title: Management of postural sensory conflict and dynamic balance control in late-stage Parkinson's disease.
abstract: Parkinson's disease (PD) is known to affect postural control, especially in situations needing a change in balance strategy or when a concurrent task is simultaneously performed. However, few studies assessing postural control in patients with PD included homogeneous population in late stage of the disease. Thus, this study aimed to analyse postural control and strategies in a homogeneous population of patients with idiopathic advanced (late-stage) PD, and to determine the contribution of peripheral inputs in simple and more complex postural tasks, such as sensory conflicting and dynamic tasks. Twenty-four subjects with advanced PD (duration: median (M)=11.0 years, interquartile range (IQR)=4.3 years; Unified Parkinson's Disease Rating Scale (UPDRS): M "on-dopa"=13.5, IQR=7.8; UPDRS: M "off-dopa"=48.5, IQR=16.8; Hoehn and Yahr stage IV in all patients) and 48 age-matched healthy controls underwent static (SPT) and dynamic posturographic (DPT) tests and a sensory organization test (SOT). In SPT, patients with PD showed reduced postural control precision with increased oscillations in both anterior-posterior and medial-lateral planes. In SOT, patients with PD displayed reduced postural performances especially in situations in which visual and vestibular cues became predominant to organize balance control, as was the ability to manage balance in situations for which visual or proprioceptive inputs are disrupted. In DPT, postural restabilization strategies were often inefficient to maintain equilibrium resulting in falls. Postural strategies were often precarious, postural regulation involving more hip joint than ankle joint in patients with advanced PD than in controls. Difficulties in managing complex postural situations, such as sensory conflicting and dynamic situations might reflect an inadequate sensory organization suggesting impairment in central information processing.
authors.affiliation: INSERM U 954, Thematic group Neurodegenerative Diseases, Neuroplasticity, Cognition, Faculty of Medicine, Vandoeuvre-lès-Nancy, France. s.coulbois@chu-nancy.fr
authors.forename: S
authors.initials: S
authors.lastname: Colnat-Coulbois
authors.forename: G C
authors.initials: GC
authors.lastname: Gauchard
authors.forename: L
authors.initials: L
authors.lastname: Maillard
authors.forename: G
authors.initials: G
authors.lastname: Barroche
authors.forename: H
authors.initials: H
authors.lastname: Vespignani
authors.forename: J
authors.initials: J
authors.lastname: Auque
authors.forename: P P
authors.initials: PP
authors.lastname: Perrin
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics; D010300:Parkinson Disease / Q000150:complications*; D010812:Physical Stimulation; D004856:Postural Balance / Q000502:physiology*; D012021:Reflex, Abnormal / Q000502:physiology*; D012678:Sensation Disorders / Q000175:diagnosis / Q000209:etiology / Q000628:therapy; D012720:Severity of Illness Index; D020886:Somatosensory Disorders / Q000175:diagnosis / Q000209:etiology / Q000628:therapy