Episodic memory and executive function impairments in non-demented older adults: which are the respective and combined effects on gait performances?

Estimating presymptomatic episodic memory impairment using simple hand movement tests: A cross-sectional study of a large sample of older adults

INTRODUCTION

Finding low-cost methods to detect early-stage Alzheimer's disease (AD) is a research priority for neuroprotective drug development. Presymptomatic Alzheimer's is associated with gait impairment but hand motor tests, which are more accessible, have hardly been investigated. This study evaluated how home-based Tasmanian (TAS) Test keyboard tapping tests predict episodic memory performance.

METHODS

1169 community participants (65.8 ± 7.4 years old; 73% female) without cognitive symptoms completed online single-key and alternate-key tapping tests and episodic memory, working memory, and executive function cognitive tests.

RESULTS

All single-key (R2 adj  = 8.8%, ΔAIC = 5.2) and alternate-key (R2 adj  = 9.1%, ΔAIC = 8.8) motor features predicted episodic memory performance relative to demographic and mood confounders only (R2 adj  = 8.1%). No tapping features improved estimation of working memory.

DISCUSSION

Brief self-administered online hand movement tests predict asymptomatic episodic memory impairment. This provides a potential low-cost home-based method for stratification of enriched cohorts.

HIGHLIGHTS

We devised two brief online keyboard tapping tests to assess hand motor function. 1169 cognitively asymptomatic adults completed motor- and cognitive tests online. Impaired hand motor function predicted reduced episodic memory performance. This brief self-administered test may aid stratification of community cohorts.

Concurrent Validity of Dual-Task Walking Speed With CERAD-NP Assessment Battery in Community-Dwelling Older Adults

Objective

To explore the concurrent validity of the dual-task walking speed assessments in older adults using the Consortium to Establish a Registry for Alzheimer's Disease Neuro-Psychological (CERAD-NP) Assessment Battery.

Design

Cross-sectional design.

Setting

Welfare care centers, Senior complex centers, and Dementia prevention care centers.

Participants

A total of 163 community-dwelling older adults (N=163) were recruited using consecutive sampling. Participants were composed of 65 older adults with cognitive decline and 98 without cognitive decline.

Interventions

Not applicable.

Main Outcome Measures

This study assessed the concurrent validity between dual-task walking speed assessments and the Total II score of CERAD-NP using Spearman's rank order correlations. The effect of the dual-task walking speed assessments on the Total II score was further investigated through multiple linear regression analysis.

Results

There was a moderate and statically significant association between the Total II score and all 8 dual-task walking speed assessments (P<.05). The Total II score was strongly associated with the dual tasks of walking on a straight path while counting backward and crossing over an obstacle (r=0.698, r=0.697, respectively; P<.05). According to multiple linear regression, only the dual task of walking while counting backward was significantly associated with the Total II score (P<.05).

Conclusion

The dual-task walking speed assessments, which involved walking and performing a secondary task such as counting backward or crossing an obstacle on a straight path, were highly indicative of cognitive decline. The combination of results from both tasks may provide a more comprehensive evaluation of cognitive decline compared with relying solely on a single-task assessment.

Demonstrating the Value of a Standardized Cognitive Assessment Tool Through the Use of Interprofessional Rapid Safety Rounds

BACKGROUND

Understanding patients' cognitive functional status is critical to prevent adverse outcomes, such as falls and injuries. However, there is variation in nurses' proficiency in assessing patients' cognitive status, and cognitive screening tools often do not provide guidance on safety interventions to keep patients safe.

PROBLEM

Lack of appropriate cognitive screening and interventions may have contributed to increased fall rates on an acute care trauma unit.

APPROACH

A comprehensive 6-level Cognitive Pyramid, including guidance on safety interventions for each level, was developed and used during interprofessional Rapid Safety Rounds to assess patients' cognitive status.

OUTCOMES

The Cognitive Pyramid demonstrated appropriate face validity from 12 subject matter experts. After implementing the Cognitive Pyramid during interdisciplinary rounds, the fall rate decreased to 0 per 1000 admissions.

CONCLUSIONS

Assessment of patients' cognition using the Cognitive Pyramid, and implementing appropriate interventions, may help improve patient safety.

Studying the relationship between cognitive impairment and frailty phenotype: a cross-sectional analysis of the Bushehr Elderly Health (BEH) program

BACKGROUND

Some pathophysiological effects of physical frailty and cognitive impairment might be similar; therefore, finding the associations in epidemiologic studies could guide clinicians and researchers to recognize effective strategies for each type of frailty such as frailty phenotype and frailty index, which in turn will result in a preventive approach. The study aimed to reveal which components of frailty phenotype are more associated with cognitive impairment. The findings of this study may help other researchers clarify the related pathways.

METHODS

This is a cross-sectional analysis of the results of the second phase of Bushehr Elderly Health Program; a community-based elderly prospective cohort study conducted in 2015-2016. The participants were selected through a multistage stratified cluster random sampling method. Frailty was assessed based on the Fried frailty phenotype criteria. Cognitive impairment was assessed by the Mini-Mental State Examination (MMSE), the Mini-Cog, and the Category Fluency Test (CFT). Multiple logistic regression models were applied to determine the association between frailty and cognitive impairment. Depression trait was assessed using the Patient Health Questionnaire-9 (PHQ-9). Activities of daily living were assessed using the Barthel Index and Instrumental Activities of Daily Living (IADLs) using Lawton's IADL.

RESULTS

The studyp conducted among people ≥ 60 years old (N = 2336) with women consisting 51.44% of the sample group. The mean age of the participants was 69.26 years old. The prevalence of pre-frailty and frailty were 42.59% and 7.66%, respectively. In the fully adjusted model, the odds ratio of the association between pre-frailty and frailty with cognitive impairment was 1.239, 95% CI: 1.011 - 1.519 and 1.765, 95% CI: 1.071 - 2.908, respectively (adjusted for age, sex, education, body mass index, smoking, diabetes mellitus, PHQ- 9, Barthel Index, and IADLs). In the fully adjusted multiple logistic regression models, all of the components of Fried frailty phenotype were significantly related to cognitive impairment except weight loss.

CONCLUSION

Cognitive impairment may be associated with frailty phenotype. Moreover, low strength and function of muscles had a stronger association with cognitive impairment. It seems that a consideration of cognitive impairment assessment in older people along with frailty and vice versa in clinical settings is reasonable.

Altered Frequency-Dependent Brain Activation and White Matter Integrity Associated With Cognition in Characterizing Preclinical Alzheimer's Disease Stages

Background

Subjective cognitive decline (SCD), non-amnestic mild cognitive impairment (naMCI), and amnestic mild cognitive impairment (aMCI) are regarded to be at high risk of converting to Alzheimer's disease (AD). Amplitude of low-frequency fluctuations (ALFF) can reflect functional deterioration while diffusion tensor imaging (DTI) is capable of detecting white matter integrity. Our study aimed to investigate the structural and functional alterations to further reveal convergence and divergence among SCD, naMCI, and aMCI and how these contribute to cognitive deterioration.

Methods

We analyzed ALFF under slow-4 (0.027-0.073 Hz) and slow-5 (0.01-0.027 Hz) bands and white matter fiber integrity among normal controls (CN), SCD, naMCI, and aMCI groups. Correlation analyses were further utilized among paired DTI alteration, ALFF deterioration, and cognitive decline.

Results

For ALFF calculation, ascended ALFF values were detected in the lingual gyrus (LING) and superior frontal gyrus (SFG) within SCD and naMCI patients, respectively. Descended ALFF values were presented mainly in the LING, SFG, middle frontal gyrus, and precuneus in aMCI patients compared to CN, SCD, and naMCI groups. For DTI analyses, white matter alterations were detected within the uncinate fasciculus (UF) in aMCI patients and within the superior longitudinal fasciculus (SLF) in naMCI patients. SCD patients presented alterations in both fasciculi. Correlation analyses revealed that the majority of these structural and functional alterations were associated with complicated cognitive decline. Besides, UF alterations were correlated with ALFF deterioration in the SFG within aMCI patients.

Conclusions

SCD shares structurally and functionally deteriorative characteristics with aMCI and naMCI, and tends to convert to either of them. Furthermore, abnormalities in white matter fibers may be the structural basis of abnormal brain activation in preclinical AD stages. Combined together, it suggests that structural and functional integration may characterize the preclinical AD progression.

Perceptual Inhibition Associated with Sensory Integration for Balance in Older Adults

AIMS

Inhibition associated with perception has been implicated in sensory integration processes for balance when sensory conflict occurs. The current study examines the associations of three measures of inhibition (perceptual inhibition, motor inhibition, and Stroop interference) with standing balance under sensory conflict conditions in younger and older adults.

METHODS

Perceptual inhibition, motor inhibition, and Stroop interference were measured in younger and older subjects. Standing balance under conditions of sensory conflict was evaluated using a modified dynamic posturography protocol. Correlative analysis was performed to examine the associations between the inhibition measures and sway.

RESULTS

In older adults only, perceptual inhibition was correlated with sway when sensory conflict was present. Stroop interference and motor inhibition were not significantly correlated with sway under any posturography conditions.

CONCLUSION

Measures of perceptual inhibition are associated with reduced sensory integration capability for balance during sensory conflict conditions in older adults.

Gait and dementia

Cognitive decline and neurodegenerative disease have been implicated in gait dysfunction via disturbance of top-down control mechanisms. Gait velocity decreases, variability increases, and ability to multitask while walking is impaired as cognition declines. Changes in gait can be used to predict incident mild cognitive impairment states as well as dementia. Slow gait velocity together with a cognitive complaint, the Motoric Cognitive Risk syndrome, can serve as a clinical biomarker for high risk of neurologic decline. While patients with Alzheimer's disease typically have quantitative gait impairment, those with other forms of dementia often manifest more overt, qualitative changes to walking. A variety of interventions may be useful to improve gait, including physical and cognitive rehabilitation, treatment of specific underlying causes of gait problems, and treatment of the dementia itself. Understanding the relationship between gait and dementia can elucidate pathology and improve patient care.

Independent association between subjective cognitive decline and frailty in the elderly

Background

The relationship between subjective cognitive decline and frailty, two components of the so-called reversible cognitive frailty, in the elderly remains unclear. This study aims to elucidate whether this association exists, independent of confounding factors such as nutritional status, kidney function, inflammation, and insulin resistance.

Methods

2386 participants (≥ 65 years of age) selected from the Healthy Aging Longitudinal Study in Taiwan (HALST) study. Fried frailty phenotype was adopted to quantify frailty status. We classified cognitive status into two categories—subjective cognitive decline (SCD), and normal cognition—and used polytomous logistic regressions to investigate the associations between SCD and frailty.

Results

There were 188 (7.88%), 1228 (51.47%), and 970 (40.65%) participants with frailty, pre-frailty, and robustness, respectively. Compared to those with normal cognition, elders with SCD were more likely to have pre-frailty (odds ratio [OR]: 1.36, 95% confidence interval [CI]: 1.10–1.67, p = 0.004) or frailty (OR: 1.78, 95% CI: 1.23–2.58, p = 0.002) after adjusting for age, gender, education level, comorbidity, nutritional status, kidney function, and biochemical-related factors.

Conclusions

A significant association between subjective cognitive decline and frailty was revealed in this study. Subjective cognitive decline was positively associated with pre-frailty or frailty even after adjusting for potential confounding factors. Our results can provide useful references in understanding mechanisms and developing suitable preventive strategies for the elderly with reversible cognitive frailty.

Comparison of Gait Parameters for Predicting Cognitive Decline: The Mayo Clinic Study of Aging

BACKGROUND

Previous studies reported that slower gait speed might predict cognitive impairment and dementing illnesses, supporting the role of gait speed as a possible subclinical marker of cognitive impairment. However, the predictive value of other gait parameters for cognitive decline is unclear.

OBJECTIVE

To investigate and compare the association with, and prediction of, specific gait parameters for cognition in a population-based sample.

METHODS

The analysis included 3,426 cognitively normal participants enrolled in the Mayo Clinic Study of Aging. At baseline and every 15 months (mean follow-up = 1.93 years), participants had a study coordinator evaluation, neurological examination, and a neuropsychological assessment using nine tests that covered four domains. Gait parameters were assessed with the GAITRite® instrument. General linear mixed effects models were used to compute the annualized rate of change in cognitive domain z-scores, controlling for age, sex, education, depression, comorbidities, body mass index, APOE ɛ4 allele, and visit number, and excluding individuals with a history of stroke, alcoholism, Parkinson's disease, subdural hematoma, and normal pressure hydrocephalus.

RESULTS

Spatial (stride length), temporal (ambulatory time, gait speed, step count, cadence, double support time), and spatiotemporal (cadence) gait parameters, and greater intraindividual variability in stride length, swing time, and stance time were associated with a significant decline in global cognition and in specific domains including memory, executive function, visuospatial, and language.

CONCLUSIONS

Spatial, temporal, and spatiotemporal measures of gait and greater variability of gait parameters were associated with and predictive of both global- and domain-specific cognitive decline.

Guidelines for Assessment of Gait and Reference Values for Spatiotemporal Gait Parameters in Older Adults: The Biomathics and Canadian Gait Consortiums Initiative

Background: Gait disorders, a highly prevalent condition in older adults, are associated with several adverse health consequences. Gait analysis allows qualitative and quantitative assessments of gait that improves the understanding of mechanisms of gait disorders and the choice of interventions. This manuscript aims (1) to give consensus guidance for clinical and spatiotemporal gait analysis based on the recorded footfalls in older adults aged 65 years and over, and (2) to provide reference values for spatiotemporal gait parameters based on the recorded footfalls in healthy older adults free of cognitive impairment and multi-morbidities. Methods: International experts working in a network of two different consortiums (i.e., Biomathics and Canadian Gait Consortium) participated in this initiative. First, they identified items of standardized information following the usual procedure of formulation of consensus findings. Second, they merged databases including spatiotemporal gait assessments with GAITRite® system and clinical information from the "Gait, cOgnitiOn & Decline" (GOOD) initiative and the Generation 100 (Gen 100) study. Only healthy-free of cognitive impairment and multi-morbidities (i.e., ≤ 3 therapeutics taken daily)-participants aged 65 and older were selected. Age, sex, body mass index, mean values, and coefficients of variation (CoV) of gait parameters were used for the analyses. Results: Standardized systematic assessment of three categories of items, which were demographics and clinical information, and gait characteristics (clinical and spatiotemporal gait analysis based on the recorded footfalls), were selected for the proposed guidelines. Two complementary sets of items were distinguished: a minimal data set and a full data set. In addition, a total of 954 participants (mean age 72.8 ± 4.8 years, 45.8% women) were recruited to establish the reference values. Performance of spatiotemporal gait parameters based on the recorded footfalls declined with increasing age (mean values and CoV) and demonstrated sex differences (mean values). Conclusions: Based on an international multicenter collaboration, we propose consensus guidelines for gait assessment and spatiotemporal gait analysis based on the recorded footfalls, and reference values for healthy older adults.

Apathy and higher level of gait control in normal pressure hydrocephalus

Apathy represents the most common behavioral disturbance in patients with suspicion of idiopathic normal pressure hydrocephalus (iNPH) and has a major impact on quality of life. However, its impact on gait -the hallmark motor disturbance of iNPH - has never been studied yet. This study aims to evaluate the impact of apathy on higher level of gait control in patients with suspicion of iNPH. Stride time variability (STV), a marker of higher level of gait control, was quantified during usual walking (single task) and during walking while performing simultaneously cognitive tasks (dual task) of counting and verbal fluency. Among 46 patients with suspicion of iNPH (77.6±6.7years; 34.8% women), 30 (65.2%) presented apathy (defined by a score≥14 on the Starkstein apathy scale). Backward counting induced more important worsening of STV (i.e. increasing STV) in apathetic compared to non-apathetic patients (14.8±25.1% versus 9.0±20.4%; p=0.005), while both groups presented similar executive functioning. These findings suggest that apathy contributes to gait disorders in iNPH. Apathy is easy to monitor and should be considered as a target symptom of treatment.

The Effect of Two Different Cognitive Tests on Gait Parameters during Dual Tasks in Healthy Postmenopausal Women

INTRODUCTION

The paper aims to evaluate the influence of two different demanding cognitive tasks on gait parameters using BTS SMART system analysis.

PATIENTS AND METHODS

The study comprised 53 postmenopausal women aged 64.5 ± 6.7 years (range: 47-79). For every subject, gait analysis using a BTS SMART system was performed in a dual-task study design under three conditions: (I) while walking only (single task), (II) walking while performing a simultaneous simple cognitive task (SCT) (dual task), and (III) walking while performing a simultaneous complex cognitive task (CCT) (dual task). Time-space parameters of gait pertaining to the length of a single support phase, double support phase, gait speed, step length, step width, and leg swing speed were analyzed.

RESULTS

Performance of cognitive tests during gait resulted in a statistically significant prolongation of the left (by 7%) and right (by 7%) foot gait cycle, shortening of the length of steps made with the right extremity (by 4%), reduction of speed of swings made with the left (by 11%) and right (by 8%) extremity, and reduction in gait speed (by 6%).

CONCLUSIONS

Performance of cognitive tests during gait changes its individual pattern in relation to the level of the difficulty of the task.