title: Association between vestibulo-ocular reflex suppression, balance, gait, and fall risk in ageing and neurodegenerative disease: protocol of a one-year prospective follow-up study.
abstract: BACKGROUND
  Falls frequency increases with age and particularly in neurogeriatric cohorts. The interplay between eye movements and locomotion may contribute substantially to the occurrence of falls, but is hardly investigated. This paper provides an overview of current approaches to simultaneously measure eye and body movements, particularly for analyzing the association of vestibulo-ocular reflex (VOR) suppression, postural deficits and falls in neurogeriatric risk cohorts. Moreover, VOR suppression is measured during head-fixed target presentation and during gaze shifting while postural control is challenged. Using these approaches, we aim at identifying quantitative parameters of eye-head-coordination during postural balance and gait, as indicators of fall risk.
  
  
  METHODS
  Patients with Progressive Supranuclear Palsy (PSP) or Parkinson's disease (PD), age- and sex-matched healthy older adults, and a cohort of young healthy adults will be recruited. Baseline assessment will include a detailed clinical assessment, covering medical history, neurological examination, disease specific clinical rating scales, falls-related self-efficacy, activities of daily living, neuro-psychological screening, assessment of mobility function and a questionnaire for retrospective falls. Moreover, participants will simultaneously perform eye and head movements (fixating a head-fixed target vs. shifting gaze to light emitting diodes in order to quantify vestibulo-ocular reflex suppression ability) under different conditions (sitting, standing, or walking). An eye/head tracker synchronized with a 3-D motion analysis system will be used to quantify parameters related to eye-head-coordination, postural balance, and gait. Established outcome parameters related to VOR suppression ability (e.g., gain, saccadic reaction time, frequency of saccades) and motor related fall risk (e.g., step-time variability, postural sway) will be calculated. Falls will be assessed prospectively over 12 months via protocols and monthly telephone interviews.
  
  
  CONCLUSIONS
  This study protocol describes an experimental setup allowing the analysis of simultaneously assessed eye, head and body movements. Results will improve our understanding of the influence of the interplay between eye, head and body movements on falls in geriatric high-risk cohorts.
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. karin.srulijes@uni-tuebingen.de.|Department of Geriatrics and Clinic of Geriatric Rehabilitation, Robert-Bosch-Hospital, Stuttgart, Germany. karin.srulijes@uni-tuebingen.de.|German Research Center for Neurodegenerative Diseases (DZNE), University of Tuebingen, Tuebingen, Germany. karin.srulijes@uni-tuebingen.de.
authors.forename: Karin
authors.initials: K
authors.lastname: Srulijes
authors.affiliation: Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. david-jule.mack@iis.ee.ethz.ch.|Clinic for Neurology, University Hospital Zurich, Zurich, Switzerland. david-jule.mack@iis.ee.ethz.ch.
authors.forename: David J
authors.initials: DJ
authors.lastname: Mack
authors.affiliation: Department of Geriatrics and Clinic of Geriatric Rehabilitation, Robert-Bosch-Hospital, Stuttgart, Germany. Jochen.Klenk@rbk.de.|Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany. Jochen.Klenk@rbk.de.
authors.forename: Jochen
authors.initials: J
authors.lastname: Klenk
authors.affiliation: Department of Geriatrics and Clinic of Geriatric Rehabilitation, Robert-Bosch-Hospital, Stuttgart, Germany. Lars.Schwickert@rbk.de.
authors.forename: Lars
authors.initials: L
authors.lastname: Schwickert
authors.affiliation: Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway. espen.ihlen@ntnu.no.
authors.forename: Espen A F
authors.initials: EA
authors.lastname: Ihlen
authors.affiliation: Department of Geriatrics and Clinic of Geriatric Rehabilitation, Robert-Bosch-Hospital, Stuttgart, Germany. Michael.Schwenk@rbk.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Schwenk
authors.affiliation: Department of Geriatrics and Clinic of Geriatric Rehabilitation, Robert-Bosch-Hospital, Stuttgart, Germany. Ulrich.Lindemann@rbk.de.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Lindemann
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. miriam.meyer@student.uni-tuebingen.de.
authors.forename: Miriam
authors.initials: M
authors.lastname: Meyer
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. srijana.k.c.@student.uni-tuebingen.de.
authors.forename: K C
authors.initials: KC
authors.lastname: Srijana
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. markus.hobert@uni-tuebingen.de.|German Research Center for Neurodegenerative Diseases (DZNE), University of Tuebingen, Tuebingen, Germany. markus.hobert@uni-tuebingen.de.
authors.forename: Markus A
authors.initials: MA
authors.lastname: Hobert
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. kathrin.brockmann@uni-tuebingen.de.|German Research Center for Neurodegenerative Diseases (DZNE), University of Tuebingen, Tuebingen, Germany. kathrin.brockmann@uni-tuebingen.de.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Brockmann
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. isabel.wurster@uni-tuebingen.de.|German Research Center for Neurodegenerative Diseases (DZNE), University of Tuebingen, Tuebingen, Germany. isabel.wurster@uni-tuebingen.de.
authors.forename: Isabel
authors.initials: I
authors.lastname: Wurster
authors.affiliation: Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. joern.pomper@uni-tuebingen.de.
authors.forename: Jörn K
authors.initials: JK
authors.lastname: Pomper
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. matthis.synofzik@uni-tuebingen.de.|German Research Center for Neurodegenerative Diseases (DZNE), University of Tuebingen, Tuebingen, Germany. matthis.synofzik@uni-tuebingen.de.
authors.forename: Matthis
authors.initials: M
authors.lastname: Synofzik
authors.affiliation: Institute of Medical Technology, Brandenburg University of Technology Cottbus -Senftenberg, Cottbus, Germany. eschneid@hs-lausitz.de.
authors.forename: Erich
authors.initials: E
authors.lastname: Schneider
authors.affiliation: Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. uwe.ilg@uni-tuebingen.de.
authors.forename: Uwe
authors.initials: U
authors.lastname: Ilg
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. daniela.berg@uni-tuebingen.de.|German Research Center for Neurodegenerative Diseases (DZNE), University of Tuebingen, Tuebingen, Germany. daniela.berg@uni-tuebingen.de.
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. walter.maetzler@uni-tuebingen.de.|German Research Center for Neurodegenerative Diseases (DZNE), University of Tuebingen, Tuebingen, Germany. walter.maetzler@uni-tuebingen.de.
authors.forename: Walter
authors.initials: W
authors.lastname: Maetzler
authors.affiliation: Department of Geriatrics and Clinic of Geriatric Rehabilitation, Robert-Bosch-Hospital, Stuttgart, Germany. Clemens.Becker@rbk.de.
authors.forename: Clemens
authors.initials: C
authors.lastname: Becker
mesh_terms: D000058:Accidental Falls; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D020233:Gait Disorders, Neurologic / Q000503:physiopathology*; D019416:Head Movements / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D011446:Prospective Studies; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D013494:Supranuclear Palsy, Progressive / Q000503:physiopathology*