Elie Matar1, James M Shine, Sharon L Naismith, Simon J G Lewis. 1. Parkinson's Disease Research Clinic, Brain and Mind Research Institute, University of Sydney, Level 4, Building F, 94 Mallett St, Camperdown, New South Wales 2050, Australia.
Abstract
BACKGROUND: The freezing phenomenon is among the most disabling symptoms of Parkinson's disease (PD) manifesting most commonly as Freezing of Gait with a paroxysmal cessation of effective stepping. Recent studies have suggested that freezing is related to both impairments in conflict resolution as well as the processing of environmentally salient information. METHODS: In this study, we utilized a virtual reality gait paradigm to investigate differences in motor outflow between PD patients with (n = 36) and without (n = 37) Freezing of Gait, as well as age-matched healthy controls (n = 18). Subjects were required to navigate a realistic on-screen environment with the use of foot pedals to simulate stepping whilst responding to either cues associated with conflict resolution (congruent 'Red', 'Green' or 'Blue') or environmental salience (wide, narrow and sliding doorways). Footstep latency was used as a measure of motor output. RESULTS: Significantly increased stepping latencies were observed in freezers compared to non-freezers (p = 0.004) and controls (p = 0.016) in response to stimuli requiring the inhibition of implicitly cued behavior ('red' cue). Patients with Freezing of Gait also demonstrated increased motor latency compared to non-freezers and controls specifically in response to environmentally salient triggers including narrow doorways (p = 0.03 and 0.01 respectively) and the opening of a sliding door (p = 0.036 and 0.048 respectively). Performance on the paradigm in relation to these triggers correlated significantly with self-reported freezing severity. CONCLUSION: These results suggest that deficits in conflict resolution and visuospatial processing may reflect some of the neural mechanisms associated with freezing behavior and that these can be probed in a virtual reality environment.
RCT Entities:
BACKGROUND: The freezing phenomenon is among the most disabling symptoms of Parkinson's disease (PD) manifesting most commonly as Freezing of Gait with a paroxysmal cessation of effective stepping. Recent studies have suggested that freezing is related to both impairments in conflict resolution as well as the processing of environmentally salient information. METHODS: In this study, we utilized a virtual reality gait paradigm to investigate differences in motor outflow between PDpatients with (n = 36) and without (n = 37) Freezing of Gait, as well as age-matched healthy controls (n = 18). Subjects were required to navigate a realistic on-screen environment with the use of foot pedals to simulate stepping whilst responding to either cues associated with conflict resolution (congruent 'Red', 'Green' or 'Blue') or environmental salience (wide, narrow and sliding doorways). Footstep latency was used as a measure of motor output. RESULTS: Significantly increased stepping latencies were observed in freezers compared to non-freezers (p = 0.004) and controls (p = 0.016) in response to stimuli requiring the inhibition of implicitly cued behavior ('red' cue). Patients with Freezing of Gait also demonstrated increased motor latency compared to non-freezers and controls specifically in response to environmentally salient triggers including narrow doorways (p = 0.03 and 0.01 respectively) and the opening of a sliding door (p = 0.036 and 0.048 respectively). Performance on the paradigm in relation to these triggers correlated significantly with self-reported freezing severity. CONCLUSION: These results suggest that deficits in conflict resolution and visuospatial processing may reflect some of the neural mechanisms associated with freezing behavior and that these can be probed in a virtual reality environment.
Authors: Patrick G Bissett; Gordon D Logan; Nelleke C van Wouwe; Christopher M Tolleson; Fenna T Phibbs; Daniel O Claassen; Scott A Wylie Journal: J Neural Transm (Vienna) Date: 2015-09-09 Impact factor: 3.575
Authors: Elie Matar; James M Shine; Moran Gilat; Kaylena A Ehgoetz Martens; Philip B Ward; Michael J Frank; Ahmed A Moustafa; Sharon L Naismith; Simon J G Lewis Journal: Hum Brain Mapp Date: 2019-01-13 Impact factor: 5.038
Authors: Courtney C Walton; James M Shine; Loren Mowszowski; Moran Gilat; Julie M Hall; Claire O'Callaghan; Sharon L Naismith; Simon J G Lewis Journal: J Neural Transm (Vienna) Date: 2014-07-22 Impact factor: 3.575
Authors: Rajal G Cohen; Krystal A Klein; Mariko Nomura; Michael Fleming; Martina Mancini; Nir Giladi; John G Nutt; Fay B Horak Journal: J Parkinsons Dis Date: 2014 Impact factor: 5.568
Authors: Christian Mathys; Julian Caspers; Robert Langner; Martin Südmeyer; Christian Grefkes; Kathrin Reetz; Alexia-Sabine Moldovan; Jochen Michely; Julia Heller; Claudia R Eickhoff; Bernd Turowski; Alfons Schnitzler; Felix Hoffstaedter; Simon B Eickhoff Journal: Hum Brain Mapp Date: 2015-12-24 Impact factor: 5.038