Auditory cueing of gait initiation in Parkinson's disease patients with freezing of gait

Objective: Impaired gait initiation (GI) in patients with advanced Parkinson's disease (PD) is a typical functional sign of akinesia. Failure to initiate the first step is frequently presented by patients with freezing of gait (FOG) and is often considered a sub-type of freezing. The literature on the effects of cueing of GI preparation and execution remains controversial. Our objective was to establish whether auditory cueing improves the preparation and/or execution of GI in PD patients with a history of FOG. Methods: We recorded first-step preparation and execution in 30 PD patients with confirmed FOG under two randomised conditions: self-triggered (ST) gait and gait cued by a sound beep in off-and on-dopa conditions. Anticipatory postural adjustments (APAs) were evaluated by monitoring the trajectory of the centre of pressure. Results: We compared the patients with 30 patients without history of FOG and 30 healthy controls (HCs). L-Dopa only slightly improved the characteristics of APAs in freezers but was effective to improve gait hypokinesia. Auditory cueing was effective in improving step preparation in freezers, who showed adequate APAs more frequently. As seen with HCs and patients without FOG, patients released their APAs more quickly when auditory cueing was applied. However, cueing did not have a significant effect on step length. Clinically, auditory cueing also improved start hesitation in freezers. Conclusions: Auditory cueing improved step preparation but not step execution in PD patients. Significance: A failure to link step preparation and execution during GI may explain the poor first-step execution seen in PD freezers. (C) 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.