[Comparative study of two on aged care-based occupational (professional) training in medical home for aged and dependent patients with neuropsychiatric behaviors]. / Évaluation comparative de deux dispositifs de formation professionnelle axés sur l'accompagnement des résidents d'Ehpad présentant des troubles psycho-comportementaux.

BACKGROUND: Neuropsychiatric behaviours of the elderly is the main issue for caregivers' distress, burn out and high turn-over. This situation will steadily worsen with longer lifetime. AIM OF THE STUDY: Specialised training of medical staff may decrease their distress: we compare both training programs Humanitude® et Formadep® outcomes. METHODS: A comparative open multicentric non randomised study included 459 elderlies of 9 EHPAD of Korian Company into 3 training groups: Humanitude®, Formadep® and a group control, with 29 weeks follow-up. We studied the scoring NPI-ES (FG and R), BMS-10, ECPA and GIR, medications, caregivers' burn out/absences/turn-over levels. Statistical significance were done by Wilcoxon signed-rank test, Ancova and linear regression. RESULTS: 320 caregivers and 3 groups of nearly 150 elderlies each, with around 50% dementia. In Formadep® group : lower scoring for a short time of total NPI-R (p<0.05), sustained lower scoring of NPI-FG « agitation/agressivity¼ (p=0.035) but transitional for its NPI-R (p<0.05), sustained higher scoring of NPI-FG «apathy/indifference¼ (p=0.002) but transitional for its NPI-R (p=0 .003), sustained lower scoring of NPI-R (p=0.0039) for Motor Aberrant Behaviours (MAB). In Humanitude® group: transitional higher scoring of NPI-R (p=0.025) for MAB et transitional lower scoring NPI-R (p=0.0032) for depression (Alzheimer Disease sub-groupe). No change for other parameters. CONCLUSION: Despite high variability of the neuropsychiatric behaviours in elderly, Formadep® training has shown a positive impact on the global distress and on three main challenging behaviours, compared to Humanitude®: this may be depend on their own philosophy. But caregivers' burden in dementia is not a one-factor problem.

Analysis of postural control in elderly subjects suffering from Psychomotor Disadaptation Syndrome (PDS).

PDS is a geriatric affliction, described in 1999, characterized by postural impairments, including backward disequilibrium, freezing, a deterioration in the ability to anticipate postural adjustments, anxiety and fear of falling, inducing loss of autonomy. This study compared 10 subjects suffering from PDS, aged 87.3+/-4.9 years, with 10 control subjects, aged 85.4+/-7.9 years concerning postural control (body sway amplitude). In all participants, postural control was assessed using the SwayStar system in natural (spontaneous) and standardized stances, eyes open and eyes closed over a period of 40 s. It was found that: (1) with eyes open, subjects with PDS showed greater body sway amplitude than did controls whatever the position (natural or standardized) and the plane (sagittal or frontal) considered (F(1,16)=6.05; p=0.026), (2) with eyes closed, subjects with PDS showed greater body sway amplitude than did controls in the natural stance whatever the plane (F(1,18)=7.65; p=0.013). In conclusion, PDS has a negative effect on postural control. This data must be taken into account during the rehabilitation of patients with this syndrome.

Walking speed-related changes in stride time variability: effects of decreased speed.

BACKGROUND: Conflicting results have been reported regarding the relationship between stride time variability (STV) and walking speed. While some studies failed to establish any relationship, others reported either a linear or a non-linear relationship. We therefore sought to determine the extent to which decrease in self-selected walking speed influenced STV among healthy young adults. METHODS: The mean value, the standard deviation and the coefficient of variation of stride time, as well as the mean value of stride velocity were recorded while steady-state walking using the GAITRite system in 29 healthy young adults who walked consecutively at 88%, 79%, 71%, 64%, 58%, 53%, 46% and 39% of their preferred walking speed. RESULTS: The decrease in stride velocity increased significantly mean values, SD and CoV of stride time (p < 0.001), whereas the repetition of trials (p = 0.534, p = 0.177 and p = 0.691 respectively for mean, SD, CoV); and step asymmetry (p = 0.971, p = 0.150 and p = 0.288 for mean, SD and CoV) had no significant effect. Additionally, the subject's effect was significant for all stride parameters (p < 0.001). The relationship between a decrease in walking speed and all stride parameters (i.e., mean values, SD and CoV of stride time) was significantly quadratic and showed higher STV at a slow speed (p < 0.001). CONCLUSION: The results support the assumption that gait variability increases while walking speed decreases and, thus, gait might be more unstable when healthy subjects walk slower compared with their preferred walking speed. Furthermore, these results highlight that a decrease in walking speed can be a potential confounder while evaluating STV.

Impact of impaired executive function on gait stability.

BACKGROUND: Executive dysfunction contributes to gait changes, but the precise mechanisms are still poorly understood. Dual-task-related gait changes depend in part on the capacity to appropriately allocate attention between tasks performed simultaneously and are mainly related to executive deficits. This study aimed to describe the impact of dysexecutive function on gait stability in subjects with dementia using dual tasking. METHODS: Mean values and coefficients of variation of stride time while only walking and while walking and backward counting (dual tasking) were measured using the GAITRite System in 18 subjects with dementia and impaired executive function (IEF), in 16 subjects with dementia and intact executive function, and in 22 nondemented subjects as controls. RESULTS: Stride time, and particularly its variability, significantly increased while performing dual tasking (p < 0.05). IEF was related to both stride time and stride time variability during walking only and to even more gait changes, while dual tasking compared to nondemented subjects and demented subjects without IEF. CONCLUSIONS: These findings confirm the role of executive function in dual tasking, but also strongly suggest their importance for gait stability.

Gait analysis in demented subjects: Interests and perspectives.

Gait disorders are more prevalent in dementia than in normal aging and are related to the severity of cognitive decline. Dementia-related gait changes (DRGC) mainly include decrease in walking speed provoked by a decrease in stride length and an increase in support phase. More recently, dual-task related changes in gait were found in Alzheimer's disease (AD) and non-Alzheimer dementia, even at an early stage. An increase in stride-to-stride variability while usual walking and dual-tasking has been shown to be more specific and sensitive than any change in mean value in subjects with dementia. Those data show that DRGC are not only associated to motor disorders but also to problem with central processing of information and highlight that dysfunction of temporal and frontal lobe may in part explain gait impairment among demented subjects. Gait assessment, and more particularly dual-task analysis, is therefore crucial in early diagnosis of dementia and/or related syndromes in the elderly. Moreover, dual-task disturbances could be a specific marker of falling at a pre-dementia stage.

Recurrent falls and dual task-related decrease in walking speed: is there a relationship?

OBJECTIVES: To determine whether dual task-related changes in walking speed were associated with recurrent falls in frail older adults. DESIGN: Twelve-month prospective cohort study. SETTING: Thirteen senior housing facilities. PARTICIPANTS: Two hundred thirteen subjects (mean age 84.4+/-5.5). MEASUREMENTS: Usual and dual-tasking walking speeds (m/s) were calculated on a 10-m straight walkway at baseline. Information on incident falls during the follow-up year was collected monthly, and participants were divided into three groups based on the occurrence of falls (0, 1, and >or=2). Recurrent falls were defined as two or more falls during the 12-month follow-up period. RESULTS: Twenty subjects (9.4%) were classified as recurrent fallers. The occurrence of recurrent falls was associated with age (crude odds ratio (OR)=1.11, P=.02), number of drugs (crude OR=1.28, P=.002), and walking speed under both walking conditions (crude OR=0.96, P=.002 for usual walking and crude OR=0.60, P=.005 for walking while counting backward). Multiple Poisson regression showed that only walking speed while dual tasking and number of drugs were associated with incident falls (incident rate ratio (IRR)=0.84, P=.045 and IRR=1.10, P=.004). CONCLUSION: Slower walking speed while counting backward was associated with recurrent falls, suggesting that changes in gait performance while dual tasking might be an inexpensive way of identifying frail older adults prone to falling.

Does change in gait while counting backward predict the occurrence of a first fall in older adults?

BACKGROUND: Dual-task-based assessment tests failed to establish a dependable relationship between dual-task-related gait changes and the risk of falls in the elderly. OBJECTIVE: The aim of this study was to examine whether changes in gait while counting backward could be associated with the occurrence of a first fall among older adults. METHODS: Walking while counting backward was investigated prospectively in a cohort of 187 older adults living independently in senior housing facilities. During enrollment, walking time, number of steps, and frequency of lateral line stepping-over and stops were measured while walking only and while walking with backward counting aloud. Information on the incident falls during the follow-up year was collected monthly. RESULTS: Walking time and the number of steps increased significantly under the dual-task condition compared to the single-task condition among fallers and non-fallers (p < 0.001). Compared to non-fallers, fallers had significantly lower scores in the Mini-Mental State Examination (p = 0.029) and higher scores in the 15-item Geriatric Depression Scale (p = 0.003) and Timed Up & Go Test (p = 0.006) and increased walking time under both walking conditions (p = 0.030 for single-task condition and p = 0.007 for dual-task condition). After adjusting for these variables, depressive symptoms (adjusted OR = 2.6 with p = 0.041 and adjusted OR = 2.5 with p = 0.045 when walking time while walking only and walking with backward counting is considered, respectively) and walking time while walking only (OR = 2.3 with p = 0.032) were significantly associated with falls. CONCLUSION: Dual-task-related gait changes were poorly associated with the occurrence of a first fall and provided no additional predictive value compared to gait performance under a single task, suggesting that changes in basic clinical gait parameters while counting backward are unsuccessful to predict the first fall among older adults.

Concurrent validity of SMTEC footswitches system for the measurement of temporal gait parameters.

The GAITRite system is a validated portable gait analysis system that allows simple objective gait measurements. The limited length of the active area of the GAITRite system may be a limitation in obtaining reliable measures of stride-to-stride variability. In contrast, the SMTEC footswitches system provides a continuous measurement of temporal step parameters for a long distance and a long period (around 24 h). The aim of the study was to examine the concurrent validity of the SMTEC footswitches system with the GAITRite system for the measurement of temporal steps parameters. Step, stride, swing and stance time were simultaneously recorded using SMTEC and GAITRite systems while walking at normal, slow and fast self-selected walking speed among 13 healthy young adults. The level of agreement between both systems was high as for the stride time with intra-class correlation coefficients (ICC) between 0.95 and 0.99 (P<0.001) and repeatability coefficients (RC) between 1.1% and 1.5% of mean values, whereas the lowest level of agreement was shown at fast self-selected walking speed and for stance time (ICC=0.52 with P<0.001 and RC=4.9%). Furthermore, the measurement of individual footstep data was excellent with an agreement ranging between -0.04 and 0.04 s (Pitman's test of difference in variance: r=-0.009, P=0.772). The present results suggest that the SMTEC footswitches system provides a valid and reliable measurement of temporal gait parameters in healthy young adults.

Stride-to-stride variability while enumerating animal names among healthy young adults: result of stride velocity or effect of attention-demanding task?

BACKGROUND: The involvement of attention in the control of the walking-related rhythmic stepping mechanism remains unclear in contrast to control of balance phases in human walking. Concurrently to the dual-task related decrease in stride velocity, an increased stride-to-stride variability has been observed and interpreted as interference caused by competing demands for attention resources. It has been also shown that stride time variability depends on stride velocity, whereas the relationship between stride length variability and stride velocity remains controversial. It remains unknown whether dual-task related changes in stride time and stride length variability result from an effect of stride velocity and/or of the attention-demanding task. OBJECTIVE: To determine the respective roles of stride velocity and attention-demanding task on dual-task related changes in stride time and stride length variability. METHODS: Mean stride velocity, mean, standard deviation and coefficient of variation of stride time and stride length were collected using the ambulatory device Physilog in 40 healthy young adults while walking at self-selected speed and while walking with enumerating animal names. RESULTS: Enumerating animal names while walking provoked significant changes in gait but not in cognitive task performance. Balanced analyses of covariance with a repeated measures design showed that stride time variability increased significantly under dual-task condition independently of dual-task related decrease in stride velocity, while stride length variability did not change under dual-task. CONCLUSION: These results show that the dual-task related increase in stride time variability depends on the attention-demanding task rather than stride velocity, suggesting that healthy young adults devote a part of their attention to the control of the rhythmic stepping mechanism at normal self-selected walking speed.

Changes in gait while backward counting in demented older adults with frontal lobe dysfunction.

BACKGROUND: Gait disorders caused by dementia have been associated with frontal lobe dysfunction. Dual-tasking is used to explore the involvement of cortical level in gait control. It has been shown that dual-task induced gait changes that could be related to (1) the efficiency of executive function, (2) the level of difficulty involved in the walking-associated task, or (3) the articulo-motor components comprised in the walking-associated task. A better understanding of dual-task related changes in demented subjects with frontal lobe dysfunction could help us to clarify the role of the frontal lobe in motor gait control. OBJECTIVE: To assess and compare the effects of two mental arithmetic tasks involving similar articulo-motor components but different level of difficulty on the mean values and coefficient of variation (CV) of stride time among demented older adults with impaired executive function. METHODS: The mean values and coefficients of variation of stride time were measured using a GAITRite-System among 16 demented older adults with impaired executive function while walking with and without forward counting (FC) and backward counting (BC). RESULTS: The mean values and CV of stride time were significantly higher under both dual-task conditions than during a simple walking task (p<0.05). The change in CV of stride time during BC was significantly higher when compared with the change during FC (p=0.015), whereas the change in mean value was not significant (p=0.056). There was no difference between the dual-task and single task condition as far the number of enumerated figures were concerned (p=0.678 for FC and p=0.069 for BC), but significantly fewer figures were enumerated while BC compared with FC (p<0.001). CONCLUSION: BC provoked more changes in gait parameters than FC with major modification in gait variability related to an inappropriate focusing of attention. These findings suggest that the CV may be a suitable criterion for the assessment of gait control.

'Faster counting while walking' as a predictor of falls in older adults.

OBJECTIVE: To establish whether changes in a spoken verbal task performance while walking compared with being at rest could predict falls among older adults. DESIGN: Prospective cohort study of 12 months' duration. SETTING: Twenty-seven senior housing facilities. PARTICIPANTS: Sample of 187 subjects aged 75-100 (mean age 84.8 +/- 5.2). During enrollment, participants were asked to count aloud backward from 50, both at rest and while walking and were divided into two groups according to their counting performance. Information on incident falls during the follow-up year was monthly collected. MEASUREMENTS: The number of enumerated figures while sitting on a chair and while walking, and the first fall that occurred during the follow up year. RESULTS: The number of enumerated figures under dual-task as compared to single task increased among 31.5% of the tested subjects (n = 59) and was associated with lower scores in MMSE (P = 0.034), and higher scores in Geriatric Depression Scale (P = 0.007) and Timed Up & Go (P = 0.005). During the 12 months follow-up, 54 subjects (28.9%) fell. After adjusting for these variables, the increase in counting performance was significantly associated with falls (adjusted OR = 53.3, P < 0.0001). Kaplan-Meier distributions of falls differed significantly between subjects who either increased or decreased their counting performance (P < 0.0001). CONCLUSIONS: Faster counting while walking was strongly associated with falls, suggesting that better performance in an additional verbal counting task while walking might represent a new way to predict falls among older adults.

Relationships between dual-task related changes in stride velocity and stride time variability in healthy older adults.

Dual-task related gait changes have been previously reported for healthy older adults, suggesting that gait control requires attention. Compared to balance control, the involvement of attention in the control of the rhythmic stepping mechanism, as reflected by stride time variability, is not well known. In particular, under dual-task, the relative contributions of a second, attention-demanding task and changes in walking speed remain unclear. Thus, the aims of this study were (1) to assess whether walking with a slow-selected speed or walking while performing an attention-demanding task affected stride time variability in a sample of healthy older participants, and (2) to establish whether stride time variability under dual-task conditions is related either to the decrease of walking speed or the simultaneous attention-demanding task, or to both. Forty-five healthy older participants performed four experimental conditions: (1) walking at a normal self-selected speed, (2) walking at a slow self-selected speed, (3) performing a verbal fluency task when sitting on a chair, and (4) performing the verbal fluency task while walking at self-selected walking speed. Gait parameters were recorded across 15 meters, using Physilog. Results showed a significant dual-task related decrease in mean values of stride velocity, as well as a significant increase in mean values and coefficients of variation of stride time. These dual-task related changes in stride time were explained by the simultaneous performance of the verbal fluency task, the decrease of gait speed and the variability between participants. Although a relationship exists between decreased walking speed and increased stride time variability, the dual-task related increase of stride time variability was also significantly associated with the attention-demanding task, suggesting some attentional control for the rhythmic stepping mechanism of walking in healthy older adults.

Impact of cognitive task on the posture of elderly subjects with Alzheimer's disease compared to healthy elderly subjects.

The aims of this study were to analyze the effects of cognitive task on static posture in Alzheimer's disease (AD) and in healthy elderly (HE) subjects and to evaluate whether those effects were greater in AD subjects than in HE subjects. We performed a posturographic analysis on 13 subjects with mild AD (mean age, 79.7+/-5.1 years, Mini-Mental State Examination scores between 18 and 23) and on 17 HE subjects (mean age, 78.5+/-4.4 years). After watching a video sequence, the subjects were asked to maintain a stable upright posture while standing on a force platform. Then, the postural sway was measured during the following two conditions: (1) quiet standing and (2) both standing and answering questions about the video sequence. We were interested in the center of pressure (CoP) area and path. For each group, the single task was compared to the dual task for the CoP area and path. We also compared the variability of both CoP area (variation of the CoP area between the single and the dual task) and path (variation of the CoP path between the single and the dual task) between the two groups. We showed that there was no significant difference between the single and the dual task in HE subjects concerning the CoP area and path, in contrast to the AD group, and that variability of both the CoP area and path were significantly greater in the AD subjects than in the HE subjects. This finding may contribute to the risk of falls in AD patients.

Relationship between dual-task related gait changes and intrinsic risk factors for falls among transitional frail older adults.

BACKGROUND AND AIMS: Gait changes in dual-task conditions have been associated with an increased risk of falling in older adults, and become more important in increasingly frail older adults. We studied the relationship between commonly known intrinsic risk factors for falls and dual-task related gait changes among transitional frail older adults. METHODS: Walking time and number of steps were measured while walking alone and while walking with counting backward on a 10-m walkway in 66 transitional frail older adults (mean age 83.6+/-6.1, 84.9% women). Uni- and multiple linear regression analyses were performed to explore the relationship between dual-task related gait changes (walking time and number of steps) and age over 85 years, polymedication, psychoactive drugs, poor distance vision, abnormal mobility and cognitive impairment. RESULTS: Compared with walking alone, both walking time and number of steps increased significantly while counting backward (p<0.001). Polymedication and abnormal mobility were associated with a significant increase of walking time and number of steps (p<0.01 for unadjusted change, p<0.05 for adjusted change). CONCLUSIONS: Dual-task related gait changes were closely correlated with polymedication and impaired mobility in our sample of transitional frail older adults. These findings give some insight into the complexity of performing attention-demanding tasks while walking and accentuate the need for multi-factorial, personalized intervention strategies, to prevent decline in dual-task performance in this fall-prone population.

Stride-to-stride variability while backward counting among healthy young adults.

BACKGROUND: Little information exists about the involvement of attention in the control of gait rhythmicity. Variability of both stride time and stride length is closely related to the control of the rhythmic stepping mechanism. We sought 1) to determine whether backward counting while walking could provoke significant gait changes in mean values and coefficients of variation of stride velocity, stride time and stride length among healthy young adults; and 2) to establish whether change in stride-to-stride variability could be related to dual-task related stride velocity change, attention, or both. METHODS: Mean values and coefficients of variation of stride velocity, stride time and stride length were recorded using the Physilog-system, at a self-selected walking speed in 49 healthy young adults (mean age 24.1 +/- 2.8 years, women 49%) while walking alone and walking with simultaneous backward counting. Performance on backward counting was evaluated by recording the number of figures counted while sitting alone and while walking. RESULTS: Compared with walking alone, a significant dual-task-related decrease was found for the mean values of stride velocity (p < 0.001), along with a small but significant increase for the mean values and coefficients of variation of stride time (p < 0.001 and p = 0.015, respectively). Stride length parameters did not change significantly between both walking conditions. Dual-task-related increase of coefficient of variation of stride time was explained by changing stride velocity and variability between subjects but not by backward counting. The number of figures counted while walking decreased significantly compared to backward counting alone. Further, the dual-task related decrease of the number of enumerated figures was significantly higher than the dual-task related decrease of stride velocity (p = 0.013). CONCLUSION: The observed performance-changes in gait and backward counting while dual tasking confirm that certain aspects of walking are attention-demanding in young adults. In the tested group of 49 young volunteers, dual tasking caused a small decrease in stride velocity and a slight increase in the stride-to-stride variability of stride time, while stride velocity variability was not affected by the attention-demanding task. The increase in stride time variability was apparently the result of a change in gait speed, but not a result of dual tasking. This suggests that young adults require minimal attention for the control of the rhythmic stepping mechanism while walking.

Decreased trunk angular displacement during sitting down: an early feature of aging.

BACKGROUND AND PURPOSE: Trunk motion plays an important role in achieving both sit-to-stand and stand-to-sit transfers. However, these 2 body transfers depend on different postural and mechanical constraints. Although the effects of aging on sit-to-stand transfers have been widely studied, there is a lack of information concerning stand-to-sit transfers. The aim of this study was to determine how angular displacements of the trunk and shank are affected by aging during sit-to-stand and stand-to-sit transfers. SUBJECTS: Ten community-dwelling older adults (mean age=75.9 years, SD=3.2) and 9 young adults (mean age=26.8 years, SD=4.7) volunteered to participate. METHODS: Maximal angular displacements of the trunk and shank with respect to the vertical (ie, orientation angles) were measured, during standing up and sitting down, using an optoelectronic movement analyzer. RESULTS: For standing up, there was no difference between the young and older adults with regard to both maximal orientation angles. During sitting down, the maximal shank orientation angle was not affected by age, whereas the older adults had a smaller trunk motion compared with the young adults (approximately 10 degrees less). DISCUSSION AND CONCLUSION: The results showed that older adults tended to minimize the forward body displacement during sitting down. This strategy could be seen as an adaptive mechanism to decrease the risk of anterior disequilibrium. The authors suggest that this feature could be used as an early marker of aging on postural control.

Dual-task-related gait changes in transitionally frail older adults: the type of the walking-associated cognitive task matters.

BACKGROUND: Changes in gait patterns due to a simultaneously performed cognitive task have been reported previously and associated with an increased falling risk among older adults. Little is known whether the type of cognitive task performed while walking is important concerning possible gait interference in older fall-prone individuals. OBJECTIVE: To quantify and compare the effects of two different cognitive tasks on gait in transitionally frail older adults. MEASUREMENTS: Gait was tested in 30 transitionally frail older adults (mean age 82.6 +/- 7.1 years, 90% female) while either walking alone, performing a simple arithmetic task, or performing a task of verbal fluency. Walking time in seconds, number of steps, frequency of lateral line stepping-over, and stops were recorded. Health status was assessed using standard instruments of geriatric assessment. The classification of Speechley and Tinetti was used to define the participants' degree of frailty. RESULTS: Walking time and number of steps increased significantly under both dual-task conditions compared to walking alone (p < 0.001) without reaching a significant difference between the two dual-task conditions (respectively, p = 0.131 and p = 0.407), whereas lateral gait instability (frequency of lateral line stepping-over) increased significantly in association with counting backward (p = 0.006) but not with the verbal fluency task (p = 1). CONCLUSION: Among the studied sample of transitional older adults, a walking- associated arithmetic task significantly interfered with lateral gait stability, whereas no lateral gait deviations were seen in association with a verbal fluency task. We, therefore, suggest that the choice of the attention-splitting task in dual-task gait assessment among older adults must be made carefully.