Profil clinique et paraclinique de la myasthénie auto-immune à Ouagadougou au Burkina Faso

INTRODUCTION: Certain differences in the epidemiological, clinical, paraclinical and evolution profiles of autoimmune myasthenia gravis (AIMG) are increasingly described in patients according to geographic origins. The present study was carried out in order to help characterize the socio-demographic, clinical and paraclinical profile of AIMG in Ouagadougou, Burkina Faso. PATIENTS AND METHODS: This was a cross-sectional, descriptive, multicenter, hospital study carried out in Ouagadougou (Burkina Faso), over a period of 5 years 6 months, from March 2015 to September 2019. The study concerned all patients who had a clinical symptomatology suggestive of myasthenia gravis, associated with the presence in the serum of anti-AChR Ab and / or anti-MuSK Ab and / or the presence of a >10% decrement in electroneuromyography and / or a positive therapeutic test for oral anticholinestherasics. Sociodemographic, clinical and paraclinical variables, were analyzed. RESULTS: A total of 25 patients (15 women and 10 men), were included. The young adult form was predominant (20 cases). The median time between the first symptoms and the diagnosis was 28.4 months +/- 44.8 (2 - 217 months). Diplopia and/or ptosis (80%) and dysphonia (72%) were the most frequent revealing clinical presentations. On admission, 7 patients (28%) had a moderate generalized form (MGFA class III) and 9 patients (36%) had a severe to very severe generalized form (MGFA class IV to V). Plasma Ab assays were performed in 17 patients (68%): anti-RACh Ab were positive in 11 patients (64.7%) and anti-MuSK Ab in 3 patients (14.3%). Thoracic CT revealed thymus hyperplasia in 12 patients (48%), thymoma in 5 patients (20%). Hyperthyroidism was associated in 2 patients (8%). CONCLUSION: AIMG in Ouagadougou, Burkina Faso is marked by delayed diagnosis, a predominance in young women, severe generalized forms and a high frequency of plasma anti-MuSK Ab. This profile appears to be different from that of Caucasian patients. Collaborative studies in the sub-Saharan region on AIMG in general populations are needed.