@article{ref1,
title="Effects of exercise on gait and motor imagery in people with Parkinson disease and freezing of gait",
journal="Parkinsonism and related disorders",
year="2018",
author="Myers, Peter S. and McNeely, Marie E. and Pickett, Kristen A. and Duncan, Ryan P. and Earhart, Gammon M.",
volume="53",
number="",
pages="89-95",
abstract="INTRODUCTION: Exercise improves gait in Parkinson disease (PD), but whether exercise differentially affects people with PD with (freezers) and without freezing of gait (non-freezers) remains unclear. This study examines exercise's effects on gait performance, neural correlates related to these effects, and potential neural activation differences between freezers and non-freezers during motor imagery (MI) of gait. <br><br>METHODS: Thirty-seven participants from a larger exercise intervention completed behavioral assessments and functional magnetic resonance imaging (fMRI) scans before and after a 12-week exercise intervention. Gait performance was characterized using gait velocity and stride length, and a region of interest (ROI) fMRI analysis examined task-based blood oxygen-level dependent (BOLD) signal changes of the somatomotor network (SMN) during MI of forward (IMG-FWD) and backward (IMG-BWD) gait. <br><br>RESULTS: Velocity (F(1,34) = 55.04, p < 0.001) and stride length (F(1,34) = 77.58, p < 0.001) were significantly lower for backward versus forward walking in all participants. The ROI analysis showed freezers had lower BOLD signal compared to non-freezers in the cerebellum (F(1,32) = 7.01, p = 0.01), primary motor (left: F(1,32) = 7.09, p = 0.01; right: F(1,32) = 7.45, p = 0.01), and primary sensory (left: F(1,32) = 9.59, p = 0.004; right: F(1,32) = 8.18, p = 0.007) cortices during IMG-BWD only. The evidence suggests the exercise intervention did not affect gait or BOLD signal during MI. <br><br>CONCLUSION: While all participants had significantly slower and shorter backward velocity and stride length, respectively, the exercise intervention had no effect. Similarly, BOLD signal during MI did not change with exercise; however, freezers had significantly lower BOLD signal during IMG-BWD compared to non-freezers. This suggests potential decreased recruitment of the SMN during MI of gait in freezers.<br><br>Copyright © 2018 Elsevier Ltd. All rights reserved.<p /> <p>Language: en</p>",
language="en",
issn="1353-8020",
doi="10.1016/j.parkreldis.2018.05.006",
url="http://dx.doi.org/10.1016/j.parkreldis.2018.05.006"
}