title: Cerebral peduncle angle: Unreliable in differentiating progressive supranuclear palsy from other neurodegenerative diseases.
abstract: The significant symptom overlap between progressive supranuclear palsy (PSP) and other parkinsonian neurodegenerative diseases frequently results in misdiagnosis. However, neuroimaging can be used to quantify disease-related morphological changes and specific markers. The cerebral peduncle angle (CPA) has been shown to differentiate clinically diagnosed PSP from other parkinsonian diseases but this result has yet to be confirmed in autopsy-proven disease.
  
  
  
  Magnetic resonance imaging (MRI) scans were obtained for 168 patients representing 69 medical facilities. Following randomization, the images were divided into two groups (Type 1 and Type 2) based upon midbrain morphological differences. Two readers were blinded and independently measured the CPA of 146 patients with autopsy-proven progressive supranuclear palsy (PSP; n = 54), corticobasal degeneration (n = 16), multiple system atrophy (MSA; n = 11) and Lewy body disease (n = 65).
  
  
  
  Applying two separate measurement techniques revealed no statistically significant differences in CPA measurements among any study groups regardless of classification measurement approach. The interobserver agreement showed significant differences in measurements using the Type 2 approach.
  
  
  
  Measuring the CPA on MRI is not a reliable way of differentiating among patients with PSP, corticobasal degeneration, MSA, or Lewy body disease.
authors.affiliation: Department of Neurology, Mayo Clinic Florida, 4500 San Pablo Road, Jacksonville, FL 32224, USA. Electronic address: tipton.philip@mayo.edu.
authors.forename: Philip W
authors.initials: PW
authors.lastname: Tipton
authors.affiliation: Department of Neurology, Mayo Clinic Florida, 4500 San Pablo Road, Jacksonville, FL 32224, USA. Electronic address: konno.takuya@mayo.edu.
authors.forename: Takuya
authors.initials: T
authors.lastname: Konno
authors.affiliation: Department of Radiology, Mayo Clinic Florida, 4500 San Pablo Road, Jacksonville, FL 32224, USA. Electronic address: Broderick.daniel.f@mayo.edu.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Broderick
authors.affiliation: Department of Neuroscience, Mayo Clinic Florida, 4500 San Pablo Road, Jacksonville, FL 32224, USA. Electronic address: dickson.dennis@mayo.edu.
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Dickson
authors.affiliation: Department of Neurology, Mayo Clinic Florida, 4500 San Pablo Road, Jacksonville, FL 32224, USA. Electronic address: wszolek.zbigniew@mayo.edu.
authors.forename: Zbigniew K
authors.initials: ZK
authors.lastname: Wszolek
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001344:Autopsy; D001480:Basal Ganglia Diseases / Q000000981:diagnostic imaging; D065850:Cerebral Peduncle / Q000000981:diagnostic imaging / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020961:Lewy Body Disease / Q000175:diagnosis / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000000981:diagnostic imaging; D013494:Supranuclear Palsy, Progressive / Q000000981:diagnostic imaging*
keywords: Cerebral peduncle angle; Corticobasal degeneration; Lewy body disease; Magnetic resonance imaging; Multiple system atrophy; Neurodegenerative diseases; PSP-Richardson Syndrome; Parkinson's disease