A sporadic, progressive adult (>30 years) onset disease

Unexplained urinary urge incontinence

Unexplained voiding difficulties with post‐void urinary residual volume

Unexplained voiding difficulties with post‐void urinary residual volume ≥100 mL

Neurogenic OH (≥20/10 mmHg blood pressure drop) within 10 minutes of standing or head‐up tilt test

Neurogenic OH (≥20/10 mmHg blood pressure drop) within 3 minutes of standing or head‐up tilt test

Parkinsonism

Poorly L‐dopa‐responsive parkinsonism

Gait ataxia

Limb ataxia

Cerebellar dysarthria

Oculomotor dysfunction

Rapid progression within 3 years of motor onset

Moderate to severe postural instability within 3 years of motor onset

Craniocervical dystonia induced or exacerbated by L‐dopa in the absence of limb dyskinesia

Severe speech impairment within 3 years of motor onset

Severe dysphagia within 3 years of motor onset

Unexplained Babinski sign

Jerky myoclonic postural or kinetic tremor

Postural deformities

Stridor

Inspiratory sighs

Cold discolored hands and feet

Erectile dysfunction (below age of 60 years for clinically probable MSA)

Pathologic laughter or crying

“Hot cross bun” sign

Atrophy of: Putamen (and signal decrease on iron‐sensitive sequences), Middle cerebellar peduncle, Pons, or Cerebellum

Increased diffusivity of: Putamen or Middle cerebellar peduncle

Substantial and persistent beneficial response to dopaminergic medications

Unexplained anosmia on olfactory testing

Fluctuating cognition with pronounced variation in attention and alertness and early decline in visuoperceptual abilities

Recurrent visual hallucinations not induced by drugs within 3 years of disease onset

Dementia according to DSM‐V within 3 years of disease onset

Downgaze supranuclear palsy or slowing of vertical saccades

Brain MRI findings suggestive of an alternative diagnosis (eg, PSP, multiple sclerosis, vascular parkinsonism, symptomatic cerebellar disease, etc.)

Documentation of an alternative condition (MSA look‐alike, including genetic or symptomatic ataxia and parkinsonism) known to produce autonomic failure, ataxia, or parkinsonism and plausibly connected to the patient's symptoms