title: When DLB, PD, and PSP masquerade as MSA: an autopsy study of 134 patients.
abstract: OBJECTIVE
  To determine ways to improve diagnostic accuracy of multiple system atrophy (MSA), we assessed the diagnostic process in patients who came to autopsy with antemortem diagnosis of MSA by comparing clinical and pathologic features between those who proved to have MSA and those who did not. We focus on likely explanations for misdiagnosis.
  
  
  METHODS
  This is a retrospective review of 134 consecutive patients with an antemortem clinical diagnosis of MSA who came to autopsy with neuropathologic evaluation of the brain. Of the 134 patients, 125 had adequate medical records for review. Clinical and pathologic features were compared between patients with autopsy-confirmed MSA and those with other pathologic diagnoses, including dementia with Lewy bodies (DLB), Parkinson disease (PD), and progressive supranuclear palsy (PSP).
  
  
  RESULTS
  Of the 134 patients with clinically diagnosed MSA, 83 (62%) had the correct diagnosis at autopsy. Pathologically confirmed DLB was the most common misdiagnosis, followed by PSP and PD. Despite meeting pathologic criteria for intermediate to high likelihood of DLB, several patients with DLB did not have dementia and none had significant Alzheimer-type pathology. Autonomic failure was the leading cause of misdiagnosis in DLB and PD, and cerebellar ataxia was the leading cause of misdiagnosis in PSP.
  
  
  CONCLUSIONS
  The diagnostic accuracy for MSA was suboptimal in this autopsy study. Pathologically confirmed DLB, PD, and PSP were the most common diseases to masquerade as MSA. This has significant implications not only for patient care, but also for research studies in MSA cases that do not have pathologic confirmation.
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Koga
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA.
authors.forename: Naoya
authors.initials: N
authors.lastname: Aoki
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Uitti
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA.
authors.forename: Jay A
authors.initials: JA
authors.lastname: van Gerpen
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA.
authors.forename: William P
authors.initials: WP
authors.lastname: Cheshire
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Josephs
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA.
authors.forename: Zbigniew K
authors.initials: ZK
authors.lastname: Wszolek
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA.
authors.forename: J William
authors.initials: JW
authors.lastname: Langston
authors.affiliation: From the Departments of Neuroscience (S.K., N.A., D.W.D.) and Neurology (R.J.U., J.A.v.G., W.P.C., Z.K.W.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (Behavioural Neurology) (K.A.J.), Mayo Clinic, Rochester, MN; and The Parkinson's Institute and Clinical Center (J.W.L.), Sunnyvale, CA. dickson.dennis@mayo.edu.
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Dickson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D001921:Brain / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis*; D010300:Parkinson Disease / Q000175:diagnosis*; D012189:Retrospective Studies; D013494:Supranuclear Palsy, Progressive / Q000175:diagnosis*