Postural orthostatic tachycardia syndrome associated with multiple sclerosis.

Background: The aim of this study was to determine if there is a difference in the frequency of postural orthostatic tachycardia syndrome (POTS) in patients with multiple sclerosis (MS) compared to patients with symptoms of orthostatic intolerance and with no evidence of MS or other neurological illness.

Methods: We analyzed data gathered from 293 patients who underwent the head-up tilt table test protocol. Group 1 included prospectively analyzed 112 with MS and group 2 included retrospectively analyzed 181 patients who were evaluated because of symptoms of orthostatic intolerance, and with no evidence of MS or other neurological illness. If POTS was identified the head-up tilt table test was repeated and supine as well as standing serum epinephrine and norepinephrine were determined.

Results: POTS was identified in 39 patients: 21 (19%) in the MS group comparing to 18 (10%) in the non MS group (p=0.035). There was no difference between groups in the occurrence of POTS associated syncope (p=0.52). There was no difference between groups in the epinephrine or norepinephrine in supine and standing positions. While both standing epinephrine and norepinephrine levels were significantly higher compared to levels in the supine position in the non MS group, only standing norepinephrine levels were significantly higher in the MS group.

Conclusions: The results of this study suggest that POTS is associated with MS.