title: Diagnostic performance of the "Huffing and Puffing" sign in psychogenic (functional) movement disorders.
abstract: OBJECTIVE
  To determine the diagnostic value of effort-associated behaviors ("huffing and puffing" spectrum) in patients with psychogenic movement disorders.
  
  
  METHODS
  Three blinded clinicians rated presence, severity, and duration of effort-associated features during standing and walking tasks on edited videos of 131 patients with psychogenic gait disorders and 37 patients with organic gait disorders.
  
  
  RESULTS
  Huffing, grunting, grimacing, and breath holding were the most common effort-associated behaviors in patients with psychogenic gait disorders, with a combined prevalence of 44% and disproportionate to the severity of gait impairment compared to organic gait disorders. The presence of "huffing and puffing"-type behaviors yielded a relatively low sensitivity but high specificity for the diagnosis of psychogenic movement disorders, increasing the odds of diagnosis 13-fold (95%, CI: 4.2-43.8) compared to organic gait disorders.
  
  
  CONCLUSIONS
  Demonstration of effort-associated behaviors during standing and walking strongly supports the psychogenic nature of disorders when gait is involved.
authors.affiliation: James J. and Joan A. Gardner Center for Parkinson disease and Movement Disorders, Department of Neurology and Rehabilitation Medicine, University of Cincinnati, Cincinnati, Ohio, USA.
authors.forename: Holly N
authors.initials: HN
authors.lastname: Laub
authors.affiliation: Division of Biostatistics & Epidemiology, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, Texas, USA.
authors.forename: Alok K
authors.initials: AK
authors.lastname: Dwivedi
authors.affiliation: James J. and Joan A. Gardner Center for Parkinson disease and Movement Disorders, Department of Neurology and Rehabilitation Medicine, University of Cincinnati, Cincinnati, Ohio, USA.
authors.forename: Fredy J
authors.initials: FJ
authors.lastname: Revilla
authors.affiliation: James J. and Joan A. Gardner Center for Parkinson disease and Movement Disorders, Department of Neurology and Rehabilitation Medicine, University of Cincinnati, Cincinnati, Ohio, USA.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Duker
authors.affiliation: James J. and Joan A. Gardner Center for Parkinson disease and Movement Disorders, Department of Neurology and Rehabilitation Medicine, University of Cincinnati, Cincinnati, Ohio, USA.
authors.forename: Cara
authors.initials: C
authors.lastname: Pecina-Jacob
authors.affiliation: James J. and Joan A. Gardner Center for Parkinson disease and Movement Disorders, Department of Neurology and Rehabilitation Medicine, University of Cincinnati, Cincinnati, Ohio, USA.
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Espay
keywords: excessive effort; psychogenic movement disorders