Improving diagnostic accuracy of multiple system atrophy: a clinicopathological study

Area of Science:

• Neurology
• Neuroscience
• Clinical Diagnostics

Background:

• Clinical diagnosis of multiple system atrophy (MSA) is often confounded by similarities with Lewy body disease (LBD) and progressive supranuclear palsy (PSP).
• Misdiagnosis rates are significant, impacting patient management and research.
• Identifying specific diagnostic markers is crucial for accurate ante-mortem diagnosis.

Purpose of the Study:

• To identify clinical features and disability milestones that improve the diagnostic accuracy of MSA.
• To differentiate MSA from LBD and PSP using clinical data.
• To analyze diagnostic pitfalls in a cohort of patients with a clinical diagnosis of MSA.

Main Methods:

• Retrospective review of clinical records of 203 patients with a clinical diagnosis of MSA.
• Analysis of 12 'red flag' features suggestive of MSA and seven disability milestones.
• Logistic regression analysis to compare clinical features between MSA, LBD, and PSP.

Main Results:

• Of 203 patients, 78.8% had pathologically confirmed MSA; 21.2% had alternative diagnoses (e.g., LBD, PSP).
• Ataxia, stridor, dysphagia, and falls were more frequent in MSA than LBD.
• Orthostatic hypotension and early urinary incontinence were significant predictors of MSA over LBD and PSP. Autonomic dysfunction within 3 years of onset differentiated MSA from PSP.
• MSA patients exhibited more 'red flag' features compared to LBD and PSP patients, particularly those with predominant parkinsonian or cerebellar signs.

Conclusions:

• Specific clinical features, including autonomic dysfunction, 'red flag' signs, and progression rates to disability milestones, can significantly improve the ante-mortem diagnostic accuracy of MSA.
• Distinguishing MSA from LBD and PSP is feasible using a combination of clinical indicators.
• These findings aid in refining diagnostic criteria and improving patient stratification for research and clinical care.