| 1. At least 1 core clinical characteristic |
| 2. Positive test for AQP4-IgG using best available detection method (cell-based assay strongly recommended) |
| 3. Exclusion of alternative diagnoses |
|
Diagnostic criteria for NMOSD without AQP4-IgG or NMOSD with unknown AQP4-IgG status
|
| 1. At least 2 core clinical characteristics occurring as a result of one or more clinical attacks and meeting all of the following requirements: |
| a. At least 1 core clinical characteristic must be optic neuritis, acute myelitis with LETM, or area postrema syndrome |
| b. Dissemination in space (2 or more different core clinical characteristics) |
| c. Fulfillment of additional MRI requirements, as applicable |
| 2. Negative tests for AQP4-IgG using best available detection method, or testing unavailable |
| 3. Exclusion of alternative diagnoses |
|
Core clinical characteristics
|
| 1. Optic neuritis |
| 2. Acute myelitis |
| 3. Area postrema syndrome: episode of otherwise unexplained hiccups or nausea and vomiting |
| 4. Acute brainstem syndrome |
| 5. Symptomatic narcolepsy or acute diencephalic clinical syndrome with NMOSD-typical diencephalic MRI lesions |
| 6. Symptomatic cerebral syndrome with NMOSD-typical brain lesions |
|
Additional MRI requirements for NMOSD without AQP4-IgG and NMOSD with unknown AQP4-IgG status
|
| 1. Acute optic neuritis: requires brain MRI showing (a) normal findings or only nonspecific white matter lesions, OR (b) optic nerve MRI with T2-hyperintense lesion or T1-weighted gadolinium- enhancing lesion extending over .1/2 optic nerve length or involving optic chiasm |
| 2. Acute myelitis: requires associated intramedullary MRI lesion extending over 3 contiguous segments (LETM) OR 3 contiguous segments of focal spinal cord atrophy in patients with history compatible with acute myelitis |
| 3. Area postrema syndrome: requires associated dorsal medulla/area postrema lesions |
| 4. Acute brainstem syndrome: requires associated periependymal brainstem lesions |
