Neuromyelitis optica spectrum disorder in Africa: What is the current state of knowledge?

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a chronic autoimmune inflammatory disease of the central nervous system, usually involving the optic nerve, brain, and spinal cord. While the disease is believed to be more common among individuals of African descent, the disease landscape across the continent has not been systematically explored. In this study, we carried out a systematic scoping review by synthesizing original studies on NMOSD from Africa. Methods: A comprehensive literature search of PubMed (MEDLINE), Scopus, Embase, and Web of Science databases with the search terms & lsquo;neuromyelitis optica & rsquo; and & lsquo;Africa & rsquo; was performed on June 17, 2020. Synthesis of the result was done using narrative analysis. Result: Of the total 133 identified records, 14 eligible studies from Africa were included. Most of the studies were from North African countries (n = 8; 57%); predominantly retrospective descriptive (n = 8; 57%), or case series (n = 3; 21%); and published within the last two decades (n = 13; 93%). The total number of cases in the studies is 332, with a reported female to male ratio of 4:1 and an age range of 12 & ndash;88 years at disease onset (average of <40 years in 50% of reports). Aquaporin-4 antibodies was tested in 214 cases and found in 61.7%. Three cases had Myelin Oligodendrocyte Glycoprotein antibody test with one of the cases testing positive and was associated with severe optic neuritis. Autoimmune disorders were reported in 23 out of 93 cases from three studies, while a few studies reported infectious disease associations. IV methylprednisolone was the rule during acute attacks from all the studies, while the choice of medication for maintenance varies, possibly depending on availability and cost. Conclusion: The research landscape on NMOSD in Africa, though limited, provides significant insight into the epidemiology, etiology, and clinical characteristics of the disease. Gaps still exist in the knowledge of disease management. Further research focusing on the African context is needed to provide customized evidence-based care to patients with NMOSD.