title: Impaired trunk stability in individuals at high risk for Parkinson's disease.
abstract: BACKGROUND
  The search for disease-modifying treatments for Parkinson's disease advances, however necessary markers for early detection of the disease are still lacking. There is compelling evidence that changes of postural stability occur at very early clinical stages of Parkinson's disease, making it tempting to speculate that changes in sway performance may even occur at a prodromal stage, and may have the potential to serve as a prodromal marker for the disease.
  
  
  RESULTS
  Balance performance was tested in 20 individuals with an increased risk of Parkinson's disease, 12 Parkinson's disease patients and 14 controls using a cross-sectional approach. All individuals were 50 years or older. Investigated groups were similar with respect to age, gender, and height. An accelerometer at the centre of mass at the lower spine quantified sway during quiet semitandem stance with eyes open and closed, as well as with and without foam. With increasing task difficulty, individuals with an increased risk of Parkinson's disease showed an increased variability of trunk acceleration and a decrease of smoothness of sway, compared to both other groups. These differences reached significance in the most challenging condition, i.e. the eyes closed with foam condition.
  
  
  CONCLUSIONS
  Individuals with an increased risk of Parkinson's disease have subtle signs of a balance deficit under most challenging conditions. This preliminary finding should motivate further studies on sway performance in individuals with an increased risk of Parkinson's disease, to evaluate the potential of this symptom to serve as a biological marker for prodromal Parkinson's disease.
authors.affiliation: Center of Neurology, Hertie Institute for Clinical Brain Research, Department for Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany. walter.maetzler@uni-tuebingen.de
authors.forename: Walter
authors.initials: W
authors.lastname: Maetzler
authors.forename: Martina
authors.initials: M
authors.lastname: Mancini
authors.forename: Inga
authors.initials: I
authors.lastname: Liepelt-Scarfone
authors.forename: Katharina
authors.initials: K
authors.lastname: Müller
authors.forename: Clemens
authors.initials: C
authors.lastname: Becker
authors.forename: Rob C
authors.initials: RC
authors.lastname: van Lummel
authors.forename: Erik
authors.initials: E
authors.lastname: Ainsworth
authors.forename: Markus
authors.initials: M
authors.lastname: Hobert
authors.forename: Johannes
authors.initials: J
authors.lastname: Streffer
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Chiari
mesh_terms: D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D012307:Risk Factors; D060726:Torso / Q000503:physiopathology*