RESUMO
OBJECTIVE: The aim of this study was to determine the prevalence of pathologic response to orthostatic challenge in patients with relapsing remitting multiple sclerosis (RRMS) and the difference of the response in patients in relapse and remission. PATIENTS AND METHODS: We included 112 RRMS patients; group 1 included 53 patients in a relapse and group 2, 59 patients in remission. The head up tilt table test was used to provoke an orthostatic reaction. RESULTS: 71 (63%) patients (60.4% and 66% of relapse and remission subjects respectively) had a pathological response to orthostatic provocation. Syncope was found in 9 (17%) patients in group 1 compared to 22 (37.3%) in group 2 (p=0.014). Postural orthostatic tachycardia syndrome (POTS) was found in 17 (32%) patients in group 1 compared to 4 (6.8%) in group 2 (p=0.001). There was a significantly negative correlation between the Expanded Disability Status Scale (EDSS) and POTS (-0.201; p=0.034) and a positive correlation between the EDSS and syncope (0.190; p=0.044). CONCLUSION: The prevalence of distinct types of orthostatic autonomic dysfunction in different phases of RRMS seems to be in direct correlation with the EDSS. Furthermore, certain autonomic dysfunctions of orthostasis, more specifically syncope and POTS, tend to be increased in remission and relapse respectively.