NMOSD is characterized by two primary clinical manifestations: optic neuritis and transverse myelitis. These manifestations can either co-occur or be separated by several years. Patients experiencing optic neuritis may present with a range of vision loss severity, often accompanied by eye pain that worsens during eye movement. On the other hand, individuals with transverse myelitis typically exhibit a symmetric weakness of the limbs( paraparesis or quadriparesis), bladder dysfunction, and sensory impairment below the level of the affected spinal cord (8). Additional clinical features that can be observed in NMOSD include encephalopathy, fulminant cerebral demyelination, hypothalamic dysfunction, area postrema syndrome, and PRES (8, 9).
Our patient meets the two core clinical criteria for the diagnosis of NMOSD, which include optic neuritis and longitudinally extensive transverse myelitis (10). The positive anti-aquaporin- 4 antibodies and the absence of other competing diagnoses further support her condition's alignment with the international consensus criteria. The previously conducted MRI, performed 18 months ago, indicated the presence of right pre-chiasmatic optic nerve swelling and contrast enhancement, which are suggestive of optic neuritis. Furthermore, the most recent Spinal MRI (Image 1) revealed longitudinally extensive transverse myelitis extending from the C7 level and involving the entire thoracic cord up to the distal cord level. Our patient does not exhibit the clinical features typically associated with systemic lupus erythematous, and no indications suggest sarcoidosis. Laboratory tests have confirmed an adequate level of serum vitamin B12, effectively ruling out the most common alternative diagnosis for NMOSD.
Left untreated, NMOSD manifests as a recurring condition characterized by intermittent attacks, partial recoveries, and persistent disabling deficits. Patients with NMSOD acute attack are usually treated with high-dose parenteral steroids and Methylprednisolone to prevent further damage and restore neurologic function (11). Patients with severe symptoms, especially with vision loss not responding to steroids, can also benefit from plasma exchange as an adjunctive therapy. Immunotherapy with Complement c5 inhibitors like eculizumab, Anti CD 19 antibodies like Inebilizumab, and Interleukin 6 receptor antagonists like Satralizumba are recommended in the prevention of future attacks in patients with AQP4 positivity as they all have shown effectiveness (12, 13, 14). These groups of medications have a better quality of data and are hence preferred as opposed to other systemic immunotherapies like Azathioprine, methotrexate, and Mycophenolate Mofetil where the evidence is based on observational studies (15, 16, 17). Yet, multiple observational studies and local data suggest that these agents can be efficaciously employed to treat NMOSD, leading to favorable clinical outcomes (18, 19, 20).
Based on our experience of treating this patient and local data from other documented cases, it is suggested that patients can be effectively treated with available therapies, leading to positive clinical and functional outcomes, unless newer immunosuppressive treatments targeting the underlying pathophysiology are available (19, 20, 21, 22, 23, 24).
In conclusion, the findings of our case report and other case reports originating from Ethiopia emphasize the importance of considering the diagnosis of NMOD for patients who meet the diagnostic criteria outlined by the 2015 International Panel for NMOSD. The diagnosis and management of NMOSD pose significant challenges within resource-limited settings. Azathioprine is an effective therapeutic option, thus serving as an alternative treatment choice for NMOSD patients residing in countries with limited access to immunotherapies such as inebilizumab, eculizumab, rituximab, and satralizumab, which are approved for NMOSD treatment. There, it is imperative to keep a high degree of clinical suspicion to avoid the detrimental effects of delayed diagnosis and treatment.