Objective: We aim 1) To describe the distribution of core clinical features of MSA, including age at onset, motor subtype, and cardinal symptoms, across global populations. 2) To describe neuroimaging, genetics and pathology biomarkers and 3) To estimate positive predictive value and misdiagnosis rates
Background: Multiple System Atrophy (MSA) is a rare, adult-onset synucleinopathy characterized by autonomic dysfunction, parkinsonism, and/or cerebellar ataxia, classified as MSA-P or MSA-C subtypes. Despite evolving clinical diagnostic criteria, main clinical variables are poorly characterized and clinicopathological concordance remains challenging.
Method: We systematically reviewed studies (January 2008–May 2025) reporting demographics, clinical and paraclinical features, with neuropathological confirmation when available. Six databases (PubMed, Embase, Web of Science, Scopus, LILACS, SciELO) were searched. Random-effects meta-analyses pooled prevalence estimates and continuous measures.
Results: Of 1,141 identified studies, 977 (after removing overlaps) represented 55,501 participants from 46 countries; 378 were meta-analyzed. The global MSA-P:MSA-C ratio was 1:1.03, with MSA-P predominating in North America/Europe and MSA-C in East Asia. Mean age at onset ranged from 36.7 to 69.0, and mean of disease duration ranged from 0.2 to 19 years. Reported symptoms frequency was 63.63% for parkinsonism, 59.22% for cerebellar signs, and 66.39% for dysautonomia. Genetic data appeared in 116 studies, and neuropathology related data in 149 studies. The overall positive predictive value was 89.41%, with a misdiagnosis rate of 10.59% (based on 48 relevant studies).
Conclusion: This largest-to-date global review highlights marked geographic variation in MSA subtypes and persistent diagnostic limitations. Greater access to neuroimaging and pathological assessments in diverse populations is essential to improve management of MSA.
Abstract presented in the Annual Investigators Meeting GP2, Hawaii, October 17, 2025. This work served as the primary research project for the Master of Science (MSc) in Clinical Neurology program at University College London (UCL) for M Cornejo-Olivas.
To cite this abstract in AMA style:
M. Cornejo-Olivas, M. Galecio-Castillo, A. Abad, Y. Nuñez-Coronado, J. Gutierrez-Arratia, C. Alarcon-Ruiz, M. Illanes-Manrique, M. Alfaro-Olivera, C. Armas-Puente, E. Sarapura-Castro, E. Gatto, H. Morris. Clinical Features of Multiple System Atrophy Across Diverse Populations: A Systematic Review of Subtypes and Diagnostic Frameworks [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/clinical-features-of-multiple-system-atrophy-across-diverse-populations-a-systematic-review-of-subtypes-and-diagnostic-frameworks/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/clinical-features-of-multiple-system-atrophy-across-diverse-populations-a-systematic-review-of-subtypes-and-diagnostic-frameworks/