Multiple system atrophy: advances in pathophysiology, diagnosis, and treatment.

Multiple system atrophy is an adult-onset, sporadic, and progressive neurodegenerative disease. People with this disorder report a wide range of motor and non-motor symptoms. Overlap in the clinical presentation of multiple system atrophy with other movement disorders (eg, Parkinson's disease and progressive supranuclear palsy) is a concern for accurate and timely diagnosis. Over the past 5 years, progress has been made in understanding key pathophysiological events in multiple system atrophy, including the seeding of α-synuclein inclusions and the detection of disease-specific α-synuclein strains. Diagnostic criteria were revised in 2022 with the intention to improve the accuracy of a diagnosis of multiple system atrophy, particularly for early disease stages. Early signals of efficacy in clinical trials have indicated the potential for disease-modifying therapies for multiple system atrophy, although no trial has yet provided unequivocal evidence of neuroprotection in this rare disease. The advances in pathophysiology could play a part in biomarker discovery for early diagnosis as well as in the development of disease-modifying therapies.