title: Short-term and practice effects of metronome pacing in Parkinson's disease patients with gait freezing while in the 'on' state: randomized single blind evaluation.
abstract: OBJECTIVE
  In a randomized single blind parallel study, we tested the efficacy of an auditory metronome on walking speed and freezing in Parkinson's disease (PD) patients with freezing gait impairment during their 'on' function.
  
  
  BACKGROUND
  No pharmacological treatment is effective in managing 'on' freezing in PD. Like visual cues that can help overcome freezing, rhythmic auditory pacing may provide cues that help normalize walking pace and overcome freezing.
  
  
  METHODS
  Non-demented PD patients with freezing during their 'on' state walked under two conditions, in randomized order: unassisted walking and walking with the use of an audiocassette with a metronome recording. The walking trials were randomized and gait variables were rated from videotapes by a blinded evaluator. Outcome measures were total walking time (total trial time-total freezing time), which was considered the time over a course of specified length, freezing time, average freeze duration and number of freezes. All outcomes were averaged across trials for each person and then compared across conditions using Signed Rank tests.
  
  
  RESULTS
  Twelve non-demented PD patients with a mean age of 65.8 +/- 11.2 years, and mean PD duration of 12.4 +/- 7.3 years were included. The use of the metronome slowed ambulation and increased the total walking time (P < 0.0005) only during the first visit, without affecting any freezing variable. In the nine patients who took the metronome recording home and used it daily for 1 week while walking, freezing remained unimproved.
  
  
  CONCLUSIONS
  Though advocated in prior publications as a walking aid for PD patients, auditory metronome pacing slows walking and is not a beneficial intervention for freezing during their 'on' periods.
authors.affiliation: Department of Neurology, Sanatorio del Rosario, Clinica de la Zarzuela, Principe de Vergara 53 28006, Madrid, Spain. ecubo@telefonica.net
authors.forename: Esther
authors.initials: E
authors.lastname: Cubo
authors.forename: Sue
authors.initials: S
authors.lastname: Leurgans
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Goetz
mesh_terms: D000161:Acoustic Stimulation; D000368:Aged; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D011214:Practice, Psychological; D016037:Single-Blind Method