title: Cognitive motor interference during walking in multiple sclerosis using an alternate-letter alphabet task.
abstract: OBJECTIVE
  To examine cognitive motor interference (CMI) during walking using a simple, standardized, and well-refined alphabet dual-task (DT) paradigm in individuals with multiple sclerosis (MS) in whom cognitive and walking impairment often co-occur.
  
  
  METHODS
  A single time point, cross-sectional study.
  
  
  METHODS
  A university clinical laboratory.
  
  
  METHODS
  Individuals with MS (N=61; mean age ± SD, 50.8±9.3 y) performed 4 walking trials over a 4.6-m walkway to determine gait parameters.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Gait parameters were assessed over 4 walking trials. The first 2 walks involved the single task (ST) of walking only; the second 2 walks involved participants performing the DT of reciting alternate letters of the alphabet while walking. The gait parameters recorded during the ST and DT walks were used to compute a dual-task cost (DTC) of walking (% change in gait parameter between ST and DT walks) as a metric of CMI.
  
  
  RESULTS
  Our multivariate analysis with univariate follow-ups indicated CMI during walking based on slower velocity (ηp(2)=.59; F=84.6; P<.001) and cadence (ηp(2)=.46; F=51.6; P<.001), shorter step length (ηp(2)=.38; F=36; P<.001), and increased step time (ηp(2)=.34; F=31; P<.001) and double-support time (ηp(2)=.31; F=27.3; P<.001) in DT versus ST conditions. The DTC of walking for the gait parameters was not correlated with clinical (disability, disease duration) and demographic (eg, education, age) factors (all |r|≤.240).
  
  
  CONCLUSIONS
  The alphabet DT paradigm is easily administered and well refined. We highlight its ability and acceptability to determine CMI during walking in people with MS, independent of disease status.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL.
authors.forename: Yvonne C
authors.initials: YC
authors.lastname: Learmonth
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Sandroff
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL.
authors.forename: Lara A
authors.initials: LA
authors.lastname: Pilutti
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Klaren
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL.
authors.forename: Ipek
authors.initials: I
authors.lastname: Ensari
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL.
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Riskin
authors.affiliation: Ferkauf Graduate School of Psychology, Yeshiva University, Bronx, NY.
authors.forename: Roee
authors.initials: R
authors.lastname: Holtzer
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL. Electronic address: robmotl@illinois.edu.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Motl
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology*; D011597:Psychomotor Performance; D016138:Walking / Q000502:physiology* / Q000523:psychology*
keywords: Cognition; Multiple sclerosis; Rehabilitation