Noninvasive spinal stimulation improves walking in chronic stroke survivors: a proof-of-concept case series.

BACKGROUND: After stroke, restoring safe, independent, and efficient walking is a top rehabilitation priority. However, in nearly 70% of stroke survivors asymmetrical walking patterns and reduced walking speed persist. This case series study aims to investigate the effectiveness of transcutaneous spinal cord stimulation (tSCS) in enhancing walking ability of persons with chronic stroke. METHODS: Eight participants with hemiparesis after a single, chronic stroke were enrolled. Each participant was assigned to either the Stim group (N = 4, gait training + tSCS) or Control group (N = 4, gait training alone). Each participant in the Stim group was matched to a participant in the Control group based on age, time since stroke, and self-selected gait speed. For the Stim group, tSCS was delivered during gait training via electrodes placed on the skin between the spinous processes of C5-C6, T11-T12, and L1-L2. Both groups received 24 sessions of gait training over 8 weeks with a physical therapist providing verbal cueing for improved gait symmetry. Gait speed (measured from 10 m walk test), endurance (measured from 6 min walk test), spatiotemporal gait symmetries (step length and swing time), as well as the neurophysiological outcomes (muscle synergy, resting motor thresholds via spinal motor evoked responses) were collected without tSCS at baseline, completion, and 3 month follow-up. RESULTS: All four Stim participants sustained spatiotemporal symmetry improvements at the 3 month follow-up (step length: 17.7%, swing time: 10.1%) compared to the Control group (step length: 1.1%, swing time 3.6%). Additionally, 3 of 4 Stim participants showed increased number of muscle synergies and/or lowered resting motor thresholds compared to the Control group. CONCLUSIONS: This study provides promising preliminary evidence that using tSCS as a therapeutic catalyst to gait training may increase the efficacy of gait rehabilitation in individuals with chronic stroke. Trial registration NCT03714282 (clinicaltrials.gov), registration date: 2018-10-18.

A Research Protocol to Study the Priming Effects of Breathing Low Oxygen on Enhancing Training-Related Gains in Walking Function for Persons With Spinal Cord Injury: The BO2ST Trial.

Brief episodes of low oxygen breathing (therapeutic acute intermittent hypoxia; tAIH) may serve as an effective plasticity-promoting primer to enhance the effects of transcutaneous spinal stimulation-enhanced walking therapy (WALKtSTIM) in persons with chronic (>1 year) spinal cord injury (SCI). Pre-clinical studies in rodents with SCI show that tAIH and WALKtSTIM therapies harness complementary mechanisms of plasticity to maximize walking recovery. Here, we present a multi-site clinical trial protocol designed to examine the influence of tAIH + WALKtSTIM on walking recovery in persons with chronic SCI. We hypothesize that daily (eight sessions, 2 weeks) tAIH + WALKtSTIM will elicit faster, more persistent improvements in walking recovery than either treatment alone. To test our hypothesis, we are conducting a placebo-controlled clinical trial on 60 SCI participants who randomly receive one of three interventions: tAIH + WALKtSTIM; Placebo + WALKtSTIM; and tAIH + WALKtSHAM. Participants receive daily tAIH (fifteen 90-sec episodes at 10% O2 with 60-sec intervals at 21% O2) or daily placebo (fifteen 90-sec episodes at 21% O2 with 60-sec intervals at 21% O2) before a 45-min session of WALKtSTIM or WALKtSHAM. Our primary outcome measures assess walking speed (10-Meter Walk Test), endurance (6-Minute Walk Test), and balance (Timed Up and Go Test). For safety, we also measure pain levels, spasticity, sleep behavior, cognition, and rates of systemic hypertension and autonomic dysreflexia. Assessments occur before, during, and after sessions, as well as at 1, 4, and 8 weeks post-intervention. Results from this study extend our understanding of the functional benefits of tAIH priming by investigating its capacity to boost the neuromodulatory effects of transcutaneous spinal stimulation on restoring walking after SCI. Given that there is no known cure for SCI and no single treatment is sufficient to overcome walking deficits, there is a critical need for combinatorial treatments that accelerate and anchor walking gains in persons with lifelong SCI. Trial Registration: ClinicalTrials.gov, NCT05563103.

Co-Regulation as a Support for Older Youth in the Context of Foster Care: a Scoping Review of the Literature.

Co-regulation is a relatively new theoretical framework for interventions that connects developmental science to adolescent needs and provides strategies that can be applied across contexts. It also has value in shifting the focus of interventions to the role of relationships and interactions with caring adults, as well as supportive environments. This framework may be particularly salient for older youth with foster care experience whose relationships with adults and availability of developmental supports are disrupted. To understand how co-regulation aligns with current understanding of needs and supports for this population, we conducted a scoping review that involved systematically searching four databases, coding and charting relevant information, and actively engaging expert consultants and other stakeholders. Across 46 primarily descriptive articles, co-regulation was discussed most often in relation to relationships, as expected (89% of articles). Despite theoretical and empirical evidence of the benefits of supportive environments and intentional day-to-day interactions in promoting developmental skills and competencies, these two domains of co-regulation were referenced much less (39% and 28%, respectively). Results highlight opportunities for co-regulation supports that can be provided to older youth with foster care experience by caring adults and near-aged peers in a wide range of roles. Notable limitations in the literature were identified in applying co-regulation within the context of employment and career readiness, healthy relationships, and teen parenting. Also under-researched is the role of adult self-regulation skills and co-regulation approaches for youth from diverse backgrounds, including those who identify as LGBTQ or have disabilities. Considerations for practice and future research are provided.

Video-Based Pose Estimation for Gait Analysis in Stroke Survivors during Clinical Assessments: A Proof-of-Concept Study.

Recent advancements in deep learning have produced significant progress in markerless human pose estimation, making it possible to estimate human kinematics from single camera videos without the need for reflective markers and specialized labs equipped with motion capture systems. Such algorithms have the potential to enable the quantification of clinical metrics from videos recorded with a handheld camera. Here we used DeepLabCut, an open-source framework for markerless pose estimation, to fine-tune a deep network to track 5 body keypoints (hip, knee, ankle, heel, and toe) in 82 below-waist videos of 8 patients with stroke performing overground walking during clinical assessments. We trained the pose estimation model by labeling the keypoints in 2 frames per video and then trained a convolutional neural network to estimate 5 clinically relevant gait parameters (cadence, double support time, swing time, stance time, and walking speed) from the trajectory of these keypoints. These results were then compared to those obtained from a clinical system for gait analysis (GAITRite®, CIR Systems). Absolute accuracy (mean error) and precision (standard deviation of error) for swing, stance, and double support time were within 0.04 ± 0.11 s; Pearson's correlation with the reference system was moderate for swing times (r = 0.4-0.66), but stronger for stance and double support time (r = 0.93-0.95). Cadence mean error was -0.25 steps/min ± 3.9 steps/min (r = 0.97), while walking speed mean error was -0.02 ± 0.11 m/s (r = 0.92). These preliminary results suggest that single camera videos and pose estimation models based on deep networks could be used to quantify clinically relevant gait metrics in individuals poststroke, even while using assistive devices in uncontrolled environments. Such development opens the door to applications for gait analysis both inside and outside of clinical settings, without the need of sophisticated equipment.

Wheelchair backs that support the spinal curves: Assessing postural and functional changes.

Objective: To compare outcomes using a wheelchair back designed to support the natural seated spinal curves versus an upholstered back that promotes posterior pelvic tilt and thoracolumbar kyphosis.Design: Cross-over intervention.Setting: Two free-standing spinal cord injury (SCI) model system hospitals.Participants: Fifty adults with motor complete SCI C6-T4, between the ages of 18-60 years who use a manual wheelchair for mobility were recruited from a convenience sample.Intervention: Each participant's wheelchair back support was removed and replaced by an upholstered back and a solid back in randomized order. Postural and functional outcomes, pain, and satisfaction were evaluated using each back.Outcome measures: Seated postural measurements included pelvic angle, spinal angle of kyphosis and linear measurement of spine. Functional outcomes included vertical forward reach, one stroke push, timed forward wheeling, ramp ascent and descent. Numerical pain rating and a satisfaction survey provided input pertaining to both backs.Results: The solid back demonstrated significance in seated postural measurements. Participants using the solid back trended to higher scores in functional outcome measures including vertical forward reach, one stroke push and timed ramp ascent. Participants reported increased satisfaction with comfort and stability with the solid back.Conclusions: This pilot study demonstrated that a wheelchair back, which supports the seated spinal curves improves upright posture, functional reach, and wheelchair propulsion skills. Further research is necessary to demonstrate statistical findings as well as to assess back height and lateral support.

Repeatability of a thyrotropin-releasing hormone stimulation test for diagnosis of pituitary pars intermedia dysfunction in mature horses.

BACKGROUND: Pituitary pars intermedia dysfunction (PPID) is a common endocrinopathy of horses diagnosed with a thyrotropin-releasing hormone (TRH) stimulation test. HYPOTHESIS/OBJECTIVES: Describe the repeatability of TRH stimulation in horses with and without PPID in winter and autumn. ANIMALS: Twenty adult horses; 6 controls and 6 with PPID tested in autumn, 8 controls and 6 with PPID tested in winter with 3 controls and 3 with PPID tested in both seasons. METHODS: Thyrotropin-releasing hormone stimulation was performed on 2 consecutive occasions, 1 week before and 1 week after the winter solstice and the autumn equinox. Blood was collected before and 30 minutes after IV injection of 1 mg of TRH. ACTH concentration was determined by a chemiluminescent assay. Repeatability and test-retest reliability were assessed by repeated measures analysis of variance, intraclass correlation coefficient and within-horse coefficients of variation (CV). Bland-Altman plots were generated to visualize agreement between repetitions. RESULTS: In winter, no week effect was detected on the results of the TRH simulation and the test had an excellent test-retest reliability. In autumn, after-TRH ACTH concentrations were significantly lower on week 2 (P = .02) and the test only had a good test-retest reliability. There were significantly larger within-horse CV during autumn (P = .04) and after TRH stimulation (P = .04). There were 2 misclassifications in winter and 4 in autumn. CONCLUSIONS AND CLINICAL IMPORTANCE: The TRH stimulation test was repeatable when performed 2 weeks apart in winter; however, in autumn, more variability in after-TRH ACTH concentrations resulted in decreased repeatability.

A Novel Technique to Reject Artifact Components for Surface EMG Signals Recorded During Walking With Transcutaneous Spinal Cord Stimulation: A Pilot Study.

Transcutaneous spinal cord electrical stimulation (tSCS) is an emerging technology that targets to restore functionally integrated neuromuscular control of gait. The purpose of this study was to demonstrate a novel filtering method, Artifact Component Specific Rejection (ACSR), for removing artifacts induced by tSCS from surface electromyogram (sEMG) data for investigation of muscle response during walking when applying spinal stimulation. Both simulated and real tSCS contaminated sEMG data from six stroke survivors were processed using ACSR and notch filtering, respectively. The performance of the filters was evaluated with data collected in various conditions (e.g., simulated artifacts contaminating sEMG in multiple degrees, various tSCS intensities in five lower-limb muscles of six participants). In the simulation test, after applying the ACSR filter, the contaminated-signal was well matched with the original signal, showing a high correlation (r = 0.959) and low amplitude difference (normalized root means square error = 0.266) between them. In the real tSCS contaminated data, the ACSR filter showed superior performance on reducing the artifacts (96% decrease) over the notch filter (25% decrease). These results indicate that ACSR filtering is capable of eliminating artifacts from sEMG collected during tSCS application, improving the precision of quantitative analysis of muscle activity.

Characterization of Motor-Evoked Responses Obtained with Transcutaneous Electrical Spinal Stimulation from the Lower-Limb Muscles after Stroke.

An increasing number of studies suggests that a novel neuromodulation technique targeting the spinal circuitry enhances gait rehabilitation, but research on its application to stroke survivors is limited. Therefore, we investigated the characteristics of spinal motor-evoked responses (sMERs) from lower-limb muscles obtained by transcutaneous spinal cord stimulation (tSCS) after stroke compared to age-matched and younger controls without stroke. Thirty participants (ten stroke survivors, ten age-matched controls, and ten younger controls) completed the study. By using tSCS applied between the L1 and L2 vertebral levels, we compared sMER characteristics (resting motor threshold (RMT), slope of the recruitment curve, and latency) of the tibialis anterior (TA) and medial gastrocnemius (MG) muscles among groups. A single pulse of stimulation was delivered in 5 mA increments, increasing from 5 mA to 250 mA or until the subjects reached their maximum tolerance. The stroke group had an increased RMT (27-51%) compared to both age-matched (TA: p = 0.032; MG: p = 0.005) and younger controls (TA: p < 0.001; MG: p<0.001). For the TA muscle, the paretic side demonstrated a 13% increased latency compared to the non-paretic side in the stroke group (p = 0.010). Age-matched controls also exhibited an increased RMT compared to younger controls (TA: p = 0.002; MG: p = 0.007), suggesting that altered sMER characteristics present in stroke survivors may result from both stroke and normal aging. This observation may provide implications for altered spinal motor output after stroke and demonstrates the feasibility of using sMER characteristics as an assessment after stroke.

Accelerated maturation in functional connectivity following early life stress: Circuit specific or broadly distributed?

Psychosocial acceleration theory and other frameworks adapted from life history predict a link between early life stress and accelerated maturation in several physiological systems. Those findings led researchers to suggest that the emotion-regulatory brain circuits of previously-institutionalized (PI) youth are more mature than youth raised in their biological families (non-adopted, or NA, youth) during emotion tasks. Whether this accelerated maturation is evident during resting-state fMRI has not yet been established. Resting-state fMRI data from 83 early adolescents (Mage = 12.9 years, SD = 0.57 years) including 41 PI and 42 NA youth, were used to examine seed-based functional connectivity between the amygdala and ventromedial prefrontal cortex (vmPFC). Additional whole-brain analyses assessed group differences in functional connectivity and associations with cognitive performance and behavior. We found group differences in amygdala - vmPFC connectivity that may be consistent with accelerated maturation following early life stress. Further, whole-brain connectivity analyses revealed group differences associated with internalizing and externalizing symptoms. However, the majority of whole-brain results were not consistent with an accelerated maturation framework. Our results suggest early life stress in the form of institutional care is associated with circuit-specific alterations to a frontolimbic emotion-regulatory system, while revealing limited differences in more broadly distributed networks.

Separable Effects of Childhood Maltreatment and Adult Adaptive Functioning on Amygdala Connectivity During Emotion Processing.

BACKGROUND: Individuals with a history of maltreatment show altered amygdala reactivity to emotional stimuli, atypical frontal regulatory control, and differences in frontolimbic connectivity compared with nonmaltreated controls. However, despite early trauma, many individuals who experience maltreatment show resilience or adaptive functioning in adulthood including positive social, educational, and occupational outcomes. METHODS: The present study used a psychophysiological interaction model to examine the effect of adult adaptive functioning on group differences between maltreated and nonmaltreated adults in task-based amygdala functional connectivity. The task used was a facial emotion-matching paradigm. Functional magnetic resonance imaging scans were collected from 41 adults with a history of substantiated childhood maltreatment and 39 nonmaltreated adults who were well matched on demographic variables, all of whom had been studied since childhood. Adaptive functioning was measured with a composite score of success on stage-salient developmental tasks. RESULTS: Consistent with previous research, we found differences in task-related amygdala functional connectivity between the maltreated and nonmaltreated groups. Effects were seen in the left hippocampus, right dorsolateral prefrontal cortex, dorsomedial prefrontal cortex, and right thalamus. However, when adult functioning was included in the model, maltreatment-related differences in amygdala connectivity were observed only in the hippocampus. Adult adaptive functioning independently predicted task-related amygdala connectivity in frontal and parietal regions across the entire sample. CONCLUSIONS: These results suggest that frontolimbic functional connectivity is predicted by positive developmental adaptation in this high-risk population, regardless of maltreatment history, whereas intralimbic connectivity (amygdala and hippocampus) is more specifically associated with maltreatment history.

Distorted payment system undermines business case for health quality and efficiency gains.

Efforts to improve the efficiency and quality of health care are unlikely to be successful if physicians and hospitals incur steep financial losses from success in accomplishing these goals, according to a new study by the Center for Studying Health System Change (HSC). Currently, most efforts to improve efficiency for a specific medical condition usually reduce the number of services per patient that can be billed, posing financial challenges for providers. These challenges are often magnified by the current fee-for-service payment structure, where some services are highly profitable and others are unprofitable, further undermining the case for redesigning care delivery to improve quality and efficiency. These dynamics are seen in the collaboration between Virginia Mason Medical Center (VMMC) and Aetna in Seattle to improve care for four common conditions. Although Aetna and participating self-insured employers have agreed to pay higher rates for certain unprofitable services if reductions in use of profitable services are achieved, VMMC still faces a financial challenge from applying more efficient care practices to patients covered by other insurers.

Redesigning care delivery in response to a high-performance network: the Virginia Mason Medical Center.

We examine how an integrated delivery system responded to threatened exclusion from an insurer's high-performance network by attempting to reduce costs through fundamental redesign of care processes. Some factors facilitating this transformation, such as its structure as a large salaried medical group exclusively affiliated with a hospital, might be specific to the organization and its market. Other essential elements could be replicated. But in a fee-for-service payment system, cost reduction from reducing the number of services or changing their mix can reduce profitability. Making the business case for sustaining desirable provider behavior may require that purchasers and plans make equally fundamental changes in payment policy.

Hospital-physician portals: the role of competition in driving clinical data exchange.

Recent policy efforts to encourage the use of health information technology are emphasizing development of communitywide health information exchanges to share clinical data across patient care settings. Interviews in twelve U.S. communities show that most large hospitals have or are developing physician portals to provide admitting physicians with remote access to patient records, but there is little data sharing among unaffiliated organizations. Competition among hospitals for physicians is a key factor driving adoption of these proprietary systems. In contrast, provider and health plan competition and adversarial relationships between providers and plans are viewed as major barriers to communitywide clinical data sharing.

Preparing for the unknown, responding to the known: communities and public health preparedness.

More than four years after September 11, 2001, bioterrorism preparedness remains a high priority for federal, state, and local governments. With reasonably flexible federal funding, communities have strengthened their ability to respond to public health emergencies, according to assessments by stakeholders and market observers. Collaborative relationships developed for bioterrorism preparedness have proved useful in addressing other threats, such as natural disasters and infectious disease outbreaks. Major ongoing challenges include funding constraints, inadequate surge capacity, public health workforce shortages, competing priorities, and jurisdictional issues.

The struggle to provide community-based care to low-income people with serious mental illnesses.

This paper describes gaps in services for low-income people with serious mental illnesses as reported by mental health professionals and other observers in twelve U.S. communities. According to respondents, service gaps have grown in recent years--especially for uninsured people--as a result of state budget pressures and Medicaid cost containment policies. Growing service gaps contribute to the high prevalence of serious mental illness among the homeless and incarcerated populations, as well as crowding of emergency departments. Some states and communities are aggressively addressing these gaps, although funding for new programs remains scarce.

Community approaches to providing care for the uninsured.

Faced with rising uninsurance rates and little response at the state or federal levels in recent years, communities have developed various strategies to provide care for uninsured people. This paper profiles local strategies in the Community Tracking Study sites, focusing on efforts that go beyond traditional safety-net access. Our findings suggest that more-recent community efforts--which tend to be privately sponsored--are relatively modest in scope compared with more-mature programs that enjoy public financing. Although local strategies can fill some holes, communities often do not have the resources necessary to fully address the problems of the uninsured on their own.