Table 3.

Exclusion criteria⁶

Exclusion criteria	Clinically established/ probable MSA	Possible prodromal MSA	Differential
Substantial and persistent beneficial response to dopaminergic medications	✓	✗	Parkinson’s disease
Unexplained anosmia on olfactory testing	✓	✓
Fluctuating cognition with pronounced variation in attention and alertness and early decline in visuo-perceptual abilities	✓	✓	Dementia with Lewy bodies
Recurrent visual hallucinations not induced by drugs within 3 years of disease onset	✓	✓
DSM-V Dementia within 3 years of disease onset	✓	✓	Dementia with Lewy bodies Progressive supranuclear palsy Corticobasal degeneration
Downgaze supranuclear palsy/slowing of vertical saccades	✓	✓	Progressive supranuclear palsy
Brain MRI findings suggesting an alternative diagnosis (eg, progressive supranuclear palsy, multiple sclerosis, vascular parkinsonism, symptomatic cerebellar disease)	✓	✓
Documentation of an alternative condition (MSA look-alike, including genetic or symptomatic ataxia and parkinsonism) known to produce similar symptoms and plausibly connected	✓	✓

DSM-V, Diagnostic and Statistical Manual of Mental Disorders; MSA, multiple system atrophy.