Postural Orthostatic Tachycardia Predicts Early Conversion to Multiple Sclerosis after Clinically Isolated Syndrome.

BACKGROUND/AIMS: There have been suggestions that interactions exist between the autonomic nervous system (ANS) and the immune system functions in multiple sclerosis (MS). We aimed to evaluate the ANS dysfunction, more specifically postural orthostatic tachycardia syndrome (POTS), as a possible predictor of conversion to MS in patients with clinically isolated syndrome (CIS).

METHODS

In this observational, prospective, longitudinal study, 84 patients were enrolled (56 females, mean age 32.9 ± 8.9 years). Disease activity during a 6-month period was monitored (relapses and/or MRI disease activity indicated by new T2 or T1 enhancing lesions), and the following predictors analyzed: age, Expanded Disability Status Scale, MRI midbrain, pontine or medulla oblongata lesions, and POTS on the head up tilt test.

RESULTS

POTS was identified in 8 (9.5%) patients. Of 84 patients, 62 (73.8%) completed the 6-month follow-up, and 28 (45.2%) patients converted to MS. Results of the multivariate regression analysis revealed age (10-year increase) and POTS as significant predictors of early conversion to MS (OR 2.34, 95% CI 1.15-4.78, p = 0.019 and OR 12.40, 95% CI 1.13-136.62, p = 0.040). The logistic model was statistically significant, χ2 (6) = 13.885, p = 0.031.

CONCLUSION

POTS may be an indicator of a more active disease course in CIS patients and possibly be used as a prognostic factor.