Application of the McDonald criteria in Latin America.

The diagnosis of multiple sclerosis (MS) is based on neurological symptoms and signs, alongside evidence of dissemination of central nervous system (CNS) lesions in space and time. In the absence of a sensitive and specific diagnostic test, diagnostic criteria are needed for diagnosing MS. The caveat to the application of the McDonald criteria is that alternative diagnoses must be excluded. The prevalence, clinical phenotype and the differential diagnosis of MS may have variations in different populations, especially in Latin America (LATAM). Considering that MS diagnostic criteria were developed with data gathered largely from adult Caucasian European and North American populations, their applicability and accuracy in ethnical/genetic diverse populations may be affected. There are scarce data in our region about the reliability of MS criteria.