Reactive postural control deficits in patients with posterior parietal cortex lesions after stroke and the influence of auditory cueing
Journal
American Journal of Physical Medicine and Rehabilitation
Journal Volume
93
Journal Issue
10
Pages
849-859
Date Issued
2014
Author(s)
Abstract
OBJECTIVE: The purpose of this study was to investigate the ways in which stroke-induced posterior parietal cortex (PPC) lesions affect reactive postural responses and whether providing auditory cues modulates these responses. DESIGN: Seventeen hemiparetic patients after stroke, nine with PPC lesions (PPCLesion) and eight with intact PPCs (PPCSpared), and nine age-matched healthy adults completed a lateral-pull perturbation experiment under noncued and cued conditions. The activation rates of the gluteus medius muscle ipsilateral (GMi) and contralateral to the pull direction, the rates of occurrence of three types of GM activation patterns, and the GMi contraction latency were investigated. RESULTS: In noncued pulls toward the paretic side, of the three groups, the PPCLesion group exhibited the lowest activation rate (56%) of the GMi (P 0.05). However, there were no significant differences in the GM activation patterns and GMi contraction latency between the noncued and cued conditions for the PPCLesion group (P > 0.05). CONCLUSIONS: The PPCLesion patients had greater deficits in recruiting paretic muscles and were more likely to use the compensatory muscle activation pattern for postural reactions than the PPCSpared patients, suggesting that PPC is part of the neural circuitry involved in reactive postural control in response to lateral perturbations. The auditory cueing used in this study, however, did not significantly modify the muscle activation patterns in the PPCLesion patients. More research is needed to explore the type and structure of cueing that could effectively improve patterns and speed of postural responses in these patients.
SDGs
Type
journal article