Juvenile and Adult-Onset ALS/MND Among Africans: Incidence, Phenotype, Survival: A Review
Résumé
Background:The few studies looking at ALS in African populations were mostly case series varying in methods, sample sizes and collected data. Nevertheless, ethnic variation in ALS incidence and phenotype is of increasing interest. We reviewed the epidemiology of ALS in subjects of African origin, principallyincidence, phenotype and prognosis.Methods:We searched Medline, Scopus, Science direct, Bibliothèque Virtuelle de Neurologie Africaine (BVNA), (http://www-ient.unilim.fr/) and African journal OnLine databases using the following search terms “amyotrophic lateral sclerosis (ALS)”, “motor neuron disease (MND)” or “Charcot disease”, in combination with “Africa”, “ethnic groups”, “blacks” or “epidemiology”. Of 1264 references examined, 35 were included in this review.Results:Among the 35 references, 19 studies were performed in the African continent and dealt with MND/ALS; four other studies focused on ALS-like syndromes; finally, 12 studies were not performed in Africa but focused on either incidence and mortality or survival of ALS in subjects of African origin. Several characteristics of ALS among Africans or subjects of African origin were identified: (i) lower incidence rates among people of Africanorigin living in western countries, (ii) higher incidence of classic ALS among men, (iii) presence of juvenile form, (iv) younger age at onset of classic ALS. We cannot draw firm conclusions about (i) the prognosis in African ALS patients, (ii) prognostic factors, (iii) genetic or behavioral factors affecting incidence or clinical phenotype