title: Postural stability limits in manifest and premanifest Huntington's disease under different sensory conditions.
abstract: Increasing evidence indicates that Huntington's disease (HD) produces postural control impairments even before the clinical diagnosis. It has been suggested that postural disorders of HD patients are explained by deficits in the processing and integration of sensory information, but this hypothesis has been under-explored. In the present study, we evaluated the amplitude of the center of pressure (COP) displacement during maximum leaning in four directions (forward, backward, rightward and leftward) and under three sensory conditions (eyes open, eyes closed and eyes closed standing on foam). We assessed the stability limits in 20 individuals with a positive HD genetic test (12 premanifests; eight manifests HD) and 15 healthy controls. The COP displacements were analyzed during the first and second phases of maintenance of the maximum leaning position. Manifest HD patients showed significantly greater COP ranges than healthy controls in both learning phases and all sensory conditions, but the greatest deterioration of their performance was found in the foam condition. In contrast, premanifest HD patients displayed larger COP ranges than controls only during the second phase of maximum learning, especially in the foam condition. Furthermore, both HD groups had significantly smaller limits of stability than healthy subjects during the second phase of maximum learning. However, their ability to maintain the maximum leaning position was degraded during both learning phases. Together, these findings demonstrate that HD reduces the limits of stability even before the clinical disease onset. Furthermore, our results indicate that dynamic postural tasks with high demand for sensorimotor integration and especially the use of proprioception are highly sensitive to early HD disease processes. This dynamic postural task may become a useful biomarker of HD progression.
authors.affiliation: Département de Kinésiologie, Université de Montréal, 2100, boul. Édouard-Montpetit, Montréal, Québec H3T 1J4, Canada. Electronic address: marieve.blanchet@umontreal.ca.
authors.forename: M
authors.initials: M
authors.lastname: Blanchet
authors.affiliation: Département de Kinésiologie, Université de Montréal, 2100, boul. Édouard-Montpetit, Montréal, Québec H3T 1J4, Canada. Electronic address: francois.prince@umontreal.ca.
authors.forename: F
authors.initials: F
authors.lastname: Prince
authors.affiliation: Services de neurologie du Centre Hospitalier de l'Université de Montréal, Hôpital Notre-Dame, Pavillon Des Champs, 1560, rue Sherbrooke est, Montréal, Québec, H2L 4M1, Canada; Faculté de médecine, Université de Montréal, Pavillon Paul-G.-Desmarais, Département de neurosciences, 2960, chemin de la Tour, local 2140, Montréal (Québec) H3T 1J4, Canada. Electronic address: sylvain.chouinard@umontreal.ca.
authors.forename: S
authors.initials: S
authors.lastname: Chouinard
authors.affiliation: Département de Kinésiologie, Université de Montréal, 2100, boul. Édouard-Montpetit, Montréal, Québec H3T 1J4, Canada; Institut universitaire de gériatrie de Montréal, 4565, chemin Queen-Mary, Montréal Québec, H3W 1W5, Canada. Electronic address: j.messier@umontreal.ca.
authors.forename: J
authors.initials: J
authors.lastname: Messier
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000235:genetics / Q000503:physiopathology*; D007858:Learning / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D062706:Prodromal Symptoms; D011597:Psychomotor Performance / Q000502:physiology*; D014785:Vision, Ocular; D055815:Young Adult
keywords: Huntington’s disease; basal ganglia; postural control; sensorimotor integration; stability limit