title: The motor signature of mild cognitive impairment: results from the gait and brain study.
abstract: BACKGROUND
  Early motor changes associated with aging predict cognitive decline, which suggests that a "motor signature" can be detected in predementia states. In line with previous research, we aim to demonstrate that individuals with mild cognitive impairment (MCI) have a distinct motor signature, and specifically, that dual-task gait can be a tool to distinguish amnestic (a-MCI) from nonamnestic MCI.
  
  
  METHODS
  Older adults with MCI and controls from the "Gait and Brain Study" were assessed with neurocognitive tests to assess cognitive performance and with an electronic gait mat to record temporal and spatial gait parameters. Mean gait velocity and stride time variability were evaluated under simple and three separate dual-task conditions. The relationship between cognitive groups (a-MCI vs nonamnestic MCI) and gait parameters was evaluated with linear regression models and adjusted for confounders.
  
  
  RESULTS
  Ninety-nine older participants, 64 MCI (mean age 76.3±7.1 years; 50% female), and 35 controls (mean age 70.4±3.9 years; 82.9% female) were included. Forty-two participants were a-MCI and 22 were nonamnestic MCI. Multivariable linear regression (adjusted for age, sex, physical activity level, comorbidities, and executive function) showed that a-MCI was significantly associated with slower gait and higher dual-task cost under dual-task conditions.
  
  
  CONCLUSIONS
  Participants with a-MCI, specifically with episodic memory impairment, had poor gait performance, particularly under dual tasking. Our findings suggest that dual-task assessment can help to differentiate MCI subtyping, revealing a motor signature in MCI.
authors.affiliation: Gait and Brain Lab, Parkwood Hospital, Lawson Health Research Institute, Schulich School of Medicine and Dentistry, Department of Medicine and Division of Geriatric Medicine and Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada. mmontero@uwo.ca.
authors.forename: Manuel
authors.initials: M
authors.lastname: Montero-Odasso
authors.affiliation: Gait and Brain Lab, Parkwood Hospital, Lawson Health Research Institute.
authors.forename: Afua
authors.initials: A
authors.lastname: Oteng-Amoako
authors.affiliation: Gait and Brain Lab, Parkwood Hospital, Lawson Health Research Institute, Schulich School of Medicine and Dentistry, Department of Medicine and Division of Geriatric Medicine and Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Speechley
authors.affiliation: Gait and Brain Lab, Parkwood Hospital, Lawson Health Research Institute.
authors.forename: Karen
authors.initials: K
authors.lastname: Gopaul
authors.affiliation: Department of Neuroscience, Division of Geriatric Medicine, Angers University Hospital, Angers, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Beauchet
authors.affiliation: Department of Neuroscience, Division of Geriatric Medicine, Angers University Hospital, Angers, France.
authors.forename: Cedric
authors.initials: C
authors.lastname: Annweiler
authors.affiliation: Gait and Brain Lab, Parkwood Hospital, Lawson Health Research Institute, Schulich School of Medicine and Dentistry, Department of Medicine and Division of Geriatric Medicine and.
authors.forename: Susan W
authors.initials: SW
authors.lastname: Muir-Hunter
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D003704:Dementia / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D018450:Disease Progression; D005260:Female; D020233:Gait Disorders, Neurologic / Q000503:physiopathology* / Q000523:psychology*; D006801:Humans; D008297:Male; D061212:Memory, Episodic; D009048:Motor Skills / Q000502:physiology; D009483:Neuropsychological Tests; D013647:Task Performance and Analysis
keywords: Cognition-motor decline.; Dual-task; Gait speed; Gait variability; Mild cognitive impairment