NMOSDlike

NMOSDlike is a descriptive term used in some medical contexts to refer to neurological presentations that resemble neuromyelitis optica spectrum disorder (NMOSD) but do not clearly meet its diagnostic criteria, or to conditions that mimic NMOSD features. The label often applies to seronegative cases or to disorders that share similar clinical syndromes yet have different underlying biology, such as MOG-IgG–associated disease (MOGAD) or other inflammatory, infectious, or vascular etiologies.

Clinical features commonly described as NMOSD-like include optic neuritis and transverse myelitis, particularly longitudinally extensive transverse myelitis (LETM). Area postrema syndrome (intractable nausea, vomiting, hiccups) and brainstem or diencephalic involvement can occur but are less typical. Because NMOSD-like presentations overlap with other diseases, laboratory testing and imaging are essential for differentiation.

Diagnostic approach emphasizes a combination of clinical assessment, MRI findings, and antibody testing. Aquaporin-4 (AQP4)–IgG positivity supports NMOSD, but many NMOSD-like cases are seronegative. Testing for MOG-IgG helps distinguish MOGAD, which can present with NMOSD-like symptoms. MRI patterns, such as LETM, optic nerve involvement, and brain lesion distribution, aid differential diagnosis from multiple sclerosis and other inflammatory or infectious conditions. CSF analysis and exclusion of alternative causes are also important.

Management focuses on treating acute attacks and reducing relapse risk. Acute therapy typically includes high-dose corticosteroids, with plasma exchange for severe or refractory cases. Long-term immunosuppression or immunomodulation is guided by the underlying diagnosis rather than the NMOSD-like label alone. Prognosis varies and depends on the specific etiology, prompt diagnosis, and treatment response.