NMOSD is an autoimmune-mediated idiopathic inflammatory demyelinating disease with typical clinical presentation of optic neuritis, acute myelitis, and area postrema syndrome.

Abbreviation
NMOSD, neuromyelitis optica spectrum disorder.

Reference
Zhang Y-X, et al. Front Immunol. 2022;13:864664.

The clinical course of NMOSD historically took one of two forms: monophasic or relapsing, with relapsing forms comprising approximately 80–90% of cases. However, after an index event, the distinction between monophasic and relapsing NMOSD is often difficult to make since relapses can occur many years after an event. In the vast majority of cases, a relapse occurs within 3 years after the index event.

Abbreviation
NMOSD, neuromyelitis optica spectrum disorder.

Reference
Oh J and Levy M. Neurol Res Int. 2012;2012:460825.

The initial workup in people with suspected NMOSD must include a detailed medical history and an extended physical and neurological examination. Additional mandatory diagnostic tests include cranial and spinal MRI and serum AQP4-IgG antibody testing. The most important antibody-related differential diagnosis of NMOSD is MOGAD, so MOG-IgG should also be tested to rule out this condition. As AQP4-IgG and MOG-IgG are produced mainly extrathecally, serum should be used for AQP4-IgG determination as the biomaterial of choice.

Abbreviations
AQP4-IgG, aquaporin-4 immunoglobulin G; MOGAD, myelin oligodendrocyte glycoprotein antibody-associated disease; MOG-IgG, myelin oligodendrocyte glycoprotein-immunoglobulin G; MRI, magnetic resonance imaging; NMOSD, neuromyelitis optica spectrum disorder.

Reference
Jarius S, et al. J Neurol. 2023;270:3341–68.

The standard of care for acute attacks in both AQP4 IgG-positive and double-negative NMOSD are high-dose glucocorticoids and plasma exchange. For patients with severe NMOSD attacks, simultaneous treatment with glucocorticoids and plasma exchange should be considered. IV methylprednisolone should be usually administered at a dose of 1,000 mg per day for 3–5 days, followed by an oral methylprednisolone taper (starting with either 1 mg/kg/day or 20–30 mg/day and then tapered to 10–15 mg/day within 2–3 weeks) in combination with proton pump inhibition and possible thrombosis prophylaxis.

Abbreviations
AQP4-IgG, aquaporin-4 immunoglobulin G; IV, intravenous; NMOSD, neuromyelitis optica spectrum disorder.

Reference
Kümpfel T, et al. J Neurol. 2024;271:141–76.

Currently, there is no known curative treatment for NMOSD; therefore, the main goals of therapy are to counteract acute attacks promptly and effectively and to prevent future attacks by initiating immunotherapy as soon as a definite diagnosis of NMOSD is established.¹ Several prospective randomized controlled trials have led to approval of immunotherapies for patients with AQP4-IgG-positive NMOSD. Eculizumab,^2,3 inebilizumab,^4,5 ravulizumab,^6,7 and satralizumab^8,9 are all approved for treatment by the FDA and the EMA, and rituximab is approved for treatment in Japan and used off-label in many other countries.¹

Abbreviations
AQP4-IgG, aquaporin-4 immunoglobulin G; NMOSD, neuromyelitis optica spectrum disorder.

References

1. Kümpfel T, et al. J Neurol. 2024;271:141–76.
2. FDA. Eculizumab PI. 2020. Available at: https://bit.ly/3LaMIO6 (accessed 25 June 2024).
3. EMA. Eculizumab SmPC. 2023. Available at: https://bit.ly/3ROBJOk (accessed 25 June 2024).
4. FDA. Inebilizumab PI. 2020. Available at: https://bit.ly/3RRWvwg (accessed 25 June 2024).
5. EMA. Inebilizumab SmPC. 2024. Available at: https://bit.ly/3RUJemJ (accessed 25 June 2024).
6. FDA. Ravulizumab PI. 2024. Available at: https://bit.ly/3xECS47 (accessed 25 June 2024).
7. EMA. Ravulizumab SmPC. 2023. Available at: https://bit.ly/4cH9eKe (accessed 25 June 2024).
8. FDA. Satralizumab PI. 2022. Available at: https://bit.ly/4cPpY2d (accessed 25 June 2024).
9. EMA. Satralizumab SmPC. 2023. Available at: https://bit.ly/4cKXF4L (accessed 25 June 2024).