Progression of Motor and Non-Motor Symptoms in Multiple System Atrophy: A Prospective Study from the Catalan-MSA Registry

Abstract

Background/Objective: Multiple system atrophy (MSA) is a highly debilitating, rare neurodegenerative disorder with two clinical motor variants (parkinsonian or MSA-P and cerebellar or MSA-C). There is a wide span of motor and non-motor symptoms (NMS) that progress over time. We studied the cohort from the Catalan Multiple System Atrophy Registry (CMSAR) to determine which symptoms are most likely to progress throughout a 2-year follow-up. Methods: We analyzed baseline, 12-month, and 24-month follow-up evaluations from the 80 cases recruited by the CMSAR. Evaluations included the UMSARS assessment, cognitive and neuropsychiatric evaluations, and a non-motor scale (NMSS-PD). Statistical analysis was done using a Generalized Estimated Equations (GEE) model. Results: Both UMSARS I and II sub-scores significantly increased at 12- and 24-month follow-ups (p<0.001), with a median total score increase of 11 and 12.5 points, respectively. Items on UMSARS I that significantly worsened were mostly motor affecting daily activities. NMS, including urinary and sexual dysfunction, as well as sleep difficulties showed a significant progression on the NMSS-PD; however, other NMS such as postural hypotension, gastrointestinal, and mood dysfunction, although prevalent, did not show a clear progression on clinical scales. Conclusion: Within 24 months and as early as 12 months, MSA cases may experience significant motor worsening, affecting basic daily activities. NMS are prevalent; however, not all clinical scales register a clear progression of symptoms, perhaps suggesting that they are not sensitive enough for non-motor evaluation.