Table 1.

Summary of 2015 international diagnostic criteria for neuromyelitis optica spectrum disorder3

Diagnosis with AQP4-Abs

  • at least one core clinical characteristic

  • positive AQP4-Abs with best available method

  • exclusion of alternative diagnosis (eg sarcoidosis, neoplastic/paraneoplastic, vascular, chronic infection).

Diagnosis without AQP4-Abs/unknown status

  • at least two core clinical characteristics resulting from one or more clinical attacks and fulfilling the following:

    • at least one of optic neuritis, LETM, APS

    • dissemination in space (two or more different core clinical characteristics)

    • fulfilment of additional MRI requirements as applicable

  • negative for AQP4-Abs with best available method, or testing unavailable

  • exclusion of alternative diagnoses.

Core clinical characteristics

  • optic neuritis

  • acute myelitis

  • APS

  • brainstem syndrome

  • symptomatic narcolepsy or acute diencephalic syndrome with NMOSD-typical diencephalic MRI lesions

  • symptomatic cerebral syndrome with NMOSD-typical brain lesions.

Additional MRI requirements for NMOSD without AQP4-Abs/unknown status

  • acute optic neuritis: normal or only non-specific white matter lesions on MRI brain; or optic nerve MRI with T2-hyperintense lesion or T1-weighted gadolinium-enhancing lesion extending over >½ optic nerve length or optic chiasm involvement

  • acute myelitis: MRI spinal cord demonstrating attack-associated lesion spanning ≥3 contiguous vertebral segments (LETM); or ≥3 contiguous segments of focal cord atrophy with previous history of acute myelitis

  • APS: dorsal medulla/area postrema lesion on MRI brain

  • acute brainstem syndrome: periependymal brainstem lesions.

  • APS = area postrema syndrome; AQP4-Abs = aquaporin-4 antibodies; LETM = longitudinally extensive transverse myelitis; NMOSD = neuromyelitis optica spectrum disorder; MRI = magnetic resonance imaging.