Effects of Ecological Rythmic-acoustic Stimulation (E-RAS) on Motor Skills in Individuals With Parkinson's Disease

The use of rhythmic auditory stimulation (RAS) has been proven useful in the management of gait disturbances induced by Parkinson's disease (PD). Typically, the stimuli used to provide RAS consist of metronome or music-based sounds, which are not related with the auditory experience of walking. Based on previous laboratory research, it is hypothesized that the use of ecological sounds deriving from biological motion (i.e., footstep sounds) could have a greater impact compared to artificial sounds (i.e., metronome sounds), within a rehabilitation program. In a double-blind experiment, it was investigated the effects of 5 weeks of supervised rehabilitation integrated with RAS. Thirty-two individuals affected by PD (age 68.2 ± 10.5, Hoehn and Yahr 1,5-3) were randomly assigned to one of the two conditions (artificial vs. ecological sounds). Spatio-temporal parameters of gait and clinical variables were assessed before the rehabilitation period, at its end, and after a 3-month follow-up. The results revealed that the rehabilitation program integrated with RAS had positive effects on the majority of objective and subjective measures, independently of the type of sound. However, when the two groups were examined separately, the patients assigned to the ecological RAS condition were the only who improved both in terms of cadence and gait speed. Overall, the hypothesized greater effect of the ecological sounds compared to artificial sounds was only partially supported by data.