Exercise Training on Locomotion in Patients with Alzheimer’s Disease: A Feasibility Study

Alzheimer's Disease: Understanding Motor Impairments

Alzheimer's disease (AD), the most prevalent neurodegenerative disorder and the leading cause of dementia worldwide, profoundly impacts health and quality of life. While cognitive impairments-such as memory loss, attention deficits, and disorientation-predominate in AD, motor symptoms, though common, remain underexplored. These motor symptoms, including gait disturbances, reduced cardiorespiratory fitness, muscle weakness, sarcopenia, and impaired balance, are often associated with advanced stages of AD and contribute to increased mortality. Emerging evidence, however, suggests that motor symptoms may be present in earlier stages and can serve as predictive markers for AD in older adults. Despite a limited understanding of the underlying mechanisms driving these motor symptoms, several key pathways have been identified, offering avenues for further investigation. This review provides an in-depth analysis of motor symptoms in AD, discussing its progression, potential mechanisms, and therapeutic strategies. Addressing motor symptoms alongside cognitive decline may enhance patient functionality, improve quality of life, and support more comprehensive disease management strategies.

Mitigating cognitive deficits with teriflunomide: unraveling PI3K-modulated behavioral outcomes in mice

BACKGROUND

Alzheimer's disease is a leading neurological disorder that gradually impairs memory and cognitive abilities, ultimately leading to the inability to perform even basic daily tasks. Teriflunomide is known to preserve neuronal activity and protect mitochondria in the brain slices exposed to oxidative stress. The current research was undertaken to investigate the teriflunomide's cognitive rescuing abilities against scopolamine-induced comorbid cognitive impairment and its influence on phosphatidylinositol-3-kinase (PI3K) inhibition-mediated behavior alteration in mice.

METHODS

Swiss albino mice were divided into 7 groups; vehicle control, scopolamine, donepezil + scopolamine, teriflunomide (10 mg/kg) + scopolamine; teriflunomide (20 mg/kg) + scopolamine, LY294002 and LY294002 + teriflunomide (20 mg/kg). Mice underwent a nine-day protocol, receiving scopolamine injections (2 mg/kg) for the final three days to induce cognitive impairment. Donepezil, teriflunomide, and LY294002 treatments were given continuously for 9 days. MWM, Y-maze, OFT and rota-rod tests were conducted on days 7 and 9. On the last day, blood samples were collected for serum TNF-α analysis, after which the mice were sacrificed, and brain samples were harvested for oxidative stress analysis.

RESULTS

Scopolamine administration for three consecutive days increased the time required to reach the platform in the MWM test, whereas, reduced the percentage of spontaneous alternations in the Y-maze, number of square crossing in OFT and retention time in the rota-rod test. In biochemical analysis, scopolamine downregulated the brain GSH level, whereas it upregulated the brain TBARS and serum TNF-α levels. Teriflunomide treatment effectively mitigated all the behavioral and biochemical alterations induced by scopolamine. Furthermore, LY294002 administration reduced the memory function and GSH level, whereas, uplifted the serum TNF-α levels. Teriflunomide abrogated the memory-impairing, GSH-lowering, and TNF-α-increasing effects of LY294002.

CONCLUSION

Our results delineate that the improvement in memory, locomotion, and motor coordination might be attributed to the oxidative and inflammatory stress inhibitory potential of teriflunomide. Moreover, PI3K inhibition-induced memory impairment might be attributed to reduced GSH levels and increased TNF-α levels.

Oxidative damage in neurodegeneration: roles in the pathogenesis and progression of Alzheimer disease

Alzheimer disease (AD) is associated with multiple etiologies and pathological mechanisms, among which oxidative stress (OS) appears as a major determinant. Intriguingly, OS arises in various pathways regulating brain functions, and it seems to link different hypotheses and mechanisms of AD neuropathology with high fidelity. The brain is particularly vulnerable to oxidative damage, mainly because of its unique lipid composition, resulting in an amplified cascade of redox reactions that target several cellular components/functions ultimately leading to neurodegeneration. The present review highlights the "OS hypothesis of AD," including amyloid beta-peptide-associated mechanisms, the role of lipid and protein oxidation unraveled by redox proteomics, and the antioxidant strategies that have been investigated to modulate the progression of AD. Collected studies from our groups and others have contributed to unraveling the close relationships between perturbation of redox homeostasis in the brain and AD neuropathology by elucidating redox-regulated events potentially involved in both the pathogenesis and progression of AD. However, the complexity of AD pathological mechanisms requires an in-depth understanding of several major intracellular pathways affecting redox homeostasis and relevant for brain functions. This understanding is crucial to developing pharmacological strategies targeting OS-mediated toxicity that may potentially contribute to slow AD progression as well as improve the quality of life of persons with this severe dementing disorder.

The Association between Physical Activity and Intrinsic Capacity in Chinese Older Adults and Its Connection to Primary Care: China Health and Retirement Longitudinal Study (CHARLS)

BACKGROUND

In 2015, intrinsic capacity (IC) was proposed by the WHO as a new measure for healthy aging. Evidence has shown that physical activity (PA) benefits the physical and mental health of older adults. However, the association between PA and IC among older adults was not well evaluated or reported. This study aims to investigate the association between PA and general and specific IC among Chinese older adults.

METHOD

The study included individuals aged 60 and above from the China Health and Retirement Longitudinal Study in 2015. The IC scores were constructed based on the WHO concept of five domains: psychological capacity, cognition, locomotion, vitality, and sensory abilities. Total PA and leisure PA were measured based on different activity purposes. Linear mixed-effects models and generalized linear mixed-effects models were developed to assess the associations between PA and IC.

RESULTS

A total of 3359 participants were included in this study. Older adults who reported some PA were associated with a higher composite IC score, with a mean difference of 0.14 (95% CI: 0.09-0.18, p < 0.001) compared to those who reported no PA. In terms of leisure PA, physically active adults had a higher composite IC score with a mean difference of 0.06 (95% CI: 0.03-0.09, p < 0.001). Older adults with a high level of leisure PA also had a significantly higher composite IC score (diff. in mean = 0.07, 95% CI: 0.01-0.13, p < 0.05) compared to those with low-level leisure PA. In addition, PA was positively and significantly associated with three specific IC domains: locomotion, cognition, and vitality.

CONCLUSIONS

Improving both general and leisure PA can be an effective way to prevent the decline in IC among older adults, thus reducing the personal and public load of primary healthcare for aging countries such as China.

Effects of traditional Chinese exercise on vascular function in patients with Alzheimer's disease: A protocol for systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with an insidious onset, usually characterized by memory impairment, visual-spatial skill impairment, executive dysfunction and personality behavioral changes. Studies have confirmed that vascular dysfunction may precede AD pathological changes and can present as vascular malformations, atherosclerosis, and impaired self-regulation, and can affect oxidative stress and amyloidosis. Therefore, it is important to improve or prevent vascular dysfunction in AD patients. Regular exercise can effectively inhibit the production of reactive oxygen species during the occurrence of AD and can improve the reduction of cerebral blood flow due to AD. Previous studies have shown that exercise can achieve superior clinical results in improving vascular function in AD patients. Therefore, we hypothesize that traditional Chinese exercises (TCEs) may have a good clinical effect in improving vascular function in patients with AD.

METHODS

We will search "PubMed," "the Cochrane Library," "Embase," "Web of Science," "CINAHL," "ProQuest Dissertations and Theses," and "ProQuest-Health & Medical Collection," "CNKI," "SinoMed," "VIP," and "Wanfang Data" to find randomized controlled trials of the effects of TCEs on AD vascular function from the creation of the database to the present, including at least 1 indicator in carotid intima-media thickness (cIMT), middle cerebral artery mean flow velocity (MFV), blood indicators [Heme Oxidase-1 (HO-1), angiopoietin I (Ang I), vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor, matrix metalloproteinase-9 (MMP-9)], and arterial stiffness [(Ankle Brachial Index (ABI), pulse wave velocity (PWV)]. For the included literature, Excel 2019 will be used for data extraction and collection. For the indicators that can be netted for network meta-analysis, Surface Under the Cumulative Ranking for each exercise modality will be calculated with the help of Stata 16.0 and rank, where the higher the SUCRA score, the higher the ranking. For the indicators that cannot be netted, Review Manager 5.4 will be used for meta-analysis will be performed to evaluate the improvement effect of TCEs on AD patients.

RESULTS

This meta-analysis will further determine the efficacy and safety of TCEs on vascular function in AD patients.

CONCLUSION

In this study, randomized controlled trials of the effects of TCEs on vascular function in AD patients will be selected to provide evidence-based medical evidence for promoting the application of TCEs by observing the order of advantages and disadvantages of various exercise modalities through network meta-analysis.

The effect of exercise on walking economy in patients with chronic neurological conditions: A systematic review and meta-analysis

Introduction

To investigate the effect of exercise on the walking economy (WE) of patients with chronic neurological conditions (CNCs) and to determine the type of physical activity that best improves the WE of patients with CNCs.

Methods

Four electronic databases were searched until December 2022 (Web of Science, PubMed, Cochrane, and CINAHL). Studies were screened using the following inclusion criteria: 1. randomized controlled or non-randomized controlled trials; 2. exercise interventions >4 weeks in duration; 3. patients aged ≥18 years with a diagnosis of CNCs. 4. walking economy of patients measured before and after the intervention. The PEDro scale was used to assess the methodological quality of the included studies.

Results and discussion

Twenty-two studies met the inclusion criteria. Meta-analysis results showed that exercise significantly improved WE (g = -0.352, 95% CI, -0.625 to -0.078, P = 0.012). Subgroup analysis revealed that patients who received exercise showed better WE compared with those who underwent no control intervention (g = -0.474, 95% CI, -0.636 to -0.311, P < 0.001). However, exercise therapy did not show a significant improvement of WE compared with control groups (g = -0.192, 95% CI, -0.451 to 0.067, P = 0.146). In addition, we found that endurance combined with resistance, high-intensity intermittent, and other training modalities resulted in better WE compared with the pre-intervention. Of these, interval training has the greatest effect on improving WE. In conclusion, exercise can improve WE in patients with CNCs. More randomized controlled trials are necessary for the future.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022361455, identifier: CRD42022361455.

Decabromodiphenyl ethane induces locomotion neurotoxicity and potential Alzheimer's disease risks through intensifying amyloid-beta deposition by inhibiting transthyretin/transthyretin-like proteins

As a major alternative to traditional brominated flame retardants (BFRs), decabromodiphenyl ethane (DBDPE) is widely used and has been commonly detected in various environmental media and organisms. Few previous studies have focused on DBDPE-induced locomotion neurotoxicity, and the exact molecular mechanisms and related health risks remain unclear. In this study, we first analyzed the locomotion indicators of nematodes following DBDPE exposure, demonstrated that DBDPE caused locomotion neurotoxicity, and identified that a series of the transthyretin (TTR)-like genes participated in the regulation of nematode motility by transcriptomic analysis, gene transcription validation and TTR-like mutant verification. Subsequently, this study demonstrated that DBDPE exacerbated amyloid-beta (Aβ) deposition by repressing TTR/TTR-like gene transcription based on Alzheimer's disease (AD) model nematodes and human SH-SY5Y cells following DBDPE exposure and further revealed that DBDPE reduced the binding between TTR and Aβ by competing with the strand G region sites on the TTR/TTR-like protein, ultimately exacerbating Aβ deposition and the risk of AD. In short, our study demonstrated that DBDPE induced locomotion neurotoxicity and potential AD risks through intensifying Aβ deposition by inhibiting TTR/TTR-like proteins, providing reference support for risk management and policy formulation related to DBDPE and similarly structured novel BFRs.

Effects of involuntary treadmill running in combination with swimming on adult neurogenesis in an Alzheimer's mouse model

Physical exercise plays a role on the prevention and treatment of Alzheimer's disease (AD), but the exercise mode and the mechanism for these positive effects is still ambiguous. Here, we investigated the effect of an aerobic interval exercise, running in combination with swimming, on behavioral dysfunction and associated adult neurogenesis in a mouse model of AD. We demonstrate that 4 weeks of the exercise could ameliorate Aβ₄₂ oligomer-induced cognitive impairment in mice utilizing Morris water maze tests. Additionally, the exercised Aβ₄₂ oligomer-induced mice exhibited a significant reduction of anxiety- and depression-like behaviors compared to the sedentary Aβ₄₂ oligomer-induced mice utilizing an Elevated zero maze and a Tail suspension test. Moreover, by utilizing 5'-bromodeoxyuridine (BrdU) as an exogenous cell tracer, we found that the exercised Aβ₄₂ oligomer-induced mice displayed a significant increase in newborn cells (BrdU⁺ cells), which differentiated into a majority of neurons (BrdU⁺ DCX⁺ cells or BrdU⁺NeuN⁺ cells) and a few of astrocytes (BrdU⁺GFAP⁺ cells). Likewise, the exercised Aβ₄₂ oligomer-induced mice also displayed the higher levels of NeuN, PSD95, synaptophysin, Bcl-2 and lower level of GFAP protein. Furthermore, alteration of serum metabolites in transgenic AD mice between the exercised and sedentary group were significantly associated with lipid metabolism, amino acid metabolism, and neurotransmitters. These findings suggest that combined aerobic interval exercise-mediated metabolites and proteins contributed to improving adult neurogenesis and behavioral performance after AD pathology, which might provide a promising therapeutic strategy for AD.

Can exercise training teach us how to treat Alzheimer's disease?

Alzheimer's disease (AD) is the most common cause of dementia and there is currently no cure. Novel approaches to treat AD and curb the rapidly increasing worldwide prevalence and costs of dementia are needed. Physical inactivity is a significant modifiable risk factor for AD, estimated to contribute to 12.7% of AD cases worldwide. Exercise interventions in humans and animals have shown beneficial effects of exercise on brain plasticity and cognitive functions. In animal studies, exercise also improved AD pathology. The mechanisms underlying these effects of exercise seem to be associated mainly with exercise performance or cardiorespiratory fitness. In addition, exercise-induced molecules of peripheral origin seem to play an important role. Since exercise affects the whole body, there likely is no single therapeutic target that could mimic all the benefits of exercise. However, systemic strategies may be a viable means to convey broad therapeutic effects in AD patients. Here, we review the potential of physical activity and exercise training in AD prevention and treatment, shining light on recently discovered underlying mechanisms and concluding with a view on future development of exercise-free treatment strategies for AD.

Exercise interventions in Alzheimer's disease: A systematic review and meta-analysis of randomized controlled trials

AIMS

To assess the potential multi-domain benefits of exercise interventions on patients with Alzheimer's disease (AD), as well as to determine the specific effects of different exercise modalities (aerobic, strength, or combined training).

METHODS

A systematic search was conducted in PubMed and Web of Science until March 2021 for randomized controlled trials assessing the effect of exercise interventions (compared with no exercise) on patients with AD. Outcomes included cognitive function (mini-mental state examination [MMSE] test), physical function (e.g., 6-minute walking test [6MWT]), functional independence (Barthel index), and neuropsychiatric symptoms (Neuropsychiatric Inventory [NPI]). A random-effects meta-analysis was conducted.

RESULTS

28 studies (total n = 1337 participants, average age 79-90 years) were included in the systematic review, of which 21 could be meta-analyzed. Although considerable heterogeneity was found, exercise interventions induced several significant benefits, including in Barthel index (n = 147 patients, mean difference [MD]=8.36 points, 95% confidence interval [CI]=0.63-16.09), 6MWT (n = 369, MD=84 m, 95% CI=44-133)), and NPI (n = 263, MD=-4.4 points, 95% CI=-8.42 to -0.38). Benefits were also found in the MMSE test, albeit significance was only reached for aerobic exercise (n = 187, MD=2.31 points, 95% CI 0.45-4.27).

CONCLUSIONS

Exercise interventions appear to exert multi-domain benefits in patients with AD.

A Three-Arm Parallel-Group Exploratory Trial documents balance improvement without much evidence of white matter integrity changes in people with multiple sclerosis following two months ambulatory neuroproprioceptive "facilitation and inhibition" physical therapy

BACKGROUND

Changes of white matter integrity in people with multiple sclerosis (MS) were documented following mainly motor/skill acquisitions physical therapy, while following neuroproprioceptive "facilitation, inhibition" (neurofacilitation) only by two pilot studies. Neurofacilitation has potential to induce white matter changes due to possibility to interfere with the neuronal tactility threshold, but stronger evidence is missing.

AIM

This study investigates whether neurofacilitation (three physical therapy types) induce white matter changes and if they relate to clinical improvement.

DESIGN

The Three-Arm Parallel-Group Exploratory Trial (NCT04355663).

SETTING

Each group underwent different kind of two months ambulatory therapy (Motor Program Activating Therapy, Vojta's reflex locomotion, and Functional Electric Stimulation in Posturally Corrected Position).

POPULATION

MS people with moderate disability.

METHODS

At baseline and after the program, participants underwent magnetic resonance diffusion tensor imaging (DTI) and clinical assessment. Fractional anisotropy maps obtained from DTI were further analyzed using tract-based spatial statistic exploring the mean values in the whole statistic skeleton. Moreover, additional exploratory analysis in 48 regions of white matter was done.

RESULTS

92 people were recruited. DTI data from 61 were analysed. The neurofacilitation (irrespective type of therapy) resulted in significant improvement on the Berg Balance Scale (p=0.0089), mainly driven by the Motor Program Activating Therapy. No statistically significant change in the whole statistic skeleton was observed (only a trend for decrement of fractional anisotropy after Vojta's reflex locomotion). Additional exploratory analysis confirmed significant decrement of fractional anisotropy in the right anterior corona radiata.

CONCLUSIONS

Neurofacilitation improved balance without much evidence of white matter integrity changes in people with MS.

CLINICAL REHABILITATION IMPACT

The study results point to the importance of neuroproprioceptive "facilitation and inhibition" physical therapy in management of balance in people with multiple sclerosis and the potential to induce white matter changes due to possibility to interfere with the neuronal tactility threshold.

Strength training or green tea prevent memory deficits in a β-amyloid peptide-mediated Alzheimer's disease model

Antioxidant supplementation and physical exercise have been discussed as strategies to minimize neurodegeneration in Alzheimer's disease (AD). We investigated the neuroprotective effects of strength exercise (StrEx) and green tea (GT) supplementation, combined or not, on memory impairments induced by β-amyloid characterizing an AD-like condition in rats. Wistar rats were submitted to 8 weeks of StrEx, GT supplementation, or StrEx and GT combined. AD-like condition was induced by injection of Aβ (25-35) in the hippocampus. We evaluate object recognition (OR) and social recognition (SR) memory, and removed the rats' hippocampus for biochemical analysis. StrEx improved OR and SR. StrEx combined with GT improved OR and did not improve SR. GT reduced antioxidant capacity and improved acetylcholinesterase activity. Both strength exercise and green tea are neuroprotective against impairments resultant of β-amyloid, but benefits do not add up when the two interventions are associated.

A Comparison of Cardiopulmonary Exercise Testing and Field Walking Tests in Community-Dwelling Older Adults With Mild-to-Moderate Alzheimer's Dementia

The purpose of this study was to investigate the relationships among peak exercise parameters on 6-min walk test, shuttle walk test, and laboratory-based cardiopulmonary exercise testing in persons with Alzheimer's dementia. This study is a cross-sectional analysis of the baseline data of 90 participants (age 77.1 [6.6] years, 43% female) from the FIT-AD trial. Cardiopulmonary exercise testing produced significantly higher peak heart rate (118.6 [17.5] vs. 106 [22.8] vs. 106 [18.8] beats/min), rating of perceived exertion (16 [2.1] vs. 12 [2.3] vs. 11 [2.1]), and systolic blood pressure (182 [23.7] vs. 156 [18.9] vs. 150 [16.9] mmHg) compared with the shuttle walk test and 6-min walk test, respectively. Peak walking distance on shuttle walk test (241.3 [127.3] m) and 6-min walk test (365.0 [107.9] m) significantly correlated with peak oxygen consumption (17.1 [4.3] ml·kg-1·min-1) on cardiopulmonary exercise testing (r = .449, p ≤ .001 and r = .435, p ≤ .001), respectively, which is considerably lower than what is seen in older adults and persons with cardiopulmonary diseases.

Exercise training improves vascular function in patients with Alzheimer's disease

PURPOSE

Vascular dysfunction has been demonstrated in patients with Alzheimer's disease (AD). Exercise is known to positively affect vascular function. Thus, the aim of our study was to investigate exercise-induced effects on vascular function in AD.

METHODS

Thirty-nine patients with AD (79 ± 8 years) were recruited and randomly assigned to exercise training (EX, n = 20) or control group (CTRL, n = 19). All subjects performed 72 treatment sessions (90 min, 3 t/w). EX included moderate-high-intensity aerobic and strength training. CTRL included cognitive stimuli (visual, verbal, auditive). Before and after the 6-month treatment, the vascular function was measured by passive-leg movement test (PLM, calculating the variation in blood flow: ∆peak; and area under the curve: AUC) tests, and flow-mediated dilation (FMD, %). A blood sample was analyzed for vascular endothelial growth factor (VEGF). Arterial blood flow (BF) and shear rate (SR) were measured during EX and CTRL during a typical treatment session.

RESULTS

EX group has increased FMD% (+ 3.725%, p < 0.001), PLM ∆peak (+ 99.056 ml/min, p = 0.004), AUC (+ 37.359AU, p = 0.037) and VEGF (+ 8.825 pg/ml, p = 0.004). In the CTRL group, no difference between pre- and post-treatment was found for any variable. Increase in BF and SR was demonstrated during EX (BF + 123%, p < 0.05; SR + 134%, p < 0.05), but not during CTRL treatment.

CONCLUSION

Exercise training improves peripheral vascular function in AD. These ameliorations may be due to the repetitive increase in SR during exercise which triggers NO and VEGF upregulation. This approach might be included in standard AD clinical practice as an effective strategy to treat vascular dysfunction in this population.

Evaluating amino acids as protectants against β-N-methylamino-l-alanine-induced developmental neurotoxicity in a rat model

With accumulating evidence that supports the role of β-N-methylamino-l-alanine (BMAA) in neurodegeneration, it is necessary to elucidate the mechanisms and modes of BMAA toxicity so as to facilitate the search for potential preventative/therapeutic strategies. Daily supplementation with l-serine was suggested as a possible therapy to treat BMAA-induced neurotoxicity, based on the hypothesized mechanism of BMAA misincorporation into proteins for l-serine. As an alternative to misincorporation, it was hypothesized that BMAA toxicity may, in part, be due to its high affinity for associating with hydroxyl group-containing amino acids, and that a dietary excess of the hydroxyl-containing l-serine might offer protection by binding to BMAA and reducing its toxicity. Additionally, l-serine can also reduce the uptake of BMAA into human cells by competitive uptake at ASCT2, and l-phenylalanine, by competitive uptake at LAT1, and l-alanine, by competitive uptake at SNAT2, can also reduce BMAA uptake into human cells. The aim of this study was therefore to determine the protective value of l-serine, l-phenylalanine and l-alanine in reducing the effects of neonatal exposure to BMAA in a Sprague Dawley rat model. Pre-treatment with l-phenylalanine reduced the observed behavioral abnormalities and neuropathologies by 60-70% in most cases. l-serine was also effective in reducing some of the behavioral abnormalities and neuropathologies, most markedly spinal cord neuronal loss. However, the protective effect of l-serine was obfuscated by neuropathies that were observed in l-serine-treated control male rats. l-alanine had no effect in protecting against BMAA-induced neurotoxicity, suggesting that competitive amino acid uptake plays a minor role in protecting against BMAA-induced neurotoxicity.

Effects of a 16-week multimodal exercise program on gait performance in individuals with dementia: a multicenter randomized controlled trial

Background

There is a high prevalence of gait impairments in individuals with dementia (IWD). Gait impairments are associated with increased risk of falls, disability, and economic burden for health care systems. Only few studies have investigated the effectiveness of physical activity on gait performance in IWD, reporting promising but inconsistent results. Thus, this study aimed to investigate the effectiveness of a multimodal exercise program (MEP) on gait performance in IWD.

Methods

In this parallel-group randomized controlled trial, we enrolled 319 IWD of mild to moderate severity, living in care facilities, aged ≥ 65 years, and being able to walk at least 10 m. The control group (n = 118) received conventional treatment, whereas the intervention group (n = 201) additionally participated in a 16-week MEP specifically tailored to IWD. We examined the effects of the MEP on spatiotemporal gait parameters and dual task costs by using the gait analysis system GAITRite. Additionally, we compared characteristics between positive, non-, and negative responders, and investigated the impact of changes in underlying motor and cognitive performance in the intervention group by conducting multiple regression analyses.

Results

Two-factor analyses of variance with repeated measurements did not reveal any statistically significant time*group effects on either spatiotemporal gait parameters or dual task costs. Differences in baseline gait performance, mobility, lower limb strength, and severity of cognitive impairments were observed between positive, non-, and negative responders. Positive responders were characterized by lower motor performance compared to negative and non-responders, while non-responders showed better cognitive performance than negative responders. Changes in lower limb strength and function, mobility, executive function, attention, and working memory explained up to 39.4% of the variance of changes in gait performance.

Conclusions

The effectiveness of a standardized MEP on gait performance in IWD was limited, probably due to insufficient intensity and amount of specific walking tasks as well as the large heterogeneity of the sample. However, additional analyses revealed prerequisites of individual characteristics and impacts of changes in underlying motor and cognitive performance. Considering such factors may improve the effectiveness of a physical activity intervention among IWD.

Trial registration

DRKS00010538 (German Clinical Trial Register, date of registration: 01 June 2016, retrospectively registered, https://www.drks.de/drks_web/setLocale_EN.do).

Recommended motor assessments based on psychometric properties in individuals with dementia: a systematic review

BACKGROUND

Motor assessments are important to determine effectiveness of physical activity in individuals with dementia (IWD). However, inappropriate and non-standardised assessments without sound psychometric properties have been used. This systematic review aims to examine psychometric properties of motor assessments in IWD combined with frequency of use and effect sizes and to provide recommendations based on observed findings.We performed a two-stage systematic literature search using Pubmed, Web of Science, Cochrane Library, ALOIS, and Scopus (inception - July/September 2018, English and German). The first search purposed to identify motor assessments used in randomised controlled trials assessing effectiveness of physical activity in IWD and to display their frequency of use and effect sizes. The second search focused on psychometric properties considering influence of severity and aetiology of dementia and cueing on test-retest reliability. Two reviewers independently extracted and analysed findings of eligible studies in a narrative synthesis.

RESULTS

Literature searches identified 46 randomised controlled trials and 21 psychometric property studies. While insufficient information was available for validity, we observed sufficient inter-rater and relative test-retest reliability but unacceptable absolute test-retest reliability for most assessments. Combining these findings with frequency of use and effect sizes, we recommend Functional Reach Test, Groningen Meander Walking Test (time), Berg Balance Scale, Performance Oriented Mobility Assessment, Timed Up & Go Test, instrumented gait analysis (spatiotemporal parameters), Sit-to-Stand assessments (repetitions> 1), and 6-min walk test. It is important to consider that severity and aetiology of dementia and cueing influenced test-retest reliability of some assessments.

CONCLUSION

This review establishes an important foundation for future investigations. Sufficient relative reliability supports the conclusiveness of recommended assessments at group level, while unacceptable absolute reliability advices caution in assessing intra-individual changes. Moreover, influences on test-retest reliability suggest tailoring assessments and instructions to IWD and applying cueing only where it is inevitable. Considering heterogeneity of included studies and insufficient examination in various areas, these recommendations are not comprehensive. Further research, especially on validity and influences on test-retest reliability, as well as standardisation and development of tailored assessments for IWD is crucial.This systematic review was registered in PROSPERO (CRD42018105399).

Non-Aβ-Dependent Factors Associated with Global Cognitive and Physical Function in Alzheimer's Disease: A Pilot Multivariate Analysis

Recent literature highlights the importance of identifying factors associated with mild cognitive impairment (MCI) and Alzheimer’s Disease (AD). Actual validated biomarkers include neuroimaging and cerebrospinal fluid assessments; however, we investigated non-Aβ-dependent factors associated with dementia in 12 MCI and 30 AD patients. Patients were assessed for global cognitive function (Mini-Mental state examination—MMSE), physical function (Physical Performance Test—PPT), exercise capacity (6-min walking test—6MWT), maximal oxygen uptake (VO₂max), brain volume, vascular function (flow-mediated dilation—FMD), inflammatory status (tumor necrosis factor—α ,TNF- α, interleukin-6, -10 and -15) and neurotrophin receptors (p75NTR and Tropomyosin receptor kinase A -TrkA). Baseline multifactorial information was submitted to two separate backward stepwise regression analyses to identify the variables associated with cognitive and physical decline in demented patients. A multivariate regression was then applied to verify the stepwise regression. The results indicated that the combination of 6MWT and VO₂max was associated with both global cognitive and physical function (MMSE = 11.384 + (0.00599 × 6MWT) − (0.235 × VO₂max)); (PPT = 1.848 + (0.0264 × 6MWT) + (19.693 × VO₂max)). These results may offer important information that might help to identify specific targets for therapeutic strategies (NIH Clinical trial identification number NCT03034746).