Frequency and characteristics of dysautonomic symptoms in multiple sclerosis: a cross-sectional double-center study with the validated Italian version of the Composite Autonomic Symptom Score-31

Background: Dysautonomic symptoms (DS) are frequent but often underrecognized in multiple sclerosis (MS) patients, despite the relevant impact on quality of life and physical performance. Objectives: To assess frequency and characteristics of DS in our MS population compared with healthy controls (HC). To investigate the relationship between DS and disease characteristics (MS subtype, disease duration, Expanded Disability Status Scale (EDSS), clinical and/or radiological activity, disability progression). Patients and methods: Cross-sectional study includes 324 MS patients (mean age 44.9 ± 10.7 years; 66% female) and 190 HC (mean age 40.60 ± 12.83 years; 63% female). DS were assessed using the Italian validated version of the Composite Autonomic Symptom Score-31 (COMPASS-31). Possible confounding factors were considered. Results: More than 94% of enrolled MS patients reported alterations in ≥ 2 domains of the COMPASS-31 scale (score > 0) and significantly higher COMPASS-31 total and single domain median scores compared with HC, independently from possible confounding factors (orthostatic intolerance: p = 0.001; vasomotor: p = 0.017; secretomotor: p = 0.040; gastrointestinal: p = 0.047; bladder: p < 0.001; pupillomotor: p < 0.001; COMPASS-31 total score: p < 0.001). COMPASS-31 total, secretomotor, gastrointestinal, and bladder domain scores showed weak to moderate correlation with disease duration (Rho = 0.19, p < 0.001; Rho = 0.18, p = 0.01; Rho = 0.25, p = 0.030; Rho = 0.28, p < 0.001, respectively). A moderate correlation between EDSS score, COMPASS-31 total, and bladder domain scores (Rho = 0.32, p < 0.001 and Rho = 0.48, p < 0.001, respectively) was observed. Progressive subtypes showed higher COMPASS-31 total (p = 0.025), gastrointestinal (p = 0.07), and bladder (p < 0.001) domain scores vs relapsing-remitting patients. Conclusions: Our findings confirm that MS-related DS are frequent and tend to increase paralleling disease duration and clinical worsening, reaching the highest clinical impact in progressive subtypes.