Effects of Auditory Cue Length and Visual Cue Superimposition on Gait Initiation in Parkinson’s Disease: A Pilot Study

Abstract

Objectives: Effects of cues on gait disturbance in Parkinson’s disease (PD) depend on features of cue presentation. We investigated the effects of the length of simple auditory cues on cue-triggered gait initiation in PD. Methods: The subjects were 8 PD patients in OFF-state (6 women and two men, aged 50-75 years) and 8 normal controls (NCs) (5 women and three men, aged 55-77 years). For the assessment of gait initiation, the subjects were instructed to take three steps without the strong constraint of a quick start. The auditory cues consisted of long and short beeps, and the visual cue was a red light-emitting diode (LED) line projected across the floor 15 cm in front of the subjects’ toes. The four experimental conditions were: (1) short Beep condition (0.1 sec), (2) long Beep condition (3 sec), (3) short Beep/LED condition and (4) long Beep/LED condition. Results: The gait initiation time was delayed, and the initial step length was short under the Beep conditions in the PD patients compared with those in the NCs. Neither parameter differed between the short Beep and the long Beep conditions. Superimposition of the visual cues improved the gait initiation time under the short Beep condition and the initial step length under the short and long Beep conditions. Conclusion: The duration of single auditory cues does not contribute to the gait initiation time and initial step length in PD. Although large-sized studies are necessary to confirm the results, instantaneous auditory perception may be the primary driving force for the effects of single auditory cues on gait initiation.