The short-term effects of different cueing modalities on turn speed in people with Parkinson's disease

Background. Turning has been associated with instability, falls, and freezing in people with Parkinson’s disease (PD). Objective. To investigate the effect of different modalities of rhythmic cueing on the duration of a functional turn in freezers and nonfreezers. Methods. A total of 133 patients with idiopathic PD while in the on phase of the medication cycle participated in this study as part of a subanalysis from the RESCUE trial. The effect of 3 different cue modalities on functional turning performance was investigated, involving a 180° turn while picking up a tray. Time to perform this task was measured using an activity monitor. Tests were performed without cues and with auditory, visual, and somatosensory cues delivered in a randomized order at preferred straight-line stepping frequency. Results. Cueing (all types) increased the speed of the turn in all subjects. There was no difference between turn performance of freezers and nonfreezers in cued and noncued conditions. Auditory cues made turning significantly faster than visual cues (P <.01) but not compared with somatosensory cues, except in nonfreezers. There was a short-term carryover in the final noncued trial. Conclusions. Rhythmical cueing yielded faster performance of a functional turn in both freezers and nonfreezers. This may be explained by enhancing attentional mechanisms during turning. Although no harmful effects were recorded, the safety of cueing for turning as a therapeutic strategy needs further study.