[Multiple sclerosis in Mexico: a multicentre study].
INTRODUCTION: Multiple sclerosis (MS) is considered to be a low prevalence disease in Mexico; its characteristics have been described in isolated studies in small populations concentrated in a single region of the country and using heterogeneous methodological tools. AIMS. In this study, our aim was define the clinical profile and some socio demographic aspects of MS in Mexico using validated homogeneous criteria and tools. PATIENTS AND METHODS: Eight hospitals representing the five most densely populated regions of the country, the north, centre and south of Mexico, took part in the study. Data were obtained through a survey created, validated and published in Spanish (k interobserver 0.73 and k intraobserver 0.76), which consisted of 142 questions arranged in 10 sections and which was applied by 12 neurologists. The procedure was verified with 50 randomly selected surveys. A total of 337 surveys were applied, which were analysed by descriptive statistics using the EPI INFO, version 6.04b, software application. All the patients presented MS that had been clinically defined with the help of paraclinical studies according to Schumaher and Poser's criteria. RESULTS: A sample of 337 patients was studied; 99.1% were mestizos, with an average age of 37 9 years, 69.7% were females and 30.3% males. 95% had access to the Social Security system and 96% had been born in Mexico to Mexican parents. No cases were found among native Mexicans. The clinical profile of the disease did not differ to that reported in other countries; the pattern observed corresponded to that found in northern latitudes. CONCLUSION: This is the first multicentre study carried out in Mexico with a population that is highly representative of the whole country and with a homogeneous methodology.