Correlations in abnormal synergies between the upper and lower extremities across various phases of stroke.

The flexion synergy and extension synergy are a representative consequence of a stroke and appear in the upper extremity and the lower extremity. Since the ipsilesional corticospinal tract (CST) is the most influential neural pathway for both extremities in motor execution, damage by a stroke to this tract could lead to similar motor pathological features (e.g., abnormal synergies) in both extremities. However, less attention has been paid to the interlimb correlations in the flexion synergy and extension synergy across different recovery phases of a stroke. We used results of the Fugl-Meyer assessment (FMA) to characterize those correlations in a total of 512 participants with hemiparesis after stroke from the acute phase to 1 year. The FMA provides indirect indicators of the degrees of the flexion synergy and extension synergy after stroke. We found that, generally, strong interlimb correlations (r > 0.65 with all P values < 0.0001) between the flexion synergy and extension synergy appeared in the acute-to-subacute phase (<90 days). However, the correlations of the lower-extremity extension synergy with the upper-extremity flexion synergy and extension synergy decreased (down to r = 0.38) 360 days after stroke (P < 0.05). These results suggest that the preferential use of alternative neural pathways after damage by a stroke to the CST enhances the interlimb correlations between the flexion synergy and extension synergy. At the same time, the results imply that the recovery of CST integrity or/and the fragmentation (remodeling) of the alternative neural substrates in the chronic phase may contribute to diversity in neural pathways in motor execution, eventually leading to reduced interlimb correlations.NEW & NOTEWORTHY For the first time, this article addresses the asynchronous relationships in the strengths of flexion and extension synergy expressions between the paretic upper extremity and lower extremity across various phases of stroke.

Explicit and implicit locomotor learning in individuals with chronic hemiparetic stroke.

Motor learning involves both explicit and implicit processes that are fundamental for acquiring and adapting complex motor skills. However, stroke may damage the neural substrates underlying explicit and/or implicit learning, leading to deficits in overall motor performance. Although both learning processes are typically used in concert in daily life and rehabilitation, no gait studies have determined how these processes function together after stroke when tested during a task that elicits dissociable contributions from both. Here, we compared explicit and implicit locomotor learning in individuals with chronic stroke to age- and sex-matched neurologically intact controls. We assessed implicit learning using split-belt adaptation (where two treadmill belts move at different speeds). We assessed explicit learning (i.e., strategy-use) using visual feedback during split-belt walking to help individuals explicitly correct for step length errors created by the split-belts. After the first 40 strides of split-belt walking, we removed the visual feedback and instructed individuals to walk comfortably, a manipulation intended to minimize contributions from explicit learning. We used a multirate state-space model to characterize individual explicit and implicit process contributions to overall behavioral change. The computational and behavioral analyses revealed that, compared with controls, individuals with chronic stroke demonstrated deficits in both explicit and implicit contributions to locomotor learning, a result that runs counter to prior work testing each process individually during gait. Since poststroke locomotor rehabilitation involves interventions that rely on both explicit and implicit motor learning, future work should determine how locomotor rehabilitation interventions can be structured to optimize overall motor learning. NEW & NOTEWORTHY Motor learning involves both implicit and explicit processes, the underlying neural substrates of which could be damaged after stroke. Although both learning processes are typically used in concert in daily life and rehabilitation, no gait studies have determined how these processes function together after stroke. Using a locomotor task that elicits dissociable contributions from both processes and computational modeling, we found evidence that chronic stroke causes deficits in both explicit and implicit locomotor learning.

Enhanced phasic calf muscle activation with swing resistance enhances propulsion of the paretic leg in people poststroke.

Reduced propulsion of the paretic leg contributes to impaired walking in people poststroke. The goal of this study was to determine whether phasic electrical stimulation to the paretic gastrocnemius muscle combined with resistance applied to the nonparetic leg during swing phase while walking would enhance muscle activation of the paretic gastrocnemius and propulsive force of the paretic leg. Fifteen individuals who had a stroke visited the lab once to complete two experimental sessions (i.e., crossover design; session order randomized). Each session consisted of 1) treadmill walking with either "motor stimulation and swing resistance" or "swing resistance only" (10-min walking: 1-min baseline, 7-min adaptation to intervention, and 2-min postadaptation) and 2) instrumented treadmill walking before and after treadmill walking. Participants showed enhanced muscle activation of the paretic gastrocnemius (P = 0.03) and improved anteroposterior ground reaction force of the paretic leg (P = 0.01) immediately after the treadmill walking with "motor stimulation and swing resistance," whereas no improvements after the walking with "swing resistance only." Those enhanced gastrocnemius muscle activation (P = 0.02) and improved ground reaction force (P = 0.03) were retained until the late postadaptation period and 10 min after treadmill walking, respectively. Walking with "motor stimulation and swing resistance" may enhance forced use of the paretic leg and improve propulsive force of the paretic leg. Applying phasic electrical stimulation to the paretic gastrocnemius muscle and swing resistance to the nonparetic leg during walking can be used as a novel intervention strategy to improve motor control of the paretic leg and walking in people poststroke.NEW & NOTEWORTHY Applying targeted motor stimulation to the paretic calf muscle and swing resistance to the nonparetic leg during walking induced significant enhancement in muscle activation of the paretic gastrocnemius and anterior-posterior ground reaction force of the paretic leg, whereas no enhancements were observed after walking with swing resistance only. Furthermore, the enhanced gastrocnemius muscle activation and ground reaction force of the paretic leg were partially retained at the late postadaptation period and 10 min after treadmill walking.

Motor interference on lateral pelvis shifting towards the paretic leg during walking and its cortical mechanisms in persons with stroke.

Motor interference, where new skill acquisition disrupts the performance of a previously learned skill, is a critical yet underexplored factor in gait rehabilitation post-stroke. This study investigates the interference effects of two different practice schedules, applying interleaved (ABA condition) and intermittent (A-A condition) pulling force to the pelvis during treadmill walking, on lateral pelvis shifting towards the paretic leg in individuals with stroke. Task A involved applying resistive pelvis force (pulling towards the non-paretic side), and Task B applied assistive force (pulling towards the paretic side) at the stance phase of the paretic leg during walking. Sixteen individuals with chronic stroke were tested for gait pattern changes, including lateral pelvis shifting and spatiotemporal gait parameters, and neurophysiological changes, including muscle activity in the paretic leg and beta band absolute power in the lesioned cortical areas. A-A condition demonstrated increased lateral pelvis shifting towards the paretic side, extended paretic stance time and longer non-paretic step length after force release while ABA condition did not show any changes. These changes in gait pattern after A-A condition were accompanied by increased muscle activities of the ankle plantarflexors, and hip adductors/abductors. A-A condition demonstrated greater changes in beta band power in the sensorimotor regions compared to ABA condition. These findings suggest that while walking practice with external force to the pelvis can improve lateral pelvis shifting towards the paretic leg post-stroke, practicing a new pelvis shifting task in close succession may hinder the performance of a previously obtained lateral pelvis shifting pattern during walking.

The CAPN3 p.Lys 254del variant is not always associated with dominant CAPN3-related muscular dystrophy.

INTRODUCTION/AIMS: Limb-girdle muscular dystrophy R1 (LGMDR1) calpain 3-related usually presents as a recessively transmitted weakness of proximal limb-girdle muscles due to pathogenic variants in the CAPN3 gene. Pathogenic variants in this gene have also been found in patients with an autosomal dominantly inherited transmission pattern (LGMDD4). The mechanism underlying this difference in transmission patterns has not yet been elucidated. Camptocormia, progressive limb weakness, myalgia, back pain, and increased CK levels are common clinical features associated with dominant forms. The p.Lys254del pathogenic variant was associated with camptocormia in two LGMDD4 families. This study aimed to present carriers found in recessively transmitted LGMDR1 families bearing the p.Lys254del variant that do not show muscle weakness. METHODS: DNA sequencing was performed on exon 5 of CAPN3 in family members to establish the carrier status of the pathogenic variant. They were evaluated clinically and MRI was performed when available. RESULTS: Two families presented with the p.Lys254del pathogenic variant in a homozygous or compound heterozygous state. Family members carrying only the pathogenic variant in the heterozygous state did not demonstrate the myopathic characteristics described in dominant patients. Camptocormia and other severe clinical symptoms were not observed. DISCUSSION: We conclude that the p.Lys254del pathogenic variant per se cannot be solely responsible for camptocormia in dominant patients. Other undisclosed factors may regulate the phenotype associated with the dominant inheritance pattern in CAPN3 pathogenic variant carriers.

Contrast extravasation mimicking intracerebral and intraventricular hemorrhage after intravenous thrombolytic treatment of ischemic stroke: a case report.

BACKGROUND: Although contrast extravasation on follow-up head computed tomography (CT) is frequently visualized after endovascular treatment, this phenomenon is rare after intravenous thrombolytic treatment in patients with acute ischemic stroke (AIS). Here, we report a case of contrast extravasation mimicking intracerebral hemorrhage (ICH) with intraventricular extension after intravenous thrombolytic treatment and computed tomography angiography (CTA). CASE PRESENTATION: A 52-year-old man presented with right-sided hemiparesis and hypoesthesia. Initial non-contrast head CT was negative for intracranial hemorrhage and acute ischemic changes. He received intravenous treatment with tenecteplase 3.8 h after the onset of stroke. CTA of the head and neck was performed at 4.3 h after stroke onset. It showed no stenosis or occlusion of the carotid and major intracranial arteries. At about 1.5 h after CTA, the right-sided hemiparesis deteriorated, accompanied by drowsiness, aphasia, and urinary incontinence. Immediate head CT showed hyperdense lesions with mild space-occupying effect in the left basal ganglia and both lateral ventricles. The hyperdense lesions were reduced in size on follow-up CT after 5 h. Two days later, CT showed that the hyperdense lesions in the lateral ventricles almost completely disappeared and only a small amount remained in the infarcted area. CONCLUSIONS: Contrast extravasation into the brain tissue and lateral ventricles, mimicking ICH with intraventricular extension, could occur after intravenous thrombolytic treatment and CTA in a patient with AIS, which might lead to misdiagnosis and wrong treatment of the patient. The rapid resolution of intracranial hyperdense lesions is key to differentiate contrast extravasation from ICH on serial non-enhanced CT.

Sensory Stimulation and Robot-Assisted Arm Training After Stroke: A Randomized Controlled Trial.

BACKGROUND AND PURPOSE: Functional recovery after stroke is often limited, despite various treatment methods such as robot-assisted therapy. Repetitive sensory stimulation (RSS) might be a promising add-on therapy that is thought to directly drive plasticity processes. First positive effects on sensorimotor function have been shown. However, clinical studies are scarce, and the effect of RSS combined with robot-assisted training has not been evaluated yet. Therefore, our objective was to investigate the feasibility and sensorimotor effects of RSS (compared to a control group receiving sham stimulation) followed by robot-assisted arm therapy. METHODS: Forty participants in the subacute phase (4.4-23.9 weeks) after stroke with a moderate to severe arm paresis were randomized to RSS or control group. Participants received 12 sessions of (sham-) stimulation within 3 weeks. Stimulation of the fingertips and the robot-assisted therapy were each applied in 45-min sessions. Motor and sensory outcome assessments (e.g. Fugl-Meyer-Assessment, grip strength) were measured at baseline, post intervention and at a 3-week follow-up. RESULTS: Participants in both groups improved their sensorimotor function from baseline to post and follow-up measurements, as illustrated by most motor and sensory outcome assessments. However, no significant group effects were found for any measures at any time ( P > 0.058). Stimulations were well accepted, no safety issues arose. DISCUSSION AND CONCLUSIONS: Feasibility of robot-assisted therapy with preceding RSS in persons with moderate to severe paresis was demonstrated. However, RSS preceding robot-assisted training failed to show a preliminary effect compared to the control intervention. Participants might have been too severely affected to identify changes driven by the RSS, or these might have been diluted or more difficult to identify because of the additional robotic training and neurorehabilitation. VIDEO ABSTRACT AVAILABLE: for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A478 ).

Neurological and neuromuscular manifestations in patients with West Nile neuroinvasive disease, Belgrade area, Serbia, season 2022.

INTRODUCTION: We aimed to describe neurological manifestations and functional outcome at discharge in patients with West Nile neuroinvasive disease. METHODS: This retrospective study enrolled inpatients treated in the University Clinic for Infectious and Tropical Diseases in Belgrade, Serbia, from 1 June until 31 October 2022. Functional outcome at discharge was assessed using modified Rankin scale. RESULTS: Among the 135 analyzed patients, encephalitis, meningitis and acute flaccid paralysis (AFP) were present in 114 (84.6%), 20 (14.8%), and 21 (15.6%), respectively. Quadriparesis/quadriplegia and monoparesis were the most frequent forms of AFP, present in 9 (6.7%) and 6 (4.4%) patients, respectively. Fourty-five (33.3%) patients had cerebellitis, 80 (59.3%) had rhombencephalitis, and 5 (3.7%) exhibited Parkinsonism. Ataxia and wide-based gait were present in 79 (58.5%) patients each. Fifty-one (37.8%) patients had tremor (41 (30.3%) had postural and/or kinetic tremor, 10 (7.4%) had resting tremor). Glasgow coma score (GCS) ≤ 8 and respiratory failure requiring mechanical ventilation developed in 39 (28.9%), and 33 (24.4%) patients, respectively. Quadriparesis was a risk factor for prolonged ventilator support (29.5 ± 16.8 vs. 12.4 ± 8.7 days, p = 0.001). At discharge, one patient with monoparesis recovered full muscle strength, whereas 8 patients with AFP were functionally dependent. Twenty-nine (21.5%) patients died. All of the succumbed had encephalitis, and 7 had quadriparesis. Ataxia, tremor and cognitive deficit persisted in 18 (16.9%), 15 (14.2%), and 22 (16.3%) patients at discharge, respectively. Age, malignancy, coronary disease, quadriparesis, mechanical ventilation, GCS ≤ 8 and healthcare-associated infections were risk factors for death (p = 0.001; p = 0.019; p = 0.004; p = 0.001; p < 0.001; p < 0.001, and p < 0.001, respectively).

Olfactory Dysfunction as a Marker for Cognitive Impairment in General Paresis of the Insane: A Clinical Study.

BACKGROUND General paresis of the insane (GPI) is characterized by cognitive impairment, neuropsychiatric symptoms, and brain structural abnormalities, mimicking many neuropsychiatric diseases. Olfactory dysfunction has been linked to cognitive decline and neuropsychiatric symptoms in numerous neuropsychiatric diseases. Nevertheless, it remains unclear whether patients with GPI experience olfactory dysfunction and whether olfactory dysfunction is associated with their clinical manifestations. MATERIAL AND METHODS Forty patients with GPI and 37 healthy controls (HCs) underwent the "Sniffin Sticks" test battery, Mini-Mental State Examination, and Neuropsychiatric Inventory to measure olfactory function, cognitive function, and neuropsychiatric symptoms, respectively. Brain structural abnormalities were evaluated using visual assessment scales including the medial temporal lobe atrophy (MTA) visual rating scale and Fazekas scale. RESULTS Compared with HCs, patients with GPI exhibited significant olfactory dysfunction, as indicated by deficits in the odor threshold (OT) (P=0.001), odor discrimination (OD) (P<0.001), and odor identification (OI) (P<0.001). In patients with GPI, the OI was positively correlated with cognitive function (r=0.57, P<0.001), but no significant correlation was found between olfactory function and neuropsychiatric symptoms, blood, or cerebrospinal fluid biomarkers (rapid plasma reagin circle card test and Treponema pallidum particle agglutination test), or brain structural abnormalities (MTA and Fazekas scale scores). Mediation analysis indicated that the impaired OI in patients with GPI was mediated by cognitive impairment and impaired OT respectively. CONCLUSIONS Patients with GPI exhibited overall olfactory dysfunction. OI is correlated with cognitive function and the impaired OI is mediated by cognitive impairment in patients with GPI. Thus, OI may serve as a marker for reflecting cognitive function in patients with GPI.

Alternating Hot-Cold Water Immersion Facilitates Motor Function Recovery in the Paretic Upper Limb After Stroke: A Pilot Randomized Controlled Trial.

OBJECTIVE: To assess the effectiveness of alternating hot-cold water immersion (AHCWI) in patients with acute stroke. DESIGN: A single-blind pilot randomized controlled trial. SETTING: Department of Rehabilitation Medicine of a medical center. PARTICIPANTS: Early stroke survivors (N=24) with moderate-to-severe arm paresis. INTERVENTIONS: In addition to conventional rehabilitation, eligible patients were randomly assigned to an AHCWI group (n=12, for AHCWI) or a control group (n=12, for upper limb [UL] cycling exercises) 5 times per week for 6 weeks. MAIN OUTCOME MEASURES: The Fugl-Meyer Assessment motor-UL (FMA-UL) score, Motricity Index-UL (MI-UL) score, modified Motor Assessment Scale (MMAS; including its UL sections, MMAS-UL) score, Berg Balance Scale score, Barthel Index (BI), and modified Ashworth Scale score were assessed by the same uninvolved physical therapist at baseline and after 4 and 6 weeks of intervention. RESULTS: Compared with the control group, the AHCWI group performed better, with significant group effects (P<.05), and exhibited significant improvements in FMA-UL, MI-UL, and MMAS-UL scores at 4 and 6 weeks (P<.05). Although the remaining outcomes were not significantly different, they favored the AHCWI group. Notably, a significant difference was observed in the BI at 4 weeks (P=.032). Significant changes in the muscle tone or adverse effects were not observed in either group after the intervention. CONCLUSIONS: AHCWI with stroke rehabilitation is feasible and may facilitate motor function recovery of the paretic UL after a stroke.

Wearable Integrated Volitional Control Electrical Stimulation Device as Treatment for Paresis of the Upper Extremity in Early Subacute Stroke Patients: A Randomized Controlled Non-inferiority Trial.

OBJECTIVE: To investigate the effect of a wearable integrated volitional control electrical stimulation (WIVES) device that has been developed as more compact and simpler to use in daily life compared with conventional integrated volitional control electrical stimulation (IVES) devices. DESIGN: Randomized controlled non-inferiority trial. SETTING: Convalescent rehabilitation ward. PARTICIPANTS: Patients with paresis of the upper extremity (UE) after early subacute stroke (N=20). INTERVENTIONS: Eligible patients were randomized to receive IVES treatment or WIVES treatment for 8 hours per day for 28 days in daily living, in addition to standard rehabilitation treatment. In both groups, the extensor digitorum communis on the affected side was the target muscle for stimulation. MAIN OUTCOME MEASURE: Primary outcomes were assessed with Fugl-Meyer Assessment of the UE (FMA-UE) before and after treatment. Non-inferiority was determined with a specified margin of non-inferiority. RESULTS: Twenty patients completed the trial (IVES group: n=10, WIVES group: n=10). FMA-UE improved in both groups. The mean change in FMA-UE was 4.7 for the IVES group and 6.0 for the WIVES group (P>.05, 95% confidence interval: -6.73 to 4.13). The mean difference between the groups was 1.3, and the upper 95% confidence interval did not exceed the non-inferiority margin. CONCLUSION: The effectiveness of WIVES treatment is non-inferior to that of IVES treatment. As a portable device, IVES may facilitate the use of affected upper extremities in daily living and may help improve paresis of the UE.

Ramen noodle neuropathy: an atypical case of partial paralysis from malnutrition.

INTRODUCTION: Due to a COVID-related job loss resulting in financial and food insecurity, a 28-year-old woman initiated a diet consisting solely of one cup of ramen noodles daily for twenty-two months, leading to 27 kg of weight loss. Ramen noodles are low in calories and lack key nutrients, including potassium, chloride, and vitamin B12. CASE DESCRIPTION: The patient presented to the emergency department with acute, worsening weakness and paresthesias in her left wrist and hand. Exam revealed no other abnormalities aside from a cachectic appearance. Labs revealed marked hypokalemia, hypochloremia, lactic acidosis, a mixed metabolic alkalosis with respiratory acidosis, and low levels of zinc and copper. An EKG revealed a prolonged QT interval. After a neurology and psychiatry consult, the patient was admitted for failure to thrive with malnutrition, peripheral neuropathy, hypokalemia, and an acid-base disorder. An MRI of the brain was unremarkable. Studies of other nutritional deficiencies, autoimmune conditions, and sexually transmitted infections were unremarkable. The patient received food and vitamin supplementation, was monitored for re-feeding syndrome, and had a significant recovery. DISCUSSION: After stroke, spinal injury, multiple sclerosis, and the most common focal mononeuropathies were ruled out, the clinical focus turned to nutritional deficiencies, the most significant of which was hypokalemia. Prior research has shown that severe hypokalemia can lead to weakness. It has also shown that chronically insufficient dietary intake is a common cause of hypokalemia. This case, with its partial paralysis of a unilateral upper extremity, may add to the known clinical manifestations of hypokalemia. We review the role of hypokalemia and hypochloremia in acid-base dynamics. Etiologies and clinical manifestations of cobalamin, thiamine, pyridoxine, and copper deficiencies, along with lead toxicity, are also discussed. Diagnostic clarity of mononeuropathies in the context of malnutrition and hypokalemia can be aided by urine potassium levels prior to repletion, neuroimaging that includes the cervical spine, and follow-up electromyography.

Clinical validation of automated depth camera-based measurement of the Fugl-Meyer assessment for upper extremity.

OBJECTIVE: Depth camera-based measurement has demonstrated efficacy in automated assessment of upper limb Fugl-Meyer Assessment for paralysis rehabilitation. However, there is a lack of adequately sized studies to provide clinical support. Thus, we developed an automated system utilizing depth camera and machine learning, and assessed its feasibility and validity in a clinical setting. DESIGN: Validation and feasibility study of a measurement instrument based on single cross-sectional data. SETTING: Rehabilitation unit in a general hospital. PARTICIPANTS: Ninety-five patients with hemiparesis admitted for inpatient rehabilitation unit (2021-2023). MAIN MEASURES: Scores for each item, excluding those related to reflexes, were computed utilizing machine learning models trained on participant videos and readouts from force test devices, while the remaining reflex scores were derived through regression algorithms. Concurrent criterion validity was evaluated using sensitivity, specificity, percent agreement and Cohen's Kappa coefficient for ordinal scores of individual items, as well as correlations and intraclass correlation coefficients for total scores. Video-based manual assessment was also conducted and compared to the automated tools. RESULT: The majority of patients completed the assessment without therapist intervention. The automated scoring models demonstrated superior validity compared to video-based manual assessment across most items. The total scores derived from the automated assessment exhibited a high coefficient of 0.960. However, the validity of force test items utilizing force sensing resistors was relatively low. CONCLUSION: The integration of depth camera technology and machine learning models for automated Fugl-Meyer Assessment demonstrated acceptable validity and feasibility, suggesting its potential as a valuable tool in rehabilitation assessment.

Surgical management of transcervical gunshot injury presented with CSF leak and progressive left upper extremity paresis: a case report and literature review.

INTRODUCTION: Penetrating neck trauma (PNT) due to gunshot injuries is one of the challenging conditions with the potential for both significant morbidities and mortality. RESEARCH QUESTION: There are significant concerns in the approach to patients with spinal gunshot injuries. Surgery indications, methods of surgery, and management of CSF leaks are the main concerns of these patients. METHODS AND MATERIALS: An 11-year-old boy was referred to our center with a single gunshot wound to the left side of the posterior cervical region 2 days ago with cerebrospinal fluid leakage and left arm weakness. RESULTS: The patient underwent surgery, and the pellet was removed. His left arm weakness fully recovered after the operation, and no new symptoms developed during the 1-year follow-up. CONCLUSION: Timely surgery could dramatically improve outcomes in PNT patients with mild symptoms and prevent worsening neurological defects.

Unusual presentation of aneurysmal bone cyst (ABC) in children: pediatric intracranial osteosarcoma with secondary ABC.

A 13-year-old female patient presented with painless vision loss and proptosis for 18 months. Imaging findings were highly suggestive of a supraorbital aneurysmal bone cyst (ABC) for which she underwent complete surgical excision. Postoperatively, she developed left hemiparesis. Computed tomography angiography (CTA) revealed right complete internal carotid arterial (ICA) thrombosis. This was managed conservatively, and she improved in hemiparesis over the next 3 weeks. Histopathology report revealed osteosarcoma with secondary ABC, for which she was referred for radiotherapy. At 1.5 months follow-up, the patient's left lower limb power improved to 4 + /5. She was walking without support, and her left upper limb power was 4/5.

Serial sarcomere number is substantially decreased within the paretic biceps brachii in individuals with chronic hemiparetic stroke.

A muscle's structure, or architecture, is indicative of its function and is plastic; changes in input to or use of the muscle alter its architecture. Stroke-induced neural deficits substantially alter both input to and usage of individual muscles. We combined in vivo imaging methods (second-harmonic generation microendoscopy, extended field-of-view ultrasound, and fat-suppression MRI) to quantify functionally meaningful architecture parameters in the biceps brachii of both limbs of individuals with chronic hemiparetic stroke and in age-matched, unimpaired controls. Specifically, serial sarcomere number (SSN) and physiological cross-sectional area (PCSA) were calculated from data collected at three anatomical scales: sarcomere length, fascicle length, and muscle volume. The interlimb differences in SSN and PCSA were significantly larger for stroke participants than for participants without stroke (P = 0.0126 and P = 0.0042, respectively), suggesting we observed muscle adaptations associated with stroke rather than natural interlimb variability. The paretic biceps brachii had ∼8,200 fewer serial sarcomeres and ∼2 cm2 smaller PCSA on average than the contralateral limb (both P < 0.0001). This was manifested by substantially smaller muscle volumes (112 versus 163 cm3), significantly shorter fascicles (11.0 versus 14.0 cm; P < 0.0001), and comparable sarcomere lengths (3.55 versus 3.59 µm; P = 0.6151) between limbs. Most notably, this study provides direct evidence of the loss of serial sarcomeres in human muscle observed in a population with neural impairments that lead to disuse and chronically place the affected muscle at a shortened position. This adaptation is consistent with functional consequences (increased passive resistance to elbow extension) that would amplify already problematic, neurally driven motor impairments.

Effects of photobiomodulation on pain, lactate and muscle performance (ROM, torque, and EMG parameters) of paretic upper limb in patients with post-stroke spastic hemiparesis-a randomized controlled clinical trial.

The objective of the study was to investigate the impact of photobiomodulation (PBM) on the paretic upper limb in post-stroke patients with spastic hemiparesis and to understand the potential of PBM as a long-term non-invasive therapy for reducing the side effects caused by spasticity in the hemiparetic upper limb after a stroke. This is a double-blind randomized clinical trial constituted of 27 participants, being Control group (CG = 12 healthy individuals) and PBM group (PBMG = 15 post-stroke individuals). In the CG, the baseline blood lactate (BL) was evaluated, followed by the evaluation of the IC torque of the biceps and triceps muscles, with the isokinetic dynamometer associated with surface electromyography (EMG) and, subsequently, a new measurement of BL. The PBMG received 10 sessions of treatment with PBM (780 nm, Power: 100 mV, Power Density: 3.18 W/cm2, Energy: 4 J, Fluency: 127.4 J/cm2, Time: 40 s per point and 1.280 s total, Spot: 0.0314 cm2, 32 Points: 16 points (brachial biceps) and 16 points (brachial triceps) applied with contact at 90°, Total Energy: 64 J), which in the pre-treatment evaluation measured BL, the visual analogue scale (VAS) of pain; torque and EMG of the same muscles in the IC, subsequently, a new measurement of VAS and BL, and measurement of range of motion (ROM) during the reaching movement. At the conclusion of the ten sessions, all participants underwent a reassessment, wherein all tests originally administered during the initial evaluation were repeated. Subsequently, the data were analyzed using the Shapiro-Wilk normality test. For related data, the paired t-test was used for normal distributions and the Wilcoxon test for non-normal data. For unrelated data, the t test was used for normal distributions and the Mann-Whitney test for non-normal data. Muscle torque was higher for the CG, with a significant difference (CGxPBMG = p < 0.0001). There was no significant difference between the EMG values of the CG in relation to the Pre-PBM phase and with the Post-PBM phase of the PBMG (p > 0.05). On the other hand, there was a 38% reduction in pain reported by hemiparetic patients (p = 0.0127) and a decrease in BL in the PBMG. Post-PBM ROM increased by 46.1% in the elbow extension of the paretic limb. In conclusion, Photobiomodulation (PBM) demonstrated significant improvements in muscle performance, reducing fatigue and pain levels, and enhancing range of motion in post-stroke patients with spastic hemiparesis. These findings support the potential integration of PBM into rehabilitation protocols, but further research and clinical trials are needed to validate and expand upon these promising outcomes.

Validity of an android device for assessing mobility in people with chronic stroke and hemiparesis: a cross-sectional study.

BACKGROUND: Incorporating instrument measurements into clinical assessments can improve the accuracy of results when assessing mobility related to activities of daily living. This can assist clinicians in making evidence-based decisions. In this context, kinematic measures are considered essential for the assessment of sensorimotor recovery after stroke. The aim of this study was to assess the validity of using an Android device to evaluate kinematic data during the performance of a standardized mobility test in people with chronic stroke and hemiparesis. METHODS: This is a cross-sectional study including 36 individuals with chronic stroke and hemiparesis and 33 age-matched healthy subjects. A simple smartphone attached to the lumbar spine with an elastic band was used to measure participants' kinematics during a standardized mobility test by using the inertial sensor embedded in it. This test includes postural control, walking, turning and sitting down, and standing up. Differences between stroke and non-stroke participants in the kinematic parameters obtained after data sensor processing were studied, as well as in the total execution and reaction times. Also, the relationship between the kinematic parameters and the community ambulation ability, degree of disability and functional mobility of individuals with stroke was studied. RESULTS: Compared to controls, participants with chronic stroke showed a larger medial-lateral displacement (p = 0.022) in bipedal stance, a higher medial-lateral range (p < 0.001) and a lower cranio-caudal range (p = 0.024) when walking, and lower turn-to-sit power (p = 0.001), turn-to-sit jerk (p = 0.026) and sit-to-stand jerk (p = 0.001) when assessing turn-to-sit-to-stand. Medial-lateral range and total execution time significantly correlated with all the clinical tests (p < 0.005), and resulted significantly different between independent and limited community ambulation patients (p = 0.042 and p = 0.006, respectively) as well as stroke participants with significant disability or slight/moderate disability (p = 0.024 and p = 0.041, respectively). CONCLUSION: This study reports a valid, single, quick and easy-to-use test for assessing kinematic parameters in chronic stroke survivors by using a standardized mobility test with a smartphone. This measurement could provide valid clinical information on reaction time and kinematic parameters of postural control and gait, which can help in planning better intervention approaches.

The influence of scaffolding on intrinsic motivation and autonomous adherence to a game-based, sparsely supervised home rehabilitation program for people with upper extremity hemiparesis due to stroke. A randomized controlled trial.

BACKGROUND: This parallel, randomized controlled trial examined intrinsic motivation, adherence and motor function improvement demonstrated by two groups of subjects that performed a 12-week, home-based upper extremity rehabilitation program. Seventeen subjects played scaffolded games, presenting eight to twelve discrete levels of increasing difficulty. Sixteen subjects performed the same activities controlled by success algorithms that modify game difficulty incrementally. METHODS: 33 persons 20-80 years of age, at least 6 months post stroke with moderate to mild hemiparesis were randomized using a random number generator into the two groups. They were tested using the Action Research Arm Test, Upper Extremity Fugl Meyer Assessment, Stroke Impact Scale and Intrinsic Motivation Inventory pre and post training. Adherence was measured using timestamps generated by the gaming system. Subjects had the Home Virtual Rehabilitation System (Qiu in J Neuroeng Rehabil 17: 1-10, 2020) placed in their homes and were taught to perform rehabilitation games using it. Subjects were instructed to train twenty minutes per day but were allowed to train as much as they chose. Subjects trained for 12 weeks without appointments and received intermittent support from study staff. Group outcomes were compared using ANOVA. Correlations between subject demographics and adherence, as well as motor outcome, were evaluated using Pearson Correlation Coefficients. RESULTS: There were 5 dropouts and no adverse events. The main effect of time was statistically significant for four of the five clinical outcome measures. There were no significant training group by time interactions. Measures of adherence did not differ significantly between groups. The combined groups improved their UEFMA scores on average by 5.85 (95% CI 4.73-6.98). 21 subjects from both groups demonstrating improvements in UEFMA scores of at least 5 points, exceeding the minimal clinically important difference of 4.25. IMI scores were stable pre to post training. CONCLUSIONS: Scaffolding challenges during game based rehabilitation did not elicit higher levels of adherence when compared to algorithm control of game difficulty. Both sparsely supervised programs of game-based treatment in the home were sufficient to elicit statistically significant, clinically meaningful improvements in motor function and activities of daily living. TRIAL REGISTRATION: Clinical Trials.gov-NCT03985761, Registered June 14, 2019.

Measurement properties of movement smoothness metrics for upper limb reaching movements in people with moderate to severe subacute stroke.

BACKGROUND: Movement smoothness is a potential kinematic biomarker of upper extremity (UE) movement quality and recovery after stroke; however, the measurement properties of available smoothness metrics have been poorly assessed in this group. We aimed to measure the reliability, responsiveness and construct validity of several smoothness metrics. METHODS: This ancillary study of the REM-AVC trial included 31 participants with hemiparesis in the subacute phase of stroke (median time since stroke: 38 days). Assessments performed at inclusion (Day 0, D0) and at the end of a rehabilitation program (Day 30, D30) included the UE Fugl Meyer Assessment (UE-FMA), the Action Research Arm Test (ARAT), and 3D motion analysis of the UE during three reach-to-point movements at a self-selected speed to a target located in front at shoulder height and at 90% of arm length. Four smoothness metrics were computed: a frequency domain smoothness metric, spectral arc length metric (SPARC); and three temporal domain smoothness metrics (TDSM): log dimensionless jerk (LDLJ); number of submovements (nSUB); and normalized average rectified jerk (NARJ). RESULTS: At D30, large clinical and kinematic improvements were observed. Only SPARC and LDLJ had an excellent reliability (intra-class correlation > 0.9) and a low measurement error (coefficient of variation < 10%). SPARC was responsive to changes in movement straightness (rSpearman=0.64) and to a lesser extent to changes in movement duration (rSpearman=0.51) while TDSM were very responsive to changes in movement duration (rSpearman>0.8) and not to changes in movement straightness (non-significant correlations). Most construct validity hypotheses tested were verified except for TDSM with low correlations with clinical metrics at D0 (rSpearman<0.5), ensuing low predictive validity with clinical metrics at D30 (non-significant correlations). CONCLUSIONS: Responsiveness and construct validity of TDSM were hindered by movement duration and/or noise-sensitivity. Based on the present results and concordant literature, we recommend using SPARC rather than TDSM in reaching movements of uncontrolled duration in individuals with spastic paresis after stroke. TRIAL REGISTRATION: NCT01383512, https://clinicaltrials.gov/ , June 27, 2011.