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BACKGROUND: It is not clear how specific gait measures reflect disease severity across the disease spectrum in Parkinson's disease (PD). OBJECTIVE: To identify the gait and mobility measures that are most sensitive and reflective of PD motor stages and determine the optimal sensor location in each disease stage. METHODS: Cross-sectional wearable-sensor records were collected in 332 patients with PD (Hoehn and Yahr scale I-III) and 100 age-matched healthy controls. Sensors were adhered to the participant's lower back, bilateral ankles, and wrists. Study participants walked in a ~15-meter corridor for 1 minute under two walking conditions: (1) preferred, usual walking speed and (2) walking while engaging in a cognitive task (dual-task). A subgroup (n = 303, 67% PD) also performed the Timed Up and Go test. Multiple machine-learning feature selection and classification algorithms were applied to discriminate between controls and PD and between the different PD severity stages. RESULTS: High discriminatory values were found between motor disease stages with mean sensitivity in the range 72%-83%, specificity 69%-80%, and area under the curve (AUC) 0.76-0.90. Measures from upper-limb sensors best discriminated controls from early PD, turning measures obtained from the trunk sensor were prominent in mid-stage PD, and stride timing and regularity were discriminative in more advanced stages. CONCLUSIONS: Applying machine-learning to multiple, wearable-derived features reveals that different measures of gait and mobility are associated with and discriminate distinct stages of PD. These disparate feature sets can augment the objective monitoring of disease progression and may be useful for cohort selection and power analyses in clinical trials of PD. © 2021 International Parkinson and Movement Disorder Society.
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Doença de Parkinson , Estudos Transversais , Marcha , Humanos , Aprendizado de Máquina , Doença de Parkinson/diagnóstico , Equilíbrio Postural , Estudos de Tempo e Movimento , CaminhadaRESUMO
INTRODUCTION: Gait impairment is common in neurodegenerative disorders. Specifically, gait variability-the stride-to-stride fluctuations in distance and time-has been associated with neurodegeneration and cognitive impairment. However, quantitative comparisons of gait impairments across the cognitive spectrum of dementias have not been systematically investigated. METHODS: Older adults (N = 500) with subjective cognitive impairment, Parkinson disease (PD), mild cognitive impairment (MCI), PD-MCI, Alzheimer's disease (AD), PD-dementia, Lewy body dementia, and frontotemporal dementia, as well cognitive normal controls, who were assessed for their gait and cognitive performance. RESULTS: Factor analyses grouped 11 quantitative gait parameters and identified four independent gait domains: rhythm, pace, variability, and postural control, for group comparisons and classification analysis. Among these domains, only high gait variability was associated with lower cognitive performance and accurately discriminated AD from other neurodegenerative and cognitive conditions. DISCUSSION: Our findings indicate that high gait variability is a marker of cognitive-cortical dysfunction, which can help to identify Alzheimer's disease dementia.
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Transtornos Cognitivos/fisiopatologia , Demência/fisiopatologia , Marcha/fisiologia , Idoso , Envelhecimento/fisiologia , Doença de Alzheimer/fisiopatologia , Biomarcadores , Encéfalo/fisiopatologia , Canadá , Demência Frontotemporal/fisiopatologia , Humanos , Doença por Corpos de Lewy/fisiopatologia , Doença de Parkinson/fisiopatologiaRESUMO
Threatening situations lead to observable gait deficits in individuals with Parkinson's disease (PD) who suffer from high trait anxiety levels. The specific characteristics of gait that are affected appear to be similar to behaviors observed while walking during a dual-task (DT) condition. Yet, it remains unclear whether anxiety is similar to a cognitive load. If it were, then those with PD who have high trait anxiety might be expected to be more susceptible to DT interference during walking. Thus, the overall aim of this study was to evaluate whether trait anxiety influences gait during single-task (ST) and DT walking. Seventy participants (high-anxiety PD [HA-PD], N=26; low-anxiety PD [LA-PD], N=26; healthy control [HC], N=18) completed three ST and three DT walking trials on a data-collecting carpet. The secondary task consisted of digit monitoring while walking. Results showed that during both ST and DT gait, the HA-PD group demonstrated significant reductions in walking speed and step length, as well as increased step length variability and step time variability compared with healthy controls and the LA-PD group. Notably, ST walking in the HA-PD group resembled (i.e., it was not significantly different from) the gait behaviors seen during a DT in the LA-PD and HC groups. These results suggest that trait anxiety may consume processing resources and limit the ability to compensate for gait impairments in PD.
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Ansiedade/etiologia , Transtornos Neurológicos da Marcha/etiologia , Doença de Parkinson/complicações , Doença de Parkinson/psicologia , Idoso , Idoso de 80 Anos ou mais , Ansiedade/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Caminhada/fisiologiaRESUMO
BACKGROUND: Little is known about how different exercise modalities influence cognition in Parkinson's disease (PD). Moreover, the focus of previous investigations on examining the effects of exercise mainly on executive functions and the exclusion of individuals with cognitive impairment may limit the potential to define exercise as a treatment for cognitive decline in PD. OBJECTIVE: The aim of this study was to compare the effects of aerobic and goal-based exercise on five cognitive domains in cognitively normal and impaired individuals with PD. METHODS: Seventy-six individuals with PD were randomly allocated into three groups: Aerobic, Goal-based, and Control. Participants in the exercise groups attended 1-h sessions 3x/week for 12â¯weeks, while those in the Control group carried on with their regular activities. Changes in cognitive domains were assessed using paper-based neuropsychological tests. RESULTS: Inhibitory control improved only in the Aerobic group (pâ¯=â¯.04), irrespective of participants cognitive status at baseline. Moreover, participants with cognitive impairment in Aerobic group maintained their set-shifting ability, whereas those in the Control group were worse at post-test (pâ¯=â¯.014). CONCLUSION: This is the first study to show that aerobic exercise is more effective than goal-based exercise for the treatment of cognition in PD with and without cognitive impairment.
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Transtornos Cognitivos/terapia , Disfunção Cognitiva/terapia , Terapia por Exercício/métodos , Exercício Físico/psicologia , Objetivos , Doença de Parkinson/complicações , Idoso , Idoso de 80 Anos ou mais , Cognição/fisiologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/psicologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/psicologia , Função Executiva/fisiologia , Terapia por Exercício/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Doença de Parkinson/psicologia , Resultado do TratamentoRESUMO
BACKGROUND: Physical exercise, cognitive training, and vitamin D are low cost interventions that have the potential to enhance cognitive function and mobility in older adults, especially in pre-dementia states such as Mild Cognitive Impairment (MCI). Aerobic and progressive resistance exercises have benefits to cognitive performance, though evidence is somewhat inconsistent. We postulate that combined aerobic exercise (AE) and progressive resistance training (RT) (combined exercise) will have a better effect on cognition than a balance and toning control (BAT) intervention in older adults with MCI. We also expect that adding cognitive training and vitamin D supplementation to the combined exercise, as a multimodal intervention, will have synergistic efficacy. METHODS: The SYNERGIC trial (SYNchronizing Exercises, Remedies in GaIt and Cognition) is a multi-site, double-blinded, five-arm, controlled trial that assesses the potential synergic effect of combined AE and RT on cognition and mobility, with and without cognitive training and vitamin D supplementation in older adults with MCI. Two-hundred participants with MCI aged 60 to 85 years old will be randomized to one of five arms, four of which include combined exercise plus combinations of dual-task cognitive training (real vs. sham) and vitamin D supplementation (3 × 10,000 IU/wk. vs. placebo) in a quasi-factorial design, and one arm which receives all control interventions. The primary outcome measure is the ADAS-Cog (13 and plus modalities) measured at baseline and at 6 months of follow-up. Secondary outcomes include neuroimaging, neuro-cognitive performance, gait and mobility performance, and serum biomarkers of inflammation (C reactive protein and interleukin 6), neuroplasticity (brain-derived neurotropic factor), endothelial markers (vascular endothelial growth factor 1), and vitamin D serum levels. DISCUSSION: The SYNERGIC Trial will establish the efficacy and feasibility of a multimodal intervention to improve cognitive performance and mobility outcomes in MCI. These interventions may contribute to new approaches to stabilize and reverse cognitive-mobility decline in older individuals with MCI. TRIAL REGISTRATION: Identifier: NCT02808676. https://www.clinicaltrials.gov/ct2/show/NCT02808676 .
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Cognição/fisiologia , Disfunção Cognitiva/reabilitação , Suplementos Nutricionais , Terapia por Exercício/métodos , Tolerância ao Exercício/fisiologia , Marcha/fisiologia , Treinamento Resistido/métodos , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/psicologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
BACKGROUND: Disorders of posture, gait, and balance in Parkinson's disease (PD) are common and debilitating. This MDS-commissioned task force assessed clinimetric properties of existing rating scales, questionnaires, and timed tests that assess these features in PD. METHODS: A literature review was conducted. Identified instruments were evaluated systematically and classified as "recommended," "suggested," or "listed." Inclusion of rating scales was restricted to those that could be used readily in clinical research and practice. RESULTS: One rating scale was classified as "recommended" (UPDRS-derived Postural Instability and Gait Difficulty score) and 2 as "suggested" (Tinetti Balance Scale, Rating Scale for Gait Evaluation). Three scales requiring equipment (Berg Balance Scale, Mini-BESTest, Dynamic Gait Index) also fulfilled criteria for "recommended" and 2 for "suggested" (FOG score, Gait and Balance Scale). Four questionnaires were "recommended" (Freezing of Gait Questionnaire, Activities-specific Balance Confidence Scale, Falls Efficacy Scale, Survey of Activities, and Fear of Falling in the Elderly-Modified). Four tests were classified as "recommended" (6-minute and 10-m walk tests, Timed Up-and-Go, Functional Reach). CONCLUSION: We identified several questionnaires that adequately assess freezing of gait and balance confidence in PD and a number of useful clinical tests. However, most clinical rating scales for gait, balance, and posture perform suboptimally or have been evaluated insufficiently. No instrument comprehensively and separately evaluates all relevant PD-specific gait characteristics with good clinimetric properties, and none provides separate balance and gait scores with adequate content validity for PD. We therefore recommend the development of such a PD-specific, easily administered, comprehensive gait and balance scale that separately assesses all relevant constructs. © 2016 International Parkinson and Movement Disorder Society.
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Técnicas e Procedimentos Diagnósticos/normas , Transtornos Neurológicos da Marcha/diagnóstico , Doença de Parkinson/diagnóstico , Equilíbrio Postural , Transtornos Neurológicos da Marcha/etiologia , Humanos , Doença de Parkinson/complicaçõesRESUMO
In order to understand how dopamine modulates the effect of anxiety on gait, the goal of this study was to use virtual reality to provoke anxiety in Parkinson's disease (PD) (in both ON and OFF states) and quantify its effect on gait. Seventeen participants with PD and 20 healthy age-matched controls were instructed to walk in a virtual environment in two anxiety-provoking conditions: (i) across a plank that was located on the GROUND and (ii) across an ELEVATED plank. All participants with PD completed this experiment in both the ON and OFF states, and were then striated into groups based on baseline trait anxiety scores for further analyses. Anxiety (skin conductance and self-report) and spatiotemporal aspects of gait were measured. Overall, the ELEVATED condition resulted in greater skin conductance levels and self-reported anxiety levels. Additionally, all participants demonstrated slower gait with increased step-to-step variability when crossing the ELEVATED plank compared with the plank on the GROUND. The results showed that dopaminergic treatment selectively improved gait in only the highly anxious PD group, by significantly improving velocity, step length, step time and step-to-step variability specifically when walking across the ELEVATED plank (ON vs. OFF comparison). In conclusion, only highly trait anxious participants with PD benefitted from dopaminergic treatment, specifically when walking in the anxiety-provoking environment. Improvements to gait during anxious walking might be a result of dopaminergic medication acting in two ways: (i) improving the basal ganglia's capacity to process information and (ii) reducing the load from anxiety and subsequently making more resources available to effectively process other competing inputs.
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Ansiedade/complicações , Di-Hidroxifenilalanina/uso terapêutico , Dopaminérgicos/uso terapêutico , Transtornos Neurológicos da Marcha/tratamento farmacológico , Transtornos Neurológicos da Marcha/etiologia , Doença de Parkinson/complicações , Idoso , Ansiedade/diagnóstico , Ansiedade/etiologia , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Resposta Galvânica da Pele , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/tratamento farmacológico , Autorrelato , Interface Usuário-ComputadorRESUMO
Although dopaminergic replacement therapy is believed to improve sensory processing in PD, while delayed perceptual speed is thought to be caused by a predominantly cholinergic deficit, it is unclear whether sensory-perceptual deficits are a result of corrupt sensory processing, or a delay in updating perceived feedback during movement. The current study aimed to examine these two hypotheses by manipulating visual flow speed and dopaminergic medication to examine which influenced distance estimation in PD. Fourteen PD and sixteen HC participants were instructed to estimate the distance of a remembered target by walking to the position the target formerly occupied. This task was completed in virtual reality in order to manipulate the visual flow (VF) speed in real time. Three conditions were carried out: (1) BASELINE: VF speed was equal to participants' real-time movement speed; (2) SLOW: VF speed was reduced by 50 %; (2) FAST: VF speed was increased by 30 %. Individuals with PD performed the experiment in their ON and OFF state. PD demonstrated significantly greater judgement error during BASELINE and FAST conditions compared to HC, although PD did not improve their judgement error during the SLOW condition. Additionally, PD had greater variable error during baseline compared to HC; however, during the SLOW conditions, PD had significantly less variable error compared to baseline and similar variable error to HC participants. Overall, dopaminergic medication did not significantly influence judgement error. Therefore, these results suggest that corrupt processing of sensory information is the main contributor to sensory-perceptual deficits during movement in PD rather than delayed updating of sensory feedback.
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Percepção de Distância/fisiologia , Retroalimentação Sensorial/fisiologia , Doença de Parkinson/psicologia , Percepção Visual/fisiologia , Caminhada/fisiologia , Feminino , Humanos , Masculino , Desempenho Psicomotor/fisiologia , Interface Usuário-ComputadorRESUMO
BACKGROUND: Recent research has argued that removal of relevant sensory information during the planning and control of simple, self-paced walking can result in increased demand on central processing resources in Parkinson's disease (PD). However, little is known about more complex gait tasks that require planning of gait adaptations to cross over an obstacle in PD. METHODS: In order to understand the interaction between availability of visual information relevant for self-motion and cognitive load, the current study evaluated PD participants and healthy controls while walking toward and stepping over an obstacle in three visual feedback conditions: (i) no visual restrictions; (ii) vision of the obstacle and their lower limbs while in complete darkness; (iii) vision of the obstacle only while in complete darkness; as well as two conditions including a cognitive load (with a dual task versus without a dual task). Each walk trial was divided into an early and late phase to examine changes associated with planning of step adjustments when approaching the obstacle. RESULTS: Interactions between visual feedback and dual task conditions during the obstacle approach were not significant. Patients with PD had greater deceleration and step time variability in the late phase of the obstacle approach phase while walking in both dark conditions compared to control participants. Additionally, participants with PD had a greater number of obstacle contacts when vision of their lower limbs was not available specifically during the dual task condition. Dual task performance was worse in PD compared to healthy control participants, but notably only while walking in the dark regardless of visual feedback. CONCLUSIONS: These results suggest that reducing visual feedback while approaching an obstacle shifts processing to somatosensory feedback to guide movement which imposes a greater demand on planning resources. These results are key to fully understanding why trips and falls occur in those with PD.
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Adaptação Fisiológica , Cognição , Retroalimentação Sensorial , Transtornos Neurológicos da Marcha/fisiopatologia , Doença de Parkinson/fisiopatologia , Idoso , Estudos de Casos e Controles , Feminino , Marcha , Transtornos Neurológicos da Marcha/etiologia , Transtornos Neurológicos da Marcha/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/complicações , Doença de Parkinson/psicologia , Desempenho Psicomotor , Análise e Desempenho de Tarefas , Percepção Visual , CaminhadaRESUMO
Freezing of gait (FOG) in Parkinson's disease (PD) is typically assumed to be a pure motor deficit, although it is important to consider how an abrupt loss of gait automaticity might be associated with an overloaded central resource capacity. If resource capacity limits are a factor underlying FOG, then obstacle crossing may be particularly sensitive to dual task effects in eliciting FOG. Participants performed a dual task (auditory digit monitoring) in order to increase cognitive load during obstacle crossing. Forty-two non-demented participants (14 PD patients with FOG, 13 PD who do not freeze, and 14 age-matched healthy control participants) were required to walk and step over a horizontal obstacle set at 15% of the participants' height. Kinematic data were split into two phases of their approach: early (farthest away from the obstacle), and late (just prior to the obstacle). Interestingly, step length variability and step time variability increased when PD patients with FOG performed the dual task, but only in the late phase prior to the obstacle (i.e. when closest to the obstacle). Additionally, immediately after crossing, freezers landed the lead foot abnormally close to the obstacle regardless of dual task condition, and also contacted the obstacle more frequently (planning errors). Strength of the dual task effect was associated with low general cognitive status, declined executive function, and inappropriate spatial planning, but only in the PD-FOG group. This study is the first to demonstrate that cognitive load differentially impacts planning of the final steps needed to avoid an obstacle in PD patients with freezing, but not non-freezers or healthy controls, suggesting specific neural networks associated with FOG behaviours.
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Cognição , Transtornos Neurológicos da Marcha/psicologia , Marcha , Doença de Parkinson/psicologia , Idoso , Fenômenos Biomecânicos , Feminino , Transtornos Neurológicos da Marcha/etiologia , Humanos , Masculino , Doença de Parkinson/complicações , Desempenho PsicomotorRESUMO
BACKGROUND: Within the spectrum of Lewy body disorders (LBD), both Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are characterized by gait and balance disturbances, which become more prominent under dual-task (DT) conditions. The brain substrates underlying DT gait variations, however, remain poorly understood in LBD. OBJECTIVE: To investigate the relationship between gray matter volume loss and DT gait variations in LBD. METHODS: Seventy-nine participants including cognitively unimpaired PD, PD with mild cognitive impairment, PD with dementia (PDD), or DLB and 20 cognitively unimpaired controls were examined across a multi-site study. PDD and DLB were grouped together for analyses. Differences in gait speed between single and DT conditions were quantified by dual task cost (DTC). Cortical, subcortical, ventricle, and cerebellum brain volumes were obtained using FreeSurfer. Linear regression models were used to examine the relationship between gray matter volumes and DTC. RESULTS: Smaller amygdala and total cortical volumes, and larger ventricle volumes were associated with a higher DTC across LBD and cognitively unimpaired controls. No statistically significant interaction between group and brain volumes were found. Adding cognitive and motor covariates or white matter hyperintensity volumes separately to the models did not affect brain volume and DTC associations. CONCLUSION: Gray matter volume loss is associated with worse DT gait performance compared to single task gait, across cognitively unimpaired controls through and the LBD spectrum. Impairment in DT gait performance may be driven by age-related cortical neurodegeneration.
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Doença de Alzheimer , Doença por Corpos de Lewy , Doença de Parkinson , Humanos , Envelhecimento , Doença de Alzheimer/complicações , Marcha , Substância Cinzenta/diagnóstico por imagem , Corpos de Lewy , Doença por Corpos de Lewy/diagnóstico por imagem , Doença por Corpos de Lewy/complicações , Doença de Parkinson/complicaçõesRESUMO
Functional brain connectivity (FBC), or areas that are anatomically separate but temporally synchronized in their activation, represent a sensitive biomarker for monitoring dementia progression. It is unclear whether frailty is associated with FBC in those at higher risk of progression to dementia (e.g., mild cognitive impairment -MCI-) and if sex plays a role. We used baseline data from the SYNERGIC trial, including participants with MCI that received brain MRI. In this cross-sectional analyses (n = 100), we measured frailty using a deficit accumulation frailty index. Using the CONN toolbox, we assessed FBC of networks and regions of interest across the entire connectome. We used Pearson's correlation to investigate the relationship between FBC and frailty index in the full sample and by sex. We also divided the full sample and each sex into tertiles based upon their frailty index score and then assessed between-tertile differences in FBC. The full sample (cluster: size = 291 p-FDR < 0.05) and males (cluster: size = 993 and 451 p-FDR < 0.01) demonstrated that increasing (stronger) connectivity between the right hippocampus and clusters in the temporal gyrus was positively correlated with increasing (worse) frailty. Males also demonstrated between-tertile differences in right hippocampus connectivity to clusters in the lateral occipital cortex (cluster: size = 289 p-FDR < 0.05). Regardless of frailty status, females demonstrated stronger within-network connectivity of the Default-Mode (p = 0.024). Our results suggest that increasing (worse) frailty was associated with increasing (stronger) connectivity between regions not typically linked, which may reflect a compensation tactic by the plastic brain. Furthermore, the relationship between the two variables appears to differ by sex. Our results may help elucidate why specific individuals progress to a dementia syndrome. NCT02808676. https://www.clinicaltrials.gov/ct2/show/NCT02808676.
Assuntos
Disfunção Cognitiva , Demência , Fragilidade , Idoso , Feminino , Humanos , Masculino , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Estudos Transversais , Demência/complicações , Fragilidade/complicaçõesRESUMO
Background: Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are part of a spectrum of Lewy body disorders, who exhibit a range of cognitive and gait impairments. Cognitive-motor interactions can be examined by performing a cognitive task while walking and quantified by a dual task cost (DTC). White matter hyperintensities (WMH) on magnetic resonance imaging have also been associated with both gait and cognition. Our goal was to examine the relationship between DTC and WMH in the Lewy body spectrum, hypothesizing DTC would be associated with increased WMH volume. Methods: Seventy-eight participants with PD, PD with mild cognitive impairment (PD-MCI), PD with dementia or DLB (PDD/DLB), and 20 cognitively unimpaired participants were examined in a multi-site study. Gait was measured on an electronic walkway during usual gait, counting backward, animal fluency, and subtracting sevens. WMH were quantified from magnetic resonance imaging using an automated pipeline and visual rating. A median split based on DTC was performed. Models included age as well as measures of global cognition and cardiovascular risk. Results: Compared to cognitively unimpaired participants, usual gait speed was lower and DTC was higher in PD-MCI and PDD/DLB. Low DTC participants had higher usual gait speed. WMH burden was greater in high counting DTC participants. Frontal WMH burden remained significant after adjusting for age, cardiovascular risk and global cognition. Conclusion: Increased DTC was associated with higher frontal WMH burden in Lewy body disorders after adjusting for age, cardiovascular risk, and global cognition. Higher DTC was associated with age.
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Changes in functional brain connectivity (FBC) may indicate how lifestyle modifications can prevent the progression to dementia; FBC identifies areas that are spatially separate but temporally synchronized in their activation and is altered in those with mild cognitive impairment (MCI), a prodromal state between healthy cognitive aging and dementia. Participants with MCI were randomly assigned to one of five study arms. Three times per week for 20-weeks, participants performed 30-min of (control) cognitive training, followed by 60-min of (control) physical exercise. Additionally, a vitamin D3 (10,000 IU/pill) or a placebo capsule was ingested three times per week for 20-weeks. Using the CONN toolbox, we measured FBC change (Post-Pre) across four statistical models that collapsed for and/or included some or all study arms. We conducted Pearson correlations between FBC change and changes in physical and cognitive functioning. Our sample included 120 participants (mean age: 73.89 ± 6.50). Compared to the pure control, physical exercise (model one; p-False Discovery Rate (FDR) < 0.01 & < 0.05) with cognitive training (model two; p-FDR = < 0.001), and all three interventions combined (model four; p-FDR = < 0.01) demonstrated an increase in FBC between regions of the Default-Mode Network (i.e., hippocampus and angular gyrus). After controlling for false discovery rate, there were no significant correlations between change in connectivity and change in cognitive or physical function. Physical exercise alone appears to be as efficacious as combined interventional strategies in altering FBC, but implications for behavioral outcomes remain unclear.
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Disfunção Cognitiva , Demência , Humanos , Idoso , Idoso de 80 Anos ou mais , Colecalciferol , Treino Cognitivo , Disfunção Cognitiva/terapia , Encéfalo , Exercício Físico/fisiologia , Exercício Físico/psicologiaRESUMO
Importance: Exercise, cognitive training, and vitamin D may enhance cognition in older adults with mild cognitive impairment (MCI). Objective: To determine whether aerobic-resistance exercises would improve cognition relative to an active control and if a multidomain intervention including exercises, computerized cognitive training, and vitamin D supplementation would show greater improvements than exercise alone. Design, Setting, and Participants: This randomized clinical trial (the SYNERGIC Study) was a multisite, double-masked, fractional factorial trial that evaluated the effects of aerobic-resistance exercise, computerized cognitive training, and vitamin D on cognition. Eligible participants were between ages 65 and 84 years with MCI enrolled from September 19, 2016, to April 7, 2020. Data were analyzed from February 2021 to December 2022. Interventions: Participants were randomized to 5 study arms and treated for 20 weeks: arm 1 (multidomain intervention with exercise, cognitive training, and vitamin D), arm 2 (exercise, cognitive training, and placebo vitamin D), arm 3 (exercise, sham cognitive training, and vitamin D), arm 4 (exercise, sham cognitive training, and placebo vitamin D), and arm 5 (control group with balance-toning exercise, sham cognitive training, and placebo vitamin D). The vitamin D regimen was a 10â¯000 IU dose 3 times weekly. Main Outcomes and Measures: Primary outcomes were changes in ADAS-Cog-13 and Plus variant at 6 months. Results: Among 175 randomized participants (mean [SD] age, 73.1 [6.6] years; 86 [49.1%] women), 144 (82%) completed the intervention and 133 (76%) completed the follow-up (month 12). At 6 months, all active arms (ie, arms 1 through 4) with aerobic-resistance exercise regardless of the addition of cognitive training or vitamin D, improved ADAS-Cog-13 when compared with control (mean difference, -1.79 points; 95% CI, -3.27 to -0.31 points; P = .02; d = 0.64). Compared with exercise alone (arms 3 and 4), exercise and cognitive training (arms 1 and 2) improved the ADAS-Cog-13 (mean difference, -1.45 points; 95% CI, -2.70 to -0.21 points; P = .02; d = 0.39). No significant improvement was found with vitamin D. Finally, the multidomain intervention (arm 1) improved the ADAS-Cog-13 score significantly compared with control (mean difference, -2.64 points; 95% CI, -4.42 to -0.80 points; P = .005; d = 0.71). Changes in ADAS-Cog-Plus were not significant. Conclusions and Relevance: In this clinical trial, older adults with MCI receiving aerobic-resistance exercises with sequential computerized cognitive training significantly improved cognition, although some results were inconsistent. Vitamin D supplementation had no effect. Our findings suggest that this multidomain intervention may improve cognition and potentially delay dementia onset in MCI. Trial Registration: ClinicalTrials.gov Identifier: NCT02808676.
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Disfunção Cognitiva , Treino Cognitivo , Humanos , Feminino , Idoso , Masculino , Disfunção Cognitiva/terapia , Disfunção Cognitiva/psicologia , Cognição , Vitaminas/uso terapêutico , Vitaminas/farmacologia , Vitamina D/uso terapêutico , Vitamina D/farmacologia , Suplementos NutricionaisRESUMO
OBJECTIVE: To examine how a cued change in motor plan influences Parkinson's disease (PD) patients with freezing of gait (FOG) (PD FOG; n=10), compared with those without FOG (PD non-FOG; n=10) and healthy controls (n=10). METHODS: Participants walked through a doorway in three experimental conditions: no cue; cue before gait initiation; and cue after gait initiation. The light cue was presented at the end of the pathway and signified that individuals must walk to the cue, turn around and return to starting position. RESULTS: Step-to-step variability (a known precursor to FOG) revealed a significant main effect of group (F2,27=32.83, p<0.001), where PD FOG walked with greater step length variability than PD non-FOG and the control group. A significant interaction (F4,54=3.035, p=0.025) demonstrated that only the PD FOG group was most variable when the cue was present before gait initiation. CONCLUSION: This study concludes that motor planning deficits affect gait, specifically in individuals who experience FOG. This may have important implications for the design of therapeutic interventions in PD FOG.
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Marcha/fisiologia , Movimento/fisiologia , Doença de Parkinson/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Sinais (Psicologia) , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Although Parkinson's disease (PD) is traditionally considered a motor output disorder, recent evidence suggests that people with PD may have sensory and perceptual impairments that may underlie movement impairments. Yet there has not been any direct testing of perceptual judgments, especially when manipulating the sensory feedback on which these judgments are made. The present study investigated how perception might be influenced by sensory feedback to contribute to height estimations and obstacle stepping in PD relative to healthy age-matched control participants. Perceptual judgment accuracy was evaluated by judging 3 typically encountered obstacle heights in 2 sensory feedback conditions: (1) vision of foot available and (2) without vision of foot (reliance on proprioceptive feedback to estimate height). Then participants proceeded to walk and step over the obstacle. Fifteen individuals with PD and 15 healthy control participants completed the task. As seen with toe elevation, toe elevation variability, and toe error measures, individuals with PD overestimated the obstacle height and were significantly more variable when relying solely on proprioception (in contrast to when vision was available) compared with healthy controls, although no differences between groups in obstacle crossing were found. These results support the notion that sensory deficits may contribute to inaccuracy of perceptual judgment and has the potential to contribute to gait behaviors such as tripping and falling, especially when vision is not available. Future studies should carefully consider the impact of sensory and perceptual deficits that might contribute to movement planning problems and consequentially movement impairments.
Assuntos
Doença de Parkinson/complicações , Transtornos da Percepção/etiologia , Transtornos de Sensação/etiologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Transtornos da Percepção/diagnóstico , Desempenho Psicomotor , Transtornos de Sensação/diagnóstico , Dedos do Pé/fisiopatologia , Caminhada/fisiologiaRESUMO
In reaction time (RT) tasks where fast ballistic movements are required, the requisite action is generally preplanned to enable the quickest responses. When a loud acoustic stimulus (e.g., >120 dB) that elicits a startle response is presented during the preplanning phase, the movement is triggered involuntarily and at a sufficiently short enough latency to discount normal cortical initiation processes. It has been suggested that the startle triggers the action by providing sufficient additional activation to surpass the initiation threshold. It is unclear, however, whether similar RT shortening due to startle would occur in the absence of an excitatory motor output. Thus, in the current study, participants performed a flexion force offset (i.e., inhibition) task within a simple RT paradigm. A startling acoustic stimulus (SAS) was presented in place of the usual "go" signal on several trials. Results from startle trials showed that the inhibitory command could be elicited substantially earlier by an SAS (latency of ~78 ms) compared to control trials (120 ms). This suggests active inhibition is preprogrammed and can be triggered early by startle in similar way to traditional "excitatory" tasks. Additionally, early startle-related EMG activity superimposed with the triggered offset suggests that the nature of the inhibitory command used in the current experiment involves the active suppression of ongoing motor output.
Assuntos
Inibição Psicológica , Movimento/fisiologia , Tempo de Reação/fisiologia , Reflexo de Sobressalto/fisiologia , Estimulação Acústica , Adolescente , Adulto , Fenômenos Biomecânicos/fisiologia , Eletromiografia , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologiaRESUMO
Freezing of gait (FOG) is a complex gait disturbance in Parkinson's disease (PD), during which the patient is not able to effectively initiate gait or continue walking. The mystery of the FOG phenomenon is still unsolved. Recent studies have revealed abnormalities in cortical activities associated with FOG, which highlights the importance of cortical and cortical-subcortical network dysfunction in PD patients with FOG. In this paper, phase-locking value (PLV) of eight frequency sub-bands between 0.05 Hz and 35 Hz over frontal, motor, and parietal areas [during an ankle dorsiflexion (ADF) task] is used to investigate EEG phase synchronization. PLV was investigated over both superficial and deeper networks by analyzing EEG signals preprocessed with and without Surface Laplacian (SL) spatial filter. Four groups of participants were included: PD patients with severe FOG (N = 5, 5 males), PD patients with mild FOG (N = 7, 6 males), PD patients without FOG (N = 14, 13 males), and healthy age-matched controls (N = 13, 10 males). Fifteen trials were recorded from each participant. At superficial layers, frontoparietal theta phase synchrony was a unique feature present in PD with FOG groups. At deeper networks, significant dominance of interhemispheric frontoparietal alpha phase synchrony in PD with FOG, in contrast to beta phase synchrony in PD without FOG, was identified. Alpha phase synchrony was more distributed in PD with severe FOG, with higher levels of frontoparietal alpha phase synchrony. In addition to FOG-related abnormalities in PLV analysis, phase-amplitude coupling (PAC) analysis was also performed on frequency bands with PLV abnormalities. PAC analysis revealed abnormal coupling between theta and low beta frequency bands in PD with severe FOG at the superficial layers over frontal areas. At deeper networks, theta and alpha frequency bands show high PAC over parietal areas in PD with severe FOG. Alpha and low beta also presented PAC over frontal areas in PD groups with FOG. The results introduced significant phase synchrony differences between PD with and without FOG and provided important insight into a possible unified underlying mechanism for FOG. These results thus suggest that PLV and PAC can potentially be used as EEG-based biomarkers for FOG.