NIH Public Access Author Manuscript Curr Alzheimer Res. Author manuscript; available in PMC 2014 July 05.
NIH-PA Author Manuscript
Published in final edited form as: Curr Alzheimer Res. 2014 ; 11(5): 494–500.
Older Adults with Amnestic Mild Cognitive Impairment Exhibit Exacerbated Gait Slowing under Dual-Task Challenges Benjamin Y. Tseng1,2, C. Munro Cullum3,4, and Rong Zhang1,2,3,* 1Institute
for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas
2Department
of Internal Medicine-Cardiology, University of Texas Southwestern Medical Center,
Dallas, TX 3Department
of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 4Department
of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
NIH-PA Author Manuscript
Abstract Background—With age, performance of motor tasks becomes more reliant on cognitive resources to compensate for the structural and functional declines in the motor control regions in the brain. We hypothesized that participants with amnestic mild cognitive impairment (aMCI) are more prone to motor dysfunctions than cognitively normal older adults under dual-task conditions where competitive demands challenge cognitive functions while performing a motor task simultaneously.
NIH-PA Author Manuscript
Methods—Sixteen aMCI participants (females=9, age=64±5yrs, clinical dementia rating score=0.5) and 10 age- and education-matched cognitively normal adults (females=5, age=62±6yrs) participated. Using a 10-meter-walk test (10MW), gait velocity was recorded at baseline and under 4 different dual-task (DT) conditions designed to challenge working memory, executive function, and episodic memory. Specifically, DT1: verbal fluency; DT2: 5-digit backward span; DT3: serial-7 subtraction; and DT4: 3-item delayed recall. Physical function was measured by Timed Up-and-Go (TUG), simple reaction time (RT) to a free-falling yardstick, and functional reach (FR). Results—No difference was found in physical functions, aerobic fitness, and exercise cardiopulmonary responses between aMCI participants and controls. However, aMCI participants
© 2014 Bentham Science Publishers *
Address correspondence to this author at the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, 7232 Greenville Avenue, Dallas, TX 75231; Tel: (214) 345-8843; Fax (214) 345-4618; [email protected]. AUTHOR CONTRIBUTION Benjamin Y. Tseng – Study concept & design, data acquisition, data analysis/interpretation, manuscript drafting/revising C. Munro Cullum – Study concept & design, data analysis/interpretation, manuscript drafting/revising Rong Zhang – Study concept & design, data analysis/interpretation, manuscript drafting/revising CONFLICT OF INTEREST The authors have no financial conflict of interest to disclose. The content of this manuscript is solely the responsibility of the authors. A portion of this study was presented at the Alzheimer's Association International Conference in Boston, MA in July, 2013. DISCLOSURE OF FUNDING This project was supported by NIA (R01 AG033106-01).
Tseng et al.
Page 2
showed more pronounced gait slowing from baseline when compared to the controls (p
NIH-PA Author Manuscript
Published in final edited form as: Curr Alzheimer Res. 2014 ; 11(5): 494–500.
Older Adults with Amnestic Mild Cognitive Impairment Exhibit Exacerbated Gait Slowing under Dual-Task Challenges Benjamin Y. Tseng1,2, C. Munro Cullum3,4, and Rong Zhang1,2,3,* 1Institute
for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas
2Department
of Internal Medicine-Cardiology, University of Texas Southwestern Medical Center,
Dallas, TX 3Department
of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 4Department
of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
NIH-PA Author Manuscript
Abstract Background—With age, performance of motor tasks becomes more reliant on cognitive resources to compensate for the structural and functional declines in the motor control regions in the brain. We hypothesized that participants with amnestic mild cognitive impairment (aMCI) are more prone to motor dysfunctions than cognitively normal older adults under dual-task conditions where competitive demands challenge cognitive functions while performing a motor task simultaneously.
NIH-PA Author Manuscript
Methods—Sixteen aMCI participants (females=9, age=64±5yrs, clinical dementia rating score=0.5) and 10 age- and education-matched cognitively normal adults (females=5, age=62±6yrs) participated. Using a 10-meter-walk test (10MW), gait velocity was recorded at baseline and under 4 different dual-task (DT) conditions designed to challenge working memory, executive function, and episodic memory. Specifically, DT1: verbal fluency; DT2: 5-digit backward span; DT3: serial-7 subtraction; and DT4: 3-item delayed recall. Physical function was measured by Timed Up-and-Go (TUG), simple reaction time (RT) to a free-falling yardstick, and functional reach (FR). Results—No difference was found in physical functions, aerobic fitness, and exercise cardiopulmonary responses between aMCI participants and controls. However, aMCI participants
© 2014 Bentham Science Publishers *
Address correspondence to this author at the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, 7232 Greenville Avenue, Dallas, TX 75231; Tel: (214) 345-8843; Fax (214) 345-4618; [email protected]. AUTHOR CONTRIBUTION Benjamin Y. Tseng – Study concept & design, data acquisition, data analysis/interpretation, manuscript drafting/revising C. Munro Cullum – Study concept & design, data analysis/interpretation, manuscript drafting/revising Rong Zhang – Study concept & design, data analysis/interpretation, manuscript drafting/revising CONFLICT OF INTEREST The authors have no financial conflict of interest to disclose. The content of this manuscript is solely the responsibility of the authors. A portion of this study was presented at the Alzheimer's Association International Conference in Boston, MA in July, 2013. DISCLOSURE OF FUNDING This project was supported by NIA (R01 AG033106-01).
Tseng et al.
Page 2
showed more pronounced gait slowing from baseline when compared to the controls (p
