Devic’s Neuromyelitis Optica with Positive Anti-Aquaporin-4 Antibody about Three Cases at the National Hospital of Niamey

Introduction: Devic’s neuromyelitis optica (NMO), or Devic’s disease, is a rare autoimmune disorder that belongs to the inflammatory demyelinating diseases of the central nervous system (CNS). It is a rare syndrome in Western countries, accounting for around 1% of demyelinating diseases of the central nervous system. However, its prevalence is rare in Niger. Objectives: To study the epidemiological, clinical, paraclinical, therapeutic and evolutionary aspects of NMO at National Hospital of Niamey. Methods: This is a case-report study conducted over a 34-month period from December 2019 to October 2022 involving patients with a diagnosis of NMO according to the latest 2015 Devic Neuromyelitis Optica Spectrum (NMOSD) criteria. Results: All cases in our study were girls aged between 12 and 23 years and met the 2015 diagnostic criteria. Initial clinical manifestations were 66% neuritis and 33% myelitis; acute transverse longitudinal myelitis was found in 66% of cases. Anti-Aquaporin-4 (anti-AQP4) antibodies were positive in 100% of cases. Management was based on corticosteroids alone in 66% of cases, and a combination of corticosteroids and prolonged immunosuppression in 33%. The Expanded Disability Status Scale (EDSS) score was 3 after 2 years of treatment and 8 after three weeks of treatment. Conclusion: NMO is an inflammatory demyelinating disease of the CNS, preferentially affecting the spinal cord and optic nerves, with a female predominance. Early diagnosis and management can limit neurological disability. Treatment in the acute phase is based on high-dose corticosteroid therapy, or plasma exchange therapy in the event of failure to respond.