The Unified Multiple System Atrophy Rating Scale: Status, Critique, and Recommendations

: The Unified Multiple System Atrophy (MSA) Rating Scale was developed to provide a surrogate marker of disease severity and clinical progression in patients with MSA. It is comprised of four subscales: UMSARS-I (12 items) rates patient-reported functional disability; UMSARS-II (14 items) assesses motor impairment based on a clinical examination; UMSARS-III records blood pressure and heart rate in the supine and standing positions; and UMSARS-IV (1 item) rates chore-based disability. Strengths of the UMSARS include its wide acceptance in the field, the comprehensive coverage of motor symptoms and its clinimetric properties (including reliability and validity). However, with its increasing use, potential areas of improvement in the UMSARS have become apparent. To address these limitations, a task force, involving clinicians, researchers, patient groups, and industry representatives, has recently been endorsed by the International Parkinson’s Disease and Movement Disorders Society. The present viewpoint summarizes strengths and weaknesses of the UMSARS and suggests a roadmap to develop an improved MSA clinical outcome assessment.