Olivier Beauchet

Poor Gait Performance and Prediction of Dementia: Results From a Meta-Analysis.

BACKGROUNDnPoor gait performance predicts risk of developing dementia. No structured critical evaluation has been conducted to study this association yet. The aim of this meta-analysis was to systematically examine the association of poor gait performance with incidence of dementia.nnnMETHODSnAn English and French Medline search was conducted in June 2015, with no limit of date, using the medical subject headings terms Gait OR Gait Disorders, Neurologic OR Gait Apraxia OR Gait Ataxia AND Dementia OR Frontotemporal Dementia OR Dementia, Multi-Infarct OR Dementia, Vascular OR Alzheimer Disease OR Lewy Body Disease OR Frontotemporal Dementia With Motor Neuron Disease (Supplementary Concept). Poor gait performance was defined by standardized tests of walking, and dementia was diagnosed according to international consensus criteria. Four etiologies of dementia were identified: any dementia, Alzheimer disease (AD), vascular dementia (VaD), and non-AD (ie, pooling VaD, mixed dementias, and other dementias). Fixed effects meta-analyses were performed on the estimates in order to generate summary values.nnnRESULTSnOf the 796 identified abstracts, 12 (1.5%) were included in this systematic review and meta-analysis. Poor gait performance predicted dementia [pooled hazard ratio (HR) combined with relative risk and odds ratioxa0=xa01.53 with Pxa0<xa0.001 for any dementia, pooled HRxa0=xa01.79 with Pxa0<xa0.001 for VaD, HRxa0=xa01.89 with P valuexa0<xa0.001 for non-AD]. Findings were weaker for predicting AD (HRxa0=xa01.03 with P valuexa0=xa0.004).nnnCONCLUSIONSnThis meta-analysis provides evidence that poor gait performance predicts dementia. This association depends on the type of dementia; poor gait performance is a stronger predictor of non-AD dementias than AD.

Gait phenotype from mild cognitive impairment to moderate dementia: results from the GOOD initiative

The differences in gait abnormalities from the earliest to the later stages of dementia and in the different subtypes of dementia have not been fully examined. This study aims to compare spatiotemporal gait parameters in cognitively healthy individuals, patients with amnestic mild cognitive impairment (MCI) and non‐amnestic MCI, and patients with mild and moderate stages of Alzheimers disease (AD) and non‐Alzheimers disease (non‐AD).

Falls, Cognitive Impairment, and Gait Performance: Results From the GOOD Initiative.

OBJECTIVESnFalls are highly prevalent in individuals with cognitive decline. The complex relationship between falls and cognitive decline (including both subtype and severity of dementia) and the influence of gait disorders have not been studied. This study aimed to examine the association between the subtype (Alzheimer disease [AD] versus non-AD) and the severity (from preclinical to moderate dementia) of cognitive impairment and falls, and to establish an association between falls and gait parameters during the course of dementia.nnnDESIGNnMulticenter cross-sectional study.nnnSETTINGnGait, cOgnitiOn & Decline (GOOD) initiative.nnnPARTICIPANTSnA total of 2496 older adults (76.6xa0±xa07.6xa0years; 55.0% women) were included in this study (1161 cognitively healthy individuals [CHI], 529 patients with mild cognitive impairment [MCI], 456 patients with mild dementia, and 350 with moderate dementia) from 7 countries.nnnMEASUREMENTSnFalls history was collected retrospectively at baseline in each study. Gait speed and stride time variability were recorded at usual walking pace with the GAITRite system.nnnRESULTSnThe prevalence of individuals who fall was 50% in AD and 64% in non-AD; whereas it was 25% in CHIs. Only mild and moderate non-AD dementia were associated with an increased risk for falls in comparison with CHI. Higher stride time variability was associated with falls in older adults without dementia (CHI and each MCI subgroup) and mild non-AD dementia, whereas lower gait speed was associated with falls in all participant groups, except in mild AD dementia. When gait speed was adjusted for, higher stride time variability was associated with falls only in CHIs (odds ratio 1.14; Pxa0=xa0.012), but not in MCI or in patients with dementia.nnnCONCLUSIONSnThese findings suggest that non-AD, but not AD dementia, is associated with increased falls in comparison with CHIs. The association between gait parameters and falls also differs across cognitive status, suggesting different mechanisms leading to falls in older individuals with dementia in comparison with CHIs who fall.

Association of Motoric Cognitive Risk Syndrome With Brain Volumes: Results From the GAIT Study

BACKGROUNDnThe motoric cognitive risk (MCR) syndrome is a newly reported predementia syndrome combining cognitive complaint and slow gait speed. We hypothesized that individuals with MCR syndrome would have lower brain volumes compared with non-MCR individuals. This study aims (i) to compare the cognitive profile of nondemented older community-dwellers with and without MCR syndrome and (ii) to examine association of global and regional brain volumes with MCR syndrome.nnnMETHODSnA total of 171 individuals (28 MCR and 143 non-MCR) were included in this cross-sectional study. Total white matter abnormalities, total white matter, total cortical and subcortical gray matters, hippocampus, motor cortex, premotor cortex, and prefrontal cortex were examined. Brain volumes were quantified from a three-dimensional T1-weighted magnetic resonance imaging using semi-automated software. Age, gender, education level, number of drugs taken daily, use of psychoactive drugs, and cognitive profile were also measured.nnnRESULTSnThe distribution of cognitively healthy individuals and those with mild cognitive impairment was not different in participants with and without MCR. Multiple logistic regression models showed that smaller volumes of total gray matter (p = .016), total cortical gray matter (p = .010), premotor cortex (p = .018), prefrontal cortex (p = .026), and dorsolateral segment of prefrontal cortex (p = .032) were associated with MCR status. The premotor cortex presented the highest mean difference for brain regional volume between MCR and non-MCR participants (p = .03).nnnCONCLUSIONSnThe findings revealed similar cognitive profile in MCR and non-MCR participants, and MCR-related smaller global and regional gray matter volumes involving premotor and prefrontal cortices, suggesting that the MCR syndrome may predict cortical neurodegenerative dementia more than subcortical dementia.

Brain volume changes in gait control in patients with mild cognitive impairment compared to cognitively healthy individuals; GAIT study results.

BACKGROUNDnDifferences in brain structures involved in gait control between normal and pathological aging are still matter of debate. This study aims to compare the regional and global brain volume patterns associated with gait performances assessed with Timed Up and Go test (TUG) between cognitively healthy individuals (CHI) and patients with mild cognitive impairment (MCI).nnnMATERIAL AND METHODSnA total of 171 (80 CHI, 25 with amnestic MCI [a-MCI] and 66 with non-amnestic MCI [na-MCI]) participants (70.2±4.0years; 37% female) consecutively realized (rTUG) and imagined (iTUG) the TUG. rTUG measures the time needed to rise from a chair, walk 3m, turn around and return to a seated position and iTUG represents the validated imagined version of the TUG. Global and regional brain volumes were quantified from three-dimensional T1-weighted MRI using a semi-automated software.nnnRESULTSnLinear regression models show that increased rTUG (i.e. worse performance) was associated with lower total white matter, total gray matter, left and right hippocampal volume in patients with na-MCI (P<0.045), and with lower right hippocampal volume in CHI (P=0.013). Increased iTUG was associated with lower gray matter and left premotor cortex volumes in patients with na-MCI (P<0.05).nnnCONCLUSIONSnThe findings showed different patterns of brain volume reduction associated with increased rTUG and iTUG between CHI and MCI patients, except for the right hippocampal volume which was smaller in both groups.

Predicting prolonged length of hospital stay in older emergency department users: use of a novel analysis method, the Artificial Neural Network.

OBJECTIVEnTo examine performance criteria (i.e., sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV], likelihood ratios [LR], area under receiver operating characteristic curve [AUROC]) of a 10-item brief geriatric assessment (BGA) for the prediction of prolonged length hospital stay (LHS) in older patients hospitalized in acute care wards after an emergency department (ED) visit, using artificial neural networks (ANNs); and to describe the contribution of each BGA item to the predictive accuracy using the AUROC value.nnnMETHODSnA total of 993 geriatric ED users admitted to acute care wards were included in this prospective cohort study. Age >85years, gender male, polypharmacy, non use of formal and/or informal home-help services, history of falls, temporal disorientation, place of living, reasons and nature for ED admission, and use of psychoactive drugs composed the 10 items of BGA and were recorded at the ED admission. The prolonged LHS was defined as the top third of LHS. The ANNs were conducted using two feeds forward (multilayer perceptron [MLP] and modified MLP).nnnRESULTSnThe best performance was reported with the modified MLP involving the 10 items (sensitivity=62.7%; specificity=96.6%; PPV=87.1; NPV=87.5; positive LR=18.2; AUC=90.5). In this model, presence of chronic conditions had the highest contributions (51.3%) in AUROC value.nnnCONCLUSIONSnThe 10-item BGA appears to accurately predict prolonged LHS, using the ANN MLP method, showing the best criteria performance ever reported until now. Presence of chronic conditions was the main contributor for the predictive accuracy.

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.

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

Gait control depends in part on cognition. This study aims to examine the separate and combined effects of episodic memory and executive function impairments on the mean value and the coefficient of variation (CoV) of stride time among non-demented older community dwellers. Based on a cross-sectional design, 1458 older community dwellers without dementia (70.6xa0±xa04.9xa0years; 49.2xa0% female) were recruited and separated into cognitively healthy individuals (CHI) and individuals with cognitive impairment. A score ≤5/6 on the Short Mini-Mental State Examination defined episodic memory impairment. Impaired executive function was defined by errors on the clock-drawing test. Mean value and CoV of stride time were measured by the GAITRite® system. A total of 517 participants (35.5xa0%) had cognitive impairment in at least one cognitive domain. Participants with memory impairment (Pxa0=xa00.006) and those with combined cognitive impairments (Pxa0<xa00.001) had greater (i.e., worse gait performance) mean value of stride time (Pxa0=xa00.006) compared to CHI. Participants with combined cognitive impairment had a greater CoV of stride time (i.e., worse gait performance) compared to CHI (Pxa0=xa00.004) and to those with separate memory impairment (Pxa0=xa00.037). Among participants with combined cognitive impairments, mean value and CoV of stride time had the highest effect size (respectively, effect sizexa0=xa00.49 [95xa0% confidence interval (CI) 0.27;0.71] and effect sizexa0=xa00.40 [95xa0%CI 0.18;0.62]). Participants with episodic memory or executive impairments had a greater mean value and CoV of stride time compared to those with no cognitive impairment. Combined episodic memory and executive impairments exceeded the sum of separate impairments on gait performances, suggesting a complex interplay going beyond a simple additive effect.

Cognitive status, fast walking speed and walking speed reserve—the Gait and Alzheimer Interactions Tracking (GAIT) study

The aims of this study were to (1) determine if older people at their fast walking speed (FWS) are able to reach the speed required at pedestrian crossings (>1.2xa0m/s) and (2) determine the role of cognitive impairment on the ability to alter speed and walk quickly. Participants were recruited from the Angers Memory Clinic, France. Gait speed was assessed at preferred and FWS using a GAITRite walkway. Walking speed reserve (WSR) was calculated as the difference between FWS and preferred speeds. Participants were classified into cognitive stages (cognitively healthy, mild cognitive impairment, mild and moderate dementia) based on neuropsychological evaluations. The proportion of participants with a FWS of <1.2xa0m/s was reported. The association between cognitive stage and preferred, fast and walking speed reserve was assessed using multivariable regression, adjusting for covariates. The mean age of the sample (nxa0=xa0681) was 73.3 (SD 5.8) years. At preferred speed 73.7%, and at FWS 12.8%, of participants had speeds less than 1.2xa0m/s. Poorer cognitive stage was associated with slower preferred speed (β −0.08, 95% CI −0.10, −0.06), FWS (β −0.13, 95% CI −0.16, −0.10) and also with smaller WSR (m/s) (β −0.05, 95% CI −0.07, −0.03), but not WSR (%) (β −1.73, 95% CI −4.38, 0.93). In older people, worse stages of cognitive impairment were associated with poorer ability to increase speed and walk quickly. Such limitations may result in reduced ability to access the community.

The relationship between hippocampal volume and static postural sway: results from the GAIT study

The role of the hippocampus in postural control, in particular in maintaining upright stance, has not been fully examined in normal aging. This study aims to examine the association of postural sway with hippocampal volume while maintaining upright stance in healthy older individuals. Seventy healthy individuals (mean age 69.7xa0±xa03.4xa0years; 41.4xa0% women) were recruited in this study based on cross-sectional design. Hippocampal volume (quantified from a three-dimensional T1-weighted MRI using semi-automated software), three center of pressure (COP) motion parameters (sway area, path length of anterior-posterior (AP) and medial-lateral (ML) displacement) while maintaining upright stance (eyes open and closed), and the relative difference between open and closed eye conditions were used as outcome measures. Age, sex, body mass index, lower limb proprioception, distance vision, 15-item geriatric depression scale score, total cranial volume, and white matter abnormalities were used as covariates. The sway area decreased from open to closed eye condition but this variation was non-significant (Pxa0=xa00.244), whereas path length of AP and ML displacement increased significantly (Pxa0<xa00.003). Increase in sway area from open to closed eyes was associated with greater hippocampal volume (β −18.21; Pxa0=xa00.044), and a trend for an association of increase in path length of AP displacement (Pxa0=xa00.075 for open eyes and Pxa0=xa00.071 for closed eyes) with greater hippocampal volume was reported. The hippocampus is involved in upright postural control in normal aging, such that an increase in sway area of COP motion from open to closed eyes is associated with greater hippocampal volume in healthy older adults.