Differential relationships between brain structure and dual task walking in young and older adults

Almost 25% of all older adults experience difficulty walking. Mobility difficulties for older adults are more pronounced when performing a simultaneous cognitive task while walking (i.e., dual task walking). Although it is known that aging results in widespread brain atrophy, few studies have integrated across more than one neuroimaging modality to comprehensively examine the structural neural correlates that may underly dual task walking in older age. We collected spatiotemporal gait data during single and dual task walking for 37 young (18-34 years) and 23 older adults (66-86 years). We also collected T1-weighted and diffusion-weighted MRI scans to determine how brain structure differs in older age and relates to dual task walking. We addressed two aims: 1) to characterize age differences in brain structure across a range of metrics including volumetric, surface, and white matter microstructure; and 2) to test for age group differences in the relationship between brain structure and the dual task cost (DTcost) of gait speed and variability. Key findings included widespread brain atrophy for the older adults, with the most pronounced age differences in brain regions related to sensorimotor processing. We also found multiple associations between regional brain atrophy and greater DTcost of gait speed and variability for the older adults. The older adults showed a relationship of both thinner temporal cortex and shallower sulcal depth in the frontal, sensorimotor, and parietal cortices with greater DTcost of gait. Additionally, the older adults showed a relationship of ventricular volume and superior longitudinal fasciculus free-water corrected axial and radial diffusivity with greater DTcost of gait. These relationships were not present for the young adults. Stepwise multiple regression found sulcal depth in the left precentral gyrus, axial diffusivity in the superior longitudinal fasciculus, and sex to best predict DTcost of gait speed, and cortical thickness in the superior temporal gyrus to best predict DTcost of gait variability for older adults. These results contribute to scientific understanding of how individual variations in brain structure are associated with mobility function in aging. This has implications for uncovering mechanisms of brain aging and for identifying target regions for mobility interventions for aging populations.

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Combining tDCS With a Motor-Cognitive Task to Reduce the Negative Impact of Dual-Tasking on the Gait of Older Adults

Innovation in Aging ◽

10.1093/geroni/igaa057.921 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 287-288

Author(s):

Jeffrey Hausdorff ◽

Nofar Schneider ◽

Marina Brozgol ◽

Pablo Cornejo Thumm ◽

Nir Giladi ◽

...

Keyword(s):

Older Adults ◽

Virtual Reality ◽

Executive Function ◽

Dual Task ◽

Gait Speed ◽

Negative Impact ◽

Virtual Reality Environment ◽

Dual Tasking ◽

Concurrent Performance ◽

Dual Task Cost

Abstract The simultaneous performance of a secondary task while walking (i.e., dual tasking) increases motor-cognitive interference and fall risk in older adults. Combining transcranial direct current stimulation (tDCS) with the concurrent performance of a task that putatively involves the same brain networks targeted by the tDCS may reduce the negative impact of dual-tasking on walking. We examined whether tDCS applied while walking reduces the dual-task costs to gait and whether this combination is better than tDCS alone or walking alone (with sham stimulation). In 25 healthy older adults (aged 75.7±10.5yrs), a double-blind, within-subject, cross-over pilot study evaluated the acute after-effects of 20 minutes of tDCS targeting the primary motor cortex and the dorsal lateral pre frontal cortex during three separate sessions:1) tDCS while walking on a treadmill in a virtual-reality environment (tDCS+walking), 2) tDCS while seated (tDCS+seated), and 3) walking in the virtual-reality environment with sham tDCS (sham+walking). The complex walking condition taxed motor and cognitive abilities. During each session, single- and dual-task walking and cognitive function were assessed before and immediately after stimulation. Compared to pre-tDCS performance, tDCS+walking reduced the dual-task cost to gait speed (p=0.004) and other gait features (e.g., variability p=0.02), and improved (p<0.001) executive function (Stroop interference score). tDCS+seated and sham+walking did not affect the dual-task cost to gait speed (p>0.17). These initial findings demonstrate that tDCS delivered during challenging walking ameliorates dual-task gait and executive function in older adults, suggesting that the concurrent performance of related tasks enhances the efficacy of the neural stimulation and mobility.

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Digital Biomarkers of Cognitive Frailty: The Value of Detailed Gait Assessment Beyond Gait Speed

Gerontology ◽

10.1159/000515939 ◽

2021 ◽

pp. 1-10

Author(s):

He Zhou ◽

Catherine Park ◽

Mohammad Shahbazi ◽

Michele K. York ◽

Mark E. Kunik ◽

...

Keyword(s):

Older Adults ◽

Steady State ◽

Dual Task ◽

Gait Speed ◽

Stride Length ◽

Cognitive Frailty ◽

Single Task ◽

Double Support ◽

Gait Parameters ◽

Digital Biomarkers

Background: Cognitive frailty (CF), defined as the simultaneous presence of cognitive impairment and physical frailty, is a clinical symptom in early-stage dementia with promise in assessing the risk of dementia. The purpose of this study was to use wearables to determine the most sensitive digital gait biomarkers to identify CF. Methods: Of 121 older adults (age = 78.9 ± 8.2 years, body mass index = 26.6 ± 5.5 kg/m2) who were evaluated with a comprehensive neurological exam and the Fried frailty criteria, 41 participants (34%) were identified with CF and 80 participants (66%) were identified without CF. Gait performance of participants was assessed under single task (walking without cognitive distraction) and dual task (walking while counting backward from a random number) using a validated wearable platform. Participants walked at habitual speed over a distance of 10 m. A validated algorithm was used to determine steady-state walking. Gait parameters of interest include steady-state gait speed, stride length, gait cycle time, double support, and gait unsteadiness. In addition, speed and stride length were normalized by height. Results: Our results suggest that compared to the group without CF, the CF group had deteriorated gait performances in both single-task and dual-task walking (Cohen’s effect size d = 0.42–0.97, p < 0.050). The largest effect size was observed in normalized dual-task gait speed (d = 0.97, p < 0.001). The use of dual-task gait speed improved the area under the curve (AUC) to distinguish CF cases to 0.76 from 0.73 observed for the single-task gait speed. Adding both single-task and dual-task gait speeds did not noticeably change AUC. However, when additional gait parameters such as gait unsteadiness, stride length, and double support were included in the model, AUC was improved to 0.87. Conclusions: This study suggests that gait performances measured by wearable sensors are potential digital biomarkers of CF among older adults. Dual-task gait and other detailed gait metrics provide value for identifying CF above gait speed alone. Future studies need to examine the potential benefits of gait performances for early diagnosis of CF and/or tracking its severity over time.

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The Benefits of Physical Activity in Individuals with Cardiovascular Risk Factors: A Longitudinal Investigation Using fNIRS and Dual-Task Walking

Journal of Clinical Medicine ◽

10.3390/jcm10040579 ◽

2021 ◽

Vol 10 (4) ◽

pp. 579

Author(s):

Deborah Talamonti ◽

Thomas Vincent ◽

Sarah Fraser ◽

Anil Nigam ◽

Frédéric Lesage ◽

...

Keyword(s):

Physical Activity ◽

Risk Factors ◽

Older Adults ◽

Cardiovascular Risk ◽

Cardiovascular Risk Factors ◽

Cognitive Performance ◽

Dual Task ◽

Gait Speed ◽

Regular Physical Activity ◽

Cortical Response

Cardiovascular fitness is linked to better executive functions, preserved gait speed, and efficient cortical activity. Older adults with cardiovascular risk factors (CVRFs) typically show poor cognitive performance, low physical fitness, and altered brain functioning compared with healthy individuals. In the current study, the impact of regular physical activity on cognition, locomotion, and brain functions was explored in a cohort of older adults with low or high CVRFs. Cortical activation of the frontal areas was investigated using functional Near-Infrared Spectroscopy (fNIRS) at baseline, at 6 months and at 12 months. Evoked cortical response and behavioral performance were assessed using the dual-task walking paradigm, consisting of three conditions: single cognitive task (2-back task), single walking task (walking), and dual-task (2-back whilst walking). Results show greater task-related cortical response at baseline in individuals with high CVRFs compared to those with low CVRFs. Moreover, participants with high CVRFs benefitted the most from participating in regular physical activity, as their cortical response decreased at the 12-month follow-up and became comparable to that of participants with low CVRFs. These changes were observed in conjunction with improved cognitive performance and stable gait speed throughout the 12-month period in both groups. Our findings provide evidence that participation in regular physical activity may be especially beneficial in individuals with CVRFs by promoting brain and cognitive health, thus potentially contributing to prevention of cognitive decline. Future research may explore whether such effects are maintained in the long-term in order to design ad-hoc interventions in this specific population.

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Mild Cognitive Impairment Affects Obstacle Negotiation in Older Adults: Results from “Gait and Brain Study”

Gerontology ◽

10.1159/000492931 ◽

2018 ◽

Vol 65 (2) ◽

pp. 164-173 ◽

Cited By ~ 13

Author(s):

Frederico Pieruccini-Faria ◽

Yanina Sarquis-Adamson ◽

Manuel Montero-Odasso

Keyword(s):

Older Adults ◽

Cognitive Impairment ◽

Executive Function ◽

Mild Cognitive Impairment ◽

Dual Task ◽

Gait Speed ◽

Step Length ◽

Gait Control ◽

Dual Tasking ◽

Brain Study

Background: Older adults with Mild Cognitive Impairment (MCI) are at higher risk of falls and injuries, but the underlying mechanism is poorly understood. Inappropriate anticipatory postural adjustments to overcome balance perturbations are affected by cognitive decline. However, it is unknown whether anticipatory gait control to avoid an obstacle is affected in MCI. Objective: Using the dual-task paradigm, we aim to assess whether gait control is affected during obstacle negotiation challenges in older adults with MCI. Methods: Seventy-nine participants (mean age = 72.0 ± 2.7 years; women = 30.3%) from the “Gait and Brain Study” were included in this study (controls = 27; MCI = 52). In order to assess the anticipatory control behaviour for obstacle negotiation, a 6-m electronic walkway embedded with sensors recorded foot prints to measure gait speed and step length variability, during early (3 steps before the late phase) and late (3 steps before the obstacle) pre-crossing phases of an ad hoc obstacle, set at 15% of participant’s height. Participants walked under single- and dual-task gait (counting backwards by 1’s from 100 while walking) conditions. Three-way mixed repeated-measures analysis of variance models examined differences in gait performance between groups when transitioning between pre-crossing phases towards an obstacle during single- and dual-task conditions. Analyses were adjusted for age, sex, years of education, lower limb function, fear of falling, medical status, depressive symptoms, baseline gait speed and executive function. Results: A significant three-way interaction among groups, pre-crossing phases and task showed that participants with MCI attenuated the gait deceleration (p = 0.02) and performed fewer step length adjustments (p = 0.03) when approaching the obstacle compared with controls while dual-tasking. These interactions were attenuated when executive function performance was added as a covariate in the adjusted statistical model. Conclusion: Older adults with MCI attenuate the anticipatory gait adjustments needed to avoid an obstacle when dual-tasking. Deficits in higher-order cognitive processing may limit obstacle negotiation capabilities in MCI populations, being a potential falls risk factor.

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Dual-task gait speed assessments with an electronic walkway and a stopwatch in older adults. A reliability study

Experimental Gerontology ◽

10.1016/j.exger.2020.111102 ◽

2020 ◽

Vol 142 ◽

pp. 111102

Author(s):

M. Montero-Odasso ◽

Y. Sarquis-Adamson ◽

N. Kamkar ◽

F. Pieruccini-Faria ◽

N. Bray ◽

...

Keyword(s):

Older Adults ◽

Dual Task ◽

Gait Speed ◽

Reliability Study

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Design of Telephone Answering Machines for Older Adults

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1071181397041002142 ◽

1997 ◽

Vol 41 (2) ◽

pp. 1367-1367

Author(s):

Chin Chin Lee ◽

Jessica D'Agostini ◽

Sara J. Czaja ◽

Joseph Sharit

Keyword(s):

Older Adults ◽

Older People ◽

Age Differences ◽

Task Analysis ◽

Age Groups ◽

Older Age ◽

Hearing Impairments ◽

Usage Patterns ◽

Automatic Teller Machines

Older adults frequently have difficulty when attempting to use various forms of technology such as computers or automatic teller machines. This study evaluated the usability of telephone answering machines for older adults. Initially, a task analysis of four commonly used answering machines was performed to identify the subtasks involved in using an answering machine. A questionnaire was then developed which assessed usage patterns and usability issues associated with answering machines. This questionnaire was administered to a sample of 68 people aged 65+ yrs. and 50 people aged 20 — 30 yrs. The data indicated that most older people own answering machines and perceive them as useful. There were, however, some age differences in aspects of usability. The older adults were more likely to have difficulty understanding messages than the younger people and to perceive the messages as distorted. Further, the older people reported that they have difficulty replaying messages and accessing messages remotely. The results also indicated that older people with hearing impairments were more likely to have problems with message distortion than those without hearing impairments. Overall, the data suggest features of answering machines which affect the usability of this technology for older age groups. Data is currently being collected regarding the ability of a sample of older people to perform a common set of tasks using two different answering machines. The results from the research are being used to develop recommendations for improving the design of telephone answering machines for people of all age groups.

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Relationship of Clinic-Based Gait Speed Measurement to Limitations in Community-Based Activities in Older Adults

Archives of Physical Medicine and Rehabilitation ◽

10.1016/j.apmr.2010.12.030 ◽

2011 ◽

Vol 92 (5) ◽

pp. 844-846 ◽

Cited By ~ 50

Author(s):

Joe Verghese ◽

Cuiling Wang ◽

Roee Holtzer

Keyword(s):

Older Adults ◽

Gait Speed ◽

Community Based ◽

Speed Measurement ◽

Relationship Of

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WEARABLES REVEAL A GAP BETWEEN GAIT PERFORMANCE IN THE LAB AND DURING 24/7 MONITORING IN OLDER ADULTS

Innovation in Aging ◽

10.1093/geroni/igz038.1218 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

pp. S335-S335

Author(s):

Inbar Hillel ◽

Laura Avanzino ◽

Andrea Cereatti ◽

Marcel Olde Rikkert ◽

Silvia Del Din ◽

...

Keyword(s):

Older Adults ◽

Dual Task ◽

Gait Speed ◽

Daily Living ◽

Laboratory Setting ◽

Gait Performance ◽

Lower Back ◽

Gait Features

Abstract We compared in-lab usual-walking (UW) and dual-task walking (DTW) to daily-living measures of gait obtained during 24/7 monitoring. In-lab gait features (e.g., gait speed, step and stride regularity) derived from UW and DTW were compared to the same gait features during daily-living in 150 elderly fallers (age: 76.5±6.3 years, 37.6% men). Features were extracted from a lower-back accelerometer. In daily-living setting, subjects wore the device for one week and pre-processing detected 30-second walking bouts. A histogram of all walking bouts was determined for each walking feature for each subject, then each subject’s typical, worst and best values were determined. Statistics of reliability were assessed using ICC and Bland-Altman. As expected, in-lab gait speed, step regularity, and stride regularity were worse during DTW, compared to UW. Gait speed, step regularity, and stride regularity during UW were significantly higher (i.e., better) from the typical daily-living values (p<0.0001) and different (p<0.000) from the worst and best values. DTW values tended to be similar to typical daily-living values (p=0.205, p=0.053, p=0.013 respectively). ICC assessment and Bland-Altman plots indicated that in-lab values do not reliably reflect the daily-walking values. Gait values during relatively long daily-living walking bouts are more similar to the corresponding values obtained in the lab during DTW, as compared to UW. Still, gait performance during most daily-living walking bouts are worse than that measured in-lab and do not reliably reflect each other. That is, an older adult’s typical daily-living gait cannot be estimated by simply measuring walking in a structured, laboratory setting.

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