Coexistence of myasthenia gravis and neuromyelitis optica spectrum disorder: case report in Colombia and literature review

Abstract

Myasthenia Gravis (MG) and Neuromyelitis Optica Spectrum Disorder (NMOSD) are antibody-mediated channelopathies caused by complex immunological mechanisms, which are thus associated with multiple autoimmune diseases. This paper describes the case of a Colombian male patient with a history of seropositive MG that required thymectomy. After four years, he had an Optic Neuritis event and 30 years later, due to suspected autoimmune comorbidities, further investigations were performed, confirming the coexistence of NMOSD with presence of Anti-Aquaporin 4 (AQP4) antibodies (Abs). Several reports in the literature show that the coexistence of these two pathologies is more common than expected by chance. Few cases have been reported in Latin America, which makes this report meaningful. In contrast to our case, the literature shows a higher incidence among women, but, on the other hand, it is consistent with an onset with mild or moderate MG symptoms at the clinical presentation, most of which led to thymectomy, followed by manifestations of NMOSD. Timely diagnosis and the consequent therapeutic adjustment may have a significant impact on the disability of these patients. There is a need for more reports in order to extend the statistical information and to improve the characterization of these patients, primarily in our Latin American region.