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Journal of Neurologic Physical Therapy... Oct 2016Impairments in metabolic capacity and economy (O2cost) are hallmark characteristics of locomotor dysfunction following stroke. High-intensity (aerobic) training has been... (Comparative Study)
Comparative Study
BACKGROUND AND PURPOSE
Impairments in metabolic capacity and economy (O2cost) are hallmark characteristics of locomotor dysfunction following stroke. High-intensity (aerobic) training has been shown to improve peak oxygen consumption in this population, with fewer reports of changes in O2cost. However, particularly in persons with subacute stroke, inconsistent gains in walking function are observed with minimal associations with gains in metabolic parameters. The purpose of this study was to evaluate changes in aerobic exercise performance in participants with subacute stroke following high-intensity variable stepping training as compared with conventional therapy.
METHODS
A secondary analysis was performed on data from a randomized controlled trial comparing high-intensity training with conventional interventions, and from the pilot study that formed the basis for the randomized controlled trial. Participants 1 to 6 months poststroke received 40 or fewer sessions of high-intensity variable stepping training (n = 21) or conventional interventions (n = 12). Assessments were performed at baseline (BSL), posttraining, and 2- to 3-month follow-up and included changes in submaximal (Equation is included in full-text article.)O2 ((Equation is included in full-text article.)O2submax) and O2cost at fastest possible treadmill speeds and peak speeds at BSL testing.
RESULTS
Significant improvements were observed in (Equation is included in full-text article.)O2submax with less consistent improvements in O2cost, although individual responses varied substantially. Combined changes in both (Equation is included in full-text article.)O2submax and (Equation is included in full-text article.)O2 at matched peak BSL speeds revealed stronger correlations to improvements in walking function as compared with either measure alone.
DISCUSSION AND CONCLUSIONS
High-intensity stepping training may elicit significant improvements in (Equation is included in full-text article.)O2submax, whereas changes in both peak capacity and economy better reflect gains in walking function. Providing high-intensity training to improve locomotor and aerobic exercise performance may increase the efficiency of rehabilitation sessions.Video Abstract available for more insights from the authors (see Supplemental Digital Content, http://links.lww.com/JNPT/A142).
Topics: Exercise; Exercise Test; Exercise Therapy; Humans; Motor Skills Disorders; Paresis; Randomized Controlled Trials as Topic; Stroke; Stroke Rehabilitation
PubMed: 27632078
DOI: 10.1097/NPT.0000000000000147 -
Neurorehabilitation and Neural Repair Sep 2019. We investigated interhemispheric interactions in stroke survivors by measuring transcranial magnetic stimulation (TMS)-evoked cortical coherence. We tested the effect...
. We investigated interhemispheric interactions in stroke survivors by measuring transcranial magnetic stimulation (TMS)-evoked cortical coherence. We tested the effect of TMS on interhemispheric coherence during rest and active muscle contraction and compared coherence in stroke and older adults. We evaluated the relationships between interhemispheric coherence, paretic motor function, and the ipsilateral cortical silent period (iSP). . Participants with (n = 19) and without (n = 14) chronic stroke either rested or maintained a contraction of the ipsilateral hand muscle during simultaneous recordings of evoked responses to TMS of the ipsilesional/nondominant (i/ndM1) and contralesional/dominant (c/dM1) primary motor cortex with EEG and in the hand muscle with EMG. We calculated pre- and post-TMS interhemispheric beta coherence (15-30 Hz) between motor areas in both conditions and the iSP duration during the active condition. . During active i/ndM1 TMS, interhemispheric coherence increased immediately following TMS in controls but not in stroke. Coherence during active cM1 TMS was greater than iM1 TMS in the stroke group. Coherence during active iM1 TMS was less in stroke participants and was negatively associated with measures of paretic arm motor function. Paretic iSP was longer compared with controls and negatively associated with clinical measures of manual dexterity. There was no relationship between coherence and. iSP for either group. No within- or between-group differences in coherence were observed at rest. . TMS-evoked cortical coherence during hand muscle activation can index interhemispheric interactions associated with poststroke motor function and potentially offer new insights into neural mechanisms influencing functional recovery.
Topics: Adult; Aged; Aged, 80 and over; Cerebral Cortex; Electroencephalography; Electromyography; Female; Functional Laterality; Hand; Humans; Male; Middle Aged; Motor Cortex; Motor Skills; Muscle Contraction; Muscle, Skeletal; Paresis; Stroke; Stroke Rehabilitation; Transcranial Magnetic Stimulation
PubMed: 31328638
DOI: 10.1177/1545968319862552 -
Journal of Neuroengineering and... Jul 2022For patients with post-stroke upper limb impairments, the currently available clinical measurement instruments are inadequate for reliable quantification of multiple...
BACKGROUND
For patients with post-stroke upper limb impairments, the currently available clinical measurement instruments are inadequate for reliable quantification of multiple impairments, such as muscle weakness, abnormal synergy, changes in elastic joint properties and spasticity. Robotic devices to date have successfully achieved precise and accurate quantification but are often limited to the measurement of one or two impairments. Our primary aim is to develop a robotic device that can effectively quantify four main motor impairments of the elbow.
METHODS
The robotic device, Shoulder Elbow Perturbator, is a one-degree-of-freedom device that can simultaneously manipulate the elbow joint and support the (partial) weight of the human arm. Upper limb impairments of the elbow were quantified based on four experiments on the paretic arm in ten stroke patients (mean age 65 ± 10 yrs, 9 males, post-stroke) and the non-dominant arm in 20 healthy controls (mean age 65 ± 14 yrs, 6 males). The maximum strength of elbow flexor and elbow extensor muscles was measured isometrically at 90-degree elbow flexion. The maximal active extension angle of the elbow was measured under different arm weight support levels to assess abnormal synergy. Torque resistance was analyzed during a slow (6°/s) passive elbow rotation, where the elbow moved from the maximal flexion to maximal extension angle and back, to assess elastic joint properties. The torque profile was evaluated during fast (100°/s) passive extension rotation of the elbow to estimate spasticity.
RESULTS
The ten chronic stroke patients successfully completed the measurement protocol. The results showed impairment values outside the 10 and 90 percentile reference intervals of healthy controls. Individual patient profiles were determined and illustrated in a radar figure, to support clinicians in developing targeted treatment plans.
CONCLUSION
The Shoulder Elbow Perturbator can effectively quantify the four most important impairments of the elbow in stroke patients and distinguish impairment scores of patients from healthy controls. These results are promising for objective and complete quantification of motor impairments of the elbow and monitoring patient prognosis. Our newly developed Shoulder Elbow Perturbator can therefore in the future be employed to evaluate treatment effects by comparing pre- and post-treatment assessments.
Topics: Aged; Elbow; Elbow Joint; Electromyography; Humans; Male; Middle Aged; Motor Disorders; Muscle Spasticity; Paresis; Stroke
PubMed: 35864498
DOI: 10.1186/s12984-022-01050-2 -
Clinical Neurophysiology : Official... Nov 2017Stroke is one of the leading causes of physical disability due to damage of the motor cortex or the corticospinal tract. In the present study we set out to investigate...
OBJECTIVE
Stroke is one of the leading causes of physical disability due to damage of the motor cortex or the corticospinal tract. In the present study we set out to investigate the role of adaptations in the corticospinal pathway for motor recovery during the subacute phase after stroke.
METHODS
We examined 19 patients with clinically diagnosed stroke and 18 controls. The patients had unilateral mild to moderate weakness of the hand. Each patient attended two sessions at approximately 3days (acute) and 38days post stroke (subacute). Task-related changes in the communication between motor cortex and muscles were evaluated from coupling in the frequency domain between EEG and EMG during movement of the paretic hand.
RESULTS
Corticomuscular coherence (CMC) and intermuscular coherence (IMC) were reduced in patients as compared to controls. Paretic hand motor performance improved within 4-6weeks after stroke, but no change was observed in CMC or IMC.
CONCLUSIONS
CMC and IMC were reduced in patients in the early phase after stroke. However, changes in coherence do not appear to be an efficient marker for early recovery of hand function following stroke.
SIGNIFICANCE
This is the first study to demonstrate sustained reduced coherence in acute and subacute stroke.
Topics: Adult; Aged; Aged, 80 and over; Brain Ischemia; Female; Hand Strength; Humans; Male; Middle Aged; Motor Cortex; Muscle, Skeletal; Paresis; Pyramidal Tracts; Stroke
PubMed: 28987993
DOI: 10.1016/j.clinph.2017.08.033 -
Stroke Dec 2019Background and Purpose- Two large, randomized trials indicated that sphenopalatine ganglion (SPG) stimulation improves final disability outcome in acute anterior...
Background and Purpose- Two large, randomized trials indicated that sphenopalatine ganglion (SPG) stimulation improves final disability outcome in acute anterior circulation patients with ischemic stroke with confirmed cortical involvement. This study evaluated 2 refinements in SPG stimulation treatment technique: (1) SPG electrode placement with real-time optical tracking guidance; and (2) stimulation intensity comfortable tolerance level selection using non-noxious facial physiological markers. Methods- This study was a single, active arm trial at 4 centers, enrolling patients with anterior circulation ischemic stroke, National Institutes of Health Stroke Scale 1 to 6 including arm weakness subitem score ≥1, not receiving recanalization therapies, and within 24 hours of onset. Stimulation level was set based on ipsilateral facial tingling sensation or lacrimation. SPG stimulation effects were assessed by measuring volumetric blood flow in the ipsilateral common carotid artery by ultrasound and grasp and pinch strength in the affected hand before and during stimulation, and by change in National Institutes of Health Stroke Scale from day 1 to 7. Results- Among 50 enrolled patients, age was median 66 years (interquartile range, 60-74), 44% were female, National Institutes of Health Stroke Scale median was 5 (interquartile range, 4-5), and median onset-to-screening time was 18 hours (interquartile range, 9-20). Median implantation skin-to-skin time was 4 minutes (interquartile range, 3-7), and all 50 implants were placed correctly. Comfortable tolerance level was found based on physiological biomarkers in 96% of patients, including 86% in the optimal, low-medium intensity range. SPG stimulation significantly increased common carotid artery peak systolic and end-diastolic blood flow (44%, <0.0001; and 52%, <0.0001) and improved pinch strength (42%, <0.0001) and grasp strength (26%, <0.0001). Degree of National Institutes of Health Stroke Scale recovery by day 7 was greater than in matched historic controls, median 75% versus 50%, =0.0003. Conclusions- SPG stimulator placement with real-time optical tracking guidance was fast and accurate, and selection of stimulation intensity levels based on non-noxious facial tingling and lacrimation was feasible in nearly all patients. SPG stimulation led to cervico-cranial blood flow augmentation and improved hand motor function. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT03551093.
Topics: Aged; Anterior Cerebral Artery; Arm; Brain Infarction; Carotid Artery, Common; Cerebrovascular Circulation; Electric Stimulation Therapy; Female; Ganglia, Parasympathetic; Hand Strength; Humans; Implantable Neurostimulators; Male; Middle Aged; Paresis; Pinch Strength; Prosthesis Implantation; Ultrasonography
PubMed: 31739771
DOI: 10.1161/STROKEAHA.119.027177 -
Annual Review of Vision Science Oct 2016Disrupting binocular vision in infancy leads to strabismus and oftentimes to a variety of associated visual sensory deficits and oculomotor abnormalities. Investigation...
Disrupting binocular vision in infancy leads to strabismus and oftentimes to a variety of associated visual sensory deficits and oculomotor abnormalities. Investigation of this disorder has been aided by the development of various animal models, each of which has advantages and disadvantages. In comparison to studies of binocular visual responses in cortical structures, investigations of neural oculomotor structures that mediate the misalignment and abnormalities of eye movements have been more recent, and these studies have shown that different brain areas are intimately involved in driving several aspects of the strabismic condition, including horizontal misalignment, dissociated deviations, A and V patterns of strabismus, disconjugate eye movements, nystagmus, and fixation switch. The responses of cells in visual and oculomotor areas that potentially drive the sensory deficits and also eye alignment and eye movement abnormalities follow a general theme of disrupted calibration, lower sensitivity, and poorer specificity compared with the normally developed visual oculomotor system.
Topics: Animals; Brain; Disease Models, Animal; Eye Movements; Macaca mulatta; Oculomotor Muscles; Paresis; Strabismus; Vision, Binocular
PubMed: 28532347
DOI: 10.1146/annurev-vision-111815-114335 -
Neural Plasticity 2021This study presents single-fiber electromyography (EMG) analysis for assessment of paretic muscle changes after stroke. Single-fiber action potentials (SFAPs) were...
This study presents single-fiber electromyography (EMG) analysis for assessment of paretic muscle changes after stroke. Single-fiber action potentials (SFAPs) were recorded from the first dorsal interosseous (FDI) muscle bilaterally in 12 individuals with hemiparetic stroke. The SFAP parameters, including the negative peak duration and the peak-peak amplitude, were measured and further used to estimate muscle fiber diameter through a model based on the quadratic function. The SFAP parameters, fiber density, and muscle fiber diameter derived from the model were compared between the paretic and contralateral muscles. The results show that SFAPs recorded from the paretic muscle had significantly smaller negative peak duration than that from the contralateral muscle. As a result, the derived muscle fiber diameter of the paretic muscle was significantly smaller than that of the contralateral muscle. The fiber density of the paretic muscle was significantly higher than that of the contralateral muscle. These results provide further evidence of remodeled motor units after stroke and suggest that paretic muscle weakness can be due to both complex central and peripheral neuromuscular alterations.
Topics: Action Potentials; Aged; Electromyography; Female; Humans; Male; Middle Aged; Muscle Fibers, Skeletal; Muscle, Skeletal; Paresis; Stroke
PubMed: 34434227
DOI: 10.1155/2021/3045990 -
Journal of Applied Physiology... Feb 2019Aerobic exercise may acutely prime the brain to be more responsive to rehabilitation, thus facilitating neurologic recovery from conditions like stroke. This aerobic... (Comparative Study)
Comparative Study Randomized Controlled Trial
Aerobic exercise may acutely prime the brain to be more responsive to rehabilitation, thus facilitating neurologic recovery from conditions like stroke. This aerobic priming effect could occur through multiple mechanisms, including upregulation of circulating brain-derived neurotrophic factor (BDNF), increased corticospinal excitability, and decreased intracortical inhibition. However, optimal exercise parameters for targeting these mechanisms are poorly understood. This study tested the effects of exercise intensity on acute BDNF and neurophysiological responses. Sixteen ambulatory persons >6 mo poststroke performed three different 20-min exercise protocols in random order, approximately 1 wk apart, including the following: 1) treadmill high-intensity interval training (HIT-treadmill); 2) seated-stepper HIT (HIT-stepper); and 3) treadmill moderate-intensity continuous exercise (MCT-treadmill). Serum BDNF and transcranial magnetic stimulation measures of paretic lower limb excitability and inhibition were assessed at multiple time points during each session. Compared with MCT-treadmill, HIT-treadmill elicited significantly greater acute increases in circulating BDNF and corticospinal excitability. HIT-stepper initially showed BDNF responses similar to HIT-treadmill but was no longer significantly different from MCT-treadmill after decreasing the intensity in reaction to two hypotensive events. Additional regression analyses showed that an intensity sufficient to accumulate blood lactate appeared to be important for eliciting BDNF responses, that the interval training approach may have facilitated the corticospinal excitability increases, and that the circulating BDNF response was (negatively) related to intracortical inhibition. These findings further elucidate neurologic mechanisms of aerobic exercise and inform selection of optimal exercise-dosing parameters for enhancing acute neurologic effects. NEW & NOTEWORTHY Acute exercise-related increases in circulating BDNF and corticospinal excitability are thought to prime the brain for learning. Our data suggest that these responses can be obtained among persons with stroke using short-interval treadmill high-intensity interval training, that a vigorous aerobic intensity sufficient to generate lactate accumulation is needed to increase BDNF, that interval training facilitates increases in paretic quadriceps corticospinal excitability, and that greater BDNF response is associated with lesser intracortical inhibition response.
Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Brain-Derived Neurotrophic Factor; Cross-Over Studies; Exercise Therapy; Female; Humans; Lower Extremity; Male; Middle Aged; Muscle, Skeletal; Paresis; Pyramidal Tracts; Recovery of Function; Stroke; Stroke Rehabilitation; Time Factors; Treatment Outcome; Young Adult
PubMed: 30571289
DOI: 10.1152/japplphysiol.00594.2018 -
Developmental Medicine and Child... Feb 2020To characterize fatigue in children with hemiparesis with perinatal stroke and explore associations with measures of motor performance and corticospinal excitability.
AIM
To characterize fatigue in children with hemiparesis with perinatal stroke and explore associations with measures of motor performance and corticospinal excitability.
METHOD
Forty-five children (16 females, 29 males), aged 6 to 18 years (mean [SD] 12y [4]), with magnetic resonance imaging-confirmed perinatal stroke participated. Associations between fatigue (Pediatric Quality of Life Inventory Version 3.0 cerebral palsy module fatigue subscale), motor performance (Assisting Hand Assessment [AHA], Box and Blocks Test, grip strength), and excitability of corticospinal projections to both hands were examined using ranked tests of correlation, robust regression, and the Mann-Whitney U test.
RESULTS
Nearly half of the participants (n=21) reported experiencing fatigue in the previous month. Function in the less affected hand (Box and Blocks Test, grip strength) was correlated with fatigue scores. Participants with preserved ipsilateral projections to the more affected hand had less fatigue, and scores correlated with the excitability of these projections. Fatigue scores were not associated with age, sex, or AHA score.
INTERPRETATION
Fatigue is common in children with hemiparesis with perinatal stroke and is associated with motor performance and the presence and excitability of ipsilateral corticospinal projections from the contralesional hemisphere to the more affected hand.
WHAT THIS PAPER ADDS
Fatigue is common in children with hemiparesis with perinatal stroke. Fatigue was associated with motor performance and strength in the less affected, but not the more affected, hand. Fatigue was associated with the presence and excitability of ipsilateral corticospinal projections from the contralesional hemisphere.
Topics: Adolescent; Child; Cohort Studies; Fatigue; Female; Hand; Humans; Male; Movement; Paresis; Pyramidal Tracts; Stroke
PubMed: 31222717
DOI: 10.1111/dmcn.14273 -
Neurorehabilitation and Neural Repair Jul 2020. Previous studies suggest that individuals poststroke can achieve substantial gains in walking function following high-intensity locomotor training (LT). Recent...
. Previous studies suggest that individuals poststroke can achieve substantial gains in walking function following high-intensity locomotor training (LT). Recent findings also indicate practice of variable stepping tasks targeting locomotor deficits can mitigate selected impairments underlying reduced walking speeds. The goal of this study was to investigate alterations in locomotor biomechanics following 3 different LT paradigms. . This secondary analysis of a randomized trial recruited individuals 18 to 85 years old and >6 months poststroke. We compared changes in spatiotemporal, joint kinematics, and kinetics following up to 30 sessions of high-intensity (>70% heart rate reserve [HRR]) LT of variable tasks targeting paretic limb and balance impairments (high-variable, HV), high-intensity LT focused only on forward walking (high-forward, HF), or low-intensity LT (<40% HRR) of variable tasks (low-variable, LV). Sagittal spatiotemporal and joint kinematics, and concentric joint powers were compared between groups. Regressions and principal component analyses were conducted to evaluate relative contributions or importance of biomechanical changes to between and within groups. . Biomechanical data were available on 50 participants who could walk ≥0.1 m/s on a motorized treadmill. Significant differences in spatiotemporal parameters, kinematic consistency, and kinetics were observed between HV and HF versus LV. Resultant principal component analyses were characterized by paretic powers and kinematic consistency following HV, while HF and LV were characterized by nonparetic powers. . High-intensity LT results in greater changes in kinematics and kinetics as compared with lower-intensity interventions. The results may suggest greater paretic-limb contributions with high-intensity variable stepping training that targets specific biomechanical deficits. . https://clinicaltrials.gov/ Unique Identifier: NCT02507466.
Topics: Adult; Aged; Humans; Middle Aged; Biomechanical Phenomena; Exercise Therapy; Gait Disorders, Neurologic; Lower Extremity; Outcome Assessment, Health Care; Paresis; Stroke; Stroke Rehabilitation; Walking; Adolescent; Young Adult; Aged, 80 and over; Randomized Controlled Trials as Topic
PubMed: 32507027
DOI: 10.1177/1545968320929675