Updated Diagnostic Criteria for Neuromyelitis Optica Spectrum Disorders

Jeffrey M. Gelfand, MS, MAS reviewing Wingerchuk DM et al. Neurology 2015 Jul 14.

These consensus criteria allow for a broader range of clinical and imaging findings to support the diagnosis.

Neuromyelitis optica (NMO) is a neuroinflammatory disorder classically characterized by optic neuritis and myelitis. Most patients with NMO have immunoglobulin G antibodies to the astrocytic aquaporin-4 water channel (AQP4).

Now, the expert International Panel for NMO Diagnosis provides updated consensus recommendations for NMO spectrum disorders (NMOSD). These new criteria collapse everything under the NMOSD heading, because no meaningful biological distinctions exist between NMO and NMOSD.

For adults, diagnosis of NMOSD with AQP4-IgG requires:

Clinical presentation with at least one core syndrome: optic neuritis, acute myelitis, area postrema syndrome (intractable nausea and vomiting, or hiccups), an acute brainstem syndrome, symptomatic narcolepsy or acute diencephalic syndrome consistent with NMOSD with characteristic brain imaging, or a symptomatic cerebral syndrome consistent with NMOSD with characteristic brain imaging.

A positive serum or cerebrospinal fluid (CSF) AQP4 antibody test using a reliable assay; a cell-based assay is preferred over enzyme-linked immunosorbent assay (ELISA) or indirect immunofluorescence but is not widely available. (Cases in which the AQP4 antibody is positive in CSF but negative in serum occur only rarely.)

Exclusion of alternate diagnoses, particularly multiple sclerosis (MS), sarcoidosis, malignancy, paraneoplasia, and central nervous system infection.

Diagnosis of NMOSD without AQP4-IgG (as >20% of NMO patients lack AQP4 antibodies using the most sensitive assays available) requires:

At least two core clinical syndromes; one must be acute optic neuritis or myelitis or an area postrema syndrome.

Magnetic resonance imaging (MRI) features consistent with NMOSD, e.g., a longitudinally extensive spinal lesion (≥3 contiguous segments), a longitudinally extensive optic nerve lesion, an otherwise normal or nonspecific (i.e., not MS) brain MRI in the context of an acute optic neuritis or typical brainstem imaging findings.

The panel noted that these criteria should also apply to children, with a few caveats, especially that longitudinally extensive transverse myelitis (LETM) is probably less specific for NMO in children than in adults, as LETM is not infrequent in pediatric MS (about 15% of myelitis presentations) and can also occur with acute disseminated encephalomyelitis.

Citation(s):

Wingerchuk DM et al. International consensus diagnostic criteria for neuromyelitis optica spectrum disorders. Neurology 2015 Jul 14; 85:177.