Postural control, gait, and dopamine functions in parkinsonian movement disorders.
ABSTRACT Balance impairments and falls, which are common in patients who have parkinsonian movement disorders, are a serious threat to the health of these individuals. However, the underlying mechanisms cannot be fully explained by presynaptic dopaminergic denervation, because balance impairment is at least responsive to L-dopa therapy. This article reviews the latest clinically relevant literature relating postural control, gait, and dopamine in patients who have parkinsonian movement disorders.
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ABSTRACT: The use of progressive resistance training (PRT) to improve gait and balance in people with Parkinson’s disease (PD) is an emerging area of interest. However, the main effects of PRT on lower limb function such as gait, balance and leg strength in people with PD remain unclear. Therefore the aim of the meta-analysis is to evaluate the evidence surrounding the use of PRT to improve gait and balance in people with PD. Five electronic databases, from inception to December 2014, were searched to identify the relevant studies. Data extraction was performed by two independent reviewers and methodological quality assessed using the PEDro scale. Standardized mean differences (SMD) and 95% confidence intervals (CIs) of fixed and random effects models were used to calculate the effect sizes between experimental and control groups and I2 33 statistics were used to determine levels of heterogeneity. In total, 7 studies were identified consisting of 172 participants (Experimental n=84; Control n=88). The pooled results showed a moderate but significant effect of PRT on leg strength (SMD 1.42, 95% CI 0.464 to 2.376), however no significant effects were observed for gait speed (SMD 0.418, 95% CI -0.219 to 1.055). No significant effects were observed for balance measures included in this review. In conclusion, our results showed no discernable effect of PRT on gait and balance measures, although this is likely due to the lack of studies available. It may be suggested that PRT be performed in conjunction with balance or task-specific functional training to elicit greater lower limb functional benefits in people with PD.Frontiers in aging series 03/2015; DOI:10.3389/fnagi.2015.00040
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ABSTRACT: Introduction. Dopamine-replacement medications may improve mobility while not improving responses to postural challenges and could therefore increase fall risk. The purpose of this study was to measure reactive postural responses and gait-related mobility of patients with PD during ON and OFF medication conditions. Methods. Reactive postural responses to the Pull Test and performance of the Functional Gait Assessment (FGA) were recorded from 15 persons with PD during ON and OFF medication conditions. Results. Persons with PD demonstrated no significant difference in the reactive postural responses between medication conditions but demonstrated significantly better performance on the FGA when ON medications compared to OFF. Discussion/Conclusion. Dopamine-replacement medications alone may improve gait-related mobility without improvements in reactive postural responses and therefore could result in iatrogenic increases in fall risk. Rehabilitation providers should be aware of the side effects and limitations of medication treatment and implement interventions to improve postural responses.01/2012; 2012:692150. DOI:10.1155/2012/692150
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ABSTRACT: Leucoaraiosis is associated with motor symptoms in otherwise normal older adults. Comorbid leucoaraiosis is predicted to contribute also to motor features in Parkinson's disease but previous studies of white matter changes in Parkinson's disease show variable results. No prior studies have compared directly the effects of both leucoaraiosis and the degree of nigrostriatal dopaminergic denervation on motor features. We investigated the effect of leucoaraiosis severity on motor impairment independent of the degree of nigrostriatal dopaminergic denervation in Parkinson's disease. Seventy-three subjects with Parkinson's disease (Hoehn and Yahr stages 1-3) underwent brain magnetic resonance and [(11)C]dihydrotetrabenazine vesicular monoamine transporter type 2 positron emission tomography imaging. Automated assessment of supratentorial fluid-attenuated inversion recovery magnetic resonance hyperintense white matter voxels was performed using cerebellar white matter as the intensity reference. White matter signal hyperintensity burden was log-transformed and normalized for brain volume. Unified Parkinson's Disease Rating Scale total and subscore ratings were assessed to determine motor impairment. Subjects receiving dopaminergic medications were examined in the clinically defined 'OFF' state. Multivariate regression analysis with measures of white matter signal hyperintensity burden and nigrostriatal denervation as independent variables demonstrated a significant overall model for total motor Unified Parkinson's Disease Rating Scale scores (F = 11.4, P < 0.0001) with significant regression effects for both white matter signal hyperintensity burden (t = 2.0, β = 0.22, P = 0.045) and striatal monoaminergic binding (t = -3.5, β = -0.38, P = 0.0008). Axial motor impairment demonstrated a robust association with white matter signal hyperintensity burden (t = 4.0, β = 0.43, P =0.0001) compared with striatal monoaminergic binding (t = -2.1, β = 0.22, P = 0.043). White matter signal hyperintensity burden regression effects for bradykinesia had borderline significance. No significant white matter signal hyperintensity burden effects were found for rigidity or tremor subscores. White matter signal hyperintensity burden was significantly higher in the subgroup with postural instability and gait difficulties compared with the tremor-predominant subgroup despite no significant differences in age or duration of disease. These findings indicate that increased white matter signal hyperintensity burden is associated with worse motor performance independent of the degree of nigrostriatal dopaminergic denervation in Parkinson's disease. Comorbid white matter disease is a greater determinant of axial motor impairment than nigrostriatal dopaminergic denervation.Brain 06/2011; 134(Pt 8):2358-65. DOI:10.1093/brain/awr139 · 10.23 Impact Factor