Interventions to Change Movement Behaviors After Stroke: A Systematic Review and Meta-analysis.

OBJECTIVE: This systematic review aimed to determine which interventions increase physical activity (PA) and decrease sedentary behavior (SB) based on objective measures of movement behavior in individuals with stroke. DATA SOURCES: The PubMed (Medline), EMBASE, Scopus, CINAHL (EBSCO), and Web of Science databases were searched for articles published up to January 3, 2023. STUDY SELECTION: The StArt 3.0.3 BETA software was used to screen titles, abstracts, and full texts for studies with randomized controlled trial designs; individuals with stroke (≥18 years of age); interventions aimed at increasing PA or decreasing SB; and objective measurement instruments. DATA EXTRACTION: Data extraction was standardized, considering participants and assessments of interest. The risk of bias and quality of evidence of the included studies were assessed. DATA SYNTHESIS: Twenty-eight studies involving 1855 patients were included. Meta-analyses revealed that in the post-stroke acute/subacute phase, exercise interventions combined with behavior change techniques (BCTs) increased both daily steps (standardized mean difference [SMD]=0.65, P=.0002) and time spent on moderate-to-vigorous intensity physical activities (MVPAs) duration of PA (SMD=0.68, P=.0004) with moderate-quality evidence. In addition, interventions based only on BCTs increased PA levels with very low-quality evidence (SMD (low-intensity physical activity)=0.36, P=.02; SMD (MVPA)=0.56, P=.0004) and decreased SB with low-quality evidence (SMD=0.48, P=.03). In the post-stroke chronic phase, there is statistical significance in favor of exercise-only interventions in PA frequency (steps/day) with moderate-quality evidence (SMD=0.68, P=.002). In general, the risk of bias in the included studies was low. CONCLUSIONS: In the acute/subacute phase after stroke, the use of BCTs combined with exercise can increase the number of daily steps and time spent on MVPA. In contrast, in the post-stroke chronic phase, exercise-only interventions resulted in a significant increase in daily steps.

Characterization of intracranial compliance in healthy subjects using a noninvasive method - results from a multicenter prospective observational study.

PURPOSE: An FDA-approved non-invasive intracranial pressure (ICP) monitoring system enables the assessment of ICP waveforms by revealing and analyzing their morphological variations and parameters associated with intracranial compliance, such as the P2/P1 ratio and time-to-peak (TTP). The aim of this study is to characterize intracranial compliance in healthy volunteers across different age groups. METHODS: Healthy participants, both sexes, aged from 9 to 74 years old were monitored for 5 min in the supine position at 0º. Age was stratified into 4 groups: children (≤ 7 years); young adults (18 ≤ age ≤ 44 years); middle-aged adults (45 ≤ age ≤ 64 years); older adults (≥ 65 years). The data obtained was the non-invasive ICP waveform, P2/P1 ratio and TTP. RESULTS: From December 2020 to February 2023, 188 volunteers were assessed, of whom 104 were male, with a median (interquartile range) age of 41 (29-51), and a median (interquartile range) body mass index of 25.09 (22.57-28.04). Men exhibited lower values compared to women for both the P2/P1 ratio and TTP (p < 0.001). There was a relative rise in both P2/P1 and TTP as age increased (p < 0.001). CONCLUSIONS: The study revealed that the P2/P1 ratio and TTP are influenced by age and sex in healthy individuals, with men displaying lower values than women, and both ratios increasing with age. These findings suggest potential avenues for further research with larger and more diverse samples to establish reference values for comparison in various health conditions. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (RBR-9nv2h42), retrospectively registered 05/24/2022. UTN: U1111-1266-8006.

Hemispheric lateralization, endothelial function, and arterial compliance in chronic post-stroke individuals: A cross-sectional exploratory study.

Purpose/Aim: Cardiovascular function is controlled and regulated by a functional brain-heart axis. Although the exact mechanism is not fully understood, several studies suggest a hemispheric asymmetry in the neural control of cardiovascular function. Thus, the purpose of this study was to examine whether endothelial function and arterial compliance differ between individuals with left- and right-sided strokes.Materials and Methods: This was a cross-sectional exploratory study. Thirty individuals more than 6 months after stroke participated in the study. The endothelial function was assessed by ultrasound-measured flow-mediated dilation of the nonparetic arm brachial artery (baFMD). The arterial stiffness was assessed by measuring carotid-femoral pulse wave velocity (cfPWV) and central aortic pulse wave analysis [augmentation index (AIx), augmentation index normalized to a heart rate of 75 bpm (AIx@75) and reflection magnitude (RM)] using applanation tonometry. Results: Participants with right-sided stroke had worse endothelial function than those with left-sided stroke. This difference (baFMD = 2.51%) was significant (p = 0.037), and it represented a medium effect size (r = 0.38). Likewise, they had higher arterial stiffness than those with left-sided stroke. This difference (AIx = 10%; RM = 7%) was significant (p = 0.011; p = 0.012), and it represented a medium effect size (r = 0.48; r = 0.47).Conclusions: Our findings suggest that individuals with right-sided stroke have reduced endothelial function and arterial compliance compared to those with left-sided stroke. These data may indicate that those with right-sided strokes are more susceptible to cardiovascular events.

Noninvasive Intracranial Pressure Monitoring in Chronic Stroke Patients with Sedentary Behavior: A Pilot Study.

OBJECTIVE: This study aimed to correlate the P2/P1 ratio of intracranial pressure waveforms with sedentary behavior during the chronic stage of stroke. MATERIALS AND METHODS: Eight patients from São Carlos, Brazil, who had hemiparesis and stroke onset within the previous 6 months, participated in this study. To monitor their intracranial pressure, we used noninvasive Brain4Care® intracranial pressure monitoring during a postural change maneuver involving 15 min in a supine position and 15 min in an orthostatic position. The patients' sedentary behavior was continually monitored at home using a StepWatch Activity Monitor™ for 1 week. Moreover, the patients completed the International Physical Activity Questionnaire before and after using the StepWatch Activity Monitor™. RESULTS: In the supine and orthostatic positions, the P2/P1 ratios were 0.84 ± 0.14 and 0.98 ± 0.17, respectively. The percentage of time spent in inactivity was 71 ± 11%, and the number of steps walked per day was 4220 ± 2239. We found a high positive correlation (r = 0.881, p = 0.004) between the P2/P1 ratio and the percentage of time spent in inactivity. CONCLUSION: This preliminary study showed a correlation between sedentary behavior and cerebral compliance. Thus, monitoring of intracranial pressure during the late stage of a stroke could guide the clinician's treatment to reduce sedentary behavior and the risks of recurrent stroke and cardiovascular diseases.

Adiponectin Concentration and Chronic Stroke Individuals, Associations with Body Composition, Physical Activity Levels and Lipid Profile: A Cross-Sectional Explorative Study.

OBJECTIVE: Higher adiponectin concentration has been associated with the presence of sarcopenia in individuals with cardiovascular diseases. Post-stroke individuals presented higher adiponectin concentrations than non-stroke ones. However, no previous study has investigated the association between the adiponectin concentration and skeletal muscle mass in post-stroke individuals. On the other hand, higher adiponectin concentration has been associated with a more favorable lipid profile and the physical activity level might regulate adiponectin concentration. These associations have not been studied in this population. Thus, the main objective of this study was to determine whether the adiponectin concentration is associated with: (1) body composition; (2) lipid profile; and (3) physical activity level in chronic post-stroke individuals. MATERIALS AND METHODS: This study was a correlational, cross-sectional exploratory study. Data on body composition and lipid profile were collected using a bioelectrical impedance analyzer (InBody® 720) and an automated method analyzer (CELL-DYN Ruby), respectively. The physical activity level was measured by the StepWatch® Activity Monitor and the serum adiponectin concentration was analyzed using an enzyme-linked immunosorbent assay kit. Correlation analyses were made using Spearman's rank correlation coefficient (rs). RESULTS: Twenty-one post-stroke participants took part in the study. The adiponectin concentration was associated with the following: skeletal muscle mass (rs = -0.78), skeletal muscle mass index (rs = -0.75) and high-density lipoprotein (rs = 0.43). CONCLUSIONS: A greater adiponectin concentration is associated with a lower skeletal muscle mass and a higher high-density lipoprotein level in chronic post-stroke individuals, but not with physical activity levels.

Correction to: Effect of aerobic exercise prior to modified constraint-induced movement therapy outcomes in individuals with chronic hemiparesis: a study protocol for a randomized clinical trial.

Following publication of the original article [1], the authors reported an error in Table 2 wherein the item numbering in the first column is wrong.

Effect of aerobic exercise prior to modified constraint-induced movement therapy outcomes in individuals with chronic hemiparesis: a study protocol for a randomized clinical trial.

BACKGROUND: Recovery of upper limb function in individuals after a stroke remains challenging. Modified constraint-induced movement therapy (m-CIMT) has strong evidence for increasing the use and recovery of sensorimotor function of the paretic upper limb. Recent studies have shown that priming with aerobic exercise prior to task-specific training potentiates upper limb recovery in individuals with stroke. This protocol describes a randomized clinical trial designed to determine whether priming with moderate-high intensity aerobic exercise prior to m-CIMT will improve the manual dexterity of the paretic upper limb in individuals with chronic hemiparesis. METHODS: Sixty-two individuals with chronic hemiparesis will be randomized into two groups: Aerobic exercise + m-CIMT or Stretching + m-CIMT. m-CIMT includes 1) restraint of the nonparetic upper limb for 90% of waking hours, 2) intensive task-oriented training of the paretic upper limb for 3 h/day for 10 days and 3) behavior interventions for improving treatment adherence. Aerobic exercise will be conducted on a stationary bicycle at intervals of moderate to high intensity. Participants will be evaluated at baseline, 3, 30, and 90 days postintervention by the following instruments: Motor Activity Log, Nottingham Sensory Assessment, Wolf Motor Function Test, Box and Block Test, Nine-Hole Peg Test, Stroke Specific Quality of Life Scale and three-dimensional kinematics. The data will be tested for normality and homogeneity. Parametric data will be analyzed by two-way ANOVA with repeated measures and Bonferroni's adjustment. For nonparametric data, the Friedman test followed by the Wilcoxon test with Bonferroni's adjustment will be used to compare the ratings for each group. To compare the groups in each assessment, the Mann-Whitney test will be used. DISCUSSION: This study will provide valuable information about the effect of motor priming for fine upper limb skill improvement in people with chronic poststroke hemiparesis, bringing new evidence about the association of two therapies commonly used in clinical practice. TRIAL REGISTRATION: This trial was retrospectively registered (registration number RBR-83pwm3 ) on 07 May 2018.

Effects of mesenchymal stromal cells on type 1 diabetes mellitus rat muscles.

INTRODUCTION: Type 1 diabetes mellitus (DM) causes marked skeletal muscle atrophy. Mesenchymal stromal cells (MSC) are an attractive therapy to avoid diabetic complications because of their ability to modify the microenvironment at sites of tissue injury. The objective of this study was to evaluate the effects of MSC transplantation on muscle adaptation caused by diabetes. METHODS: DM was induced by streptozotocin (STZ), and the diabetic animals received systemic MSC transplantation. The von Frey test and footprint analysis were used to assess sensation and sensory motor performance, respectively. Tibialis anterior muscles were investigated by morphology; molecular markers atrogin-1/muscle RING-finger protein-1, nuclear factor κB/p38 mitogen-activated protein kinase, tumor necrosis-like weak inducer of apoptosis/fibroblast growth factor-inducible 14, myostatin, myogenic differentiation 1, and insulin-like growth factor 1 were also assessed. RESULTS: MSC transplantation improved sensation and walking performance and also decreased muscle fibrosis in DM rats by modulating atrogenes but did not prevent muscle atrophy. DISCUSSION: MSCs can reduce muscle and functional complications that result from type 1 DM in rats. Muscle Nerve 58: 583-591, 2018.

Kinematic Analysis of a Drinking Task in Chronic Hemiparetic Patients Using Features Analysis and Statistical Parametric Mapping.

OBJECTIVE: To compare sitting posture and movement strategies between chronic hemiparetic and healthy subjects while performing a drinking task, using statistical parametric mapping (SPM) and feature analysis. DESIGN: Cross-sectional study. SETTING: A university physical therapy department. PARTICIPANTS: Participants (N=26) consisted of chronic hemiparetic (n=13) and healthy individuals (n=13) matched for sex and age. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The drinking task was divided into phases: reaching, transporting the glass to mouth, transporting the glass to table, and returning to initial position. An SPM 2-sample t test was used to compare the entire kinematic waveforms of different joint angles (trunk, scapulothoracic, humerothoracic, elbow). Joint angles at the beginning and end of the motion, movement time, peak velocity timing, trajectory deviation, normalized integrated jerk, and range of motion were extracted from the motion data. Group differences for these parameters were analyzed using independent t tests. RESULTS: At the static posture and beginning of the reaching phase, patients showed a shoulder position more deviated from the midline and externally rotated with increased scapula protraction, medial rotation, anterior tilting, trunk anterior flexion and inclination to the paretic side. Altered spatiotemporal variables throughout the task were found in all phases, except for the returning phase. Patients returned to a similar posture as the task onset, except for the scapula, which was normalized after the reaching phase. CONCLUSIONS: Chronic hemiparetic subjects showed more deviations in the proximal joints during seated posture and reaching. However, the scapular movement drew nearer to the healthy individuals' patterns after the first phase, showing an interesting point to consider in rehabilitation programs.

Midfemoral Bone Volume of Walking Subjects with Chronic Hemiparesis Post Stroke.

BACKGROUND AND PURPOSE: Muscle and bone form a functional unit. Residual physical poststroke impairments such as muscle weakness, spasticity, and decrease in function can promote metabolic bone changes. Moreover, muscle strength can influence this process. Thus, the purpose of the present study was to investigate bone volume and mobility performance in subjects with chronic hemiparesis post stroke. METHODS: A cross-sectional study was performed on 14 subjects post stroke who were paired with healthy controls. Bone volume, isometric muscle performance, and mobility levels were measured. Midfemoral bone volumes were determined using magnetic resonance imaging, and muscular performance was measured by dynamometry. Mobility was measured using the Timed Up and Go Test and the 10-Meter Walk Test. RESULTS: Regarding bone volume total, there was no difference in the medullary and cortical groups (P ≥ .05). During torque peak isometric flexion, the paretic group was significantly different compared with the other groups (P = .001). However, the control presented no difference compared with the nonparetic limb (P = .40). With regard to the extension isometric torque peak, the paretic limb was significantly different compared with the nonparetic (P = .033) and the control (P = .001) limbs, and the control was different from the nonparetic limb (P = .045). Bone volume variables correlated with the isometric torque peak. CONCLUSIONS: Chronic hemiparetic subjects maintain bone geometry compared with healthy volunteers matched by age, body mass index, and gender. The correlation between bone volume midfemoral structures and knee isometric torque was possible.

Decreased Brain-Derived Neurotrophic Factor Serum Concentrations in Chronic Post-Stroke Subjects.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) plays a critical role in sensorimotor recovery after a stroke. However, few studies have assessed the circulating BDNF levels in post-stroke humans to understand its changes. This study was conducted to measure BDNF serum concentrations in subjects with chronic hemiparesis, as well as to correlate serum concentrations with age, post-stroke time, total score of Stroke Specific Quality of Life Scale (SS-QOL), mobility subscale score, and motor function of SS-QOL. METHODS: Seventeen chronic post-stroke subjects matched by age and gender with healthy controls took part in the study. Personal data (age, hemiparesis side, and post-stroke time) were collected, and a physical examination (weight, height, body mass index) and SS-QOL assessment were carried out. On the same day, after the initial evaluation, venous blood samples were collected from the chronic post-stroke subjects and the healthy subjects. The BDNF serum concentrations were measured blindly by enzyme-linked immunosorbent assay. RESULTS: Subjects with chronic hemiparesis presented a decrease in BDNF serum compared with healthy subjects (P < .01). There was no correlation between BDNF serum levels with post-stroke time, age or quality of life, mobility, and the upper extremity motor function (P > .05). BDNF concentrations are related to structural and functional recovery after stroke; thus, this reduction is important to understand the rehabilitation process more clearly. However, more studies are needed considering the genetic variations and other tools to assess motor impairment and functional independence. CONCLUSION: Chronic post-stroke subjects presented a decrease in BDNF serum concentrations, without a correlation with post-stroke time, age, and quality of life.

Joint position sense is bilaterally reduced for shoulder abduction and flexion in chronic hemiparetic individuals.

BACKGROUND: The stroke is the leading cause of adult disability in the world. One of the main complaints of individuals post-stroke refers to the loss of function of the upper limb, as evidenced during the performance of activities of daily living. This difficulty may be related to an important component of sensorimotor control, joint position sense, a submodality of proprioception. OBJECTIVES: To investigate whether the proprioception of both shoulders of chronic hemiparetic patients is altered during abduction and flexion. METHODS: Thirteen subjects with chronic hemiparesis due to ischemic stroke and 13 healthy subjects matched for gender and age was included. The joint sense position was assessed using a dynamometer. Absolute error for shoulder abduction and flexion at the 30 and 60° was calculated. RESULTS: No difference was found between the paretic and non-paretic limbs in movements at both 30 and 60°. Higher values of absolute error for both paretic and non-paretic limbs compared to the control were observed during abduction at 30 and at 60°. CONCLUSIONS: Chronic ischemic post-stroke patients have bilateral proprioceptive deficits in the shoulder during abduction and flexion. But these deficits are dependent on the movement performed and the angle tested. The results demonstrate the need to include bilateral exercises and/or visual feedback in the rehabilitation program.

Measurement properties of activity monitoring for a rehabilitation (AMoR) platform in post-stroke individuals in a simulated home environment.

AIM: The aim of this study was to evaluate the measurement properties of activity monitoring for a rehabilitation (AMoR) platform for step counting, time spent in sedentary behavior, and postural changes during activities of daily living (ADLs) in a simulated home environment. METHODS: Twenty-one individuals in the post-stroke chronic phase used the AMoR platform during an ADL protocol and were monitored by a video camera. Spearman's correlation coefficient, mean absolute percent error (MAPE), intraclass correlation coefficient (ICC), and Bland-Altman plot analyses were used to estimate the validity and reliability between the AMoR platform and the video for step counting, time spent sitting/lying, and postural changes from sit-to-stand (SI-ST) and sit-to-stand (ST-SI). RESULTS: Validity of the platform was observed with very high correlation values for step counting (rs = 0.998) and time spent sitting/lying (rs = 0.992) and high correlation for postural change of SI-ST (rs = 0.850) and ST-SI (rs = 0.851) when compared to the video. An error percentage above 5% was observed only for the SI-ST postural change (7.13%). The ICC values show excellent agreement for step counting (ICC3, k = 0.999) and time spent sitting/lying (ICC3, k = 0.992), and good agreement for SI-ST (ICC3, k = 0.859) and ST-SI (ICC3, k = 0.936) postural change. Values of the differences for step counting, sitting/lying time, and postural change were within the limits of agreement according to the analysis of the Bland-Altman graph. CONCLUSION: The AMoR platform presented validity and reliability for step counting, time spent sitting/lying, and identification of SI-ST and ST-SI postural changes during tests in a simulated environment in post-stroke individuals.

Neuronal activation of cerebellum functional circuits in motor and non-motor functions in mice.

The cerebellum is involved in the control of balance, movement and the acquisition of motor skills. Scientific and technological advances have shown that the cerebellum also participates in non-motor functions, such as emotional control, memory and language. However, which cerebellar areas and functional circuits are predominantly activated in these different functions is not known. The current study analyzed the neuronal activation of cerebellar areas and other brain structures (e.g., hippocampus, amygdala, prelimbic cortex and infralimbic cortex) after exposure to rotarod and inhibitory avoidance behavioral models to establish possible neuronal circuits for motor and non-motor functions. Naïve male Swiss albino mice weighing 25 to 35 g were used. The animals were subjected to three conditions for behavioral evaluation: inhibitory avoidance, which is a model used to infer emotional memory; rotarod, which assesses motor performance and motor learning; and housing box/control. The mice remained in their housing box in Condition 1. Mice in Condition 2 were exposed to the inhibitory avoidance box for 2 days, and mice in Condition 3 were exposed to the rotarod for 3 days. The animals were euthanized after the last exposure to the apparatus then perfused with paraformaldehyde. Brains were extracted and sectioned for immunofluorescence analysis of c-Fos protein in pre-established structures. Images of the brain structures were obtained, and neuronal activation was analyzed microscopically. One-way analysis of variance was used, followed by Tukey's post-hoc test. There was no significant difference in c-Fos expression in lobe VI of the cerebellum between the different conditions. Differences in c-Fos expression were observed in the basolateral amygdala, infralimbic cortex and prelimbic cortex, which are relevant to emotional processes, after exposure to the evaluation apparatuses. Pearson's r correlation coefficient test showed a positive correlation between the variables of structures related to emotional processes. We concluded that there was no significant difference in c-Fos expression in lobe VI of the cerebellum after exposure of the animals to the evaluation apparatus. However, there was a difference in c-Fos expression in other brain structures related to emotional processes after exposure of animals to the apparatus.

Intracranial Compliance Concepts and Assessment: A Scoping Review.

Background: Intracranial compliance (ICC) has been studied to complement the interpretation of intracranial pressure (ICP) in neurocritical care and help predict brain function deterioration. It has been reported that ICC is related to maintaining ICP stability despite changes in intracranial volume. However, this has not been properly translated to clinical practice. Therefore, the main objective of this scoping review was to map the key concepts of ICC in the literature. This review also aimed to characterize the relationship between ICC and ICP and systematically describe the outcomes used to assess ICC using both invasive and non-invasive measurement methods. Methods: This review included the following: (1) population: animal and humans, (2) concept of compliance or its inverse "elastance," and (3) context: neurocritical care. Therefore, literature searches without a time frame were conducted on several databases using a combination of keywords and descriptors. Results and Discussion: 43,339 articles were identified, and 297 studies fulfilled the inclusion criteria after the selection process. One hundred and five studies defined ICC. The concept was organized into three main components: physiological definition, clinical interpretation, and localization of the phenomena. Most of the studies reported the concept of compliance related to variations in volume and pressure or its inverse (elastance), primarily in the intracranial compartment. In addition, terms like "accommodation," "compensation," "reserve capacity," and "buffering ability" were used to describe the clinical interpretation. The second part of this review describes the techniques (invasive and non-invasive) and outcomes used to measure ICC. A total of 297 studies were included. The most common method used was invasive, representing 57-88% of the studies. The most commonly assessed variables were related to ICP, especially the absolute values or pulse amplitude. ICP waveforms should be better explored, along with the potential of non-invasive methods once the different aspects of ICC can be measured. Conclusion: ICC monitoring could be considered a complementary resource for ICP monitoring and clinical examination. The combination and validation of invasive/non-invasive or non-invasive measurement methods are required.

Electrical stimulation impairs early functional recovery and accentuates skeletal muscle atrophy after sciatic nerve crush injury in rats.

Neuromuscular recovery after peripheral nerve lesion depends on the regeneration of severed axons that re-establish their functional connection with the denervated muscle. The aim of this study was to determine the effects of electrical stimulation (ES) on the neuromuscular recovery after nerve crush injury in rats. Electrical stimulation was carried out on the tibialis anterior (TA) muscle after sciatic nerve crush injury in a rat model. Six ES sessions were administered every other day starting from day 3 postinjury until the end of the experiment (day 14). The sciatic functional index was calculated. Muscle excitability, neural cell adhesion molecule (N-CAM) expression, and muscle fiber cross-sectional area (CSA) were accessed from TA muscle. Regenerated sciatic nerves were analyzed by light and confocal microscopy. Both treated (crush+ES) and untreated (crush) groups had their muscle weight and CSA decreased compared with the normal group (P < 0.05). Electrical stimulation accentuated muscle fiber atrophy more in the crush+ES than in the crush group (P < 0.05). N-CAM expression increased in both crush and crush+ES groups compared with the normal group (P < 0.05). Regenerated nerves revealed no difference between the crush and crush+ES groups. Nevertheless, functional recovery at day 14 post-injury was significantly lower in crush+ES group compared with the crush group. In addition, the crush+ES group had chronaxie values significantly higher on days 7 and 13 compared with the crush group, which indicates a decrease in muscle excitability in the crush+ES animals. The results of this study do not support a benefit of the tested protocol of ES during the period of motor nerve recovery following injury.

Effects of 660 and 780 nm low-level laser therapy on neuromuscular recovery after crush injury in rat sciatic nerve.

BACKGROUND AND OBJECTIVE: Post-traumatic nerve repair is still a challenge for rehabilitation. It is particularly important to develop clinical protocols to enhance nerve regeneration. The present study investigated the effects of 660 and 780 nm low-level laser therapy (LLLT) using different energy densities (10, 60, and 120 J/cm²) on neuromuscular and functional recovery as well as on matrix metalloproteinase (MMP) activity after crush injury in rat sciatic nerve. MATERIALS AND METHODS: Rats received transcutaneous LLLT irradiation at the lesion site for 10 consecutive days post-injury and were sacrificed 28 days after injury. Both the sciatic nerve and tibialis anterior muscles were analyzed. Nerve analyses consisted of histology (light microscopy) and measurements of myelin, axon, and nerve fiber cross-sectional area (CSA). S-100 labeling was used to identify myelin sheath and Schwann cells. Muscle fiber CSA and zymography were carried out to assess the degree of muscle atrophy and MMP activity, respectively. Statistical significance was set at 5% (P≤0.05). RESULTS: Six hundred sixty nanometer LLLT either using 10 or 60 J/cm² restored muscle fiber, myelin and nerve fiber CSA compared to the normal group (N). Furthermore, it increased MMP-2 activity in nerve and decreased MMP-2 activity in muscle and MMP-9 activity in nerve. In contrast, 780 nm LLLT using 10 J/cm² decreased MMP-9 activity in nerve compared to the crush group (CR) and N; it also restored normal levels of myelin and nerve fiber CSA. Both 60 and 120 J/cm² decreased MMP-2 activity in muscle compared to CR and N. 780 nm did not prevent muscle fiber atrophy. Functional recovery in the irradiated groups did not differ from the non-irradiated CR. CONCLUSION: Data suggest that 660 nm LLLT with low (10 J/cm²) or moderate (60 J/cm²) energy densities is able to accelerate neuromuscular recovery after nerve crush injury in rats.

Underlying mechanisms of oxygen uptake kinetics in chronic post-stroke individuals: A correlational, cross-sectional pilot study.

Post-stroke individuals presented deleterious changes in skeletal muscle and in the cardiovascular system, which are related to reduced oxygen uptake ([Formula: see text]) and take longer to produce energy from oxygen-dependent sources at the onset of exercise (mean response time, MTRON) and during post-exercise recovery (MRTOFF). However, to the best of our knowledge, no previous study has investigated the potential mechanisms related to [Formula: see text] kinetics response (MRTON and MRTOFF) in post-stroke populations. The main objective of this study was to determine whether the MTRON and MRTOFF are related to: 1) body composition; 2) arterial compliance; 3) endothelial function; and 4) hematological and inflammatory profiles in chronic post-stroke individuals. Data on oxygen uptake ([Formula: see text]) were collected using a portable metabolic system (Oxycon Mobile®) during the six-minute walk test (6MWT). The time to achieve 63% of [Formula: see text] during a steady state (MTRON) and recovery (MRTOFF) were analyzed by the monoexponential model and corrected by a work rate (wMRTON and wMRTOFF) during 6MWT. Correlation analyses were made using Spearman's rank correlation coefficient (rs) and the bias-corrected and accelerated bootstrap method was used to estimate the 95% confidence intervals. Twenty-four post-stroke participants who were physically inactive took part in the study. The wMRTOFF was correlated with the following: skeletal muscle mass (rs = -0.46), skeletal muscle mass index (rs = -0.45), augmentation index (rs = 0.44), augmentation index normalized to a heart rate of 75 bpm (rs = 0.64), reflection magnitude (rs = 0.43), erythrocyte (rs = -0.61), hemoglobin (rs = -0.54), hematocrit (rs = -0.52) and high-sensitivity C-reactive protein (rs = 0.58), all p < 0.05. A greater amount of oxygen uptake during post-walking recovery is partially related to lower skeletal muscle mass, greater arterial stiffness, reduced number of erythrocytes and higher systemic inflammation in post-stroke individuals.

The Effect of Priming on Outcomes of Task-Oriented Training for the Upper Extremity in Chronic Stroke: A Systematic Review and Meta-analysis.

Background. Priming results in a type of implicit memory that prepares the brain for a more plastic response, thereby changing behavior. New evidence in neurorehabilitation points to the use of priming interventions to optimize functional gains of the upper extremity in poststroke individuals. Objective. To determine the effects of priming on task-oriented training on upper extremity outcomes (body function and activity) in chronic stroke. Methods. The PubMed, CINAHL, Web of Science, EMBASE, and PEDro databases were searched in October 2019. Outcome data were pooled into categories of measures considering the International Classification Functional (ICF) classifications of body function and activity. Means and standard deviations for each group were used to determine group effect sizes by calculating mean differences (MDs) and 95% confidence intervals via a fixed effects model. Heterogeneity among the included studies for each factor evaluated was measured using the I2 statistic. Results. Thirty-six studies with 814 patients undergoing various types of task-oriented training were included in the analysis. Of these studies, 17 were associated with stimulation priming, 12 with sensory priming, 4 with movement priming, and 3 with action observation priming. Stimulation priming showed moderate-quality evidence of body function. Only the Wolf Motor Function Test (time) in the activity domain showed low-quality evidence. However, gains in motor function and in use of extremity members were measured by the Fugl-Meyer Assessment (UE-FMA). Regarding sensory priming, we found moderate-quality evidence and effect size for UE-FMA, corresponding to the body function domain (MD 4.77, 95% CI 3.25-6.29, Z = 6.15, P < .0001), and for the Action Research Arm Test, corresponding to the activity domain (MD 7.47, 95% CI 4.52-10.42, Z = 4.96, P < .0001). Despite the low-quality evidence, we found an effect size (MD 8.64, 95% CI 10.85-16.43, Z = 2.17, P = .003) in movement priming. Evidence for action observation priming was inconclusive. Conclusion. Combining priming and task-oriented training for the upper extremities of chronic stroke patients can be a promising intervention strategy. Studies that identify which priming techniques combined with task-oriented training for upper extremity function in chronic stroke yield effective outcomes in each ICF domain are needed and may be beneficial for the recovery of upper extremities poststroke.

Compensatory neuromuscular junction adaptations of forelimb muscles in focal cortical ischemia in rats.

INTRODUCTION: Upper limb movements are affected frequently by brain ischemia (BI). Mechanisms involved in recovery and compensatory movements have developed several studies. However, less attention is given to skeletal muscles, where neuromuscular junction (NMJ) has an important role on muscle tropism and functional performance. METHODS: Animals were divided into two groups: control (C) and BI. Then, animals were skilled to perform single-pellet retrieval task, following these procedures: habituation, shaping, and single-pellet retrieval task. BI was induced using stereotaxic surgery in order to apply endothelin-1 in motor cortex, representative of movements of dominant paw. Reaching task performance was evaluated by single-pellet retrieval task 1 day before BI induction, 4 and 15 days after BI induction. After that, biceps, triceps, fingers flexor, and extensor muscles were extracted. NMJ was assessed in morphometric characteristics (total area, total perimeter, and feret). Muscle fiber cross-sectional area and connective tissue percentage were also evaluated for characterization. Student's t test was used for comparisons between C and BI groups. Tau Kendall's correlation was applied among variables from BI group. RESULTS: An increase in all NMJ morphometric parameters, as well as increase of atrophy and fibrosis in BI group compared with C. There was a high level of direct correlation between mean values of NMJ morphometry with percentage of success in reaching task in BI group. CONCLUSION: Brain ischemia-induced NMJ compensatory expansion, muscle atrophy, and fibrosis in forelimb muscles that are related to reaching performance.