title: Role of hypokinesia and bradykinesia in gait disturbances in Huntington's disease: a biomechanical study.
abstract: OBJECTIVE
  To evaluate specific patterns of locomotion in Huntington's disease (HD) and notably the respective roles of hypokinesia (i. e. a decrease in the amplitude of movement) and bradykinesia (i. e. difficulty in executing a movement, slowness) in gait disturbance.
  
  
  METHODS
  Kinematic, spatial (stride length, speed), temporal (cadence, speed, and stride time) and angular gait parameters (joint ankle range) were recorded in 15 early-stage HD patients by means of a video motion analysis system and then compared with 15 controls and 15 Parkinson's disease (PD) patients. Hypokinesia was studied in terms of both spatial (decrease in stride length) and angular gait parameters (decrease in joint ankle range), whereas hyperkinesia was characterized by an increase in joint ankle range. Bradykinesia (defined by a decrease in gait velocity) was also assessed in terms of temporal parameters (cadence, stride time). We studied the influence of clinical symptoms (motor dysfunction, chorea, overall disability and cognitive impairment) and the CAG repeat number on gait abnormalities.
  
  
  RESULTS
  we observed a clear decrease in gait speed, a decrease in cadence and an increase in stride time (i. e. bradykinesia) for HD, with significant intra-individual variability. Cadence remained normal in PD. In HD, there was no evidence for a clear decrease in stride length, although the latter is a characteristic feature of hypokinetic gait (such as that observed in PD). Angle analysis revealed the coexistence of hyperkinesia and hypokinesia in HD, which thus participate in gait abnormalities. Gait speed in HD was correlated to the motor part of the UHDRS.
  
  
  CONCLUSIONS
  Gait in HD is mainly characterized by a timing disorder: bradykinesia was present, with severe intra-individual variability in temporal gait parameters.
authors.affiliation: Department of Neurology and Movement, Disorders, EA 2683, Hospital R. Salengro, Regional University Hospital, 59037, Lille cedex, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Delval
authors.forename: Pierre
authors.initials: P
authors.lastname: Krystkowiak
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Blatt
authors.forename: Etienne
authors.initials: E
authors.lastname: Labyt
authors.forename: Kathy
authors.initials: K
authors.lastname: Dujardin
authors.forename: Alain
authors.initials: A
authors.lastname: Destée
authors.forename: Philippe
authors.initials: P
authors.lastname: Derambure
authors.forename: Luc
authors.initials: L
authors.lastname: Defebvre
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena / Q000379:methods; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D006816:Huntington Disease / Q000150:complications*; D006948:Hyperkinesis / Q000503:physiopathology*; D018476:Hypokinesia / Q000503:physiopathology*; D007596:Joints / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000379:methods; D010300:Parkinson Disease / Q000503:physiopathology