Differential time- and frequency-dependent structure of postural sway and finger tremor in Parkinson's disease

Morrison, S., Kerr, G., Newell, K. M., & Silburn, P.A. (2008) Differential time- and frequency-dependent structure of postural sway and finger tremor in Parkinson's disease. Neuroscience Letters, 443(3), pp. 123-128.

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The time- and frequency-dependent patterns of standing balance centre of pressure (COP) and finger postural/resting tremor of 12 older individuals and eight age-matched Parkinsonian (PD) participants (on/off medication) were investigated. Tremor and COP data were analysed using measures of signal amplitude (RMS), time-dependent structure (approximate entropy, ApEn), time–frequency analysis and synchrony (Cross ApEn).Results showedthat thePDindividuals had significantly greater tremoramplitude and COP excursions in comparison to controls. Differences in the time-dependent structure were also observed between groups. In comparison to the elderly, the resting/postural tremor output of the PD subjects was more regular (lower ApEn). However, for the postural measures, a reciprocal pattern was observed with the COP being more complex (higher ApEn). All group differences were magnified when the PD individuals were off their medication. There was also greater synchrony between tremor and postural sway for the PD individuals, indicating a high degree of association between thesemotor outputs. These results are consistent with the view that the neural signal driving the enhanced limb tremor in PD is propagated throughout the motor system, consequently emerging within the postural sway dynamics. This commonality of motor output may be a contributing factor in the differential pattern in the dynamics of effector signal structure in PD as a function of task.

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22 citations in Scopus
19 citations in Web of Science®
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ID Code: 18892
Item Type: Journal Article
Refereed: Yes
Additional URLs:
Keywords: Parkinson's disease, Tremor, Postural sway, Regularity
DOI: 10.1016/j.neulet.2008.07.071
ISSN: 0304-3940
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > HUMAN MOVEMENT AND SPORTS SCIENCE (110600)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Current > Schools > School of Exercise & Nutrition Sciences
Copyright Owner: Copyright 2008 Elsevier
Deposited On: 15 Apr 2009 00:08
Last Modified: 29 Feb 2012 13:51

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