Provides a list of possible MSA mimics and when to consider them
| MSA mimics | Consider if… |
| Parkinson’s disease | Significant and sustained response to L-dopa (>30% improvement in UPDRS-III), anosmia, delayed onset of autonomic symptoms |
| Dementia with Lewy bodies60 | Fluctuating consciousness and cognitive change with hallucination (particularly visual), not secondary to L-dopa treatment |
| Progressive supranuclear palsy63 | Vertical saccade slowing, supranuclear gaze palsy Frontalis overactivity and retropulsion Frontal cognitive change, non-fluent variant primary progressive aphasia |
| Corticobasal degeneration64 | Asymmetrical limb dystonia, alien limb |
| Vascular Parkinsonism65 | Onset >75 years, vascular risk factors, dementia |
| Normal pressure hydrocephalus | Cognitive impairment, lack of upper limb signs |
| Neurogenetic conditions | |
| Spinocerebellar ataxia types 1,2,3,6,7,12,1766 | May have a positive family history, but deterioration likely slow |
| CANVAS67 | Chronic dry cough, positive head impulse test, peripheral neuropathy |
| C9ORF72 expansion68 | Positive family history, lower motor neuron signs (eg, fasciculation, wasting) |
| Friedreich’s ataxia66 | Peripheral neuropathy, pes cavus, loss of lower limb reflexes cardiomyopathy, type two diabetes mellitus |
| Fragile X tremor–ataxia syndrome66 | X-linked inheritance, peripheral neuropathy, behavioural disorders with executive dysfunction |
CANVAS, cerebellar ataxia, neuropathy, vestibular areflexia syndrome; MSA, multiple system atrophy; UPDRS-III, Unified Parkinson’s Disease Rating Scale part III.