The use of rhythmic auditory cues to influence gait in patients with Parkinson's disease, the differential effect for freezers and non-freezers, an explorative study.

PURPOSE: To study the effect of rhythmic auditory cues on gait in Parkinson's disease subjects with and without freezing and in controls. METHOD: A volunteer sample of 20 patients (10 freezers, 10 non-freezers) and 10 age-matched controls performed five randomized cued walking conditions in a gait-laboratory. Auditory cues were administered at baseline frequency, at an increased step frequency of 10 and 20% above baseline and at a decreased step frequency of 10 and 20% below baseline. Mean step frequency, walking speed, stride length and double support duration were collected. RESULTS: Rhythmical auditory cueing induced speed changes in all subjects. Stride length was not influenced by rhythmical auditory cues in controls, whereas patients showed a larger stride length in the -10% condition (p < 0.01). Freezers and non-freezers showed the same response to rhythmical auditory cues. Within group analysis for stride length showed different cueing effects. Stride length decreased at the +10% condition for freezers (p < 0.05), whereas it increased for non-freezers. CONCLUSIONS: This study points to fact that physiotherapists might need to carefully adjust the cueing frequency to the needs of patients with and without freezing. On the basis of the present results we recommend to lower the frequency setting for freezers, whereas for non-freezers an increase of up to +10% may have potential therapeutic use