Temporal variability of gait in Parkinson disease: effects of a rehabilitation programme based on rhythmic sound cues.

It has been suggested that sequential movements in patients with Parkinson's disease (PD) might be improved by the effects of external rhythmic cues. We studied spatiotemporal gait parameters and temporal gait variability in patients with PD and control subjects under different walking conditions in order to investigate whether rhythmic auditory cues could improve temporal variability. A total of 30 subjects were recruited, comprising 15 patients with idiopathic PD and 15 control subjects with no history of neurological disorder. As an indicator for temporal stability, we used the coefficient of variability (CV=standard deviation/mean X 100) of recorded intervals between two consecutive steps (gait variability). After control values were obtained, subjects underwent a Physical Rehabilitation Programme (PRP) consisting of a variety of motor tasks performed in combination with rhythmic sounds with different cadences. Sessions lasted 1h/day, five times a week for a period of four consecutive weeks. At the end of the PRP subjects were evaluated again. Following completion of the programme the patients' coefficients of variability improved significantly for the preferred gait (gait: t=2.950, p=0.011) but were not significantly different from those obtained in control subjects (gait: t=3.873, p=0.391). These results are consistent with and extend prior studies of rhythmic auditory facilitation in PD and suggest a valuable method of improving gait timing in these patients.