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.

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 ).

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.

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.

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.

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.

Decoding hand and wrist movement intention from chronic stroke survivors with hemiparesis using a user-friendly, wearable EMG-based neural interface.

OBJECTIVE: Seventy-five percent of stroke survivors, caregivers, and health care professionals (HCP) believe current therapy practices are insufficient, specifically calling out the upper extremity as an area where innovation is needed to develop highly usable prosthetics/orthotics for the stroke population. A promising method for controlling upper extremity technologies is to infer movement intention non-invasively from surface electromyography (EMG). However, existing technologies are often limited to research settings and struggle to meet user needs. APPROACH: To address these limitations, we have developed the NeuroLife® EMG System, an investigational device which consists of a wearable forearm sleeve with 150 embedded electrodes and associated hardware and software to record and decode surface EMG. Here, we demonstrate accurate decoding of 12 functional hand, wrist, and forearm movements in chronic stroke survivors, including multiple types of grasps from participants with varying levels of impairment. We also collected usability data to assess how the system meets user needs to inform future design considerations. MAIN RESULTS: Our decoding algorithm trained on historical- and within-session data produced an overall accuracy of 77.1 ± 5.6% across 12 movements and rest in stroke participants. For individuals with severe hand impairment, we demonstrate the ability to decode a subset of two fundamental movements and rest at 85.4 ± 6.4% accuracy. In online scenarios, two stroke survivors achieved 91.34 ± 1.53% across three movements and rest, highlighting the potential as a control mechanism for assistive technologies. Feedback from stroke survivors who tested the system indicates that the sleeve's design meets various user needs, including being comfortable, portable, and lightweight. The sleeve is in a form factor such that it can be used at home without an expert technician and can be worn for multiple hours without discomfort. SIGNIFICANCE: The NeuroLife EMG System represents a platform technology to record and decode high-resolution EMG for the real-time control of assistive devices in a form factor designed to meet user needs. The NeuroLife EMG System is currently limited by U.S. federal law to investigational use.

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.

Implementation of a unilateral hip flexion exosuit to aid paretic limb advancement during inpatient gait retraining for individuals post-stroke: a feasibility study.

BACKGROUND: During inpatient rehabilitation, physical therapists (PTs) often need to manually advance patients' limbs, adding physical burden to PTs and impacting gait retraining quality. Different electromechanical devices alleviate this burden by assisting a patient's limb advancement and supporting their body weight. However, they are less ideal for neuromuscular engagement when patients no longer need body weight support but continue to require assistance with limb advancement as they recover. The objective of this study was to determine the feasibility of using a hip flexion exosuit to aid paretic limb advancement during inpatient rehabilitation post-stroke. METHODS: Fourteen individuals post-stroke received three to seven 1-hour walking sessions with the exosuit over one to two weeks in addition to standard care of inpatient rehabilitation. The exosuit assistance was either triggered by PTs or based on gait events detected by body-worn sensors. We evaluated clinical (distance, speed) and spatiotemporal (cadence, stride length, swing time symmetry) gait measures with and without exosuit assistance during 2-minute and 10-meter walk tests. Sessions were grouped by the assistance required from the PTs (limb advancement and balance support, balance support only, or none) without exosuit assistance. RESULTS: PTs successfully operated the exosuit in 97% of sessions, of which 70% assistance timing was PT-triggered to accommodate atypical gait. Exosuit assistance eliminated the need for manual limb advancement from PTs. In sessions with participants requiring limb advancement and balance support, the average distance and cadence during 2-minute walk test increased with exosuit assistance by 2.2 ± 3.1 m and 3.4 ± 1.9 steps/min, respectively (p < 0.017). In sessions with participants requiring balance support only, the average speed during 10-meter walk test increased with exosuit by 0.07 ± 0.12 m/s (p = 0.042). Clinical and spatiotemporal measures of independent ambulators were similar with and without exosuit (p > 0.339). CONCLUSIONS: We incorporated a unilateral hip flexion exosuit into inpatient stroke rehabilitation in individuals with varying levels of impairments. The exosuit assistance removed the burden of manual limb advancement from the PTs and resulted in improved gait measures in some conditions. Future work will understand how to optimize controller and assistance profiles for this population.

Effects of robot-assisted gait training using the Welwalk on gait independence for individuals with hemiparetic stroke: an assessor-blinded, multicenter randomized controlled trial.

BACKGROUND: Gait disorder remains a major challenge for individuals with stroke, affecting their quality of life and increasing the risk of secondary complications. Robot-assisted gait training (RAGT) has emerged as a promising approach for improving gait independence in individuals with stroke. This study aimed to evaluate the effect of RAGT in individuals with subacute hemiparetic stroke using a one-leg assisted gait robot called Welwalk WW-1000. METHODS: An assessor-blinded, multicenter randomized controlled trial was conducted in the convalescent rehabilitation wards of eight hospitals in Japan. Participants with first-ever hemiparetic stroke who could not walk at pre-intervention assessment were randomized to either the Welwalk group, which underwent RAGT with conventional physical therapy, or the control group, which underwent conventional physical therapy alone. Both groups received 80 min of physical therapy per day, 7 days per week, while the Welwalk group received 40 min of RAGT per day, 6 days per week, as part of their physical therapy. The primary outcome was gait independence, as assessed using the Functional Independence Measure Walk Score. RESULTS: A total of 91 participants were enrolled, 85 of whom completed the intervention. As a result, 91 participants, as a full analysis set, and 85, as a per-protocol set, were analyzed. The primary outcome, the cumulative incidence of gait-independent events, was not significantly different between the groups. Subgroup analysis revealed that the interaction between the intervention group and stroke type did not yield significant differences in either the full analysis or per-protocol set. However, although not statistically significant, a discernible trend toward improvement with Welwalk was observed in cases of cerebral infarction for the full analysis and per-protocol sets (HR 4.167 [95%CI 0.914-18.995], p = 0.065, HR 4.443 [95%CI 0.973-20.279], p = 0.054, respectively). CONCLUSIONS: The combination of RAGT using Welwalk and conventional physical therapy was not significantly more effective than conventional physical therapy alone in promoting gait independence in individuals with subacute hemiparetic stroke, although a trend toward earlier gait independence was observed in individuals with cerebral infarction. TRIAL REGISTRATION: This study was registered with the Japan Registry of Clinical Trials ( https://jrct.niph.go.jp ; jRCT 042180078) on March 3, 2019.

Defining pseudoparalysis and pseudoparesis: a consensus study.

BACKGROUND: The purpose of this study was to establish consensus statements via a modified Delphi process on the definition of shoulder pseudoparalysis and pseudoparesis. METHODS: A consensus process on the definition of a diagnosis of pseudoparalysis utilizing a modified Delphi technique was conducted, and 26 shoulder/sports surgeons from 11 countries, selected based on their level of expertise in the field, participated in these consensus statements. Consensus was defined as achieving 80%-89% agreement, whereas strong consensus was defined as 90%-99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: Three statements regarding the diagnosis of pseudoparalysis reached strong (>89%) consensus: passive range of motion should be unaffected, the passive range of abduction should not be considered, and diagnosis should be excluded if lidocaine injection produces a substantial improvement in range of motion. Additionally, consensus (>79%) was reached that the active range of external rotation should not be considered for diagnosis, pain as a cause of restricted motion must be excluded, and that distinctions between restricted active flexion and external rotation should be made by range of motion rather than tear characteristics. No consensus could be reached on statements regarding the size, number of tendons or chronicity of cuff tears. Nor was there agreement on the active range of flexion permitted or on the difference between pseudoparalysis and pseudoparesis. CONCLUSION: A modified Delphi process was utilized to establish consensus on the definition of shoulder pseudoparalysis and pseudoparesis. Unfortunately, almost half of the statements did not reach consensus, and agreement could not be reached across all domains for a unifying definition for the diagnosis of pseudoparalysis in the setting of rotator cuff tears. Furthermore, it was not agreed how or whether pseudoparalysis should be differentiated from pseudoparesis. Based on the lack of a consensus for these terms, studies should report explicitly how these terms are defined when they are used.

Tumefactive Demyelination Lesions: Report on three cases.

PURPOSE: Tumefactive demyelination (TD) lesion and its subtype Balo's concentric sclerosis (BCS), are rare manifestations of central nervous system demyelinating disease. Because of its rarity, physicians might hesitate in reaching a diagnosis or initiating steroid pulse therapy. This study aims at pinpointing the key neuroimaging features to distinguish TD lesions from surgical conditions, and illustrating the clinical outcomes of patients with TD lesions. CASE REPORT: Two of the three patients had solitary TD lesions, one 47-year-old man presenting with newly onset seizure and another 54-year-old women suffering from progressive hemiparesis. The male patient underwent craniotomy for mass excision without further steroid therapy, while the female patient received methylprednisolone pulse therapy only. Both patients remained free of clinical and radiological relapses over the past 6-7 years, leading to the diagnosis of clinically isolated syndrome. The third case is a 30-year-old woman with subacute onset of dysarthria and hemiparesis. She had two BCS lesions along with other demyelinating lesions in the juxtacortical and periventricular regions, cerebellar peduncles, and spinal cord, fulfilling dissemination in time and space. Her neurological deficits resolved after pulse therapy, and she received long-term disease modifying therapy for multiple sclerosis. CONCLUSION: This study underscores the diverse neuroimaging and clinical presentations of patients with TD lesions, and emphasizes the importance of clinical vigilance regarding this rare condition.

Diaphragmatic dysfunction is associated with postoperative pulmonary complications and phrenic nerve paresis in patients undergoing thoracic surgery.

PURPOSE: We aimed to quantify perioperative changes in diaphragmatic function and phrenic nerve conduction in patients undergoing routine thoracic surgery. METHODS: A prospective observational study was performed in patients undergoing esophageal resection or pulmonary lobectomy. Examinations were carried out the day prior to surgery, 3 days and 10-14 days after surgery. Endpoints for diaphragmatic function included ultrasonographic measurements of diaphragmatic excursion and thickening fraction. Endpoints for phrenic nerve conduction included baseline-to-peak amplitude, peak-to-peak amplitude, and transmission delay. Measurements were assessed on both the surgical side and the non-surgical side of the thorax. RESULTS: Forty patients were included in the study. Significant reductions in diaphragmatic excursion were seen on the surgical side of the thorax for all excursion measures (posterior part of the right hemidiaphragm, p < 0.001; hemidiaphragmatic top point, p < 0.001; change in intrathoracic area, p < 0.001). Significant changes were seen for all phrenic nerve measures (baseline-to-peak amplitude, p < 0.001; peak-to-peak amplitude, p < 0.001; transmission delay, p = 0.041) on the surgical side. However, significant changes were also seen on the non-surgical side for all phrenic nerve measures (baseline-to-peak amplitude, p < 0.001; peak-to-peak amplitude, p < 0.001; transmission delay, p = 0.022). A postoperative reduction in posterior diaphragmatic excursion of more than 50% was significantly associated with postoperative pulmonary complications (coefficient: 2.69 (95% CI [1.38, 4.01], p < 0.001). CONCLUSION: Thoracic surgery caused a significant unilateral reduction in diaphragmatic excursion on the surgical side of the thorax, which was accompanied by significant changes in phrenic nerve conduction. However, phrenic nerve conduction was also significantly affected on the non-surgical side to a lesser extent, which was not mirrored in diaphragmatic excursion. Our findings suggest that phrenic nerve paresis plays a role in postoperative diaphragmatic dysfunction, which may be a contributing factor in the pathogenesis of postoperative pulmonary complications. CLINICAL TRIALS REGISTRATION NUMBER: NCT04507594.

Spinal Cord Stimulation for Poststroke Hemiparesis: A Scoping Review.

IMPORTANCE: Spinal cord stimulation (SCS) is a neuromodulation technique that can improve paresis in individuals with spinal cord injury. SCS is emerging as a technique that can address upper and lower limb hemiparesis. Little is understood about its effectiveness with the poststroke population. OBJECTIVE: To summarize the evidence for SCS after stroke and any changes in upper extremity and lower extremity motor function. DATA SOURCES: PubMed, Web of Science, Embase, and CINAHL. The reviewers used hand searches and reference searches of retrieved articles. There were no limitations regarding publication year. STUDY SELECTION AND DATA COLLECTION: This review followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. The inclusion and exclusion criteria included a broad range of study characteristics. Studies were excluded if the intervention did not meet the definition of SCS intervention, used only animals or healthy participants, did not address upper or lower limb motor function, or examined neurological conditions other than stroke. FINDINGS: Fourteen articles met the criteria for this review. Seven studies found a significant improvement in motor function in groups receiving SCS. CONCLUSIONS AND RELEVANCE: Results indicate that SCS may provide an alternative means to improve motor function in the poststroke population. Plain-Language Summary: The results of this study show that spinal cord stimulation may provide an alternative way to improve motor function after stroke. Previous neuromodulation methods have targeted the impaired supraspinal circuitry after stroke. Although downregulated, spinal cord circuitry is largely intact and offers new possibilities for motor recovery.

Direction-dependent differences in the quality and quantity of horizontal reaching in people after stroke.

Arm reaching is often impaired in individuals with stroke. Nonetheless, how aiming directions influence reaching performance and how such differences change with motor recovery over time remain unclear. Here, we elucidated kinematic parameters of reaching toward various directions in people with poststroke hemiparesis in the subacute phase. A total of 13 and 15 participants with mild and moderate-to-severe hemiparesis, respectively, performed horizontal reaching in eight directions with their more-affected and less-affected sides using an exoskeleton robotic device at the time of admission to and discharge from the rehabilitation ward of the hospital. The movement time, path length, and number of velocity peaks were computed for the mild group (participants able to reach toward all eight directions). In addition, the total amount of displacement (i.e., movement quantity) toward two simplified directions (mediolateral or anteroposterior) was evaluated for the moderate-to-severe group (participants who showed difficulty in completing the reaching task). Motor recovery was evaluated using the Fugl-Meyer assessment. The mild group showed worse values of movement parameters during reaching in the anteroposterior direction, irrespective of the side of the arm or motor recovery achieved. The moderate-to-severe group exhibited less movement toward the anteroposterior direction than toward the mediolateral direction at admission; however, this direction-dependent bias in movement quantity decreased, with the movement expanding toward the anteroposterior direction with motor recovery at discharge. These results suggest that direction-dependent differences in the quality and quantity of reaching performance exist in people after stroke, regardless of the presence or severity of hemiparesis. This highlights the need to consider the task work area when designing rehabilitative training.NEW & NOTEWORTHY Arm reaching, a fundamental function required for the upper extremities, is often impaired after stroke due to muscle weakness and abnormal synergies. Nonetheless, how aiming directions influence performance remains unclear. Here, we report that direction-dependent differences in the quality and quantity of reaching performance exist, surprisingly regardless of the presence or severity of hemiparesis. This result highlights the need to consider the task work area when designing rehabilitative training.

Overground walking with a constraint force on the nonparetic leg during swing improves weight shift toward the paretic side in people after stroke.

Targeting enhancing the use of the paretic leg during locomotor practice might improve motor function of the paretic leg. The purpose of this study was to determine whether application of constraint force to the nonparetic leg in the posterior direction during overground walking would enhance the use of the paretic leg in people with chronic stroke. Fifteen individuals after stroke participated in two experimental conditions, i.e., overground walking with a constraint force applied to the nonparetic leg and overground walking only. Each participant was tested in the following procedures that consisted of overground walking with either constraint force or no constraint force, instrumented split-belt treadmill walking, and pressure-sensitive gait mat walking before and after the overground walking. Overground walking practice with constraint force resulted in greater enhancement in lateral weight shift toward the paretic side (P < 0.01), muscle activity of the paretic hip abductors (P = 0.04), and propulsion force of the paretic leg (P = 0.05) compared with the results of the no-constraint condition. Overground walking practice with constraint force tended to induce greater increase in self-selected overground walking speed (P = 0.06) compared with the effect of the no-constraint condition. The increase in propulsion force from the paretic leg was positively correlated with the increase in self-selected walking speed (r = 0.6, P = 0.03). Overground walking with constraint force applied to the nonparetic leg during swing phase of gait may enhance use of the paretic leg, improve weight shifting toward the paretic side and propulsion of the paretic leg, and consequently increase walking speed.NEW & NOTEWORTHY Application of constraint force to the nonparetic leg during overground walking induced improved lateral weight shifts toward the paretic leg and enhanced muscle activity of the paretic leg during walking. In addition, one session of overground walking with constraint force might induce an increase in propulsive force of the paretic leg and an increase in self-selected overground walking speed, which might be partially due to the improvement in motor control of the paretic leg.

Use of multi-perturbation Shapley analysis in lesion studies of functional networks: The case of upper limb paresis.

Understanding the impact of variation in lesion topography on the expression of functional impairments following stroke is important, as it may pave the way to modeling structure-function relations in statistical terms while pointing to constraints for adaptive remapping and functional recovery. Multi-perturbation Shapley-value analysis (MSA) is a relatively novel game-theoretical approach for multivariate lesion-symptom mapping. In this methodological paper, we provide a comprehensive explanation of MSA. We use synthetic data to assess the method's accuracy and perform parameter optimization. We then demonstrate its application using a cohort of 107 first-event subacute stroke patients, assessed for upper limb (UL) motor impairment (Fugl-Meyer Assessment scale). Under the conditions tested, MSA could correctly detect simulated ground-truth lesion-symptom relationships with a sensitivity of 75% and specificity of ~90%. For real behavioral data, MSA disclosed a strong hemispheric effect in the relative contribution of specific regions-of-interest (ROIs): poststroke UL motor function was mostly contributed by damage to ROIs associated with movement planning (supplementary motor cortex and superior frontal gyrus) following left-hemispheric damage (LHD) and by ROIs associated with movement execution (primary motor and somatosensory cortices and the ventral brainstem) following right-hemispheric damage (RHD). Residual UL motor ability following LHD was found to depend on a wider array of brain structures compared to the residual motor ability of RHD patients. The results demonstrate that MSA can provide a unique insight into the relative importance of different hubs in neural networks, which is difficult to obtain using standard univariate methods.