Skeletal muscle changes following stroke: a systematic review and comparison to healthy individuals

Stroke-induced excess in capillarization relative to oxidative capacity in rats is muscle specific

Stroke is not only associated with muscle weakness, but also associated with reduced muscle fatigue resistance and reduced desaturation during exercise that may be caused by a reduced oxidative capacity and/or microvasculature. Therefore, the objective of the present study was to determine the effects of stroke on muscle mass, fiber size and shape, capillarization and oxidative capacity of the rat m. extensor carpi radialis (ECR) and m. flexor carpi ulnaris (FCU) after a photothrombotic stroke in the forelimb region of the primary sensorimotor cortex. The main observation of the present study was that 4 weeks after induction of stroke there were no significant changes in muscle fiber size and shape. Although there was no significant capillary rarefaction, there was some evidence for remodeling of the capillary bed as reflected by a reduced heterogeneity of capillary spacing (p = 0.006) that may result in improved muscle oxygenation. In the ECR, but not in the FCU, this was accompanied by reduction in muscle fiber oxidative capacity as reflected by reduced optical density of sections stained for succinate dehydrogenase (p = 0.013). The reduced oxidative capacity and absence of significant capillary rarefaction resulted in a capillary to fiber ratio per unit of oxidative capacity that was higher after stroke in the ECR (p = 0.01), but not in the FCU. This suggests that at least during the early stages, stroke is not necessarily accompanied by muscle fiber atrophy, and that stroke-induced reductions in oxidative capacity resulting in relative excess of capillarization are muscle specific.

Reduced oxygen desaturation in the vastus lateralis of chronic stroke survivors during graded muscle contractions

BACKGROUND

Few studies have examined changes in skeletal muscle physiology post-stroke. This study examined changes in tissue oxygen saturation (StO2) of the vastus lateralis (VL) muscle of stroke survivors and age-matched control participants during maximal and submaximal isometric contractions of the knee extensor muscles.

OBJECTIVES

We hypothesized that tissue oxygen desaturation (ΔStO2) during knee extensor muscle contractions would be less in the VL in the paretic vs. the non-paretic and control legs.

METHODS

Ten chronic stroke survivors (>6 months post-stroke) with lower extremity muscle weakness and 10 age-matched controls completed this prospective cohort study. Maximum voluntary contractions (MVCs) of the knee extensor muscles were assessed with a Biodex dynamometer and StO2 of the VL was measured using near-infrared spectroscopy.

RESULTS

In the paretic leg of the stroke survivors little change in StO2 of the VL was observed during an MVC (ΔStO2 = -1.7 ± 1.8%) compared to the non-paretic (ΔStO2 = -5.1 ± 6.1%; p < 0.05) and control legs (ΔStO2 = -14.4 ± 8.8%; p < 0.05 vs. paretic and non-paretic leg). These differences remained when normalizing for strength differences between the legs. Compared to controls, both the paretic and non-paretic VL showed pronounced reductions in ΔStO2 during ramp and hold contractions equal to 20%, 40%, or 60% of the MVC (p < 0.05 vs. controls at all load levels).

CONCLUSIONS

These results indicate that oxygen desaturation in response to isometric muscle contractions is impaired in both the paretic and non-paretic leg muscle of stroke survivors compared to age-matched controls, and these differences are independent of differences in muscle strength.

Peripheral vascular function in stroke: systematic review and meta-analysis

Peripheral vascular dysfunction, measured as flow-mediated dilation (FMD), is present across all phases of stroke recovery and elevates the risk for recurrent cardiovascular events. The objective of this systematic review and meta-analysis was to characterize baseline FMD in individuals' poststroke, with consideration for each phase of stroke recovery. Three databases (PubMed, CINAHL, and Embase) were searched between January 1, 2000 and October 12, 2023 for studies that examined baseline FMD in stroke. Three reviewers conducted abstract and full-text screening, data extraction, and quality assessment. A random effects model was used to estimate FMD across studies. Meta-regression was used to examine the impact of age and time since stroke (acute, subacute, chronic) on FMD. Twenty-eight studies with ischemic and hemorrhagic stroke were included. Descriptive statistics for the demographics and FMD values of each study are presented. For the meta-analysis, average estimate FMD was 3.9% (95% CI: 2.5-5.3%). We report a large amount of heterogeneity (Cochrane's Q P value <0.001, and I2 = 99.6%). Differences in average age and the time poststroke between studies were not significantly associated with differences in FMD values. Despite the large heterogeneity for FMD values across studies, our primary finding suggests that FMD remains impaired across all phases of stroke.NEW & NOTEWORTHY This systematic review and meta-analysis offers invaluable insight into poststroke vascular function. Despite the inherent heterogeneity among the 28 studies analyzed, we report that peripheral vascular dysfunction, as quantified by flow-mediated dilation, exists across all stages of stroke recovery. This finding underscores the importance for interventions that focus on improving vascular health and secondary stroke prevention.

Lower middle cerebral artery blood velocity during low-volume high-intensity interval exercise in chronic stroke

High-intensity interval training (HIIE) may present unique challenges to the cerebrovascular system in individuals post-stroke. We hypothesized lower middle cerebral artery blood velocity (MCAv) in individuals post-stroke: 1) during 10 minutes of HIIE, 2) immediately following HIIE, and 3) 30 minutes after HIIE, compared to age- and sex-matched controls (CON). We used a recumbent stepper submaximal exercise test to determine workloads for high-intensity and active recovery. Our low volume HIIE protocol consisted of 1-minute intervals for 10 minutes. During HIIE, we measured MCAv, mean arterial pressure (MAP), heart rate (HR), and end tidal carbon dioxide (PETCO2). We assessed carotid-femoral pulse wave velocity as a measure of arterial stiffness. Fifty participants completed the study (25 post-stroke, 76% ischemic, 32% moderate disability). Individuals post-stroke had lower MCAv during HIIE compared to CON (p = 0.03), which remained 30 minutes after HIIE. Individuals post-stroke had greater arterial stiffness (p = 0.01) which was moderately associated with a smaller MCAv responsiveness during HIIE (r = -0.44). No differences were found for MAP, HR, and PETCO2. This study suggests individuals post-stroke had a lower MCAv during HIIE compared to their peers, which remained during recovery up to 30 minutes. Arterial stiffness may contribute to the lower cerebrovascular responsiveness post-stroke.

A modified rehabilitation paradigm bilaterally increased rat extensor digitorum communis muscle size but did not improve forelimb function after stroke

Malnutrition after stroke may lessen the beneficial effects of rehabilitation on motor recovery through influences on both brain and skeletal muscle. Enriched rehabilitation (ER), a combination of environmental enrichment and forelimb reaching practice, is used preclinically to study recovery of skilled reaching after stroke. However, the chronic food restriction typically used to motivate engagement in reaching practice is a barrier to using ER to investigate interactions between nutritional status and rehabilitation. Thus, our objectives were to determine if a modified ER program comprised of environmental enrichment and skilled reaching practice motivated by a short fast would enhance post-stroke forelimb motor recovery and preserve forelimb muscle size and metabolic fiber type, relative to a group exposed to stroke without ER. At one week after photothrombotic cortical stroke, male, Sprague-Dawley rats were assigned to modified ER or standard care for 2 weeks. Forelimb recovery was assessed in the Montoya staircase and cylinder task before stroke and on days 5-6, 22-23, and 33-34 after stroke. ER failed to improve forelimb function in either task (p > 0.05). Atrophy of extensor digitorum communis (EDC) and triceps brachii long head (TBL) muscles was not evident in the stroke-targeted forelimb on day 35, but the area occupied by hybrid fibers was increased in the EDC muscle (p = 0.038). ER bilaterally increased EDC (p = 0.046), but not TBL, muscle size; EDC muscle fiber type was unchanged by ER. While the modified ER did not promote forelimb motor recovery, it does appear to have utility for studying the role of skeletal muscle plasticity in post-stroke recovery.

Upper-Limb Functional Recovery in Chronic Stroke Patients after COVID-19-Interrupted Rehabilitation: An Observational Study

Background/Objectives: Upper-limb function of chronic stroke patients declined when outpatient rehabilitation was interrupted and outings restricted, owing to the novel coronavirus infection (COVID-19) pandemic. We investigated whether these patients recovered upper-limb function post-resumption of outpatient rehabilitation. Methods: In this observational study, 43 chronic stroke hemiparesis patients with impaired upper extremity function were scored for limb function via the Fugl-Meyer assessment of the upper extremity (FMA-UE) and the Action Research Arm Test (ARAT) after a structured interview, evaluation, and intervention. Scores at 6 and 3 months pre- and 3 months post-rehabilitation interruption were examined retrospectively; scores immediately and at 3 and 6 months post-resumption of care were examined prospectively. The amount of change for each time period and an analysis of covariance were performed with time as a factor, changes in the FMA-UE and the ARAT scores as dependent variables, and statistical significance at 5%. Results: The time of evaluation significantly impacted the total score, as well as part C and part D of FMA-UE and total, pinch, and gross movement of the ARAT. Post-hoc tests showed that the magnitude of change in limb-function scores from immediately to 3 months post-resumption was significantly higher than the change from 3 months pre- to immediately post-interruption for the total score and part D of the FMA-UE, as well as grip and gross movement of the ARAT (p < 0.05). Conclusions: Upper-limb functional decline in chronic stroke patients, caused by the COVID-19 pandemic-related therapy interruption and outing restrictions, was resolved approximately 3 months post-resumption of rehabilitation therapy. Our data can serve as reference standards for planning and evaluating treatment for chronic stroke patients with inactivity-related impaired upper-limb function.

Improvements of mid-thigh circumferences following robotic rehabilitation in hemiparetic stroke patients

INTRODUCTION

Stroke has emerged as the leading cause of disability globally. The provision of long-term rehabilitation to stroke survivors poses a health care burden to many countries. Robotic devices have created a major turning point in stroke rehabilitation program. Currently, the anthropometric evidence to support the benefit of robotic rehabilitation (RR) among stroke patients is scarce. Therefore, the aim of this study was to evaluate the impact of RR on the mid-thigh circumferences of the paretic limbs in stroke patients.

METHODS

Twenty stroke patients from conventional rehabilitation (CR) (n = 10) and RR (n = 10) groups were recruited through a purposive sampling method. Patients in the CR group received a two-hour session of a five-day-a-week home-based CR program for 4 weeks. Patients in the RR group received a five-day-a-week of an hour combined physiotherapy and occupational therapy session and a one-hour robotic therapy session using the HAL® Cyberdyne lower-limb, for 4 weeks. The mid-thigh circumferences of both limbs were measured on day 1 (baseline), week 2 and week 4 of rehabilitation program.

RESULTS

The results revealed no statistically significant difference in the mid-thigh circumferences between the paretic (F1.05,9.44 = 1.96, p = 0.20), and the normal (F1.05,9.44 = 1.96, p = 0.20) sides in the CR group (n = 10). For the comparison between the paretic and normal sides in the RR group (n = 10), the paretic mid-thigh circumferences revealed significant time effect results (F2,18 = 11.91, p = 0.001), which were due to changes between baseline and week 2, and baseline and week 4 measurements. Interestingly, the normal mid-thigh circumferences also revealed a significant time effect (F2,18 = 6.56, p = 0.007), which is due to changes between baseline and week 4. One-way analysis of variance was employed to compare the mean average between groups due to the difference in the baseline measurements of the mid-thigh circumferences between the paretic side of the CR and the RR groups. With this adjustment, the average means mid-thigh circumferences after 4 weeks of therapy were shown to be significantly different between the CR and RR groups (F1,18 = 12.49, p = 0.02).

CONCLUSION

Significant increments in the mid-thigh circumferences following RR were seen in the paretic limbs of stroke patients. Hence, this study may provide some insights into further potential research related to the benefits of RR in stroke patients.

Factors influencing the reduction in quadriceps muscle thickness in the paretic limbs of patients with acute stroke

BACKGROUND & AIMS

Muscle atrophy is an early event that occurs after stroke, but there are few reports on the changes in skeletal muscle thickness in acute stroke. This study investigated the factors contributing to reduced muscle thickness in patients with acute stroke.

METHODS

In total, 51 patients with stroke and the National Institute of the Health Stroke Scale (NIHSS) > 3 were included in our study. They were admitted to our hospital between July 2017 and May 2020. The quadriceps muscle thickness was measured with an ultrasound device within 2 days after admission and 14 days later. The collected data included age, sex, body mass index, stroke type, neuromuscular electrical stimulation, NIHSS, serum albumin at admission, start of enteral nutrition, Functional Oral Intake Scale (FOIS), start of mobilization and ambulation, number of physical and occupational therapy units, C-reactive protein at admission and whether surgery had been performed. These data were retrospectively retrieved from medical documents. A dietician calculated energy intake, protein intake, and energy adequacy. Multiple regression analysis was used to identify the factors associated with reduced quadriceps muscle thickness. The independent variables were NIHSS, date of start of enteral feeding, protein intake, FOIS, date of mobilization, and date of start of ambulation training.

RESULTS

The rate of change in quadriceps muscle thickness of the paretic limb was -15.3 % (interquartile range, -46.1-14.8 %). Multiple regression analysis showed that the factors responsible for the decrease in muscle thickness on the paretic side were FOIS (β: 0.376; 95 % Cl, 0.999 to 4.541) and the start date of ambulation (β: -0.378; 95 % Cl, -2.575 to -0.543), with a multiple correlation coefficient of 0.456.

CONCLUSION

The FOIS and the start date of ambulation after acute stroke were related to the rate of reduction in muscle thickness on the paretic side.

Treadmill training impacts the skeletal muscle molecular clock after ischemia stroke in rats

Objective

Stroke is frequently associated with muscle mass loss. Treadmill training is considered the most effective treatment for sarcopenia. Circadian rhythms are closely related to exercise and have been extensively studied. The skeletal muscle has its molecular clock genes. Exercise may regulate skeletal muscle clock genes. This study evaluated the effects of early treadmill training on the skeletal muscle molecular clock machinery in rats with stroke and determined the relationship of these changes with exercise-induced improvements in skeletal muscle health.

Materials and methods

Overall, 168 Sprague-Dawley rats were included in this study. We established an ischemic stroke rat model of sarcopenia. Finally, 144 rats were randomly allocated to four groups (36 per group): normal, sham, middle cerebral artery occlusion, and training. Neurological scores, rotating rod test, body weight, muscle circumference, wet weight, and hematoxylin-eosin staining were assessed. Twenty-four rats were used for transcriptome sequencing. Gene and protein expressions of skeletal muscles, such as brain muscle arnt-like 1, period 1, and period 2, were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assays.

Results

Neurological function scores and rotating rod test results improved after treadmill training. Nine differentially expressed genes were identified by comparing the sham group with the hemiplegic side of the model group. Seventeen differentially expressed genes were identified between the hemiplegic and non-hemiplegic sides. BMAL1, PER1, and PER2 mRNA levels increased on both sides after treadmill training. BMAL1 expression increased, and PER1 expression decreased on both sides, whereas PER2 expression decreased on the hemiplegic side but increased on the non-hemiplegic side.

Conclusion

Treadmill training can mitigate muscle loss and regulate skeletal muscle clock gene expression following ischemic stroke. Exercise affects the hemiplegic side and has a positive regulatory effect on the non-hemiplegic side.

The Relationship of Gastrocnemius-Soleus Muscle Architecture with Balance and Functional Strength in Acute Stroke Patients

Balance and functional impairment could occur due to the weakness of the gastrocsoleus muscles in acute stroke patients. This study was planned to determine the muscle architecture and its relationship to balance and functional strength functional ability in patients with acute stroke. A cross-sectional analysis of 22 stroke patients (68.59 ± 8.16) was performed in this study. Gastrocnemius muscle thickness and cross-sectional area were significantly greater on the non-paretic than on the paretic sides (p = 0.004, p = 0.005, respectively). Partial correlation analysis showed that soleus muscle thickness and cross-sectional area was significantly correlated with Berg Balance Scale, Single Leg Stance Test, Five Times Sit to Stand Test and Tandem test results in the paretic side (r = 0.49-0.77, p < 0.05). The gastrocnemius muscle thickness of the non-paretic side had a significant relationship with balance (r = 0.45-0.65, p < 0.05). The muscle thickness and cross-sectional area of the soleus muscle on the paretic sides was significantly related with the functional strength and balance after stroke. It may be beneficial to develop clinical assessment and intervention programs focusing on distal plantar flexor muscle groups in order to improve the functional status and balance.

Exploring the experiences of an exercise-based telerehabilitation program among Canadian community-dwelling adults with stroke

PURPOSE

Telerehabilitation is emerging as a means for delivering stroke rehabilitation to address unmet lower extremity rehabilitation needs. However, there is currently limited and low-quality evidence supporting the use telerehabilitation interventions for lower extremity recovery after stroke. Thus, we developed an exercise-based telerehabilitation program (TRAIL) for safe and effective promotion of lower extremity function after stroke. This study reports on the qualitative findings from the feasibility study of the TRAIL program.

METHODS

An interpretive description methodology and inductive thematic analysis approach were undertaken. One-on-one semi-structured interviews were conducted on a subset of participants who completed the TRAIL feasibility study. Participants were recruited via email and enrolled into the study based on pre-determined purposeful sampling strategies.

RESULTS

Ten participants (6 men, 4 women) completed a semi-structured interview. Two main themes emerged: (i) TRAIL ingredients for success and (ii) telerehabilitation is a viable option for stroke rehabilitation.

CONCLUSION

Exercise-based telerehabilitation appears to be well-received by men and women post-stroke when social support, professional guidance, and program resources are offered. TRAIL may also prolong the continuum of care that individuals receive once they are discharged back into the community, and contribute to improvements in mobility, lower extremity strength and balance.

Immediate Effects of TECAR Therapy on Gastrocnemius and Quadriceps Muscles with Spastic Hypertonia in Chronic Stroke Survivors: A Randomized Controlled Trial

BACKGROUND

The aim of this study was to assess changes in muscle properties after a single session of capacitive and resistive energetic transfer (TECAR) therapy on spastic gastrocnemius and quadriceps muscles in chronic post-stroke.

METHODS

A total of 36 chronic stroke survivors with lower limb hypertonia were enrolled in a double-blind randomized controlled trial. The experimental group (n = 18) received a single 30 min session of TECAR therapy in combination with functional massage (FM) on the gastrocnemius and quadriceps muscles. The control group (n = 18) received a sham treatment of TECAR therapy (without electrical stimulation) in combination with real FM. The primary outcome was muscle tone of the lower limb muscles assessed with the Modified Ashworth Scale (MAS). The secondary outcomes were goniometric degrees of the MAS (goniometer), neuromuscular properties of the gastrocnemius/quadriceps (myotonometer), and passive range of motion (inclinometer). All measurements were performed at baseline (T0), immediately after treatment (T1), and at 30 min post-treatment (T2) by a blinded assessor.

RESULTS

The MAS score ankle dorsiflexion significantly decreased at T0-T1 (p = 0.046), and the change was maintained at T0-T2 (p = 0.019) in the experimental group. Significant improvements were noted in the passive range of motion for knee flexion (p = 0.012) and ankle dorsiflexion (p = 0.034) at T2. In addition, knee flexion improved at T1 (p = 0.019).

CONCLUSION

A single session of Tecar therapy at the same time with FM on the gastrocnemius and rectus femoris immediately reduces muscle tone and increases the passive range of motion of both ankle and knee in chronic stroke survivors. There were no significant changes in the neuromuscular properties measured with myotonometer.

Relationship between physical activity levels and changes in skeletal muscle characteristics in patients with stroke

PURPOSE

This study aimed to investigate the relationship between physical activity (PA) levels and short-term changes in skeletal muscle characteristics in patients with subacute hemiparetic stroke.

MATERIALS AND METHODS

This prospective observational study included 76 patients with stroke who received inpatient care in a convalescent rehabilitation ward. The PA level was measured as the duration of daily total PA (≥ 1.5 metabolic equivalents) using a triaxial accelerometer for 7 days after admission. The outcomes were changes in the quadriceps muscle quality and quantity on the affected and unaffected sides, as assessed by ultrasonography at admission and 1 month after admission.

RESULTS

Multiple regression analysis indicated that the duration of total PA was significantly associated with a percentage change in quadriceps muscle quality (p = 0.011) and quantity (p = 0.012) on the affected side. However, no significant relationship was observed between the muscle quality and quantity on the unaffected side.

CONCLUSIONS

The results revealed that PA was associated with changes in the quadriceps muscle quality and quantity on the affected side in patients with subacute hemiparetic stroke. These findings highlight the importance of promoting PA in stroke rehabilitation to improve muscle properties and functional outcomes.

Effect of lower limb resistance training on ICF components in chronic stroke: A systematic review and meta-analysis of RCTs

BACKGROUND

Resistance training (RT) effectively promotes functional independence after stroke.

OBJECTIVES

To investigate the effect of lower limb RT on body structure and function (muscle strength, postural balance), activity (mobility, gait) and participation (quality of life, impact of stroke on self-perceived health) outcomes in individuals with chronic stroke.

METHODS

Six databases were searched from inception until September 2022 for randomized controlled trials comparing lower limb RT to a control intervention. The random-effects model was used in the meta-analyses. Effect sizes were reported as standardized mean differences (SMD). Quality of evidence was assessed using the GRADE approach.

RESULTS

Fourteen studies were included. Significant improvements were found in body structure and function after lower limb RT: knee extensors (paretic side - SMD: 1.27; very low evidence), knee flexors (paretic side - SMD: 0.51; very low evidence; non-paretic side - SMD: 0.52; low evidence), leg press (paretic side - SMD: 0.83; very low evidence) and global lower limb muscle strength (SMD: -1.47; low evidence). No improvement was found for knee extensors (p = 0.05) or leg press (p = 0.58) on the non-paretic side. No improvements were found in the activity domain after lower limb RT: mobility (p = 0.16) and gait (walking speed-usual: p = 0.17; walking speed-fast: p = 0.74). No improvements were found in the participation domain after lower limb RT: quality of life (p > 0.05), except the bodily pain dimension (SMD: 1.02; low evidence) or the impact of stroke on self-perceived health (p = 0.38).

CONCLUSION

Lower limb RT led to significant improvements in the body structure and function domain (knee extensors and flexors, leg press, global lower limb muscle strength) in individuals with chronic stroke. No improvements were found in the activity (mobility, gait [walking speed]) or participation (quality of life, impact of stroke on self-perceived health) domains.

PROSPERO REGISTRATION NUMBER

CRD42021272645.

Assessing Stroke-Related Sarcopenia in Chronic Stroke: Identification of Clinical Assessment Tools-A Pilot Study

Stroke-related sarcopenia has recently been defined as the muscle atrophy consequent to stroke and assessing it following the guidelines with simple clinical tools is crucial in chronic stroke survivors. The aim of this study was to determine the characteristics of patient-friendly instruments sarcopenia in a chronic stroke sample (SG) compared to non-stroke counterparts (CG). Each participant underwent a single assessment which consisted of: SARC-F questionnaire, assessment of muscle strength (hand grip and five-times sit-to-stand test, 5STS), the calf circumference (CC) of both legs, the short physical performance battery (SPPB), and the 10 m walk test. A total of 68 participants were included (SG, n = 34 and CG, n = 34). All variables showed statistical differences (p < 0.05) between the SG and the CG, except handgrip although it showed lower values for SG. The values of the 5STS (16.26 s) and the SPPB (7 points) were below to the cutoff values for the SG. The five-times sit-to-stand test, SPPB, and gait speed can lead clinicians to detect stroke-related sarcopenia. Maximum handgrip shows a trend of low values for men and women in the SG, however, CC did not detect sarcopenia in our sample.

Structural and pathophysiological muscle changes up to one year after post-stroke hemiplegia: a systematic review

INTRODUCTION

Muscle changes after stroke cannot be explained solely on the basis of corticospinal bundle damage. Muscle-specific changes contribute to limited functional recovery but have been poorly characterized.

EVIDENCE ACQUISITION

We conducted a systematic review of muscular changes occurring at the histological, neuromuscular and functional levels during the first year after the onset of post-stroke hemiplegia. A literature search was performed on PubMed, Embase and CINHAL databases up to November 2022 using a keyword combination comprising cerebral stroke, hemiplegic, atrophy, muscle structure, paresis, skeletal muscle fiber type, motor unit, oxidative stress, strength, motor control.

EVIDENCE SYNTHESIS

Twenty-seven trial reports were included in the review, out of 12,798 articles screened. Structural modifications described on the paretic side include atrophy, transformation of type II fibers into type I fibers, decrease in fiber diameter and apparent myofilament disorganization from the first week post-stroke up to the fourth month. Reported biochemical changes comprise the abnormal presence of lipid droplets and glycogen granules in the subsarcolemmal region during the first month post-stroke. At the neurophysiological level, studies indicate an early decrease in the number and activity of motor units, correlated with the degree of motor impairment. All these modifications were present to a lesser degree on the non-paretic side. Although only sparse data concerning the subacute stage are available, these changes seem to appear during the first two weeks post-stroke and continue up to the third or fourth month.

CONCLUSIONS

Considering these early pathophysiological changes on both the paretic and non-paretic sides, it seems crucial to promptly stimulate central and also peripheral muscular activation after stroke through specific rehabilitation programs focused on the maintenance of muscle capacities associated with neurological recovery or plasticity.

Measuring Shear Wave Velocity in Adult Skeletal Muscle with Ultrasound 2-D Shear Wave Elastography: A Scoping Review

Ultrasound 2-D shear wave elastography (US 2D-SWE) is a non-invasive, cost-effective tool for quantifying tissue stiffness. Amidst growing interest in US 2D-SWE for musculoskeletal research, it has been recommended that shear wave velocity (SWV) should be reported instead of elastic moduli to avoid introducing unwanted error into the data. This scoping review examined the evolving use of US 2D-SWE to measure SWV in skeletal muscle and identified strengths and weaknesses to guide future research. We searched electronic databases and key review reference lists to identify articles published between January 2000 and May 2021. Two reviewers assessed the eligibility of records during title/abstract and full-text screening, and one reviewer extracted and coded the data. Sixty-six studies met the eligibility criteria, of which 58 were published in 2017 or later. We found a striking lack of consensus regarding the effects of age and sex on skeletal muscle SWV, and widely variable reliability values. Substantial differences in methodology between studies suggest a pressing need for developing standardized, validated scanning protocols. This scoping review illustrates the breadth of application for US 2D-SWE in musculoskeletal research, and the data synthesis exposed several notable inconsistencies and gaps in current literature that warrant consideration in future studies.

Effect of power training on rate of torque development and spatiotemporal gait parameters post stroke

BACKGROUND

Maximizing independence and function post-stroke are two common therapy goals. Rate of torque development in lower-extremity muscles was recently reported to be associated with walking speed; however, trainability and subsequent effect on gait is unknown. This study aimed to determine effect of power training on paretic and non-paretic limb torque parameters, spatiotemporal gait parameters, and walking speed in chronic stroke survivors.

METHODS

Individuals with chronic stroke (n = 22; 7 females; 62.7 ± 8.8 yrs) completed 24 progressive power-training sessions over 8 weeks with pre and post assessments. Knee extensor strength was assessed via dynamometry with torque parameters measured from maximal voluntary isometric contractions. Gait speed and spatiotemporal gait parameters were assessed via an instrumented gait mat, and a 6-min walk test was performed.

FINDINGS

Rate of torque development at 200 ms and peak torque improved 58.6% and 14.1%, respectively, in the quadricep of the paretic limb (p < 0.05); conversely the non-paretic limb was unchanged. On average, self-selected walking speed, fastest-comfortable walking speed, and 6-min walk test improved 21.7%, 21.1%, and 19.5%, respectively (all p < 0.05). Change in torque development at 100 ms in the quadricep of the non-paretic limb was positively associated with improvements in self-selected and fastest-comfortable walking speeds (both r = 0.70, p < 0.05) and 6-min walk (r = 0.78, p < 0.001).

INTERPRETATIONS

These findings suggest power training may be an effective intervention for improving torque development in the quadricep of the paretic limb in individuals with chronic stroke. Further research to explore utility and mechanistic aspects of force development for gait function in chronic stroke survivors is warranted.

Determinants of in-hospital muscle loss in acute ischemic stroke - Results of the Muscle Assessment in Stroke Study (MASS)

BACKGROUND & AIMS

There is a change in the mass and composition of paretic and non-paretic skeletal muscles in the chronic phase of stroke. The multi-center, prospective, and observational Muscle Assessment in Stroke Study (MASS) was performed to evaluate the degree of muscle loss during the in-hospital acute stroke setting and determine factors contributing to this loss.

METHODS

Acute dysphagic ischemic stroke patients (n = 107) admitted to neuro-intensive care units were evaluated by computed tomography on days 1 and 14 after admission to determine the cross-sectional muscle area (CSMA) at the level of the mid-humerus, mid-thigh, and third lumbar vertebra. The percentage change in CSMA and variables associated with this change were evaluated by univariate and multivariate analyses.

RESULTS

There were significant reductions in CSMA in all the muscle groups analyzed; the most prominent change was observed in the arms (both: 14.2 ± 10.7%; paretic: 17.7 ± 11.6%; non-paretic: 10.1 ± 12.5%), followed by the muscles in the legs (both: 12.4 ± 8.7%; paretic: 12.9 ± 9.9%; non-paretic: 12.0 ± 9.3%) and L3-vertebra level (5.6 ± 9.8%) (P < 0.001 for all). Higher calorie (r = -0.378, P < 0.001) or protein (r = -0.352, P < 0.001) intake was negatively associated with the decrease in CSMA of upper extremities. A substantial protein (≥0.4 g/kg/d) or calorie (≥5 kcal/kg/d) gap between targeted or actual intake was related to a larger decrease in CSMA in all the anatomic regions (P ≤ 0.05 for all). Other significant predictors of muscle loss included history of diabetes mellitus, male sex, higher BMI, in-hospital infections, and the necessity for invasive mechanical ventilation.

CONCLUSIONS

There is a considerable degree of loss in the global muscle mass in acute ischemic stroke patients over a two-week period. Along with several factors, falling significantly behind the daily protein or calorie targets was related to the decrease in the muscle area. TRIAL REGISTRATION INFORMATION: clinicaltrials.gov identifier NCT03825419.

Strength Training of the Nonhemiplegic Side Promotes Motor Function Recovery in Patients With Stroke: A Randomized Controlled Trial

OBJECTIVE

To observe the effect of strength training of the nonhemiplegic side (NHS) on balance function, mobility, and muscle strength of patients with stroke.

DESIGN

A single-blinded (evaluator) randomized controlled trial.

SETTING

A tertiary hospital rehabilitation center.

PARTICIPANTS

139 patients with first stroke (N=139) were recruited and randomly separated into a trial (n=69) or control group (n=70).

INTERVENTIONS

The control group underwent usual rehabilitation training, including step training and trunk control training in standing position. The trial group underwent strength training of NHS on the basis of usual rehabilitation training. The strength training of NHS included lower limb stepping training with resisting elastic belt and upper limb pulling elastic belt training in standing position. The training for both groups was 45 min, once a day, 5 days a week for 6 weeks.

MAIN OUTCOME MEASURES

Balance evaluation was done with the Berg Balance Scale (BBS); mobility assessment with the 6-minute walk test (6-MWT); activities of daily life was examined via the modified Barthel Index (MBI); muscle strengths of the biceps brachii, iliopsoas, and quadriceps were measured via the isokinetic muscle strength testing system. All assessments were performed at baseline (T0) and after intervention (T1).

RESULTS

The trial group performed better than control group in BBS scores (adjusted mean difference: 6.83; 95% confidence interval [CI]: 4.71-8.94) and 6-MWT (adjusted mean difference: 50.32; 95% CI: 40.58-60.05) after intervention. In terms of muscle strength of the hemiplegic side, the trial group displayed greater gains in biceps brachii, iliopsoas, and quadriceps than control group after intervention.

CONCLUSION

Strength training of the NHS can promote recovery of balance, mobility, and muscle strength of the paretic side of patients with stroke.

Comitant strabismus etiology: extraocular muscle integrity and central nervous system involvement-a narrative review

Strabismus is not a condition in itself but the consequence of an underlying problem. Eye misalignment can be caused by disease, injury, and/or abnormalities in any of the structures and processes involved in visual perception and oculomotor control, from the extraocular muscles and their innervations to the oculomotor and visual processing areas in the brain. A small percentage of all strabismus cases are the consequence of well-described genetic syndromes, acquired insult, or disease affecting the extraocular muscles (EOMs) or their innervations. We will refer to them as strabismus of peripheral origin since their etiology lies in the peripheral nervous system. However, in most strabismus cases, that is comitant, non-restrictive, non-paralytic strabismus, the EOMs and their innervations function properly. These cases are not related to specific syndromes and their precise causes remain poorly understood. They are generally believed to be caused by deficits in the central neural pathways involved in visual perception and oculomotor control. Therefore, we will refer to them as central strabismus. The goal of this narrative review is to discuss the possible causes behind this particular type of eye misalignment and to raise awareness among eyecare professionals about the important role the central nervous system plays in strabismus etiology, and the subsequent implications regarding its treatment. A non-systematic search was conducted using PubMed, Medline, Cochrane, and Google Scholar databases with the keywords "origins," "causes," and "etiology" combined with "strabismus." A snowball approach was also used to find relevant references. In the following article, we will first describe EOM integrity in central strabismus; next, we will address numerous reasons that support the idea of central nervous system (CNS) involvement in the origin of the deviation, followed by listing several possible central causes of the ocular misalignment. Finally, we will discuss the implications CNS etiology has on strabismus treatment.

Characterization of the Structural and Mechanical Changes of the Biceps Brachii and Gastrocnemius Muscles in the Subacute and Chronic Stage after Stroke

The objective of this study was to characterize the changes of muscle tone, stiffness, and thickness of upper and lower limb muscles in stroke survivors. Forty patients with subacute or chronic stroke and 31 controls were included and measured using myotonometry (MyotonPRO), with multiple site assessments at muscle belly (MB) and musculotendinous (MT) locations of the biceps brachii and gastrocnemius muscles. Muscle thickness (ultrasonography) was obtained for each muscle. Upper and lower limb motor performance was evaluated with the Fugl−Meyer Assessment for Upper Extremity and the Functional Ambulance Category. Overall, muscle tone and stiffness were significantly higher at MT than at MB sites. Among stroke patients, differences between the paretic and nonparetic limb were found for the biceps brachii, with lower muscle tone, stiffness, and thickness of the paretic side (all, p < 0.05). There were weak to moderate correlations between mechanical (myotonometry) and structural (ultrasound) muscular changes, regardless of the post-stroke stage. This suggests that myotonometry and ultrasonography assess similar, although different, constructs and can be combined in the clinical setting. Their discriminative ability between the paretic and nonparetic sides and between participants with and without stroke differs depending on the muscle, the functional level, and the stroke stage.

Motor performance, motor impairments, and quality of life after eccentric resistance training in neurological populations: A systematic review and meta-analyses

BACKGROUND

Many overlapping factors impair motor performance and quality of life in neurological patients. Eccentric resistance training (ET) has potential benefits for improving motor performance and treating motor impairments better than some traditional rehabilitation approaches.

OBJECTIVE

To estimate the effect of ET in neurological settings.

METHODS

Seven databases were reviewed up to May 2022 according to PRSIMA guidelines to find randomized clinical trials involving adults with a neurological condition, who underwent ET as set by the American College of Sports Medicine. Motor performance (main outcome) was assessed as strength, power and capacities during activity. Secondary outcomes (impairments) were muscle structure, flexibility, muscle activity, tone, tremor, balance and fatigue. Tertiary outcomes were risk of fall, and self-reports of quality of life.

RESULTS

Ten trials were included, assessed using Risk of Bias 2.0 tool, and used to compute meta-analyses. Effective effects in favour of ET were found for strength and power, but not for capacities during activity. Mixed results were found for secondary and tertiary outcomes.

CONCLUSION

ET may be a promising intervention to better improve strength/power in neurological patients. More studies are needed to improve the quality of evidence underlying changes responsible for these results.

Quantification of Tissue Oxygen Saturation in the Vastus Lateralis Muscle of Chronic Stroke Survivors during a Graded Exercise Test

Purpose

This study examined tissue oxygen saturation (StO2) of the vastus lateralis (VL) muscles of chronic stroke survivors during a graded exercise test (GXT). We hypothesized the reduction in StO2 will be blunted in the paretic vs. non-paretic VL during a maximum-effort GXT.

Methods

Chronic stroke survivors performed a GXT and StO2 of the VL in each leg was measured using near infrared spectroscopy. Twenty-six stroke survivors performed a GXT.

Results

At rest, there was no difference in StO2 between the paretic and non-paretic VL (65±9% vs. 68±7%, respectively, p=0.32). The maximum change in StO2 from rest during the GXT was greater in the non-paretic vs. the paretic VL (-16±14% vs. -9±10%, respectively, p<0.001). The magnitude of the oxygen resaturation response was also greater in the non-paretic vs. the paretic VL (29±23% vs. 18±15%, respectively, p<0.001). VO2 Peak was associated with the magnitude of the VL StO2 change during (r2=0.54, p<0.0001) and after (r2=0.56, p<0.001) the GXT.

Conclusions

During a GXT there is a blunted oxygen desaturation response in the paretic vs. the non-paretic VL of chronic stroke survivors. In the paretic VL there was a positive correlation between the oxygen desaturation response during the GXT and VO2 Peak.

Trajectories of the Prevalence of Sarcopenia in the Pre- and Post-Stroke Periods: A Systematic Review

Interventions for stroke-related sarcopenia in patients with stroke are needed, but the details of the target population are unclear. This systematic review aimed to identify trajectories of the prevalence of sarcopenia in the pre- and post-stroke periods and to determine the diagnostic criteria used in patients with stroke. We searched for literature in six databases: MEDLINE, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, CINAHL, and Ichushi-web (in Japanese). We included 1627 studies in the primary screening, and 35 studies were finally included. Of the 35 studies, 32 (91.4%) included Asian patients, and the criteria of the Asian Working Group for Sarcopenia was mainly used as the diagnostic criteria. Nineteen studies used muscle strength and muscle mass to diagnose sarcopenia, whereas a full assessment, including physical performance, was performed in five studies. The estimated prevalences of sarcopenia in pre-stroke, within 10 days of stroke, and from 10 days to 1 month after stroke were 15.8%, 29.5%, and 51.6%, respectively. Sarcopenia increased by approximately 15% from pre-stroke to 10 days, and increased by approximately 20% from 10 days to 1 month. Healthcare providers should note that the prevalence of sarcopenia increases during the acute phase in patients with stroke.

Does grip strength of the less-affected side of ischemic stroke survivors influences performance of self-care activities?

Background and aim

Adequate grip strength is needed to execute various self-care activities. This study was aimed to assess the influence of grip strength of the less-affected side of ischemic stroke survivors on performance of self-care activities, and also to determine the reference values of less-affected grip strength needed for independent performance of each of the self-care activities.

Methods

Seventy-three consenting patients with ischemic stroke participated in this cross-sectional study. Handheld dynamometer was used to measure grip strength of the less-affected hand, while functional independence measure was used to evaluate self-care activities (eating, grooming, bathing, dressing of upper body, dressing of lower body and toileting) as independent and dependent. Data was analyzed using inferential statistics of Pearson’s correlation, binomial logistic regression, and receiver operating characteristics. Alpha level was set at p < 0.05.

Results

The mean hand grip strength, functional independence measure and trunk control test scores were 23.8 kg, 29.9 kg, and 68.2 kg respectively. Grip strength was significantly associated with independence in all of the self-care activities (p < 0.05). Less-affected grip strength of 19.5 kg (sensitivity, 80.4%; specificity, 80.1%; area under curve, 0.85), 23.7 kg (sensitivity, 79%; specificity, 72.2%; area under curve, 0.79), 24.8 kg (sensitivity, 70.2%; specificity, 65.2%; area under curve, 0.75), 24.7 kg (sensitivity, 82.1%; specificity, 80.1%; area under curve, 0.84), 23.7 kg (sensitivity, 80.1%; specificity, 76.1%; area under curve, 0.84), and 19.9 kg (sensitivity, 76.9%; specificity, 76.2%; area under curve, 0.79) was needed for independent performance in eating, grooming, bathing, dressing of upper body, dressing of lower body, and toileting respectively.

Conclusion

The less-affected grip strength of patients with ischemic stroke influences their ability to independently perform self-care activities. The reference values of less-affected grip strength in association with other stroke-related characteristics may help clinicians to estimate independence in eating, grooming, bathing, dressing of upper body, dressing of lower body, and toileting among patients with ischemic stroke.

The association between nutritional intake one week after admission and outcome in acute ischemic stroke patients

OBJECTIVES

Although associations between malnutrition status at stroke admission and poor stroke outcomes have been established, the effect of nutritional intake during the acute phase remains unclear. We aimed to evaluate the associations between nutritional intake one week after admission and the outcome at three months among acute ischemic stroke (AIS) patients.

MATERIALS AND METHODS

Consecutive AIS patients were investigated. Nutritional status at admission was evaluated using the Controlling Nutritional Status score, calculated from the serum albumin, lymphocyte count, and total cholesterol. We retrospectively evaluated nutritional intake (energy and protein) one week after admission, and the cutoff value of each nutritional intake level for good outcome was defined as the modified Rankin Scale 0-2 at three months after stroke onset using the receiver operating characteristic curve.

RESULTS

Of the 205 patients, 146 patients had good outcomes. Mild initial neurological symptoms and good nutritional status at admission were associated with good outcome. The cutoff value of good outcome for protein intake was 0.812 g/kg/day (sensitivity: 0.884, specificity: 0.509) and that for energy intake was 19.0 kcal/kg/day (sensitivity: 0.918, specificity: 0.424). Those nutritional intake indicators were independently associated with good outcome after adjusting for baseline confounders, including stroke severity and nutritional status at admission (protein intake: odds ratio (OR), 4.04; 95% confidence intervals (CIs), 1.14-13.1, and energy intake: OR, 5.00; 95% CIs, 1.41-17.8, respectively).

CONCLUSIONS

Adequate nutritional intake at one week after admission was independently associated with good outcome regardless of the nutritional status at admission or stroke severity.

Ultrasound Assessment of Changes in Muscle Architecture of the Brachialis Muscle After Stroke—A Prospective Study

Objective

To investigate changes in ultrasound-derived muscle architecture parameters of the brachialis and correlations in patients with subacute stroke.

Design

Prospective longitudinal observational study.

Setting

Tertiary inpatient rehabilitation center.

Participants

Fifty adult patients (N=50) who were recruited within the first month poststroke. The patients had a mean age of 57.2±12.3 years and 68.0% were male. The majority of patients had significant upper limb weakness with a low mean Motricity Index of 18.5±24.7 and median elbow flexor strength of grade 0.

Intervention

Not applicable.

Main Outcome Measures

Ultrasound of the intact and hemiparetic brachialis was performed at 3-time intervals: within 1 month of stroke onset and at 1 and 6 months after first assessment. Clinical variables captured included upper limb motor power and elbow flexor spasticity.

Results

Compared to the intact brachialis, there was reduced muscle thickness (1.93 cm vs 2.07 cm, 1.86 cm vs 2.08 cm, 1.85 cm vs 2.05 cm; P=.022) and increased echo intensity (63.3 arbitrary units [AU] vs 56.8 AU, 69.4 AU vs 56.6 AU, 77.4 AU vs 58.2 AU; P<.001) in the hemiparetic brachialis at all assessment intervals (baseline, 1 month, 6 months). Reduction in muscle mass was greater in older patients, with the correlation coefficient ranging from −0.30 (P=.03) at baseline to −0.50 (P<.001) at 6 months. Presence of elbow flexor spasticity at 1-month assessment interval was associated with lower muscle mass reduction (1.93 cm vs 1.74 cm; P=.017), lower echo intensity (65.1 AU vs 75.1 AU; P=.023), and longer fascicle lengths (12.92 cm vs 9.83 cm; P=.002).

Conclusions

Changes including decreased muscle thickness and increased echo intensity of the hemiparetic brachialis were noted over time. Elbow flexor spasticity at 1-month assessment interval appears to mitigate against these changes.

Prevalence and risk factors of stroke-related sarcopenia at the subacute stage: A case control study

Purpose

To investigate the prevalence and risk factors of stroke-related sarcopenia (SRS) in hospitalized patients receiving rehabilitation treatment.

Methods

Approximately, 259 patients with stroke that satisfied the inclusion and exclusion criteria were consecutively recruited between June 2020 and July 2022. The epidemiologic data, history, clinical data, and measured data of the skeletal muscle index were collected. The patients were divided into the sarcopenia and non-sarcopenia group for comparison and analysis with the univariate and multivariate analysis.

Results

SRS was presented in 121 (46.7%) patients with a mean age of 59.6 ± 9.7 years, including 42 women and 79 men. Multivariate logistic regression analysis revealed the following parameters to be significant (p < 0.05) risk factors for SRS: college degree or above (OR, 2.1, 95% CI, 1.1–4.1), ICU stay (OR, 1.7, 95% CI, 1.06–2.8), pneumonia (OR, 1.9, 9% CI, 1.1–3.6), walking ability (OR, 2.6, 95% CI, 1.5–4.6), cognitive impairment (OR, 1.8, 95%, 1.1–2.9), aphasia (OR, 2.1, 95% CI, 1.2–3.5), nasogastric feeding (OR, 3.7, 95%, 1.9–7.3), age (OR, 1.04, 95% CI, 1–1.1), and creatine kinase (OR, 1.1, 95% CI,0.9–1.2).

Conclusions

Older age, light weight, severer clinical conditions, cognitive impairment, and significantly decreased levels of albumin, RAG, creatinine, uric acid, red blood cell count, hemoglobin, prealbumin, iron, and creatine kinase are more significantly present in patients with SRS compared with those without SRS.

Impairments and Compensations of Static Balance and Plantar Load Distribution in Patients With Chronic Stroke: An Observational Study

OBJECTIVES

The purpose of this study was to explore impairment and compensation characteristics of static balance and plantar load distribution in patients with chronic stroke.

METHODS

We recruited 68 patients who had chronic stroke who could stand independently (stroke group) and 30 healthy individuals (control group) with the Zebris FDM platform. Static balance parameters, including center of pressure (COP) ellipse sway area, COP path length, and angle-θ between y and major axis, were compared between 2 groups under standard standing posture. In the stroke group, balance parameters were re-tested under their preferring standing posture. Plantar load distribution was also assessed. Another 8 patients with chronic stroke who could not stand independently and had to rely on a crutch were enrolled to analyze the characteristics of balance compensation.

RESULTS

In the stroke group, the ellipse sway area, COP path length, and angle-θ were significantly larger than those of the control group. Sixty-one (89.7%) patients preferred standing with the affected foot outward-forward supporting, and their preferring standing balance was better than that of standard standing. All patients who could not stand independently tended to compensate for balance with a crutch supporting laterally and also preferred standing with a typical posture- the affected foot was outward-forward.

CONCLUSIONS

In patients post stroke, static balance is impaired mainly at the lateral direction, and patients commonly locate the crutch laterally for compensation of lateral balance. Patients preferred standing with the affected foot outward-forward supporting, and their preferring standing balance was better than that of standard standing, which challenged the necessity of training standing symmetrically.

Brazilian Academy of Neurology practice guidelines for stroke rehabilitation: part I

The Guidelines for Stroke Rehabilitation are the result of a joint effort by the Scientific Department of Neurological Rehabilitation of the Brazilian Academy of Neurology aiming to guide professionals involved in the rehabilitation process to reduce functional disability and increase individual autonomy. Members of the group participated in web discussion forums with predefined themes, followed by videoconference meetings in which issues were discussed, leading to a consensus. These guidelines, divided into two parts, focus on the implications of recent clinical trials, systematic reviews, and meta-analyses in stroke rehabilitation literature. The main objective was to guide physicians, physiotherapists, speech therapists, occupational therapists, nurses, nutritionists, and other professionals involved in post-stroke care. Recommendations and levels of evidence were adapted according to the currently available literature. Part I discusses topics on rehabilitation in the acute phase, as well as prevention and management of frequent conditions and comorbidities after stroke.

Assessment of changes in muscle mass, strength, and quality and activities of daily living in elderly stroke patients

Whether poststroke rehabilitation improves muscle mass and quality along with the recovery of muscle strength is not clear. In this study, we examined the changes in muscle strength, muscle mass, and muscle quality in patients undergoing poststroke rehabilitation and assessed the relationship of these variables with improvement in activities of daily living (ADL). This prospective study was conducted at stroke rehabilitation unit in Japan. Muscle mass and quality were assessed using bioelectrical impedance analysis (BIA). ADLs were assessed using the functional independence measure (FIM). Grip strength of the nonaffected and affected sides was measured using hand dynamometer. All measurements were performed at admission to the stroke rehabilitation unit and at 4 weeks thereafter. We assessed changes in motor FIM items and examined the relationships among the measured variables. This study included 179 patients. Patients received stroke rehabilitation 7 days a week individually. Muscle strength and quality significantly increased after 4 weeks on both the sides. Muscle mass decreased after 4 weeks; however, there was no significant difference between the two time points. Changes in muscle strength and quality showed a significant correlation with improvement in ADLs [r = 0.66 (male), 0.45 (female) and 0.55 (male), 0.31 (female), respectively]; however, muscle mass showed no correlation with improvement in ADLs. Poststroke rehabilitation improves muscle strength and quality, as well as ADLs. Muscle mass is not an appropriate measure to assess the effects of stroke rehabilitation; it is desirable to instead use muscle strength and quality to assess stroke rehabilitation.

Brain’s Energy After Stroke: From a Cellular Perspective Toward Behavior

Stroke is a neurological condition that impacts activity performance and quality of life for survivors. While neurological impairments after the event explain the performance of patients in specific activities, the origin of such impairments has traditionally been explained as a consequence of structural and functional damage to the nervous system. However, there are important mechanisms related to energy efficiency (trade-off between biological functions and energy consumption) at different levels that can be related to these impairments and restrictions: first, at the neuronal level, where the availability of energy resources is the initial cause of the event, as well as determines the possibilities of spontaneous recovery. Second, at the level of neural networks, where the “small world” operation of the network is compromised after the stroke, implicating a high energetic cost and inefficiency in the information transfer, which is related to the neurological recovery and clinical status. Finally, at the behavioral level, the performance limitations are related to the highest cost of energy or augmented energy expenditure during the tasks to maintain the stability of the segment, system, body, and finally, the behavior of the patients. In other words, the postural homeostasis. In this way, we intend to provide a synthetic vision of the energy impact of stroke, from the particularities of the operation of the nervous system, its implications, as one of the determinant factors in the possibilities of neurological, functional, and behavioral recovery of our patients.

How Does Stroke Affect Skeletal Muscle? State of the Art and Rehabilitation Perspective

Long-term disability caused by stroke is largely due to an impairment of motor function. The functional consequences after stroke are caused by central nervous system adaptations and modifications, but also by the peripheral skeletal muscle changes. The nervous and muscular systems work together and are strictly dependent in their structure and function, through afferent and efferent communication pathways with a reciprocal “modulation.” Knowing how altered interaction between these two important systems can modify the intrinsic properties of muscle tissue is essential in finding the best rehabilitative therapeutic approach. Traditionally, the rehabilitation effort has been oriented toward the treatment of the central nervous system damage with a central approach, overlooking the muscle tissue. However, to ensure greater effectiveness of treatments, it should not be forgotten that muscle can also be a target in the rehabilitation process. The purpose of this review is to summarize the current knowledge about the skeletal muscle changes, directly or indirectly induced by stroke, focusing on the changes induced by the treatments most applied in stroke rehabilitation. The results of this review highlight changes in several muscular features, suggesting specific treatments based on biological knowledge; on the other hand, in standard rehabilitative practice, a realist muscle function evaluation is rarely carried out. We provide some recommendations to improve a comprehensive muscle investigation, a specific rehabilitation approach, and to draw research protocol to solve the remaining conflicting data. Even if a complete multilevel muscular evaluation requires a great effort by a multidisciplinary team to optimize motor recovery after stroke.

Changes in muscle architecture on ultrasound in patients early after stroke

BACKGROUND

Early muscle changes are believed to occur in patients with stroke. However, there are insufficient data on the changes in muscle mass and architecture of these patients.

OBJECTIVES

This study investigates differences in ultrasound-derived muscle architecture parameters of the hemiplegic upper and lower limbs in patients with subacute stroke.

METHODS

This is a prospective observational study, which recruited 40 adult patients who had experienced a first ever unilateral stroke (ischemic or hemorrhagic), with a duration of < 1 month post stroke. The brachialis, vastus lateralis and medial gastrocnemius on both the hemiplegic and normal side were evaluated via ultrasound. We recorded clinical variables including Motricity Index, Modified Ashworth Scale (MAS) and Functional Independence Measure (FIM)-walk.

RESULTS

We found reduced mean muscle thickness (p < 0.001) and increased echo intensity (p < 0.001) in the brachialis muscle, increased echo intensity (p = 0.002) in the vastus lateralis muscle, and reduced muscle thickness (p < 0.001) with increased echo intensity (p < 0.001) in the medial gastrocnemius muscle compared to the normal side. There were no significant correlations between ultrasound findings and Motricity Index.

CONCLUSIONS

We report changes in ultrasound-derived muscle architecture in the hemiplegic limbs of patients with subacute stroke, with consistent findings of decreased muscle mass and increased echo intensity.

Ultrasonographic Evaluation of Three Approaches for Botulinum Toxin Injection into Tibialis Posterior Muscle in Chronic Stroke Patients with Equinovarus Foot: An Observational Study

Spastic equinovarus (SEV) foot deformity is commonly observed in patients with post-stroke spasticity. Tibialis posterior (TP) is a common target for botulinum toxin type-A (BoNT-A) injection, as a first-line treatment in non-fixed SEV deformity. For this deep muscle, ultrasonographic guidance is crucial to achieving maximum accuracy for the BoNT-A injection. In current clinical practice, there are three approaches to target the TP: an anterior, a posteromedial, and a posterior. To date, previous studies have failed to identify the best approach for needle insertion into TP. To explore the ultrasonographic characteristics of these approaches, we investigated affected and unaffected legs of 25 stroke patients with SEV treated with BoNT-A. We evaluated the qualitative (echo intensity) and quantitative (muscle depth, muscle thickness, overlying muscle, subcutaneous tissue, cross-sectional area) ultrasound characteristics of the three approaches for TP injection. In our sample, we observed significant differences among almost all the parameters of the three approaches, except for the safety window. Moreover, our analysis showed significant differences in cross-sectional area between treated and untreated. Advantages and disadvantages of each approach were investigated. Our findings can thus provide a suitable reference for clinical settings, especially for novice operators.

Immediate Effect of Whole Body Vibration on Knee Extensor Tendon Stiffness in Hemiparetic Stroke Patients

Background and Objectives: Whole body vibration is widely used to enhance muscle performance, but evidence of its effects on the tendon stiffness of the knee extensor tendon in stroke remains inconclusive. Our study was aimed to determine the difference in patellar and quadriceps tendon stiffness between hemiparetic and unaffected limbs in stroke patients and to investigate the immediate effect of whole body vibration on tendon stiffness. Materials and Methods: The patellar and quadriceps tendon stiffness of first-ever hemiplegic stroke patients was evaluated with elastography to compare the differences between hemiparetic and unaffected limbs. After one 20 min session of whole body vibration exercise in the standing position, tendon stiffness was again measured to evaluate the immediate effects of whole body vibration on tendon stiffness. Results: The results showed no significant differences in the tendon stiffness of the patellar and quadriceps tendons between hemiparetic and unaffected limbs. However, significant associations were found between the tendon stiffness of the patellar and quadriceps tendons and knee extensor spasticity on the hemiparetic side (ρ = 0.62; p = 0.044). There were no significant changes in tendon stiffness after a single session of whole body vibration. Conclusions: In conclusion, knee extensor tendon stiffness in hemiparetic limbs is positively correlated to the degree of knee extensor spasticity in stroke patients. However, a single session of whole body vibration does not alter tendon stiffness.

Elderly Patients after Stroke Increase Skeletal Muscle Mass by Exercise Therapy in Rehabilitation Wards

BACKGROUND

Loss of skeletal muscle is a critical health issue that frequently occurs due to aging and various pathologies. No studies have reported increases in appendicular skeletal muscle mass among elderly patients after stroke. Our hypothesis was that even older individuals after stroke could increase skeletal muscle mass by rehabilitation.

OBJECTIVES

This study aimed to evaluate changes to skeletal muscle mass in elderly patients after stroke rehabilitation and to assess factors associated with skeletal muscle mass increases.

MATERIALS AND METHODS

Participants in this case-control study were 159 patients ≥ 80 years old in rehabilitation wards after stroke. Body mass index (BMI), appendicular skeletal muscle index (SMI), Functional Independence Measure (FIM), interval from onset to transfer, presence of hemiplegia, National Institutes of Health Stroke Scale (NIHSS), length of hospital stay for rehabilitation, period of exercise therapy per day, and protein intake were examined. Multivariate logistic regression analysis was performed to identify association between these values and SMI increases.

RESULTS

SMI at discharge was significantly increased (5.30 kg/m²) compared to baseline (5.20kg/m²; p = 0.002). Multiple logistic regression analysis showed that length of hospital stay and protein intake were significantly associated with SMI increases, with odds ratios of 1.013 (95% confidence interval, 1.005-1.022) and 3.746 (95% confidence interval, 1.077-13.028), respectively.

CONCLUSIONS

The SMI of patients ≥ 80 years old increased significantly with rehabilitation after stroke. In addition, length of hospital stay and protein intake were independently associated with increases in SMI.

Effect of Improvement in Sarcopenia on Functional and Discharge Outcomes in Stroke Rehabilitation Patients

This cross-sectional study investigated the proportion of patients’ recovery from sarcopenia status and the relationship between improvement in sarcopenia (IS) and function and discharge outcome in hospitalized patients with stroke. This study included patients with stroke, aged 65 years or more, with a diagnosis of sarcopenia, who were admitted to a convalescent rehabilitation ward. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 criteria. Patients were divided according to the presence or absence of sarcopenia at discharge: IS group and non-improvement in sarcopenia (NIS) group. Among the 227 participants (mean age: 80.5 years; 125 females), 30% (69/227) of the patients were in the IS group, while 70% (158/227) were in the NIS group. The IS group showed a higher Functional Independence Measure (FIM) than the NIS group (median 112 vs. 101, p = 0.003). The results demonstrated that IS was independently associated with higher FIM (partial regression coefficient, 5.378; 95% confidence interval (CI), 0.709–10.047). The IS group had higher odds of home discharge than the NIS group (odds ratio, 2.560; 95% CI, 0.912–7.170). In conclusion, recovery from sarcopenia may be associated with better function in patients with stroke.

An Exercise Mimetic Approach to Reduce Poststroke Deconditioning and Enhance Stroke Recovery

Evidence supports early rehabilitation after stroke to limit disability. However, stroke survivors are typically sedentary and experience significant cardiovascular and muscular deconditioning. Despite growing consensus that preclinical and clinical stroke recovery research should be aligned, there have been few attempts to incorporate cardiovascular and skeletal muscle deconditioning into animal models of stroke. Here, we demonstrate in rats that a hindlimb sensorimotor cortex stroke results in both cardiovascular and skeletal muscle deconditioning and impairments in gait akin to those observed in humans. To reduce poststroke behavioral, cardiovascular, and skeletal muscle perturbations, we then used a combinatorial intervention consisting of aerobic and resistance exercise in conjunction with administration of resveratrol (RESV), a drug with exercise mimetic properties. A combination of aerobic and resistance exercise mitigated decreases in cardiovascular fitness and attenuated skeletal muscle abnormalities. RESV, beginning 24 hours poststroke, reduced acute hindlimb impairments, improved recovery in hindlimb function, increased vascular density in the perilesional cortex, and attenuated skeletal muscle fiber changes. Early RESV treatment and aerobic and resistance exercise independently provided poststroke benefits, at a time when individuals are rapidly becoming deconditioned as a result of inactivity. Although no additive effects were observed in these experiments, this approach represents a promising strategy to reduce poststroke behavioral impairments and minimize deconditioning. As such, this treatment regime has potential for enabling patients to engage in more intensive rehabilitation at an earlier time following stroke when mechanisms of neuroplasticity are most prevalent.

BoNT-A for Post-Stroke Spasticity: Guidance on Unmet Clinical Needs from a Delphi Panel Approach

There is extensive literature supporting the efficacy of botulinum toxin (BoNT-A) for the treatment of post-stroke spasticity, however, there remain gaps in the routine management of patients with post-stroke spasticity. A panel of 21 Italian experts was selected to participate in this web-based survey Delphi process to provide guidance that can support clinicians in the decision-making process. There was a broad consensus among physicians that BoNT-A intervention should be administered as soon as the spasticity interferes with the patients' clinical condition. Patients monitoring is needed over time, a follow-up of 4-6 weeks is considered necessary. Furthermore, physicians agreed that treatment should be offered irrespective of the duration of the spasticity. The Delphi consensus also stressed the importance of patient-centered goals in order to satisfy the clinical needs of the patient regardless of time of onset or duration of spasticity. The findings arising from this Delphi process provide insights into the unmet needs in managing post-stroke spasticity from the clinician's perspective and provides guidance for physicians for the utilization of BoNT-A for the treatment of post-stroke spasticity in daily practice.

Validity and reliability of myotonometry for assessing muscle viscoelastic properties in patients with stroke: a systematic review and meta-analysis

There is a lack of consensus about the measurement of the muscle viscoelastic features in stroke patients. Additionally, the psychometric properties of the most-commonly used clinical tools remain controversial. Our objective is to investigate the validity and reliability of myotonometry to assess viscoelastic muscle features in stroke survivors. Pubmed, PEDro, Scopus and Cinahl were systematically searched to include studies reporting the psychometric properties of myotonometric devices used in people after stroke. The QUADAS-2 and the COSMIN checklists were used to assess the methodological quality of the studies and the psychometric properties of myotonometry. Nine studies were included in the qualitative synthesis and data from five of these were pooled in a meta-analysis. Overall, low to moderate risk of bias and applicability concerns were observed. Pooled data from intra-rater reliability for muscle tone showed a mean coefficient of correlation of 0.915 (95% CI: 0.880-0.940, I 2 = 69.2%) for upper limbs, and a mean coefficient of 0.785 (95%CI: 0.708-0.844, I 2 = 4.02%) for lower limbs. Myotonometry seems to be a valid and reliable complementary tool to assess muscle viscoelastic properties in stroke survivors, although definite conclusions about concurrent validity need further research.

Effects of a Music-Based Rhythmic Auditory Stimulation on Gait and Balance in Subacute Stroke

Gait and balance impairments are common after stroke. This study aimed to evaluate the effect of a music-based rhythmic auditory stimulation (RAS) in combination with conventional physiotherapy on gait parameters and walking ability in subacute stroke. This single-blind, historical controlled trial, included 55 patients who had suffered a stroke within the three weeks prior to enrolment. Patients from 2018 (n = 27) were assigned as the historical control group whereas 2019 patients (n = 28) received music-based RAS three times a week. Both groups received 11 h of conventional physiotherapy per week during hospitalization. Primary outcomes were gait and balance parameters (Tinetti test and Timed Up&Go test) and walking ability (Functional Ambulation Category scale). Secondary outcomes were trunk control, assistive devices, functional independence (Functional Independence Measure, Barthel index), and stroke severity and disability (modified Rankin scale, National Institutes of Health Stroke Scale). Results: No between-group differences were identified for gait and balance parameters nor for secondary outcomes. Significant between-group differences were observed in the Functional Ambulation Category: the intervention group (Δmean ± SD; 3.43 ± 1.17) showed greater improvement (p = 0.002) than the control group (Δmean ± SD; 2.48 ± 1.09). Compared with conventional physiotherapy alone, our results suggest that the walking ability of subacute stroke patients might be improved with music-based RAS combined with conventional physiotherapy, but this treatment is not more effective than conventional physiotherapy in obtaining gait and balance gains.

Central activation deficits contribute to post stroke lingual weakness in a rat model

Lingual weakness frequently occurs after stroke and is associated with deficits in speaking and swallowing. Chronic weakness after stroke has been attributed to both impaired central activation of target muscles and reduced force-generating capacity within muscles. How these factors contribute to lingual weakness is not known. We hypothesized that lingual weakness due to middle cerebral artery occlusion (MCAO) would manifest as reduced muscle force capacity and reduced muscle activation. Rats were randomized into MCAO or sham surgery groups. Maximum volitional tongue forces were quantified 8 wk after surgery. Hypoglossal nerve stimulation was used to assess maximum stimulated force, muscle twitch properties, and force-frequency response. The central activation ratio was determined by maximum volitional/maximum stimulated force. Genioglossus muscle fiber type properties and neuromuscular junction innervation were assessed. Maximum volitional force and the central activation ratio were significantly reduced with MCAO. Maximum stimulated force was not significantly different. No significant differences were found for muscle twitch properties, unilateral contractile properties, muscle fiber type percentages, or fiber size. However, the twitch/tetanus ratio was significantly increased in the MCAO group relative to sham. A small but significant increase in denervated neuromuscular junctions (NMJs) and fiber-type grouping occurred in the contralesional genioglossus. Results suggest that the primary cause of chronic lingual weakness after stroke is impaired muscle activation rather than a deficit of force-generating capacity in lingual muscles. Increased fiber type grouping and denervated NMJs in the contralesional genioglossus suggest that partial reinnervation of muscle fibers may have preserved force-generating capacity, but not optimal activation patterns.NEW & NOTEWORTHY Despite significant reductions in maximum volitional forces, the intrinsic force-generating capacity of the protrusive lingual muscles was not reduced with unilateral cerebral ischemia. Small yet significant increases in denervated NMJs and fiber-type grouping of the contralesional genioglossus suggest that the muscle underwent denervation and reinnervation. Together these results suggest that spontaneous neuromuscular plasticity was sufficient to prevent atrophy, yet central activation deficits remain and contribute to chronic lingual weakness after stroke.

Association Between Length of Stay in the Intensive Care Unit and Sarcopenia Among Hemiplegic Stroke Patients

Objective

To discuss the association between the length of stay at the intensive care unit (ICU) and sarcopenia among hemiplegic stroke patients.

Methods

This study evaluated 66 hemiplegic stroke patients with history of ICU admission using handgrip strength and bioelectrical impedance analysis to obtain height-adjusted appendicular skeletal muscle mass. The diagnosis of sarcopenia was made according to the muscle mass based on the Asian Working Group for Sarcopenia. The patients were divided into sarcopenic and non-sarcopenic groups. The two groups were statistically analyzed, and the significant factors with differences were studied. A multivariate logistic regression analysis was performed to examine the association between length of stay in the ICU and sarcopenia, after adjusting for potential confounders.

Results

Among 66 hemiplegic patients with an ICU admission history, 12 patients were diagnosed with sarcopenia. Sarcopenia patients showed lower scores on the Korean version of the Modified Barthel Index and the Korean version of the Mini-Mental State Examination. Additionally, patients with sarcopenia had a longer length of stay in the ICU, and univariate and multivariate analyses confirmed that the ICU length of stay was significantly related to sarcopenia (adjusted odds ratio=1.187; 95% confidence interval, 1.019–1.382; p=0.028).

Conclusion

The length of stay in the ICU was significantly associated with sarcopenia in hemiplegic stroke patients.

Malondialdehyde as a Useful Biomarker of Low Hand Grip Strength in Community-Dwelling Stroke Patients

The assessment of muscle strength by hand grip strength (HGS) is used to evaluate muscle weakness and wasting among stroke patients. This study aimed to investigate the association of oxidative stress/oxidative damage and inflammatory biomarkers with muscle strength and wasting, as evaluated by HGS, among community-dwelling post-stroke patients. The HGS of both paretic and non-paretic limbs was negatively associated with modified Rankin scale (mRS) values. The serum levels of catalase activity and malondialdehyde (MDA), and plasma tumor necrosis factor (TNF)-α levels were significantly increased in post-stroke patients compared with non-stroke controls. Further analysis highlighted that hydrogen peroxide was positively correlated with HGS in the paretic limbs. Interestingly, an elevated MDA level, excluding advanced age and high mRS, increased the risk of low HGS in the non-paretic limbs of stroke patients. This study suggests that there is a detrimental association between MDA and muscle strength and early muscle wasting among post-stroke patients. Hence, MDA is a potentially useful biomarker of muscle weakness and wasting in post-stroke patients living in the community.

Stroke and sarcopenia

Purpose of review

to evaluate recent scientific research studies related to the changes in skeletal muscle after stroke and the presence of sarcopenia in stroke survivors to establish its incidence and effects on function.

Recent Findings

Recently published findings on stroke-related sarcopenia are limited. This might be due to changes in the consensus definition of sarcopenia. Sarcopenia in stroke patients is estimated at 14 to 54%. The presence of sarcopenia at the time of a stroke can lead to worse recovery and functional outcomes.

Summary

Presence of sarcopenia prior to a stroke may be more common than suspected and can lead to worse functional recovery. Clinicians should be aware of this to better identify and treat stroke-related sarcopenia. Future research should focus on larger population studies to more accurately establish correlation between stroke and sarcopenia.

Patterns of lower limb muscular activity and joint moments during directional efforts using a static dynamometer

Background

Strength and coordination of lower muscle groups typically identified in healthy subjects are two prerequisites to performing functional activities. These physical qualities can be impaired following a neurological insult. A static dynamometer apparatus that measures lower limb joint moments during directional efforts at the foot was developed to recruit different patterns of muscular activity. The objectives of the present study were to 1) validate joint moments estimated by the apparatus, and 2) to characterize lower limb joint moments and muscular activity patterns of healthy subjects during progressive static efforts. Subjects were seated in a semi-reclined position with one foot attached to a force platform interfaced with a laboratory computer. Forces and moments exerted under the foot were computed using inverse dynamics, allowing for the estimation of lower limb joint moments.

To achieve the study’s first objective, joint moments were validated by comparing moments of various magnitudes of force applied by turnbuckles on an instrumented leg equipped with strain gauges with those estimated by the apparatus. Concurrent validity and agreement were assessed using Pearson correlation coefficients and Bland and Altman analysis, respectively. For the second objective, joint moments and muscular activity were characterized for five healthy subjects while exerting progressive effort in eight sagittal directions. Lower limb joint moments were estimated during directional efforts using inverse dynamics. Muscular activity of eight muscles of the lower limb was recorded using surface electrodes and further analyzed using normalized root mean square data.

Results

The joint moments estimated with the instrumented leg were correlated (r > 0.999) with those measured by the dynamometer. Limits of agreement ranged between 8.5 and 19.2% of the average joint moment calculated by both devices. During progressive efforts on the apparatus, joint moments and patterns of muscular activity were specific to the direction of effort. Patterns of muscular activity in four directions were similar to activation patterns reported in the literature for specific portions of gait cycle.

Conclusion

This apparatus provides valid joint moments exerted at the lower limbs. It is suggested that this methodology be used to recruit muscular activity patterns impaired in neurological populations.