title: The effects of gait impairment with and without freezing of gait in Parkinson's disease.
abstract: OBJECTIVE
  To compare the effects of gait impairment without freezing of gait (FOG) versus FOG without gait impairment in Parkinson's disease (PD) on disability and quality of life.
  
  
  BACKGROUND
  FOG is frequently characterized as the major cause of gait-related disability in PD. However, gait impairment may also result from other PD symptoms including slowing, motor asymmetry, gait variability, dystonia or stooped posture.
  
  
  METHODS
  The Unified Parkinson's Disease Rating Scale (UPDRS), Older Americans Resources and Services Disability Scale (OARS) and the SF-12 Health Status Survey were used to evaluate patients with PD. Responses to UPDRS Items #14 (Freezing) and # 29 (Gait) were used to create 4 subgroups: 1) No FOG or gait impairment, 2) FOG, no gait impairment, 3) Gait impairment, no FOG, and 4) Both FOG and gait impairment. Disease severity, disability, and quality of life were compared across the subgroups with ANOVAs, and between subgroups with t-tests.
  
  
  RESULTS
  916 PD patients were divided into 4 subgroups based on their gait and freezing score (#1: n = 213, #2: n = 41, #3: n = 323 and #4: n = 339). Total UPDRS progressively increased from Group 1 through Group 4 (1 = 25.2, 2 = 33.7, 3 = 39.2, 4 = 59.2; p < 0.001). Motor UPDRS also progressively increased (1 = 17.4, 2 = 19.7, 3 = 26.9, 4 = 36.5; p < 0.0001). Similarly, disability and health-related quality of life progressively increased from Group 1 through Group 4 (Total OARS: 1 = 15.3, 2 = 17.2, 3 = 18.9, 4 = 28.4; p < 0.001). Group 3 (Gait impairment, no FOG) showed greater disease severity than Group 2 (FOG, no gait impairment; Total and Motor UPDRS; p < 0.05), but the difference did not reach significance for disability or quality of life.
  
  
  CONCLUSIONS
  Gait impairment without FOG was associated with greater disease severity than FOG without gait impairment. The combination of gait impairment and FOG was associated with the greatest disease severity and disability. These results show differential effects of diverse features of gait impairment in PD and demonstrate the importance of gait features unrelated to freezing.
authors.affiliation: University of Maryland School of Medicine, MD, USA.
authors.forename: Anne F
authors.initials: AF
authors.lastname: Josiah
authors.forename: Ann L
authors.initials: AL
authors.lastname: Gruber-Baldini
authors.forename: Karen E
authors.initials: KE
authors.lastname: Anderson
authors.forename: Paul S
authors.initials: PS
authors.lastname: Fishman
authors.forename: William J
authors.initials: WJ
authors.lastname: Weiner
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Reich
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Shulman
mesh_terms: D000368:Aged; D004185:Disability Evaluation; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology* / Q000523:psychology*; D006801:Humans; D008297:Male; D010300:Parkinson Disease / Q000150:complications*; D011788:Quality of Life