Progressive multiple sclerosis patients have a higher burden of autonomic dysfunction compared to relapsing remitting...

To determine autonomic dysfunction (AD) differences in patients with relapsing remitting multiple sclerosis (pwRRMS) and progressive MS (pwPMS).

Composite autonomic scoring scale (CASS) and heart rate variability (HRV) were performed in 40 pwRRMS and 30 pwPMS.

pwPMS had a significantly higher sudomotor index and total CASS score compared to pwRRMS (p < 0.001 and p < 0.001, respectively). Disease duration positively correlated with sudomotor index and total CASS (r_s = 0.409, p < 0.001 and r_s = 0.472, p < 0.001, respectively), while the Expanded Disability Status Scale (EDSS) positively correlated with sudomotor index and total CASS (r_s = 0.411, p < 0.001 and r_s = 0.402, p = 0.001, respectively) in all patients. Type of multiple sclerosis (pwRRMS or pwPMS) corrected for age, sex and disease duration, was a statistically significant predictor of CASS value (B = 1.215, p = 0.019). Compared to pwRRMS, pwPMS had a significantly lower standard deviation of NN intervals (SDNN), low frequency (LF), and high frequency (HF), during both the supine and tilt-up phases (all p-values <0.006). pwPMS had a significantly lower LF/HF (p = 0.008) during tilt-up.

There is a significant difference in autonomic function in pwRRMS and pwPMS; with pwPMS having a higher burden of AD, which is particularly evident for sweating dysfunction.

Further research is needed to establish whether parasympathetic and sudomotor dysfunction may serve as markers of progressive MS.