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BACKGROUND: While the cognitive sequelae of traumatic brain injury (TBI) are well known, emotional impairments after TBI are suboptimally characterized. Lack of awareness of emotional difficulties can make self-report unreliable. However, individuals with TBI demonstrate involuntary changes in heart rate variability which may enable objective quantification of emotional dysfunction. METHODS: Sixteen subjects with chronic TBI and 10 age-matched controls were tested on an emotional function battery during which they watched a series of film clips normed to elicit specific positively and negatively valenced emotions: amusement, sexual amusement, sadness, fear and disgust. Subjective responses to the emotional stimuli were also obtained. Additionally, surface electrodes measured cardiac and respiratory signals to compute heart rate variability (HRV), from which measures of parasympathetic activity, the respiratory frequency area (RFA) and sympathetic activity, the low frequency area (LFA), of the HRV frequency spectrum were derived. The Neurobehavioral Rating Scale-Revised (NRS-R) and the King-Devick (KD) test were administered to assess neurobehavioral dysfunction. RESULTS: The two groups showed no differences in subjective ratings of emotional intensity. Subjects with TBI showed significantly decreased sympathetic activity when viewing amusing stimuli and significantly increased sympathetic activity when viewing sad stimuli compared to controls. Most of the subjects did not show agitation, anxiety, depression, blunted affect, emotional withdrawal, decreased motivation or mental fatiguability on the NRS-R. However, 13/16 subjects with TBI demonstrated attention difficulty on the NRS-R which was positively correlated with the increased sympathetic activity during sad stimuli. Both attention difficulty and abnormal autonomic responses to sad stimuli were correlated with the timing on the KD test, which reflected difficulty with visual attention shifting. CONCLUSIONS: The HRV spectrum may be useful to identify subclinical emotional dysfunction in individuals with TBI. Attention difficulites, specifically impairment in visual attention shifting, may contribute to abnormal reactivity to sad stimuli that may be detected and potentially treated to improve emotional function.
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Conscientização/fisiologia , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/psicologia , Transtornos Cognitivos/etiologia , Frequência Cardíaca/fisiologia , Transtornos do Humor/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Transtornos Cognitivos/reabilitação , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Humor/reabilitação , Psicoterapia/métodos , Respiração , Adulto JovemRESUMO
Adaptation of fingertip forces to friction at the grasping surface is necessary to prevent use of inadequate or excessive grip forces. In the current study we investigated the effect of blocking tactile information from the fingertips noninvasively on the adaptation and efficiency of grip forces to surface friction during precision grasp. Ten neurologically intact subjects grasped and lifted an instrumented grip device with 18 different frictional surfaces under three conditions: with bare hands or with a thin layer of plastic (Tegaderm) or an additional layer of foam affixed to the fingertips. The coefficient of friction at the finger-object interface of each surface was obtained for each subject with bare hands and Tegaderm by measuring the slip ratio (grip force/load force) at the moment of slip. We found that the foam layer reduced sensibility for two-point discrimination and pressure sensitivity at the fingertips, but Tegaderm did not. However, Tegaderm reduced static, but not dynamic, tactile discrimination. Adaptation of fingertip grip forces to surface friction measured by the rate of change of peak grip force, and grip force efficiency measured by the grip-load force ratio at lift, showed a proportional relationship with bare hands but were impaired with Tegaderm and foam. Activation of muscles engaged in precision grip also varied with the frictional surface with bare hands but not with Tegaderm and foam. The results suggest that sensitivity for static tactile discrimination is necessary for feedforward and feedback control of grip forces and for adaptive modulation of muscle activity during precision grasp.
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Adaptação Fisiológica , Discriminação Psicológica , Força da Mão , Percepção do Tato , Tato , Adulto , Retroalimentação Fisiológica , Feminino , Dedos/inervação , Dedos/fisiologia , Humanos , Masculino , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Tempo de Reação , Propriedades de SuperfícieRESUMO
The ability to predict the optimal fingertip forces according to object properties before the object is lifted is known as feedforward control, and it is thought to occur due to the formation of internal representations of the object's properties. The control of fingertip forces to objects of different weights has been studied extensively by using a custom-made grip device instrumented with force sensors. Feedforward control is measured by the rate of change of the vertical (load) force before the object is lifted. However, the precise relationship between the rate of change of load force and object weight and how it varies across healthy individuals in a population is not clearly understood. Using sets of 10 different weights, we have shown that there is a log-linear relationship between the fingertip load force rates and weight among neurologically intact individuals. We found that after one practice lift, as the weight increased, the peak load force rate (PLFR) increased by a fixed percentage, and this proportionality was common among the healthy subjects. However, at any given weight, the level of PLFR varied across individuals and was related to the efficiency of the muscles involved in lifting the object, in this case the wrist and finger extensor muscles. These results quantify feedforward control during grasp and lift among healthy individuals and provide new benchmarks to interpret data from neurologically impaired populations as well as a means to assess the effect of interventions on restoration of feedforward control and its relationship to muscular control.
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Dedos/fisiologia , Força da Mão/fisiologia , Modelos Neurológicos , Atividade Motora/fisiologia , Adulto , Feminino , Humanos , Aprendizagem/fisiologia , Modelos Lineares , MasculinoRESUMO
PURPOSE: To understand how the experience of Music Upper Limb Therapy - Integrated (MULT-I) interconnects with the experience of stroke. METHODS: Thematic analysis of semi-structured interviews and video-recorded MULT-I sessions from a larger mixed-methods study. Thirty adults with post-stroke hemiparesis completed pre-intervention interviews, of whom fifteen participated in MULT-I. Thirteen of the participants in MULT-I completed post-intervention interviews. RESULTS: The experience of stroke was characterized by five themes: (1) sudden loss of functional abilities, (2) disrupted participation, (3) desire for independence, (4) emotional distress and the need for support, and (5) difficulty negotiating changes in sense of self. The experience of MULT-I was characterized by three themes: (1) MULT-I activated movement and empowered personal choice, (2) MULT-I created a safe place to process emotional distress and take on challenges, and (3) MULT-I fostered a sense of belonging and a positive transformation in sense of self. These themes combined create a framework which illustrates the process by which MULT-I addressed each challenge described by survivors of stroke, facilitating a positive transformation in sense of self. CONCLUSION: MULT-I promotes physical, emotional, and social wellbeing following a stroke. This integrated approach supports a positive transformation in sense of self. These findings have implications for improving psychosocial well-being post stroke.
The experience of stroke is characterized by disruptions in physical, emotional, and social well-beingSurvivors of stroke describe difficulty obtaining support for emotional distress and experience negative perceptions of their sense of selfMULT-I addresses functional needs post stroke through motivating physical movement and participation, while also supporting autonomy and providing psychosocial support that facilitates a positive transformation in sense of self.
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OBJECTIVE: This study's aims were to refine Music Upper Limb Therapy-Integrated (MULT-I) to create a feasible enriched environment for stroke rehabilitation and compare its biologic and behavioral effects with that of a home exercise program (HEP). DESIGN: This was a randomized mixed-methods study of 30 adults with post-stroke hemiparesis. Serum brain-derived neurotrophic factor and oxytocin levels measured biologic effects, and upper limb function, disability, quality of life, and emotional well-being were assessed as behavioral outcomes. Participant experiences were explored using semistructured interviews. RESULTS: MULT-I participants showed reduced depression from preintervention to postintervention as compared with HEP participants. Brain-derived neurotrophic factor levels significantly increased for MULT-I participants but decreased for HEP participants, with a significant difference between groups after excluding those with post-stroke depression. MULT-I participants additionally improved quality of life and self-perceived physical strength, mobility, activity, participation, and recovery from preintervention to postintervention. HEP participants improved upper limb function. Qualitatively, MULT-I provided psychosocial support and enjoyment, whereas HEP supported self-management of rehabilitation. CONCLUSIONS: Implementation of a music-enriched environment is feasible, reduces post-stroke depression, and may enhance the neural environment for recovery via increases in brain-derived neurotrophic factor levels. Self-management of rehabilitation through an HEP may further improve upper limb function.
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Produtos Biológicos , Musicoterapia , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Adulto , Fator Neurotrófico Derivado do Encéfalo , Depressão/etiologia , Depressão/terapia , Terapia por Exercício/métodos , Humanos , Projetos Piloto , Qualidade de Vida , Recuperação de Função Fisiológica , Reabilitação do Acidente Vascular Cerebral/métodos , Resultado do Tratamento , Extremidade SuperiorRESUMO
Background. High-intensity repetitive training is challenging to provide poststroke. Robotic approaches can facilitate such training by unweighting the limb and/or by improving trajectory control, but the extent to which these types of assistance are necessary is not known. Objective. The purpose of this study was to examine the extent to which robotic path assistance and/or weight support facilitate repetitive 3D movements in high functioning and low functioning subjects with poststroke arm motor impairment relative to healthy controls. Methods. Seven healthy controls and 18 subjects with chronic poststroke right-sided hemiparesis performed 300 repetitions of a 3D circle-drawing task using a 3D Cable-driven Arm Exoskeleton (CAREX) robot. Subjects performed 100 repetitions each with path assistance alone, weight support alone, and path assistance plus weight support in a random order over a single session. Kinematic data from the task were used to compute the normalized error and speed as well as the speed-error relationship. Results. Low functioning stroke subjects (Fugl-Meyer Scale score = 16.6 ± 6.5) showed the lowest error with path assistance plus weight support, whereas high functioning stroke subjects (Fugl-Meyer Scale score = 59.6 ± 6.8) moved faster with path assistance alone. When both speed and error were considered together, low functioning subjects significantly reduced their error and increased their speed but showed no difference across the robotic conditions. Conclusions. Robotic assistance can facilitate repetitive task performance in individuals with severe arm motor impairment, but path assistance provides little advantage over weight support alone. Future studies focusing on antigravity arm movement control are warranted poststroke.
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Exoesqueleto Energizado , Atividade Motora/fisiologia , Avaliação de Processos e Resultados em Cuidados de Saúde , Paresia/reabilitação , Desempenho Psicomotor/fisiologia , Robótica , Reabilitação do Acidente Vascular Cerebral/métodos , Acidente Vascular Cerebral/terapia , Extremidade Superior/fisiopatologia , Adulto , Idoso , Fenômenos Biomecânicos/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paresia/etiologia , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações , Reabilitação do Acidente Vascular Cerebral/instrumentaçãoRESUMO
The brachial plexus is a complex network of peripheral nerves that enables sensing from and control of the movements of the arms and hand. Nowadays, the coordination between the muscles to generate simple movements is still not well understood, hindering the knowledge of how to best treat patients with this type of peripheral nerve injury. To acquire enough information for medical data analysis, physicians conduct motion analysis assessments with patients to produce a rich dataset of electromyographic signals from multiple muscles recorded with joint movements during real-world tasks. However, tools for the analysis and visualization of the data in a succinct and interpretable manner are currently not available. Without the ability to integrate, compare, and compute multiple data sources in one platform, physicians can only compute simple statistical values to describe patient's behavior vaguely, which limits the possibility to answer clinical questions and generate hypotheses for research. To address this challenge, we have developed MOTION BROWSER, an interactive visual analytics system which provides an efficient framework to extract and compare muscle activity patterns from the patient's limbs and coordinated views to help users analyze muscle signals, motion data, and video information to address different tasks. The system was developed as a result of a collaborative endeavor between computer scientists and orthopedic surgery and rehabilitation physicians. We present case studies showing physicians can utilize the information displayed to understand how individuals coordinate their muscles to initiate appropriate treatment and generate new hypotheses for future research.
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BACKGROUND: Few options exist for training arm movements in participants with severe post-stroke hemiparesis who have little active range of motion. The purpose of this study was to test the safety and feasibility of training with a non-powered device, the Bimanual Arm Trainer (BAT), to facilitate motor recovery in individuals with severe hemiparesis. The BAT enabled coupled bimanual training of shoulder external rotation, which is reduced in individuals with severe post-stroke hemiplegia. The rationale for bimanual training was to harness contralesional cortical activity to drive voluntary movement in the affected arm in patients who could barely perform unimanual movements. METHODS: Nine participants with post-stroke hemiparesis, preserved passive range of motion and Modified Ashworth score of <3 in the shoulder and elbow joints, trained with the device for 45 minutes, twice a week for six weeks, and were assessed pre- and post-training. RESULTS: All participants tolerated the training and no adverse events were reported. Participants showed significant improvement in the upper extremity Fugl-Meyer score post-training with an effect size of 0.89. Changes in the flexor synergy pattern accounted for 64.7% of the improvement. Improvement in active range of motion in the paretic limb occurred for both trained and untrained movements. Some participants showed improvement in the time taken to perform selected tasks on the Wolf Motor Function Test post-training. CONCLUSION: The results demonstrate the safety and feasibility of using the Bimanual Arm Trainer to facilitate motor recovery in individuals with severe hemiparesis.
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Stroke is a leading cause of disability worldwide. It leads to a sudden and overwhelming disruption in one's physical body, and alters the stroke survivors' sense of self. Long-term recovery requires that bodily perception, social participation and sense of self are restored; this is challenging to achieve, particularly with a single intervention. However, rhythmic synchronization of movement to external stimuli facilitates sensorimotor coupling for movement recovery, enhances emotional engagement and has positive effects on interpersonal relationships. In this proof-of-concept study, we designed a group music-making intervention, Music Upper Limb Therapy-Integrated (MULT-I), to address the physical, psychological and social domains of rehabilitation simultaneously, and investigated its effects on long-term post-stroke upper limb recovery. The study used a mixed-method pre-post design with 1-year follow up. Thirteen subjects completed the 45-min intervention twice a week for 6 weeks. The primary outcome was reduced upper limb motor impairment on the Fugl-Meyer Scale (FMS). Secondary outcomes included sensory impairment (two-point discrimination test), activity limitation (Modified Rankin Scale, MRS), well-being (WHO well-being index), and participation (Stroke Impact Scale, SIS). Repeated measures analysis of variance (ANOVA) was used to test for differences between pre- and post-intervention, and 1-year follow up scores. Significant improvement was found in upper limb motor impairment, sensory impairment, activity limitation and well-being immediately post-intervention that persisted at 1 year. Activities of daily living and social participation improved only from post-intervention to 1-year follow up. The improvement in upper limb motor impairment was more pronounced in a subset of lower functioning individuals as determined by their pre-intervention wrist range of motion. Qualitatively, subjects reported new feelings of ownership of their impaired limb, more spontaneous movement, and enhanced emotional engagement. The results suggest that the MULT-I intervention may help stroke survivors re-create their sense of self by integrating sensorimotor, emotional and interoceptive information and facilitate long-term recovery across multiple domains of disability, even in the chronic stage post-stroke. Randomized controlled trials are warranted to confirm the efficacy of this approach. CLINICAL TRIAL REGISTRATION: National Institutes of Health, clinicaltrials.gov, NCT01586221.
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In order to develop evidence-based rehabilitation protocols post-stroke, one must first reconcile the vast heterogeneity in the post-stroke population and develop protocols to facilitate motor learning in the various subgroups. The main purpose of this study is to show that auditory constraints interact with the stage of recovery post-stroke to influence motor learning. We characterized the stages of upper limb recovery using task-based kinematic measures in 20 subjects with chronic hemiparesis. We used a bimanual wrist extension task, performed with a custom-made wrist trainer, to facilitate learning of wrist extension in the paretic hand under four auditory conditions: (1) without auditory cueing; (2) to non-musical happy sounds; (3) to self-selected music; and (4) to a metronome beat set at a comfortable tempo. Two bimanual trials (15 s each) were followed by one unimanual trial with the paretic hand over six cycles under each condition. Clinical metrics, wrist and arm kinematics, and electromyographic activity were recorded. Hierarchical cluster analysis with the Mahalanobis metric based on baseline speed and extent of wrist movement stratified subjects into three distinct groups, which reflected their stage of recovery: spastic paresis, spastic co-contraction, and minimal paresis. In spastic paresis, the metronome beat increased wrist extension, but also increased muscle co-activation across the wrist. In contrast, in spastic co-contraction, no auditory stimulation increased wrist extension and reduced co-activation. In minimal paresis, wrist extension did not improve under any condition. The results suggest that auditory task constraints interact with stage of recovery during motor learning after stroke, perhaps due to recruitment of distinct neural substrates over the course of recovery. The findings advance our understanding of the mechanisms of progression of motor recovery and lay the foundation for personalized treatment algorithms post-stroke.