RESUMO
BACKGROUND: The escalating impact of diabetes and its complications, including diabetic foot ulcers (DFUs), presents global challenges in quality of life, economics, and resources, affecting around half a billion people. DFU healing is hindered by hyperglycemia-related issues and diverse diabetes-related physiological changes, necessitating ongoing personalized care. Artificial intelligence and clinical research strive to address these challenges by facilitating early detection and efficient treatments despite resource constraints. This study establishes a standardized framework for DFU data collection, introducing a dedicated case report form, a comprehensive dataset named Zivot with patient population clinical feature breakdowns and a baseline for DFU detection using this dataset and a UNet architecture. RESULTS: Following this protocol, we created the Zivot dataset consisting of 269 patients with active DFUs, and about 3700 RGB images and corresponding thermal and depth maps for the DFUs. The effectiveness of collecting a consistent and clean dataset was demonstrated using a bounding box prediction deep learning network that was constructed with EfficientNet as the feature extractor and UNet architecture. The network was trained on the Zivot dataset, and the evaluation metrics showed promising values of 0.79 and 0.86 for F1-score and mAP segmentation metrics. CONCLUSIONS: This work and the Zivot database offer a foundation for further exploration of holistic and multimodal approaches to DFU research.
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Aprendizado Profundo , Diabetes Mellitus , Pé Diabético , Humanos , Pé Diabético/diagnóstico , Inteligência Artificial , Metadados , Qualidade de VidaRESUMO
Background: Functional electrical stimulation (FES) of paralyzed muscles can facilitate walking after spinal cord injury (SCI). Objectives: To test the orthotic effects of different FES walking protocols on lower joint kinematics and walking speed. Methods: Three adults with incomplete SCI participated in this study. Their lower extremity motor scores and 10-meter walk test results were as follows: subject A: 50, 1.05 m/s, subject B: 44, 0.29 m/s, and subject C: 32, 0.27 m/s. Participants completed four conditions of over-ground walking including no FES and three bilateral FES-walking protocols as follows: multi-muscle stimulation (stimulation of quadriceps and gastrocnemius in the stance phase, and hamstring and tibialis anterior in the swing phase), drop foot (tibialis anterior stimulation), and flexor withdrawal (common peroneal nerve stimulation). The FES system obtained gait phase information from foot switches located under the individuals' heels. Three-dimensional kinematic analysis was undertaken to measure minimum toe clearance (MTC); ankle, knee, and hip range of motion (ROM); stride length; and stride speed. Results: Compared to no-FES walking, MTC increased during drop foot (all subjects), flexor withdrawal (subjects A and B), and multi-muscle stimulation (subjects B and C) protocols. A significant decrease in ankle ROM was seen with drop foot (all subjects), flexor withdrawal (subjects A), and multi-muscle stimulation (subjects A and C) protocols. Hip ROM increased with drop foot (subjects B and C), flexor withdrawal (subject B), and multi-muscle stimulation (subject C) protocols. Conclusion: Three FES walking protocols induced positive kinematic changes as indicated by increased MTC, decreased ankle ROM, and increased hip ROM during walking in subjects with incomplete SCI.
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Terapia por Estimulação Elétrica , Traumatismos da Medula Espinal , Adulto , Humanos , Caminhada/fisiologia , Marcha/fisiologia , Estimulação Elétrica , Músculo Esquelético/fisiologia , Terapia por Estimulação Elétrica/métodosRESUMO
INTRODUCTION: The integration of brain-computer interface (BCI) and functional electrical stimulation (FES) has brought about a new rehabilitation strategy: BCI-controlled FES therapy or BCI-FEST. During BCI-FEST, the stimulation is triggered by the patient's brain activity, often monitored using electroencephalography (EEG). Several studies have demonstrated that BCI-FEST can improve voluntary arm and hand function after an injury, but few studies have investigated the FES interference in EEG signals during BCI-FEST. In this study, we evaluated the effectiveness of band-pass filters, used to extract the BCI-relevant EEG components, in simultaneously reducing stimulation interference. METHODS: We used EEG data from eight participants recorded during BCI-FEST. Additionally, we separately recorded the FES signal generated by the stimulator to estimate the spectral components of the FES interference, and extract the noise in time domain. Finally, we calculated signal-to-noise ratio (SNR) values before and after band-pass filtering, for two types of movements practiced during BCI-FEST: reaching and grasping. RESULTS: The SNR values were greater after filtering across all participants for both movement types. For reaching movements, mean SNR values increased between 1.31 dB and 36.3 dB. Similarly, for grasping movements, mean SNR values increased between 2.82 dB and 40.16 dB, after filtering. CONCLUSIONS: Band-pass filters, used to isolate EEG frequency bands for BCI application, were also effective in reducing stimulation interference. In addition, we provide a general algorithm that can be used in future studies to estimate the frequencies of FES interference as a function of the selected stimulation pulse frequency, FSTIM , and the EEG sampling rate, FS .
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Interfaces Cérebro-Computador , Terapia por Estimulação Elétrica , Eletroencefalografia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão Sinal-Ruído , Traumatismos da Medula Espinal/reabilitaçãoRESUMO
CONTEXT/OBJECTIVE: Functional electrical stimulation (FES) is commonly used in rehabilitation to generate electrically-induced muscle contractions. FES has been shown to assist in the recovery of voluntary motor functions after stroke or spinal cord injury. However, discomfort associated with FES can motivate patients to withdraw their participation from FES therapy despite its benefits. To address this issue, a functional electrical stimulator, called MyndMove™ (MyndTec Inc., Canada), has been developed to generate more comfortable contractions than conventional stimulators. DESIGN: Cross-sectional, interventional, with two treatment arms. SETTING: A laboratory within a rehabilitation center. PARTICIPANTS: Twelve able-bodied participants. INTERVENTION: FES delivered with two different stimulators, MyndMove™ and Compex Motion (Compex, Switzerland), during muscle contractions of high, moderate and low stimulation intensity. OUTCOME MEASURES: Comfort-related preference to a given stimulator and the discomfort score rated through a Numeric Rating Scale (NRS-101) for both stimulators. RESULTS: Participants perceived a reduction in discomfort during high-intensity stimulation generated using MyndMove™. In addition, MyndMove™ stimulations were preferred in 60% of all contractions. The reduction in discomfort associated with MyndMove™ might be due the fact that MyndMove™ delivers less charge to generate contractions of equivalent intensity, compared to Compex Motion. CONCLUSION: Reducing discomfort during FES may help in generating stronger and more clinically useful contractions, increasing accessibility of FES therapy to include individuals with low tolerance to FES.
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Terapia por Estimulação Elétrica , Traumatismos da Medula Espinal , Estudos Transversais , Estimulação Elétrica , Humanos , Contração Muscular , Músculo Esquelético , Traumatismos da Medula Espinal/terapia , TorqueRESUMO
CONTEXT/OBJECTIVE: Integrating brain-computer interface (BCI) technology with functional electrical stimulation therapy (FEST) is an emerging strategy for upper limb motor rehabilitation after spinal cord injury (SCI). Despite promising results, the combined use of these technologies (BCI-FEST) in clinical practice is minimal. To address this issue, we developed KITE-BCI, a BCI system specifically designed for clinical application and integration with dynamic FEST. In this paper, we report its technical features and performance. In addition, we discuss the differences in distributions of the BCI- and therapist-triggered stimulation latencies. DESIGN: Two single-arm 40-session interventional studies to test the feasibility of BCI-controlled FEST for upper limb motor rehabilitation in individuals with cervical SCI. SETTING: Rehabilitation programs within the University and Lyndhurst Centres of the Toronto Rehabilitation Institute - University Health Network, Toronto, Canada. PARTICIPANTS: Five individuals with sub-acute (< 6 months post-injury) SCI at the C4-C5 level, AIS B-D, and three individuals with chronic (> 24 months post-injury) SCI at C4 level, AIS B-C. OUTCOME MEASURES: We measured BCI setup duration, and to characterize the performance of KITE-BCI, we recorded BCI sensitivity, defined as the percentage of successful BCI activations out of the total number of cued movements. RESULTS: The overall BCI sensitivities were 74.46% and 79.08% for the sub-acute and chronic groups, respectively. The average KITE-BCI setup duration across the two studies was 11 min and 13 s. CONCLUSION: KITE-BCI demonstrates a clinically viable single-channel BCI system for integration with FEST resulting in a versatile technology-enhanced upper limb motor rehabilitation strategy after SCI.
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Interfaces Cérebro-Computador , Terapia por Estimulação Elétrica , Traumatismos da Medula Espinal , Humanos , Movimento , Traumatismos da Medula Espinal/terapia , Extremidade SuperiorRESUMO
BACKGROUND: Clinical applications of conventional functional electrical stimulation (FES) administered via a single electrode are limited by rapid onset neuromuscular fatigue. "Sequential" (SEQ) stimulation, involving the rotation of pulses between multiple active electrodes, has been shown to reduce fatigue compared to conventional FES. However, there has been limited adoption of SEQ in research and clinical settings. METHODS: The SEQ adapter is a small, battery-powered device that transforms the output of any commercially available electrical stimulator into SEQ stimulation. We examined the output of the adaptor across a range of clinically relevant stimulation pulse parameters to verify the signal integrity preservation ability of the SEQ adapter. Pulse frequency, amplitude, and duration were varied across discrete states between 4 and 200 Hz, 10 and100 mA, and 50 and 2000 µs, respectively. RESULTS: A total of 420 trials were conducted, with 80 stimulation pulses per trial. The SEQ adapter demonstrated excellent preservation of signal integrity, matching the pulse characteristics of the originating stimulator within 1% error. The SEQ adapter operates as expected at pulse frequencies up to 160 Hz, failing at a frequency of 200 Hz. CONCLUSION: The SEQ adapter represents an effective and low-cost solution to increase the utilization of SEQ in existing rehabilitation paradigms.
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Terapia por Estimulação Elétrica , Fadiga Muscular , Estimulação Elétrica , Eletrodos , Músculo EsqueléticoRESUMO
Brain-machine interfaces allow neuroscientists to causally link specific neural activity patterns to a particular behaviour. Thus, in addition to their current clinical applications, brain-machine interfaces can also be used as a tool to investigate neural mechanisms of learning and plasticity in the brain. Decades of research using such brain-machine interfaces have shown that animals (non-human primates and rodents) can be operantly conditioned to self-regulate neural activity in various motor-related structures of the brain. Here, we ask whether the human brain, a complex interconnected structure of over 80 billion neurons, can learn to control itself at the most elemental scale-a single neuron. We used the unique opportunity to record single units in 11 individuals with epilepsy to explore whether the firing rate of a single (direct) neuron in limbic and other memory-related brain structures can be brought under volitional control. To do this, we developed a visual neurofeedback task in which participants were trained to move a block on a screen by modulating the activity of an arbitrarily selected neuron from their brain. Remarkably, participants were able to volitionally modulate the firing rate of the direct neuron in these previously uninvestigated structures. We found that a subset of participants (learners), were able to improve their performance within a single training session. Successful learning was characterized by (i) highly specific modulation of the direct neuron (demonstrated by significantly increased firing rates and burst frequency); (ii) a simultaneous decorrelation of the activity of the direct neuron from the neighbouring neurons; and (iii) robust phase-locking of the direct neuron to local alpha/beta-frequency oscillations, which may provide some insights in to the potential neural mechanisms that facilitate this type of learning. Volitional control of neuronal activity in mnemonic structures may provide new ways of probing the function and plasticity of human memory without exogenous stimulation. Furthermore, self-regulation of neural activity in these brain regions may provide an avenue for the development of novel neuroprosthetics for the treatment of neurological conditions that are commonly associated with pathological activity in these brain structures, such as medically refractory epilepsy.
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Encéfalo/fisiologia , Aprendizagem/fisiologia , Neurorretroalimentação/métodos , Neurônios/fisiologia , Volição/fisiologia , Adulto , Interfaces Cérebro-Computador , Eletrocorticografia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
STUDY DESIGN: Feasibility and preliminary clinical efficacy analysis in a single-arm interventional study. OBJECTIVES: We developed a brain-computer interface-triggered functional electrical stimulation therapy (BCI-FEST) system for clinical application and conducted an interventional study to (1) assess its feasibility and (2) understand its potential clinical efficacy for the rehabilitation of reaching and grasping in individuals with sub-acute spinal cord injury (SCI). SETTING: Spinal cord injury rehabilitation hospital-Toronto Rehabilitation Institute-Lyndhurst Centre. METHODS: Five participants with sub-acute SCI completed between 12 and 40 1-hour sessions using BCI-FEST, with up to 5 sessions a week. We assessed feasibility by measuring participants' compliance with treatment, the occurrence of adverse events, BCI sensitivity, and BCI setup duration. Clinical efficacy was assessed using Functional Independence Measure (FIM) and Spinal Cord Independence Measure (SCIM), as primary outcomes. In addition, we used two upper-limb function tests as secondary outcomes. RESULTS: On average, participants completed 29.8 sessions with no adverse events. Only one of the 149 sessions was affected by technical challenges. The BCI sensitivity ranged between 69.5 and 80.2%, and the mean BCI setup duration was ~11 min. In the primary outcomes, three out of five participants showed changes greater than the minimal clinically important differences (MCIDs). Additionally, the mean change in secondary outcome measures met the threshold for detecting MCID as well; four out of five participants achieved MCID. CONCLUSIONS: The new BCI-FEST intervention is safe, feasible, and promising for the rehabilitation of reaching and grasping after SCI.
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Interfaces Cérebro-Computador , Terapia por Estimulação Elétrica , Traumatismos da Medula Espinal , Estudos de Viabilidade , Força da Mão , Humanos , Traumatismos da Medula Espinal/terapiaRESUMO
PURPOSE: Functional electrical stimulation (FES), through repetitive training (FES-therapy) or continuous assistance (neuro-prosthesis), can restore motor function after paralysis due to spinal cord injury or stroke. With current technology, patients are often incapable of independently applying FES, thereby limiting its use. Novel FES-garments with embedded stimulation electrodes were developed in collaboration with Myant, Canada, to address this problem. The purpose of this study was to collect the views of future end-users to inform the refinement of the device design and to obtain insights on subsequent commercialization of this rehabilitation and assistive technology. METHODS: A qualitative study was undertaken to determine the needs of potential users (patients and clinicians; n = 19). Participant took part in interviews or focus groups after a presentation of the garments. An inductive content analysis was used to generate the themes from the data and identify data saturation. RESULTS: The identified themes and sub-themes were: (1) User Perspectives: users' characteristics (needs, limitations), expected benefits (beliefs), and anticipated problems (fears); (2) Device Design: technical features, usability, and disadvantages of the garment, cables, stimulator, software, and interface; (3) Acquisition Process: organizational procedures (acquisition and adoption steps); and (4) Business Model: financial and strategic aspects to facilitate commercialization and support users. CONCLUSIONS: The insights obtained from end-users and clinicians provide guidelines to optimize the development of novel FES-garments, and strategies for bringing the device to the market. The themes identified can serve to inform other rehabilitation and assistive technology developers with processes and ideas on how to meet these groups' needs.IMPLICATIONS FOR REHABILITATIONParticipants with neurological paralysis have interest and critical views on new rehabilitation and assistive technology, and the repercussions of using new technologies to address their function, health and wellbeing.The FES-garment design presented appeared acceptable to the end-users, pending resolution of certain shortcomings (wiring, operating duration, robustness, easiness to don and doff).End-users and clinicians had specific views regarding the acquisition process of new technologies (training, customization, and follow-up/support), which are important to take into consideration to ensure broad stakeholders uptake.
Assuntos
Atitude Frente a Saúde , Vestuário , Terapia por Estimulação Elétrica/instrumentação , Desenho de Equipamento , Traumatismos da Medula Espinal/reabilitação , Reabilitação do Acidente Vascular Cerebral/instrumentação , Dispositivos Eletrônicos Vestíveis , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do PacienteRESUMO
Delivering short trains of electric pulses to the muscles and nerves can elicit action potentials resulting in muscle contractions. When the stimulations are sequenced to generate functional movements, such as grasping or walking, the application is referred to as functional electrical stimulation (FES). Implications of the motor and sensory recruitment of muscles using FES go beyond simple contraction of muscles. Evidence suggests that FES can induce short- and long-term neurophysiological changes in the central nervous system by varying the stimulation parameters and delivery methods. By taking advantage of this, FES has been used to restore voluntary movement in individuals with neurological injuries with a technique called FES therapy (FEST). However, long-lasting cortical re-organization (neuroplasticity) depends on the ability to synchronize the descending (voluntary) commands and the successful execution of the intended task using a FES. Brain-computer interface (BCI) technologies offer a way to synchronize cortical commands and movements generated by FES, which can be advantageous for inducing neuroplasticity. Therefore, the aim of this review paper is to discuss the neurophysiological mechanisms of electrical stimulation of muscles and nerves and how BCI-controlled FES can be used in rehabilitation to improve motor function.
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Interfaces Cérebro-Computador , Terapia por Estimulação Elétrica/métodos , Músculos , Sistema Nervoso , Próteses e Implantes , Reabilitação/métodos , HumanosRESUMO
Functional electrical stimulation is a technique to produce functional movements after paralysis. Electrical discharges are applied to a person's muscles making them contract in a sequence that allows performing tasks such as grasping a key, holding a toothbrush, standing, and walking. The technology was developed in the sixties, during which initial clinical use started, emphasizing its potential as an assistive device. Since then, functional electrical stimulation has evolved into an important therapeutic intervention that clinicians can use to help individuals who have had a stroke or a spinal cord injury regain their ability to stand, walk, reach, and grasp. With an expected growth in the aging population, it is likely that this technology will undergo important changes to increase its efficacy as well as its widespread adoption. We present here a series of functional electrical stimulation systems to illustrate the fundamentals of the technology and its applications. Most of the concepts continue to be in use today by modern day devices. A brief description of the potential future of the technology is presented, including its integration with brain-computer interfaces and wearable (garment) technology.
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Terapia por Estimulação Elétrica , Atividade Motora , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/terapia , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , HumanosRESUMO
Functional electrical stimulation therapy (FEST) is a state-of-the-art treatment for retraining motor function after neurological injuries. Recent literature suggests that FEST can be further improved with brain-computer interface (BCI) technology. In this case study, we assessed the feasibility of using BCI-triggered FEST (BCI-FEST) to restore upper limb function in a 57-yr-old man with severe left hemiplegia resulting from a stroke 6 yrs before enrollment in the study. The intervention consisted of two blocks of forty 1-hr BCI-FEST sessions, with three sessions delivered weekly. During therapy, a single-channel BCI was used to trigger the stimulation programmed to facilitate functional movements. The measure of the feasibility of the BCI-FEST included assessing the implementation and safety of the intervention. Clinical improvements were assessed using (a) Functional Independence Measure, (b) Action Research Arm Test, (c) Toronto Rehabilitation Institute - Hand Function Test, and (d) Fugl-Meyer Assessment Upper Extremity test. Upon completion of 80 therapy sessions, 14-, 17-, and 18-point changes were recorded on Action Research Arm Test, Fugl-Meyer Assessment Upper Extremity test, and Toronto Rehabilitation Institute - Hand Function Test, respectively. The participant also indicated improvement as demonstrated by his ability to perform various day-to-day tasks. The results suggest that BCI-FEST is safe and viable.
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Interfaces Cérebro-Computador , Terapia por Estimulação Elétrica , Hemiplegia/fisiopatologia , Hemiplegia/reabilitação , Reabilitação do Acidente Vascular Cerebral/métodos , Extremidade Superior/fisiopatologia , Estudos de Viabilidade , Humanos , Masculino , Pessoa de Meia-Idade , Recuperação de Função FisiológicaRESUMO
BACKGROUND: Currently, the mainstay of treatment in patients diagnosed with major depressive disorder (MDD) requiring medical attention is second generation anti-depressants. However, about 40% of patients treated with second-generation anti-depressants do not respond to initial treatment and approximately 70% do not achieve remission during the first-step treatment. There are a few non-pharmacological options available, but none have shown consistently positive results. There is a need for an intervention that is relatively easy to administer, produces consistently positive results and is associated with minimal side effects. In the current study, we assessed the feasibility of using transcutaneous Functional Electrical Stimulation Therapy (FEST) of the facial muscles, as a tool for improving depressive symptoms in individuals with MDD. RESULTS: Ten (10) individuals with moderate to severe MDD received three FEST sessions/week for a minimum of 10 to a maximum of 40 sessions. All study participants completed the required 10 therapy sessions, and 5 of the 10 participants completed additional 30 (totalling 40) FEST sessions. There were no adverse events or concerns regarding compliance to therapy. We found statistically significant improvements on Hamilton Rating Scale for Depression (HDS) and Inventory of Depressive Symptomatology (IDS) measures. However, no significant improvements were found on Positive and Negative Affect Scale and 10-point Visual Analogue Scale scales. Participants reported improvements in sleeping patterns, and this correlated with statistically significant improvements on sleep parameters of HDS and IDS measures. CONCLUSION: This study indicates that facial FEST is an acceptable, practical, and safe treatment in individuals with MDD. We provide preliminary evidence to show improvements in depressive symptoms following a minimum of 10 FEST sessions.
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Transtorno Depressivo Maior/fisiopatologia , Transtorno Depressivo Maior/terapia , Terapia por Estimulação Elétrica , Músculos Faciais/fisiopatologia , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Resultado do TratamentoRESUMO
Context: Following spinal cord injury (SCI) at the cervical or upper-thoracic level, orthostatic hypotension (OH) is observed in 13-100% of patients. This study aimed to test the feasibility of conducting a randomized controlled trial combining a dynamic tilt-table (Erigo®) and functional electrical stimulation (FES) to mitigate OH symptoms in the subacute phase after SCI. Design: Pilot study. Setting: A tertiary rehabilitation hospital. Participants: Inpatients who had a C4-T6 SCI (AIS A-D) less than 12 weeks before recruitment, and reported symptoms of OH in their medical chart. Interventions: Screening sit-up test to determine eligibility, then 1 assessment session and 3 intervention sessions with Erigo® and FES for eligible participants. Outcome measures: Recruitment rate, duration of assessment and interventions, resources used, blood pressure, and Calgary Presyncope Form (OH symptoms). Results: Amongst the 232 admissions, 148 inpatient charts were reviewed, 11 inpatients met all inclusion criteria, 7 participated in a screening sit-up test, and 2 exhibited OH. Neither of the two participants recruited in the pilot study was able to fully complete the assessment and intervention sessions due to scheduling issues (i.e. limited available time). Conclusion: This pilot study evidenced the non-feasibility of the clinical trial as originally designed, due to the low recruitment rate and the lack of available time for research in participant's weekday schedule. OH in the subacute phase after SCI was less prevalent and less incapacitating than expected. Conventional management and spontaneous resolution of symptoms appeared sufficient to mitigate OH in most patients with subacute SCI.
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Hipotensão Ortostática/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Traumatismos da Medula Espinal/complicações , Adulto , Idoso , Terapia por Estimulação Elétrica/efeitos adversos , Terapia por Estimulação Elétrica/métodos , Estudos de Viabilidade , Feminino , Humanos , Hipotensão Ortostática/etiologia , Masculino , Pessoa de Meia-Idade , Traumatismos da Medula Espinal/reabilitação , Teste da Mesa Inclinada/efeitos adversos , Teste da Mesa Inclinada/métodosRESUMO
Ventral intermediate thalamic deep brain stimulation is a standard therapy for the treatment of medically refractory essential tremor and tremor-dominant Parkinson's disease. Despite the therapeutic benefits, the mechanisms of action are varied and complex, and the pathophysiology and genesis of tremor remain unsubstantiated. This intraoperative study investigated the effects of high frequency microstimulation on both neuronal firing and tremor suppression simultaneously. In each of nine essential tremor and two Parkinson's disease patients who underwent stereotactic neurosurgery, two closely spaced (600 µm) microelectrodes were advanced into the ventral intermediate nucleus. One microelectrode recorded action potential firing while the adjacent electrode delivered stimulation trains at 100 Hz and 200 Hz (2-5 s, 100 µA, 150 µs). A triaxial accelerometer was used to measure postural tremor of the contralateral hand. At 200 Hz, stimulation led to 68 ± 8% (P < 0.001) inhibition of neuronal firing and a 53 ± 5% (P < 0.001) reduction in tremor, while 100 Hz reduced firing by 26 ± 12% (not significant) with a 17 ± 6% (P < 0.05) tremor reduction. The degree of cell inhibition and tremor suppression were significantly correlated (P < 0.001). We also found that the most ventroposterior stimulation sites, closest to the border of the ventral caudal nucleus, had the best effect on tremor. Finally, prior to the inhibition of neuronal firing, microstimulation caused a transient driving of neuronal activity at stimulus onset (61% of sites), which gave rise to a tremor phase reset (73% of these sites). This was likely due to activation of the excitatory glutamatergic cortical and cerebellar afferents to the ventral intermediate nucleus. Temporal characteristics of the driving responses (duration, number of spikes, and onset latency) significantly differed between 100 Hz and 200 Hz stimulation trains. The subsequent inhibition of neuronal activity was likely due to synaptic fatigue. Thalamic neuronal inhibition seems necessary for tremor reduction and may function in effect as a thalamic filter to uncouple thalamo-cortical from cortico-spinal reflex loops. Additionally, our findings shed light on the gating properties of the ventral intermediate nucleus within the cerebello-thalamo-cortical tremor network, provide insight for the optimization of deep brain stimulation technologies, and may inform controlled clinical studies for assessing optimal target locations for the treatment of tremor.
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Estimulação Encefálica Profunda/métodos , Tremor/fisiopatologia , Tremor/terapia , Potenciais de Ação/fisiologia , Idoso , Mapeamento Encefálico , Cerebelo/fisiopatologia , Tremor Essencial/fisiopatologia , Feminino , Humanos , Masculino , Microeletrodos , Pessoa de Meia-Idade , Neurônios/fisiologia , Procedimentos Neurocirúrgicos/métodos , Doença de Parkinson/fisiopatologia , Núcleos Talâmicos/fisiopatologia , Tálamo/fisiopatologia , Núcleos Ventrais do Tálamo/fisiopatologiaRESUMO
OBJECTIVES: To determine the efficacy of functional electrical stimulation therapy assisted walking (FES-T) compared to a conventional aerobic and resistance training (CONV) with respect to bone biomarkers and lower extremity bone strength outcomes among adults with chronic motor incomplete spinal cord injury (SCI). DESIGN: Parallel group randomized controlled trial ( www.clinicaltrials.gov - NCT0020196819). Site: Tertiary academic rehabilitation centre in Canada. METHODS: Adults with chronic (≥18 months) motor incomplete SCI (C2-T12 AIS C-D) were consented and randomized to FES-T or CONV training for 45 minutes thrice-weekly for 4 months. Osteocalcin (OC), ß-cross laps (CTX) and sclerostin were assessed at baseline, and 4 months. Similarly, total hip, distal femur and proximal tibia region bone mineral density (BMD) via DXA (4500A, Hologic Inc. Waltham, MA, USA) and tibia bone quality via pQCT (Stratec XCT-2000, Mezintecknik, Pforzheim, Germany) were assessed at baseline, 4, and 12 months. Between group differences were analyzed using repeated measures general linear models. RESULTS: Thirty-four participants (17 FES-T, 17 CONV) consented and were randomized, 27 participants completed the 4-month intervention and 12-month outcome assessments. Participants in the FES-T arm had a decrease in CTX and a significant increase in OC at intervention completion (P<0.05). Significant biomarker changes were not observed in the CONV group. No within or between group differences from baseline were observed in sclerostin or bone strength. CONCLUSIONS: Four months of FES-T improved bone turnover (increase in OC and decrease in CTX) but not bone strength among individuals with chronic SCI. Future, long term FES-T may augment lower extremity bone strength.
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Densidade Óssea , Proteínas Morfogenéticas Ósseas/sangue , Terapia por Estimulação Elétrica/métodos , Osteocalcina/sangue , Traumatismos da Medula Espinal/terapia , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Idoso , Biomarcadores/sangue , Terapia por Estimulação Elétrica/efeitos adversos , Terapia por Exercício/efeitos adversos , Terapia por Exercício/métodos , Feminino , Marcadores Genéticos , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Stroke is the leading cause of long-term disability. Stroke survivors seldom improve their upper-limb function when their deficit is severe, despite recently developed therapies. PURPOSE: This study aims to assess the efficacy of functional electrical stimulation therapy in improving voluntary reaching and grasping after severe hemiplegia. METHOD: A post hoc analysis of a previously completed randomized control trial ( clinicaltrials.gov , No. NCT00221078) was carried out involving 21 participants with severe upper-limb hemiplegia (i.e., Fugl-Meyer Assessment-Upper Extremity [FMA-UE] ≤ 15) resulting from stroke. FINDINGS: Functional Independence Measure Self-Care subscores increased 22.8 (±6.7) points in the intervention group and 9 (±6.5) in the control group, following 40 hr of equal-intensity therapy. FMA-UE score changes were 27.2 (±13.5) and 5.3 (±11.0) for the intervention and control groups, respectively. IMPLICATIONS: The results may represent the largest upper-limb function improvements in any stroke population to date, especially in those with severe upper-limb deficit.
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Terapia por Estimulação Elétrica , Hemiplegia/fisiopatologia , Hemiplegia/terapia , Reabilitação do Acidente Vascular Cerebral/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia por Exercício , Feminino , Hemiplegia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Movimento , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações , Extremidade Superior/fisiopatologiaRESUMO
Balance training in the aquatic environment is often used in rehabilitation practice to improve static and dynamic balance. Although aquatic therapy is widely used in clinical practice, we still lack evidence on how immersion in water actually impacts postural control. We examined how postural sway measured using centre of pressure and trunk acceleration parameters are influenced by the aquatic environment along with the effects of visual information. Our results suggest that the aquatic environment increases postural instability, measured by the centre of pressure parameters in the time-domain. The mean velocity and area were more significantly affected when individuals stood with eyes closed in the aquatic environment. In addition, a more forward posture was assumed in water with eyes closed in comparison to standing on land. In water, the low frequencies of sway were more dominant compared to standing on dry land. Trunk acceleration differed in water and dry land only for the larger upper trunk acceleration in mediolateral direction during standing in water. This finding shows that the study participants potentially resorted to using their upper trunk to compensate for postural instability in mediolateral direction. Only the lower trunk seemed to change acceleration pattern in anteroposterior and mediolateral directions when the eyes were closed, and it did so depending on the environment conditions. The increased postural instability and the change in postural control strategies that the aquatic environment offers may be a beneficial stimulus for improving balance control.
Assuntos
Aceleração , Movimento , Equilíbrio Postural , Tronco/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Hidroterapia , Masculino , Adulto JovemRESUMO
INTRODUCTION: Transcutaneous neuromuscular electrical stimulation (NMES) can generate muscle contractions for rehabilitation and exercise. However, NMES-evoked contractions are limited by fatigue when they are delivered "conventionally" (CONV) using a single active electrode. Researchers have developed "sequential" (SEQ) stimulation, involving rotation of pulses between multiple "aggregated" (AGGR-SEQ) or "distributed" (DISTR-SEQ) active electrodes, to reduce fatigue (torque-decline) by reducing motor unit discharge rates. The primary objective was to compare fatigue-related outcomes, "potentiation," "variability," and "efficiency" between CONV, AGGR-SEQ, and DISTR-SEQ stimulation of knee extensors in healthy participants. METHODS: Torque and current were recorded during testing with fatiguing trains using each NMES type under isometric and isokinetic (180°/s) conditions. RESULTS: Compared with CONV stimulation, SEQ techniques reduced fatigue-related outcomes, increased potentiation, did not affect variability, and reduced efficiency. CONCLUSIONS: SEQ techniques hold promise for reducing fatigue during NMES-based rehabilitation and exercise; however, optimization is required to improve efficiency. Muscle Nerve 56: 271-281, 2017.
Assuntos
Fadiga/fisiopatologia , Fadiga/reabilitação , Contração Muscular/fisiologia , Estimulação Elétrica Nervosa Transcutânea , Adulto , Biofísica , Eletrodos , Eletromiografia , Feminino , Humanos , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Torque , Adulto JovemRESUMO
Trunk muscles are responsible for maintaining trunk stability during sitting. However, the effects of anticipation of perturbation on trunk muscle responses are not well understood. The objectives of this study were to identify the responses of trunk muscles to sudden support surface translations and quantify the effects of anticipation of direction and time of perturbation on the trunk neuromuscular responses. Twelve able-bodied individuals participated in the study. Participants were seated on a kneeling chair and support surface translations were applied in the forward and backward directions with and without direction and time of perturbation cues. The trunk started moving on average approximately 40ms after the perturbation. During unanticipated perturbations, average latencies of the trunk muscle contractions were in the range between 103.4 and 117.4ms. When participants anticipated the perturbations, trunk muscle latencies were reduced by 16.8±10.0ms and the time it took the trunk to reach maximum velocity was also reduced, suggesting a biomechanical advantage caused by faster muscle responses. These results suggested that trunk muscles have medium latency responses and use reflexive mechanisms. Moreover, anticipation of perturbation decreased trunk muscles latencies, suggesting that the central nervous system modulated readiness of the trunk based on anticipatory information.