboratory criteria. Due to the identification of a specific autoantibody response against the astrocyte water channel aquaporin-4 (AQP4) in the vast majority of affected individuals, the clinical spectrum of NMO has greatly expanded necessitating the development of new international criteria for the diagnosis of NMO spectrum disorder (NMOSD). The routine application of new diagnostic criteria for NMOSD in clinical practice will be critical for future refinement and correlation with therapeutic outcomes.

Conflict of interest statement

The author reports no conflicts of interest.

Figures

FIG. 1

Magnetic resonance imaging in neuromyelitis optica spectrum disorders. A. Sagittal T2 scan shows longitudinally extensive cervical cord lesion extending into dorsal medulla. T2 (B) and postcontrast T1 (B′) central spinal cord lesions. C. Postcontrast T1 scan reveals extensive enhancing lesion of the optic nerve. D. Fluid-attenuated inversion recovery (FLAIR) imaging demonstrates bilateral prechiasmal and chiasmal optic nerve inflammation. E. Bilateral FLAIR lesions involve the dorsal medulla (area postrema). F. Bilateral confluent T2 lesions in the mid-pons. G. Sagittal FLAIR image demonstrates periependymal lesions around the fourth ventricle. H. Sagittal FLAIR image reveals diffuse hypothalamic inflammation. Axial FLAIR images show bilateral, confluent deep white matter (I, J) and thalamic (J) lesions.