title: Detecting and predicting balance decline in Parkinson disease: a prospective cohort study.
abstract: BACKGROUND
  The natural progression of balance decline in individuals with Parkinson disease (PD) is not well understood.
  
  
  OBJECTIVE
  We aimed to: 1) compare the utility of three standardized clinical measures for detecting balance decline over 1-year, 2) identify components of balance susceptible to decline, and 3) identify factors useful for predicting future balance decline.
  
  
  METHODS
  Eighty people with PD (59% male; mean age 68.2 ± 9.3; Hoehn & Yahr range I-IV) completed Balance Evaluation Systems Test (BESTest), Mini-BESTest, and Berg Balance Scale (BBS) assessments. Baseline predictor variables included the MDS-UPDRS III sub-score, presence of freezing, 6-month fall history, age, gender, and physical activity. Balance and MDS-UPDRS III assessments were repeated at 6 (n = 51) and 12 months (n = 44).
  
  
  RESULTS
  BESTest and Mini-BESTest score declined over 6 and 12 months (P < 0.01). Postural responses, stability limits, and sensory orientation were most susceptible to decline. BBS score did not change (P > 0.01). MDS-UPDRS III score was unchanged over 6 months (P > 0.01), but declined over 12 months (P < 0.01). Change in BESTest score over 6 months was related to baseline MDS-UPDRS III, H&Y, freezing, and fall history (P < 0.05). Change in BESTest score over 12 months was related to baseline MDS-UPDRS III and freezing (P < 0.05). Change in Mini-BESTest over 12 months was related to baseline MDS-UPDRS III and age (P < 0.05).
  
  
  CONCLUSIONS
  The BESTest and Mini-BESTest were responsive to balance decline in individuals with PD and helped to identify decline in underlying balance components. Disease severity and freezing most consistently predicted balance decline in persons with PD.
authors.affiliation: Washington University in St. Louis School of Medicine, Program in Physical Therapy, MO, USA Department of Neurology, Washington University in St. Louis School of Medicine, MO, USA.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Duncan
authors.affiliation: Rehabilitation Hospital of the Pacific, Department of Physical Therapy, HI, USA.
authors.forename: Abigail L
authors.initials: AL
authors.lastname: Leddy
authors.affiliation: Department of Physical Therapy, University of New England, ME, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Cavanaugh
authors.affiliation: Department of Physical Therapy, University of Utah, UT, USA.
authors.forename: Leland E
authors.initials: LE
authors.lastname: Dibble
authors.affiliation: Department of Physical Therapy and Athletic Training, Boston University, MA, USA.
authors.forename: Terry D
authors.initials: TD
authors.lastname: Ellis
authors.affiliation: Department of Physical Therapy, Samford University, AL, USA.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Ford
authors.affiliation: Department of Physical Therapy, University of Utah, UT, USA.
authors.forename: K Bo
authors.initials: KB
authors.lastname: Foreman
authors.affiliation: Washington University in St. Louis School of Medicine, Program in Physical Therapy, MO, USA Department of Anatomy & Neurobiology, Washington University in St. Louis School of Medicine, MO, USA Department of Neurology, Washington University in St. Louis School of Medicine, MO, USA.
authors.forename: Gammon M
authors.initials: GM
authors.lastname: Earhart
mesh_terms: D000368:Aged; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications*; D004856:Postural Balance / Q000502:physiology*; D011237:Predictive Value of Tests; D012678:Sensation Disorders / Q000175:diagnosis* / Q000209:etiology*; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013997:Time Factors
keywords: Parkinson disease; outcome assessment; physical therapy; postural balance; rehabilitation