Variability in Obstacle Clearance May (Not) Indicate Cognitive Disorders in Alzheimer Disease

Characteristics of transitional locomotor tasks performed by patients with dementia

Elderly individuals may be at increased risk of falls than their peers. Early identification of balance disorders and their appropriate intervention are crucial for patients with dementia. The aim of this study was to identify postural instability in patients from mild to moderate dementia while performing transitional locomotor tasks under different conditions. Fifty-four patients with dementia and 30 healthy controls voluntarily participated in the study. The transitional locomotor task was performed on two force platforms under four conditions: unimpeded transition, obstacle clearance, step-up and step-down trials. The recording of center of foot pressure displacements was divided into three distinct phases: 1st phase-quiet standing before the transitional locomotor task, 2nd phase-forward stepping, 3rd phase-quiet standing after the transitional locomotor task. Patients with dementia were characterized by a longer transitional locomotor task time than the control group under all conditions (P < 0.03). Significant differences in quiet standing before the transitional locomotor task were observed between patients with dementia and the control group, but only in unimpeded transition and obstacle clearance trials (P < 0.02). No significant differences in quiet standing after step transition were observed between patients with dementia and the control group (P > 0.05). Postural control research in patients with dementia should focus on the functional motor task rather than on a simple motor task (quiet standing). Because even patients with mild dementia have impaired dynamic balance, the assessment of transitional locomotor tasks performed by patients with dementia might provide an indicator of an early diagnosis of dementia and might lead to better individualized physiotherapy.

Association of age-related cognitive and obstacle avoidance performances

An association between cognitive impairment and tripping over obstacles during locomotion in older adults has been suggested. However, owing to its memory-guided movement, whether this is more pronounced in the trailing limb is poorly known. We examined age-related changes in stepping over, focusing on trailing limb movements, and their association with cognitive performance. Age-related changes in obstacle avoidance were examined by comparing the foot kinematics of 105 older and 103 younger adults when stepping over an obstacle. The difference in the clearance between the leading and trailing limbs (Δ clearance) was calculated to determine the degree of decrement in the clearance of the trailing limb. A cognitive test battery was used to evaluate cognitive function among older adults to assess their association with Δ clearance. Older adults showed a significantly lower clearance of the trailing limb than young adults, resulting in greater Δ clearance. Significant correlations were observed between greater Δ clearance and scores on the Montreal Cognitive Assessment and immediate recall of the Wechsler Memory Scale-Revised Logical Memory test. Therefore, memory functions may contribute to the control of trailing limb movements, which can secure a safety margin to avoid stumbling over an obstacle during obstacle avoidance locomotion.

Feasibility of dual-task gait to estimate Alzheimer's related cognitive decline in Down syndrome

INTRODUCTION

The striatum and frontal lobes have been shown to have early Alzheimer's disease (AD) neuropathology and are critical for motor and cognitive function. We hypothesized gait would be associated with early-stage dementia in Down syndrome (DS), a cohort at risk for AD.

METHODS

Twenty-eight participants with DS were enrolled in the study. Participants walked at their self-selected pace and while completing a dual task (counting, obstacle, or counting+obstacle).

RESULTS

All participants were able to complete the self-paced condition and 78.57-96.42% completed the dual-task conditions. There was a trend for greater dual-task effects on gait velocity based on dementia diagnosis. Gait velocity had stronger associations with clinical dementia assessments than age or diagnosis.

DISCUSSION

A dual-task gait paradigm is feasible to conduct with adults with DS and is associated with age and cognitive impairment. Dual-task gait may serve as an indicator of early stage dementia in DS.

Complex Gait Is Related to Cognitive Functioning in Older People: A Cross-Sectional Study Providing an Innovative Test

BACKGROUND

Many studies have demonstrated an inverse relationship between gait performance and cognitive impairment. The main purposes of this study were: (1) to design and validate a complex gait test (CGT) in older people, (2) to analyze the effects of age and sex on CGT, and (3) to analyze the association between CGT performance and physical functioning and cognitive measures.

METHODS

A total of 279 older people (60-97 years) were analyzed in 2019. Fitness tests, gait performance, and several cognitive measures such asthe Trail-Walking Test and Montreal Cognitive Assessment were used.

RESULTS

The CGT reported adequate reliability and validity parameters. In the test-retest analysis, the intra-class correlation coefficient was 0.868 (p < 0.001). There was a significant correlation between the CGT and Trail-Walking Test (r = 0.592; p < 0.001). The linear regression analysis showed that the CGT was associated with the Montreal Cognitive Assessment (R2 = 0.357; p =0.001). The binary logistic regression analysis revealed that a high CGT score was a risk factor for mild cognitive impairment (odds ratio 1.201, 95% CI 1.081-1.334; p = 0.001). The ROC curve of the mild cognitive impairment was predicted by the CGT performance (area under the curve = 0.768, 95% CI 0.647-0.889; p < 0.001), reaching the cut-off point at 20.25 s.

CONCLUSIONS

The CGT showed good reliability and validity and may serve as a potential biomarker in mild cognitive impairment prediction in older adults aged 60-97 years.

Risk factors for falls in terms of attention during gait in community-dwelling older adults

AIM

We examined factors related to conditions of life function and falls, including eye movements and gait variability, in community-dwelling older adults in Japan.

METHODS

Participants were 82 older adults (21 men, 61 women, mean age 76.1 years). We measured eye movements and gait variability during walking, and cognitive, attentional and life function. We compared two groups according to their fall history, and used a multiple logistic regression analysis to determine its relevance.

RESULTS

Fixation time, which was estimated from eye movements during obstacle crossing, and gait variability (vertical) were significantly associated with falls. There was also a significant correlation between fixation time and gait variability during obstacle crossing. In other words, the higher the gait variability in older adults, the higher the risk of falls, which was due to reduced attention estimated from eye movements during obstacle crossing that required obstacle avoidance.

CONCLUSIONS

These results show that poor attention during gait is a critical risk factor for falls in community-dwelling older adults. For fall prevention, it is necessary to promote exercises for attention, and to maintain an older adult-friendly pedestrian environment. Geriatr Gerontol Int 2018; 18: 1267-1271.