To describe clinical characteristics and disease progression in a natural history cohort of patients with Multiple System Atrophy (MSA)

MSA is a rare, progressive, and fatal neurodegenerative disorder that manifests with a range of motor and non-motor symptoms, leading to significant physical impairments as disease progresses. Characterizing the disease progression in a cohort of patients who correspond to typical enrollment criteria employed in MSA interventional treatment clinical trials is of interest to the MSA research community.

402 Patients with a diagnosis of possible and probable MSA were recruited into the Natural History Study of Synucleinopathies cohort and followed annually. Among these, a subset of patients was selected to represent enrollment criteria employed in MSA interventional treatment clinical trials (N=43).  Progression was examined using Parts I and II of the validated and commonly used Unified MSA Rating Scale (UMSARS). 

Disease progression was evident after one and two years on each evaluation of the UMSARS.  The association between disease progression and UMSARS Part I (via linear regression) after 1 and 2 years was evident (R = 0.59, P < 0.001).  Mean UMSARS Part I scores (SD) at baseline, year 1 and year 2 were 18.7 (4.6), 24.6 (5.3), and 29.2 (6.9), respectively.    Similarly, the measure of association between UMSARS Part II on disease progression was R = 0.58 (P < 0.001), with mean scores (SD) at baseline, year 1 and year 2 of 18.5 (6.1), 23.6 (5.4), and 32.2 (8.2), respectively.