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Hôpital-Camfrout, France

Bonnet C.T.,French National Center for Scientific Research | Delval A.,EA 1046 | Defebvre L.,EA 1046
Journal of Neurophysiology | Year: 2014

Patients with Parkinson’s disease display impairments of postural control most particularly in active, challenging conditions. The objective of the present study was to analyze early signs of disease-related and also age-related impairments in mediolateral body extension and postural control. Fifty-five participants (18 Hoehn and Yahr stage 2 patients in the off-drug condition, 18 healthy elderly control subjects, and 19 young adults) were included in the study. The participants performed a quiet stance task and two active tasks that analyzed the performance in mediolateral body motion: a limit of stability and a rhythmic weight shift task. As expected, the patients displayed significantly lower and slower body displacement (head, neck, lower back, center of pressure) than elderly control subjects when performing the two body excursion tasks. However, the behavioral variability in both tasks was similar between the groups. Under these active conditions, the patients showed significantly lower contribution of the hip postural control mechanisms compared with the elderly control subjects. Overall, the patients seemed to lower their performance in order to prevent a mediolateral postural instability. However, these patients, at an early stage of their disease, were not unstable in quiet stance. Complementarily, elderly control subjects displayed slower body performance than young adults, which therefore showed an additional age-related impairment in mediolateral postural control. Overall, the study illustrated markers of age-related and Parkinson’s disease impairments in mediolateral postural control that may constrain everyday activities in elderly adults and even more in patients with Parkinson’s disease. © 2014 the American Physiological Society.


Introduction: In younger patients, the in vivo clinical diagnosis of Alzheimer's disease (AD) and of the frontotemporal type (FTD) may be cumbersome. The gold standard diagnostic proof is currently still based upon pathology examination. It is crucial to find reliable techniques to make an accurate in vivo diagnosis and to differentiate the etiology of the dementia. Patients and method: Twenty-four patients bearing clinically diagnosed AD (n=16) and FTD (n=8) underwent [18F] FDG-PET/CT brain scan. Four nuclear medicine physicians with varying expertise in neuroimaging read each scan according to: visual analysis; automated analysis computed by BRASS® Hermes® software; automated analysis computed by Cortex ID® General Electric® software. Interpretation aimed at assessing the global scan aspect, the cerebral metabolism per hemisphere (in five relevant regions) and the diagnostic degree of confidence. Diagnostic interpretations derived from visual and automated analyses were compared to clinical diagnosis. Inter-observer agreement and Kappa scores were calculated. Results: Kappa analyses showed a gain in diagnostic accuracy for a nonexpert physician, a gain in diagnostic confidence with Cortex ID® and a gain in interobserver diagnostic agreement with BRASS®. Conclusion: Using automated software such as Cortex ID® or BRASS® helps standardizing the interpretation of [18F] FDG distribution pattern in AD or FTD. © 2011 Elsevier Masson SAS.

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