Insights into the neural control of locomotion from walking through doorways in Parkinson's disease

Abstract

. (2010) 'Insights into the neural control of locomotion from walking through doorways in Parkinson's disease. ', Neuropsychologia., 48 (9). pp. 2750-2757. Further information on publisher's website:http://dx.doi.org/10. 1016/j.neuropsychologia.2010.05.022 Publisher's copyright statement: NOTICE: this is the author's version of a work that was accepted for publication in Neuropsychologia. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reected in this document. Changes may have been made to this work since it was submitted for publication. A denitive version was subsequently published in Neuropsychologia, 48, 9, July 2010, 10.1016/j.neuropsychologia.2010.05.022. Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. behaviour to investigate the visual control of locomotion and the role of the basal ganglia in this system. We use a variable-width doorway to measure the scaling of motor output to visual input specifying door width. By measuring walking behaviour as participants passed through the doorway, we show that both PD and healthy control participants scaled their locomotor outputs to door width. Both groups reacted to narrower doors by walking more slowly with shorter strides. However, the changes were greater in the PD group, where walking speed dramatically decreased while approaching the doorway. Such a pattern could help explain why doorways cause freezing episodes in PD. Neither explicit perceptual judgements of door width, nor performance on motor tasks, predicted the door behaviour.On the basis of these findings, we propose that PD is associated with a visuomotor disturbance, such that responses to action-relevant visual information are exaggerated. In the PD group, dopaminergic medications improved many baseline gait variables but did not affect their sensitivity to door width, suggesting that this visuomotor effect is not mediated by the basal ganglia. This hypothesis provides a novel framework for interpreting a variety of results with PD patients.

Dopaminergic contributions to distance estimation in Parkinson's disease: A sensory-perceptual deficit?

“…Here, results showed that similar to the previous study, gait worsened in PD when approaching the narrow doorway, however, body-scaled judgments of the doorway width did not differ from those of healthy control participants, and no effects of dopaminergic medication were found (Cowie, Limousin, Peters, & Day, 2010). Therefore, these researchers did not find evidence of a perceptual judgment deficit in PD after they had walked through the doorway, yet FOG was still worse in the narrow width condition.…”

“…However, those with PD were expected to perform similar to age-matched control participants in static visual perception of distance, since previous studies investigating judgments of size (i.e., doorway width and obstacle height) did not find differences between those with PD and healthy control participants (Cowie et al, 2010;Martens & Almeida, 2011). This would confirm that those with PD are able to correctly perceive the target location and build a spatial representation.…”

Levodopa-Resistant Freezing of Gait and Executive Dysfunction in Parkinson's Disease

“…planning, attention, inhibition, initiation, mental flexibility, fluency, multitasking ...). Recently published results suggested that mental flexibility (set shifting) could be particularly involved [3], while others suggested that impaired visuospatial abilities could interfere with movement planning [22,23]. In addition to frontal lobe dysfunction, imaging data showed that the metabolism of the parietal, occipital and temporal sensory cortices is decreased in patients with FOG [26], which is consistent with the reported visuospatial processing deficits.…”

Regional Gray Matter Atrophy in Patients with Parkinson Disease and Freezing of Gait

“…As reported, previous studies have shown an association between frontal dysfunction and FOG in patients with PD. 6,7,30 Recent studies 43,44 have demonstrated, by evaluating the influence of space perception on gait in patients with PD, that visuospatial ability appears to be more greatly affected in patients with PD who experience FOG. Furthermore, external visual, mental, and auditory cues (ie, extrinsic drivers) can usually improve FOG.…”