SENSe: Study of the Effectiveness of Neurorehabilitation on Sensation: a randomized controlled trial

Finger-Individuating Exoskeleton System with Non-Contact Leader-Follower Control Strategy

This paper proposes a novel finger-individuating exoskeleton system with a non-contact leader-follower control strategy that effectively combines motion functionality and individual adaptability. Our solution comprises the following two interactive components: the leader side and the follower side. The leader side processes joint angle information from the healthy hand during motion via a Leap Motion Controller as the system input, providing more flexible and active operations owing to the non-contact manner. Then, as the follower side, the exoskeleton is driven to assist the user's hand for rehabilitation training according to the input. The exoskeleton mechanism is designed as a universal module that can adapt to various digit sizes and weighs only 40 g. Additionally, the current motion of the exoskeleton is fed back to the system in real time, forming a closed loop to ensure control accuracy. Finally, four experiments validate the design effectiveness and motion performance of the proposed exoskeleton system. The experimental results indicate that our prototype can provide an average force of about 16.5 N for the whole hand during flexing, and the success rate reaches 82.03% in grasping tasks. Importantly, the proposed prototype holds promise for improving rehabilitation outcomes, offering diverse options for different stroke stages or application scenarios.

An Overview of the Bodily Awareness Representation and Interoception: Insights and Progress in the Field of Neurorehabilitation Research

In the last two decades, the scientific literature on so-called body representations has been increasing, and the notion of body awareness (BA) is particularly interesting for neurorehabilitation. In this article, we present results derived from recent studies on this representation, considering the different definitions and explicative models proposed as well as the empirical settings used to test it, providing an extensive overview of these issues. This article discusses the challenge of understanding how we integrate the sensory experiences of proprioception (knowing where our body is in space) and interoception (sensing internal bodily sensations, like hunger of thirst) with our perception of self. This is a difficult problem to analyze because our awareness of our body is inherently linked to our perspective, since the body is the means through which we interact with the world. Presenting the different viewpoints offered by recent theories on this concern, we highlighted that the neurorehabilitation and psychiatric settings offer two important fields useful for the study of BA because in them it is possible to analyze bodily representations by inducing/observing a controlled discrepancy between dysfunctional content and sensory inputs.

Does somatosensory discrimination therapy alter sensorimotor upper limb function differently compared to motor therapy in children and adolescents with unilateral cerebral palsy: study protocol for a randomized controlled trial

BACKGROUND

Besides motor impairments, up to 90% of the children and adolescents with unilateral cerebral palsy (uCP) present with somatosensory impairments in the upper limb. As somatosensory information is of utmost importance for coordinated movements and motor learning, somatosensory impairments can further compromise the effective use of the impaired upper limb in daily life activities. Yet, intervention approaches specifically designated to target these somatosensory impairments are insufficiently investigated in children and adolescents with uCP. Therefore, the aim of this randomized controlled trial (RCT) is to compare the effectiveness of somatosensory discrimination therapy and dose-matched motor therapy to improve sensorimotor upper limb function in children and adolescents with uCP, who experience somatosensory impairments in the upper limb. We will further explore potential behavioral and neurological predictors of therapy response.

METHODS

A parallel group, evaluator-blinded, phase-II, single-center RCT will be conducted for which 50 children and adolescents with uCP, aged 7 to 15 years, will be recruited. Participants will be randomized to receive 3 weekly sessions of 45 minutes of either somatosensory discrimination therapy or upper limb motor therapy for a period of 8 weeks. Stratification will be performed based on age, manual ability, and severity of tactile impairment at baseline. Sensorimotor upper limb function will be evaluated at baseline, immediately after the intervention and after 6 months follow-up. The primary outcome measure will be bimanual performance as measured with the Assisting Hand Assessment. Secondary outcomes include a comprehensive test battery to objectify somatosensory function and measures of bimanual coordination, unimanual motor function, and goal attainment. Brain imaging will be performed at baseline to investigate structural brain lesion characteristics and structural connectivity of the white matter tracts.

DISCUSSION

This protocol describes the design of an RCT comparing the effectiveness of somatosensory discrimination therapy and dose-matched motor therapy to improve sensorimotor upper limb function in children and adolescents with uCP. The results of this study may aid in the selection of the most effective upper limb therapy, specifically for children and adolescents with tactile impairments.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT06006065). Registered on August 8, 2023.

2023 Sylvia Docker lecture: Ignite your passion, and connect, to make a difference

Together, we grow our profession of occupational therapy as we engage in understanding and addressing the issues that challenge the people we work with. In this Sylvia Docker Lecture, I will share the collective journeys of myself and other occupational therapists and health professionals who have undertaken (or are currently undertaking) their PhDs and are actively involved in research, to address these challenges. Together, we will explore three themes: understanding the WHY that ignites one's passion; living the journey-the EXPERIENCE; and making a difference-the IMPACT. Stories will be told through the lived experience of those engaged in research as currently enrolled PhD students, emerging researchers, and experienced researchers. These stories will capture the lived experience across individuals, and at different times in the research journey. Stories are summarised and captured using natural language processing. Topics are identified, concept maps visualised, and outputs interpreted in context of related theoretical models. Key topics identified include: the clinical and personal motivators that have ignited the passion in individuals; the value of connecting with others and growing networks; and how one's research has made a difference. The impact of discoveries and outcomes are highlighted, together with the importance of people and networks. Analysis of connections and synthesis over time revealed frequent and strong connections across themes, concepts and topics; with synthesising concepts of passion, networks, knowledge translation, opportunities, supervision and communication emerging and being shaped over time. These collective journeys provide inspiration and pathways to creative careers that have future potential in the growth of the profession of occupational therapy. It is recommended that each occupational therapist take the time to reflect on the 'why' that ignites your passion, your journey and how you can make a difference!

Inhibiting metabotropic glutamate receptor 5 after stroke restores brain function and connectivity

Stroke results in local neural disconnection and brain-wide neuronal network dysfunction leading to neurological deficits. Beyond the hyper-acute phase of ischaemic stroke, there is no clinically-approved pharmacological treatment that alleviates sensorimotor impairments. Functional recovery after stroke involves the formation of new or alternative neuronal circuits including existing neural connections. The type-5 metabotropic glutamate receptor (mGluR5) has been shown to modulate brain plasticity and function and is a therapeutic target in neurological diseases outside of stroke. We investigated whether mGluR5 influences functional recovery and network reorganization rodent models of focal ischaemia. Using multiple behavioural tests, we observed that treatment with negative allosteric modulators (NAMs) of mGluR5 (MTEP, fenobam and AFQ056) for 12 days, starting 2 or 10 days after stroke, restored lost sensorimotor functions, without diminishing infarct size. Recovery was evident within hours after initiation of treatment and progressed over the subsequent 12 days. Recovery was prevented by activation of mGluR5 with the positive allosteric modulator VU0360172 and accelerated in mGluR5 knock-out mice compared with wild-type mice. After stroke, multisensory stimulation by enriched environments enhanced recovery, a result prevented by VU0360172, implying a role of mGluR5 in enriched environment-mediated recovery. Additionally, MTEP treatment in conjunction with enriched environment housing provided an additive recovery enhancement compared to either MTEP or enriched environment alone. Using optical intrinsic signal imaging, we observed brain-wide disruptions in resting-state functional connectivity after stroke that were prevented by mGluR5 inhibition in distinct areas of contralesional sensorimotor and bilateral visual cortices. The levels of mGluR5 protein in mice and in tissue samples of stroke patients were unchanged after stroke. We conclude that neuronal circuitry subserving sensorimotor function after stroke is depressed by a mGluR5-dependent maladaptive plasticity mechanism that can be restored by mGluR5 inhibition. Post-acute stroke treatment with mGluR5 NAMs combined with rehabilitative training may represent a novel post-acute stroke therapy.

Design and Evaluation of Cyclic Vibrotactile Funneling Illusion Method for Proprioceptive Position Sense Feedback

The sense of proprioception plays a critical role in motor function by providing a sense of body position and movement. Recent research has highlighted the impact of impaired proprioception on rehabilitation outcomes for stroke patients. To address this issue, various studies have explored the use of vibrotactile feedback to aid and enhance impaired proprioception. Since most studies focused on investigating the characteristics of human proprioceptive position or movement sense, the fixed and cumbersome equipment used for those studies is inappropriate for daily use where compact and portable device is preferred. To address this limitation, we propose a novel vibrotactile feedback method that provides joint-level state information using the cyclic vibrotactile funneling illusion. The proposed method was validated in first experiment with eleven healthy subjects, and the accuracy of proposed method in bi-directional scheme was evaluated through second experiments with three healthy subjects. Our methods demonstrated sufficient ability to transmit proprioceptive position information, making them potentially applicable to various wearable rehabilitation devices, thereby enabling more effective rehabilitation for patients with proprioceptive impairment.

Proposal of a common terminology for the neuropsychological rehabilitation

The literature on neuropsychological intervention (NI) uses a variety of terms to refer to equivalent constructs, making it difficult to compare intervention programmes and their outcomes. The purpose of this work is to propose a unified terminological framework for describing NI programmes. The terminological framework was developed based on a previous proposal for common terminology by Johnstone and Stonnington (Rehabilitation of neuropsychological disorders: A practical guide for rehabilitation professionals. Psychology Press, 2011) and driven by Cognitive Psychology concepts. The terminological framework was organized into two sections: (a) NI, which includes types of NI, methods and approaches, instructional methods, and strategies; and (b) neurocognitive functions, which include temporal and spatial orientation, sensation, perception, visuo-constructional abilities, attention, memory, language, reasoning of several sorts (e.g., abstract reasoning, and numerical reasoning), and executive functions. Most NI tasks target a main neurocognitive function, but there are underlying neurocognitive functions that may impair performance in the former. Since it is difficult to create a task that is solely focused on one neurocognitive function, the proposed terminology should not be viewed as a taxonomy, but rather as dimensional, with the same task allowing to work different functions, in varying grades. Adopting this terminological framework will allow to define the targeted neurocognitive functions more accurately and simplify the comparison between NI programmes and their outcomes. Future research should focus on describing the main techniques/strategies for each neurocognitive function and non-cognitive interventions.

Profiling Somatosensory Impairment after Stroke: Characterizing Common "Fingerprints" of Impairment Using Unsupervised Machine Learning-Based Cluster Analysis of Quantitative Measures of the Upper Limb

Altered somatosensory function is common among stroke survivors, yet is often poorly characterized. Methods of profiling somatosensation that illustrate the variability in impairment within and across different modalities remain limited. We aimed to characterize post-stroke somatosensation profiles ("fingerprints") of the upper limb using an unsupervised machine learning cluster analysis to capture hidden relationships between measures of touch, proprioception, and haptic object recognition. Raw data were pooled from six studies where multiple quantitative measures of upper limb somatosensation were collected from stroke survivors (n = 207) using the Tactile Discrimination Test (TDT), Wrist Position Sense Test (WPST) and functional Tactile Object Recognition Test (fTORT) on the contralesional and ipsilesional upper limbs. The Growing Self Organizing Map (GSOM) unsupervised machine learning algorithm was used to generate a topology-preserving two-dimensional mapping of the pooled data and then separate it into clusters. Signature profiles of somatosensory impairment across two modalities (TDT and WPST; n = 203) and three modalities (TDT, WPST, and fTORT; n = 141) were characterized for both hands. Distinct impairment subgroups were identified. The influence of background and clinical variables was also modelled. The study provided evidence of the utility of unsupervised cluster analysis that can profile stroke survivor signatures of somatosensory impairment, which may inform improved diagnosis and characterization of impairment patterns.

Calibration of Impairment Severity to Enable Comparison across Somatosensory Domains

Comparison across somatosensory domains, important for clinical and scientific goals, requires prior calibration of impairment severity. Provided test score distributions are comparable across domains, valid comparisons of impairment can be made by reference to score locations in the corresponding distributions (percentile rank or standardized scores). However, this is often not the case. Test score distributions for tactile texture discrimination (n = 174), wrist joint proprioception (n = 112), and haptic object identification (n = 98) obtained from pooled samples of stroke survivors in rehabilitation settings were investigated. The distributions showed substantially different forms, undermining comparative calibration via percentile rank or standardized scores. An alternative approach is to establish comparable locations in the psychophysical score ranges spanning performance from just noticeably impaired to maximally impaired. Several simulation studies and a theoretical analysis were conducted to establish the score distributions expected from completely insensate responders for each domain. Estimates of extreme impairment values suggested by theory, simulation and observed samples were consistent. Using these estimates and previously discovered values for impairment thresholds in each test domain, comparable ranges of impairment from just noticeable to extreme impairment were found. These ranges enable the normalization of the three test scales for comparison in clinical and research settings.

Development of an audit checklist to evaluate treatment fidelity of a complex rehabilitation intervention

PURPOSE

The process of examining treatment fidelity is critical to the successful implementation of rehabilitation interventions. Videotaping is considered the 'gold standard' assessment; however, may be considered resource-intensive and intrusive for intervention providers and patients. An audit checklist is an alternative approach recommended in the literature. The purpose of this study was to develop a documentation audit checklist for assessing treatment fidelity during delivery of SENSe therapy, a complex rehabilitation intervention targeting upper limb somatosensory impairment post-stroke.

METHODS

Checklist development comprised: content determination and design; checklist testing via audit of 38 therapy records from an existing data set; and exploration of rater agreement between two assessors, using a subset of 10 therapy records.

RESULTS

The developed audit checklist comprised 29 components core to the delivery of SENSe therapy. Six SENSe therapy records were delivered with high fidelity (>80% adherence to core components), and 32 with moderate fidelity (51-79%). Rater agreement was 80% across the subset of 10 records.

CONCLUSION

Findings highlight the importance of using a theoretically-guided approach to checklist development, with the use of rater agreement to identify areas for refinement. A documentation audit checklist was developed that can be used to evaluate treatment fidelity of complex rehabilitation interventions.IMPLICATIONS FOR REHABILITATIONDevelopment of an audit checklist that evaluates clinician documentation of therapy delivery, is feasible as one strategy to measure and enhance the treatment fidelity of complex rehabilitation interventions.The process of audit checklist development should be structured and based on conceptual frameworks, to ensure it accurately measures quality of delivery and adherence to core intervention components.Audit checklists can be used to support clinicians delivering complex rehabilitation interventions.

Characterizing Touch Discrimination Impairment from Pooled Stroke Samples Using the Tactile Discrimination Test: Updated Criteria for Interpretation and Brief Test Version for Use in Clinical Practice Settings

Somatosensory loss post-stroke is common, with touch sensation characteristically impaired. Yet, quantitative, standardized measures of touch discrimination available for clinical use are currently limited. We aimed to characterize touch impairment and re-establish the criterion of abnormality of the Tactile Discrimination Test (TDT) using pooled data and to determine the sensitivity and specificity of briefer test versions. Baseline data from stroke survivors (n = 207) and older neurologically healthy controls (n = 100) assessed on the TDT was extracted. Scores were re-analyzed to determine an updated criterion of impairment and the ability of brief test versions to detect impairment. Updated scoring using an area score was used to calculate the TDT percent maximum area (PMA) score. Touch impairment was common for the contralesional hand (83%) but also present in the ipsilesional hand (42%). The criterion of abnormality was established as 73.1 PMA across older adults and genders. High sensitivity and specificity were found for briefer versions of the TDT (25 vs. 50 trials; 12 or 15 vs. 25 trials), with sensitivity ranging between 91.8 and 96.4% and specificity between 72.5 and 95.0%. Conclusion: Updated criterion of abnormality and the high sensitivity and specificity of brief test versions support the use of the TDT in clinical practice settings.

Sensory and motor cortical excitability changes induced by rTMS and sensory stimulation in stroke: A randomized clinical trial

Background

The ability to produce coordinated movement is dependent on dynamic interactions through transcallosal fibers between the two cerebral hemispheres of the brain. Although typically unilateral, stroke induces changes in functional and effective connectivity across hemispheres, which are related to sensorimotor impairment and stroke recovery. Previous studies have focused almost exclusively on interhemispheric interactions in the primary motor cortex (M1).

Objective

To identify the presence of interhemispheric asymmetry (ASY) of somatosensory cortex (S1) excitability and to investigate whether S1 repetitive transcranial magnetic stimulation (rTMS) combined with sensory stimulation (SS) changes excitability in S1 and M1, as well as S1 ASY, in individuals with subacute stroke.

Methods

A randomized clinical trial. Participants with a single episode of stroke, in the subacute phase, between 35 and 75 years old, were allocated, randomly and equally balanced, to four groups: rTMS/sham SS, sham rTMS/SS, rTMS/SS, and sham rTMS/Sham SS. Participants underwent 10 sessions of S1 rTMS of the lesioned hemisphere (10 Hz, 1,500 pulses) followed by SS. SS was applied to the paretic upper limb (UL) (active SS) or non-paretic UL (sham SS). TMS-induced motor evoked potentials (MEPs) of the paretic UL and somatosensory evoked potential (SSEP) of both ULs assessed M1 and S1 cortical excitability, respectively. The S1 ASY index was measured before and after intervention. Evaluator, participants and the statistician were blinded.

Results

Thirty-six participants divided equally into groups (nine participants per group). Seven patients were excluded from MEP analysis because of failure to produce consistent MEP. One participant was excluded in the SSEP analysis because no SSEP was detected. All somatosensory stimulation groups had decreased S1 ASY except for the sham rTMS/Sham SS group. When compared with baseline, M1 excitability increased only in the rTMS/SS group.

Conclusion

S1 rTMS and SS alone or in combination changed S1 excitability and decreased ASY, but it was only their combination that increased M1 excitability.

Clinical trial registration

clinicaltrials.gov, identifier (NCT03329807).

Somatosensory Impairment and Chronic Pain Following Stroke: An Observational Study

BACKGROUND

Chronic pain and somatosensory impairment are common following a stroke. It is possible that an interaction exists between pain and somatosensory impairment and that a change in one may influence the other. We therefore investigated the presence of chronic pain and self-reported altered somatosensory ability in individuals with stroke, aiming to determine if chronic pain is more common in stroke survivors with somatosensory impairment than in those without.

METHODS

Stroke survivors were invited to complete an online survey that included demographics, details of the stroke, presence of chronic pain, and any perceived changes in body sensations post-stroke.

RESULTS

Survivors of stroke (n = 489) completed the survey with 308 indicating that they experienced chronic pain and 368 reporting perceived changes in somatosensory function. Individuals with strokes who reported altered somatosensory ability were more likely to experience chronic pain than those who did not (OR = 1.697; 95% CI 1.585, 2.446). Further, this difference was observed for all categories of sensory function that were surveyed (detection of light touch, body position, discrimination of surfaces and temperature, and haptic object recognition).

CONCLUSIONS

The results point to a new characteristic of chronic pain in strokes, regardless of nature or region of the pain experienced, and raises the potential of somatosensory impairment being a rehabilitation target to improve pain-related outcomes for stroke survivors.

Efficacy and feasibility of SENSory relearning of the UPPer limb (SENSUPP) in people with chronic stroke: A pilot randomized controlled trial

BACKGROUND

Sensorimotor impairments of the upper limb (UL) are common after stroke, but there is a lack of evidence-based interventions to improve functioning of UL.

OBJECTIVE

To evaluate (1) the efficacy of sensory relearning and task-specific training compared to task-specific training only, and (2) the feasibility of the training in chronic stroke.

DESIGN

A pilot randomized controlled trial.

SETTING

University hospital outpatient clinic.

PARTICIPANTS

Twenty-seven participants (median age; 62 years, 20 men) were randomized to an intervention group (IG; n = 15) or to a control group (CG; n = 12).

INTERVENTION

Both groups received training twice weekly in 2.5-hour sessions for 5 weeks. The training in the IG consisted of sensory relearning, task-specific training, and home training. The training in the CG consisted of task-specific training.

MAIN OUTCOME MEASURES

Primary outcome was sensory function (touch thresholds, touch discrimination, light touch, and proprioception). Secondary outcomes were dexterity, ability to use the hand in daily activities, and perceived participation. A blinded assessor conducted the assessments at baseline (T1), post intervention (T2), and at 3-month follow-up (T3). Nonparametric analyses and effect-size calculations (r) were performed. Feasibility was evaluated by a questionnaire.

RESULTS

After the training, only touch thresholds improved significantly from T1 to T2 (p = .007, r = 0.61) in the IG compared to the CG. Within the IG, significant improvements were found from T1 to T2 regarding use of the hand in daily activities (p = .001, r = 0.96) and movement quality (p = .004, r = 0.85) and from T1 to T3 regarding satisfaction with performance in meaningful activities (p = .004, r = 0.94). The CG significantly improved the performance of using the hand in meaningful activities from T1 to T2 (p = .017, r = 0.86). The training was well tolerated by the participants and performed without any adverse events.

CONCLUSIONS

Combined sensory relearning and task-specific training may be a promising and feasible intervention to improve UL sensorimotor function after stroke.

Interventions for perceptual disorders following stroke

BACKGROUND

Perception is the ability to understand information from our senses. It allows us to experience and meaningfully interact with our environment. A stroke may impair perception in up to 70% of stroke survivors, leading to distress, increased dependence on others, and poorer quality of life. Interventions to address perceptual disorders may include assessment and screening, rehabilitation, non-invasive brain stimulation, pharmacological and surgical approaches.

OBJECTIVES

To assess the effectiveness of interventions aimed at perceptual disorders after stroke compared to no intervention or control (placebo, standard care, attention control), on measures of performance in activities of daily living.  SEARCH METHODS: We searched the trials registers of the Cochrane Stroke Group, CENTRAL, MEDLINE, Embase, and three other databases to August 2021. We also searched trials and research registers, reference lists of studies, handsearched journals, and contacted authors.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adult stroke survivors with perceptual disorders. We defined perception as the specific mental functions of recognising and interpreting sensory stimuli and included hearing, taste, touch, smell, somatosensation, and vision. Our definition of perception excluded visual field deficits, neglect/inattention, and pain.

DATA COLLECTION AND ANALYSIS

One review author assessed titles, with two review authors independently screening abstracts and full-text articles for eligibility. One review author extracted, appraised, and entered data, which were checked by a second author. We assessed risk of bias (ROB) using the ROB-1 tool, and quality of evidence using GRADE.  A stakeholder group, comprising stroke survivors, carers, and healthcare professionals, was involved in this review update.

MAIN RESULTS

We identified 18 eligible RCTs involving 541 participants. The trials addressed touch (three trials, 70 participants), somatosensory (seven trials, 196 participants) and visual perception disorders (seven trials, 225 participants), with one (50 participants) exploring mixed touch-somatosensory disorders. None addressed stroke-related hearing, taste, or smell perception disorders. All but one examined the effectiveness of rehabilitation interventions; the exception evaluated non-invasive brain stimulation. For our main comparison of active intervention versus no treatment or control, one trial reported our primary outcome of performance in activities of daily living (ADL):  Somatosensory disorders: one trial (24 participants) compared an intervention with a control intervention and reported an ADL measure.  Touch perception disorder: no trials measuring ADL compared an intervention with no treatment or with a control intervention.  Visual perception disorders: no trials measuring ADL compared an intervention with no treatment or control.  In addition, six trials reported ADL outcomes in a comparison of active intervention versus active intervention, relating to somatosensation (three trials), touch (one trial) and vision (two trials).   AUTHORS' CONCLUSIONS: Following a detailed, systematic search, we identified limited RCT evidence of the effectiveness of interventions for perceptual disorders following stroke. There is insufficient evidence to support or refute the suggestion that perceptual interventions are effective. More high-quality trials of interventions for perceptual disorders in stroke are needed. They should recruit sufficient participant numbers, include a 'usual care' comparison, and measure longer-term functional outcomes, at time points beyond the initial intervention period. People with impaired perception following a stroke should continue to receive neurorehabilitation according to clinical guidelines.

Current clinical practice in managing somatosensory impairments and the use of technology in stroke rehabilitation

Stroke-induced somatosensory impairments seem to be clinically overlooked, despite their prevalence and influence on motor recovery post-stroke. Interest in technology has been gaining traction over the past few decades as a promising method to facilitate stroke rehabilitation. This questionnaire-based cross-sectional study aimed to identify current clinical practice and perspectives on the management of somatosensory impairments post-stroke and the use of technology in assessing outcome measures and providing intervention. Participants were 132 physiotherapists and occupational therapists currently working with stroke patients in public hospitals and rehabilitation centres in Singapore. It was found that the majority (64.4%) of the therapists spent no more than half of the time per week on somatosensory interventions. Functional or task-specific training was the primary form of intervention applied to retrain somatosensory functions in stroke survivors. Standardised assessments (43.2%) were used less frequently than non-standardised assessments (97.7%) in clinical practice, with the sensory subscale of the Fugl-Meyer Assessment being the most popular outcome measure, followed by the Nottingham Sensory Assessment. While the adoption of technology for assessment was relatively scarce, most therapists (87.1%) reported that they have integrated technology into intervention. There was a common agreement that proprioception is an essential component in stroke rehabilitation, and that robotic technology combined with conventional therapy is effective in enhancing stroke rehabilitation, particularly for retraining proprioception. Most therapists identified price, technology usability, and lack of available space as some of the biggest barriers to integrating robotic technology in stroke rehabilitation. Standardised assessments and interventions targeting somatosensory functions should be more clearly delineated in clinical guidelines. Although therapists were positive about technology-based rehabilitation, obstacles that make technology integration challenging ought to be addressed.

Reduced wrist flexor H-reflex excitability is linked with increased wrist proprioceptive error in adults with cerebral palsy

Although most neurophysiological studies of persons with cerebral palsy (CP) have been focused on supraspinal networks, recent evidence points toward the spinal cord as a central contributor to their motor impairments. However, it is unclear if alterations in the spinal pathways are also linked to deficits in the sensory processing observed clinically. This investigation aimed to begin to address this knowledge gap by evaluating the flexor carpi radialis (FCR) H-reflex in adults with CP and neurotypical (NT) controls while at rest and during an isometric wrist flexion task. The maximal H-wave (Hmax) and M-wave (Mmax) at rest were calculated and utilized to compute Hmax/Mmax ratios (H:M ratios). Secondarily, the facilitation of the H-wave was measured while producing an isometric, voluntary wrist flexion contraction (i.e., active condition). Finally, a wrist position sense test was used to quantify the level of joint position sense. These results revealed that the adults with CP had a lower H:M ratio compared with the NT controls while at rest. The adults with CP were also unable to facilitate their H-reflexes with voluntary contraction and had greater position sense errors compared with the controls. Further, these results showed that the adults with CP that had greater wrist position sense errors tended to have a lower H:M ratio at rest. Overall, these findings highlight that aberration in the spinal cord pathways of adults with CP might play a role in the sensory processing deficiencies observed in adults with CP.

Enhancing touch sensibility by sensory retraining in a sensory discrimination task via haptic rendering

Stroke survivors are commonly affected by somatosensory impairment, hampering their ability to interpret somatosensory information. Somatosensory information has been shown to critically support movement execution in healthy individuals and stroke survivors. Despite the detrimental effect of somatosensory impairments on performing activities of daily living, somatosensory training—in stark contrast to motor training—does not represent standard care in neurorehabilitation. Reasons for the neglected somatosensory treatment are the lack of high-quality research demonstrating the benefits of somatosensory interventions on stroke recovery, the unavailability of reliable quantitative assessments of sensorimotor deficits, and the labor-intensive nature of somatosensory training that relies on therapists guiding the hands of patients with motor impairments. To address this clinical need, we developed a virtual reality-based robotic texture discrimination task to assess and train touch sensibility. Our system incorporates the possibility to robotically guide the participants' hands during texture exploration (i.e., passive touch) and no-guided free texture exploration (i.e., active touch). We ran a 3-day experiment with thirty-six healthy participants who were asked to discriminate the odd texture among three visually identical textures –haptically rendered with the robotic device– following the method of constant stimuli. All participants trained with the passive and active conditions in randomized order on different days. We investigated the reliability of our system using the Intraclass Correlation Coefficient (ICC). We also evaluated the enhancement of participants' touch sensibility via somatosensory retraining and compared whether this enhancement differed between training with active vs. passive conditions. Our results showed that participants significantly improved their task performance after training. Moreover, we found that training effects were not significantly different between active and passive conditions, yet, passive exploration seemed to increase participants' perceived competence. The reliability of our system ranged from poor (in active condition) to moderate and good (in passive condition), probably due to the dependence of the ICC on the between-subject variability, which in a healthy population is usually small. Together, our virtual reality-based robotic haptic system may be a key asset for evaluating and retraining sensory loss with minimal supervision, especially for brain-injured patients who require guidance to move their hands.

Design and Preliminary Evaluation of a Robot-assisted Assessment-driven Finger Proprioception Therapy

Neurological injuries such as stroke often lead to motor and somatosensory impairments of the hand. Deficits in somatosensation, especially proprioception, result in difficulties performing activities of daily living involving fine motor tasks. However, it is challenging to accurately detect those impairments due to the limitations of clinical assessments. Hence therapies rarely focus on proprioception specifically, while such training could promote functional benefits. In this work we propose and preliminarily evaluate a robot-assisted, assessment-driven therapy of finger proprioception. We designed and implemented two therapeutic exercises, one targeting passive and the other active position sense. The difficulty level of the therapy exercises was adapted to each patient's proprioceptive impairment. We evaluated the exercises and their usability with 7 stroke participants and 8 clinicians in a 45-minutes protocol. We found that the exercises were feasible for stroke participants, as 5 individuals progressed in difficulty levels over multiple exercise repetitions, indicating adequacy of the adaptation algorithm. Moreover, usability was rated mostly as satisfactory by the patients (System Usability Scale = 73), and they also found the exercises interesting. Clinicians rated the exercises as difficult but clinically meaningful. Overall, these promising preliminary results pave the way for further development and validation of the proposed therapy approach.

Construct validity, reliability, and responsiveness of the Wrist Position Sense Test for use in children with hemiplegic cerebral palsy

INTRODUCTION

We investigate the construct validity, test re-test reliability, and responsiveness of the Wrist Position Sense Test (WPST) for children with hemiplegic cerebral palsy (CP).

METHODS

Twenty-eight children with spastic hemiplegic CP [mean age 10.8 years; SD 2.4 years] and 39 typically developing (TD) children [mean age 11 years; SD 2.9 years] participated in a cross-sectional study to investigate construct validity and association with an upper limb activity measure, the Box and Block Test (BBT). Twenty-two TD children were tested at a second time-point to examine reliability. Test responsiveness was determined by random allocation of 17 children with CP to a treatment (n = 10) or control (n = 7) group with assessments completed at four time-points.

RESULTS

Significantly greater differences were observed in mean error of indicated wrist position (p < 0.01) in children with CP at baseline (M = 21.6°, SD = 21.6°) than in TD children (M = 12.8°, SD = 11.0°). Larger WPST errors were associated with poorer performance on the BBT (p < 0.01) indicating a substantial association, and there were no consistent differences between time-points indicating test re-test reliability within a TD population. The WPST demonstrated responsiveness to intervention with a statistically significant reduction in mean error following treatment (p < 0.001), not seen in the control group (p = 0.28).

CONCLUSION

The WPST demonstrated construct validity in this preliminary study. Scores were associated with an upper limb activity measure, and scores changed significantly following somatosensory training. These findings support further research and future psychometric investigation of the WPST in children with CP.

KEY POINTS FOR OCCUPATIONAL THERAPY

This study provides psychometric knowledge about the WPST tool The WPST shows promise as a discriminative measure with preliminary evidence of responsiveness and intra-rater reliability Until further testing, the WPST can be used cautiously in future research studies to measure wrist position sense.

Tactile Sensation Improves Following Motor Rehabilitation for Chronic Stroke: The VIGoROUS Randomized Controlled Trial

Background. Up to 85% of people with chronic stroke experience somatosensory impairment, which contributes to poor sensorimotor control and non-use of the affected limb. Neurophysiological mechanisms suggest motor rehabilitation may improve tactile sense post-stroke, however, somatosensory recovery has rarely been reported in controlled trials. Objective. To compare the effect of four upper limb motor rehabilitation programs on the recovery of tactile sensation in adults with chronic stroke. Methods. Adults with chronic stroke and mild or moderate upper extremity hemiparesis (n = 167) were enrolled in a multi-site randomized controlled trial. Participants completed three weeks of gaming therapy, gaming therapy with additional telerehabilition, Constraint-Induced Movement therapy, or traditional rehabilitation. Here, we report the results of a secondary outcome, tactile sensation, measured with monofilaments, before and after treatment, and 6 months later. Results. A mixed-effects general linear model revealed similar positive change in tactile sensitivity regardless of the type of training. On average, participants were able to detect a stimulus that was 32% and 33% less after training and at 6-month follow-up, respectively. One-third of participants experienced recategorization of their level of somatosensory impairment (e.g., regained protective sensation) following training. Poorer tactile sensation at baseline was associated with greater change. Conclusions. About one-third of individuals with mild/moderate chronic hemiparesis experience sustained improvements in tactile sensation following motor rehabilitation, regardless of the extent of tactile input in the rehabilitation program. Potential for sensory improvement is an additional motivator for those post-stroke. Characteristics of those who improve and mechanisms of improvement are important future questions. Clinicaltrials.gov NCT02631850.

Explicit versus implicit lower extremity sensory retraining for post-stroke chronic sensory deficits: a randomized controlled trial

PURPOSE

Sensory impairment post-stroke limits rehabilitation of balance and gait. This study aims to compare the effect of explicit sensory retraining (ESR) versus implicit repeated exposure (IRE) to stimuli of the lower extremity, assessing their effects on sensation, balance, and gait in individuals with chronic post-stroke sensory impairment.

MATERIALS AND METHODS

A two-arm parallel double-blind multicenter randomized controlled trial was conducted in physical therapy outpatient clinics. Volunteers with chronic sensory impairment post-stroke participated in 10 sessions of 45 min ESR or IRE, according to a detailed protocol. Outcome measures assessed sensation, balance, mobility, and participation.

RESULTS

A total of 64 participants were recruited (ESR, n = 34; IRE, n = 30). The intention-to-treat pre-post analysis demonstrated clinically meaningful changes for both interventions (10-31% improvement for the various measures), with no between-group difference or time × group interaction. The effect size for the time effect varied, with the largest being 0.63 for the miniBEST.

CONCLUSIONS

Sensory rehabilitation treatment by either ESR or IRE led to similar clinically significant changes in the performance of the lower extremity and participation in subjects with sensory loss post-stroke. Both treatment protocols are easy to implement in an outpatient clinic.  .

CLINICALTRIALS.GOV REGISTRATION

NCT01988220. Implications for rehabilitationStandardized, structured, sensory-focused training can improve balance and gait in subjects with chronic post-stroke sensory impairment.Both explicit and implicit learning-based sensory protocols focused on the lower extremity effectively improved balance, mobility, and gait abilities, resulting in enhanced participation of individuals in the chronic post-stroke phase.A series of ten 45-minute treatment sessions in outpatient clinics lead to clinically significant improvements.

Somatosensory Cortex Repetitive Transcranial Magnetic Stimulation and Associative Sensory Stimulation of Peripheral Nerves Could Assist Motor and Sensory Recovery After Stroke

Background

We investigated whether transcranial magnetic stimulation (rTMS) over the primary somatosensory cortex (S1) and sensory stimulation (SS) could promote upper limb recovery in participants with subacute stroke.

Methods

Participants were randomized into four groups: rTMS/Sham SS, Sham rTMS/SS, rTMS/SS, and control group (Sham rTMS/Sham SS). Participants underwent ten sessions of sham or active rTMS over S1 (10 Hz, 1,500 pulses, 120% of resting motor threshold, 20 min), followed by sham or active SS. The SS involved active sensory training (exploring features of objects and graphesthesia, proprioception exercises), mirror therapy, and Transcutaneous electrical nerve stimulation (TENS) in the region of the median nerve in the wrist (stimulation intensity as the minimum intensity at which the participants reported paresthesia; five electrical pulses of 1 ms duration each at 10 Hz were delivered every second over 45 min). Sham stimulations occurred as follows: Sham rTMS, coil was held while disconnected from the stimulator, and rTMS noise was presented with computer loudspeakers with recorded sound from a real stimulation. The Sham SS received therapy in the unaffected upper limb, did not use the mirror and received TENS stimulation for only 60 seconds. The primary outcome was the Body Structure/Function: Fugl-Meyer Assessment (FMA) and Nottingham Sensory Assessment (NSA); the secondary outcome was the Activity/Participation domains, assessed with Box and Block Test, Motor Activity Log scale, Jebsen-Taylor Test, and Functional Independence Measure.

Results

Forty participants with stroke ischemic (n = 38) and hemorrhagic (n = 2), men (n = 19) and women (n = 21), in the subacute stage (10.6 ± 6 weeks) had a mean age of 62.2 ± 9.6 years, were equally divided into four groups (10 participants in each group). Significant somatosensory improvements were found in participants receiving active rTMS and active SS, compared with those in the control group (sham rTMS with sham SS). Motor function improved only in participants who received active rTMS, with greater effects when active rTMS was combined with active SS.

Conclusion

The combined use of SS with rTMS over S1 represents a more effective therapy for increasing sensory and motor recovery, as well as functional independence, in participants with subacute stroke.

Clinical Trial Registration

[clinicaltrials.gov], identifier [NCT03329807].

Improved proprioception does not benefit visuomotor adaptation

Visuomotor adaptation arises when reaching in an altered visual environment, where one's seen hand position does not match their felt (i.e., proprioceptive) hand position in space. Here, we asked if proprioceptive training benefits visuomotor adaptation, and if these benefits arise due to implicit (unconscious) or explicit (conscious strategy) processes. Seventy-two participants were divided equally into 3 groups: proprioceptive training with feedback (PTWF), proprioceptive training no feedback (PTNF), and Control (CTRL). The PTWF and PTNF groups completed passive proprioceptive training, where a participant's hand was moved to an unknown reference location and they judged the felt position of their unseen hand relative to their body midline on every trial. The PTWF group received verbal feedback with respect to their response accuracy on the middle 60% of trials, whereas the PTNF did not receive any feedback during training. The CTRL group did not complete proprioceptive training and instead sat quietly during this time. Following proprioceptive training or time delay, all three groups reached when seeing a cursor that was rotated 30° clockwise relative to their hand motion. The experiment ended with participants completing a series of no-cursor reaches to assess implicit and explicit adaptation. Results indicated that the PTWF group improved the accuracy of their sense of felt hand position following proprioceptive training. However, this improved proprioceptive acuity (i.e., the accuracy of their sense of felt hand) did not benefit visuomotor adaptation, as all three groups showed similar visuomotor adaptation across rotated reach training trials. Visuomotor adaptation arose implicitly, with minimal explicit contribution for all three groups. Together, these results suggest that passive proprioceptive training does not benefit, nor hinder, the extent of implicit visuomotor adaptation established immediately following reach training with a 30° cursor rotation.

Experiences of SENSory Relearning of the UPPer Limb (SENSUPP) after Stroke and Perceived Effects: A Qualitative Study

Recently, it was shown that sensory relearning of the upper limb (SENSUPP) is a promising intervention to improve sensorimotor function after stroke. There is limited knowledge, however, of how participants perceive the training. Here, we explored how persons with sensory impairments in the upper limb experienced the SENSUPP protocol (combined sensory- and motor training and home exercises for 5 weeks) and its effect. Fifteen persons (mean age 59 years; 10 men; >6 months post-stroke) were individually interviewed, and data were analyzed with qualitative content analysis. An overall theme ‘Sensory relearning was meaningful and led to improved ability to perform daily hand activities’ and two categories with six subcategories emerged. The outpatient training was perceived as meaningful, although the exercises were demanding and required concentration. Support from the therapist was helpful and training in small groups appreciated. The home training was challenging due to lack of support, time, and motivation. Small improvements in sensory function were perceived, whereas increased movement control and ability in performing daily hand activities were reported. In conclusion, the SENSUPP protocol is meaningful and beneficial in improving the functioning of the UL in chronic stroke. Improving compliance to the home training, regular follow-ups, and an exercise diary are recommended.

Rehabilitation of somatic sensation and related deficit of motor control by Mirror Box Therapy: a case report

Somatosensory disorders are often present after cerebral stroke. These deficits are associated with patients' disability. Therefore, their rehabilitation takes an importance in recovery program. However, the treatment of sensation remains poorly considered during neurorehabilitation and evidence for active sensory training is limited. Mirror Box Therapy is a simple training used to treat upper extremity motor deficits and pain also in patients with stroke. However, the effects of Mirror Box Therapy on somatosensory impairments in post-stroke patients are not deeply investigated and often exclusively motor exercises are provided during therapy.The aim of the present study was to investigate the effects of Mirror Box Therapy sensory training on somatosensory deficits in a stroke patient presenting upper limb impairment.The patient underwent to four weeks of training, five days a week. Before, during and after the Mirror Box Therapy treatment, the patient was assessed by Rivermead Assessment of Somatosensory Performance. Before and after training also upper limb motor function and performance in activities of daily living were assessed.After training patient showed an improvement in somatosensory performance. The gain was maintained at follow-up.This case report shows the effects of Mirror Box Therapy sensory training on the upper extremity for the improvement of sensation and movement in a patient with a thalamo-capsular hemorrhagic stroke during the subacute phase.

Proprioceptive Training with Visual Feedback Improves Upper Limb Function in Stroke Patients: A Pilot Study

Proprioceptive deficit is one of the common sensory impairments following stroke and has a negative impact on motor performance. However, evidence-based training procedures and cost-efficient training setups for patients with poststroke are still limited. We compared the effects of proprioceptive training versus nonspecific sensory stimulation on upper limb proprioception and motor function rehabilitation. In this multicenter, single-blind, randomized controlled trial, 40 participants with poststroke hemiparesis were enrolled from 3 hospitals in China. Participants were assigned randomly to receive proprioceptive training involving passive and active movements with visual feedback (proprioceptive training group [PG]; n = 20) or nonspecific sensory stimulation (control group [CG]; n = 20) 20 times in four weeks. Each session lasted 30 minutes. A clinical assessor blinded to group assignment evaluated patients before and after the intervention. The primary outcome was the change in the motor subscale of the Fugl-Meyer assessment for upper extremity (FMA-UE-M). Secondary outcomes were changes in box and block test (BBT), thumb localization test (TLT), the sensory subscale of the Fugl-Meyer assessment for upper extremity (FMA-UE-S), and Barthel Index (BI). The results showed that the mean change scores of FMA-UE were significantly greater in the PG than in the CG (p = 0.010 for FMA-UE-M, p = 0.033 for FMA-UE-S). The PG group was improved significantly in TLT (p = 0.010) and BBT (p = 0.027), while there was no significant improvement in TLT (p = 0.083) and BBT (p = 0.107) for the CG group. The results showed that proprioceptive training was effective in improving proprioception and motor function of the upper extremity in patients with poststroke. This trial is registered in the Chinese Clinical Trial Registry (ChiCTR2000037808).

Recovery of Body Awareness After Stroke: An Observational Study

Background: Body awareness (BA) is a process that involves sensory awareness originating from the body's physiological states, processes and actions, and is shaped by one's attitudes, perceptions, beliefs and experience of social and cultural context. Impairments in body awareness after stroke are believed to be common and may be an important influence on recovery outcomes. However, recovery of body awareness is poorly understood and receives little consideration in rehabilitation.

Aims: To investigate if body awareness changes over time following stroke; and identify if body awareness after stroke is associated with sensation, motor impairment, self-efficacy and quality of life.

Methods: An exploratory longitudinal observational study was performed. Participants with a stroke diagnosis and associated motor impairment were recruited from an acute stroke unit. An assessment battery consisting of sensory and motor impairment and function, body awareness, self-efficacy and quality of life measures were used at baseline, 1, 3 and 6 months.

Results: A total of 105 people with stroke were recruited. Most recovery in sensation and body awareness occurred within the first month after stroke (all p < 0.01). Sensation and body awareness were correlated with other clinical outcomes (motor impairment, self-efficacy and quality of life), demographics, and stroke specific clinical characteristics (all p < 0.01).

Conclusions: This is the first study to track recovery of body awareness after stroke and investigate the relationship it may have in recovery of sensation, motor impairment and function, self-efficacy and quality of life. Further research is now warranted to continue investigation of body awareness and to develop effective stroke-specific assessment and intervention strategies.

Validation of Spanish Erasmus-Modified Nottingham Sensory Assessment Stereognosis Scale in Acquired Brain Damage

Acquired brain injury (ABI) is the third leading cause of death in Spain. The disability derived from ABI can include considerable difficulties in upper-limb use due to somatosensory deficits. One of the assessments most commonly used to evaluate ABI is the Nottingham Sensory Assessment (NSA); however, there is no complete psychometric analysis or standardized version in Spanish. We aimed to develop and validate a Spanish version of the stereognosis component of the NSA for evaluating Spanish adults with ABI via a single-center, observational, cross-sectional study. The Spanish version of the NSA was developed in two steps. The first was based on the standardization and collection of normative data in 120 asymptomatic participants. For the second, we recruited 25 participants with ABI to establish concurrent criterion-related validity, internal consistency, and floor/ceiling effects. Criterion validity was assessed against two-point discrimination and tactile-localization tests. Our normative data showed significant differences among the various age groups (p < 0.05), supporting the validity of the Spanish-version assessment. For the ABI sample, we also found further evidence of validity with Spearman’s rho coefficient between the total scores and the two-point discrimination and tactile-localization tests, which showed low and moderate correlations (rho = 0.50–0.75, p < 0.05). Internal consistency was excellent, with a Cronbach’s alpha of 0.91. No ceiling or floor effects were found. We conclude that the stereognosis component of the NSA in its Spanish version is a valid scale that can be used to comprehensively and accurately assess stereognosis capacity in adults with ABI. As a low-cost evaluation, this assessment has great potential to be widely used in clinical practice and research settings.

Robotic-based ACTive somatoSENSory (Act.Sens) retraining on upper limb functions with chronic stroke survivors: study protocol for a pilot randomised controlled trial

Background

Prior studies have established that senses of the limb position in space (proprioception and kinaesthesia) are important for motor control and learning. Although nearly one-half of stroke patients have impairment in the ability to sense their movements, somatosensory retraining focusing on proprioception and kinaesthesia is often overlooked. Interventions that simultaneously target motor and somatosensory components are thought to be useful for relearning somatosensory functions while increasing mobility of the affected limb. For over a decade, robotic technology has been incorporated in stroke rehabilitation for more controlled therapy intensity, duration, and frequency. This pilot randomised controlled trial introduces a compact robotic-based upper-limb reaching task that retrains proprioception and kinaesthesia concurrently.

Methods

Thirty first-ever chronic stroke survivors (> 6-month post-stroke) will be randomly assigned to either a treatment or a control group. Over a 5-week period, the treatment group will receive 15 training sessions for about an hour per session. Robot-generated haptic guidance will be provided along the movement path as somatosensory cues while moving. Audio-visual feedback will appear following every successful movement as a reward. For the same duration, the control group will complete similar robotic training but without the vision occluded and robot-generated cues. Baseline, post-day 1, and post-day 30 assessments will be performed, where the last two sessions will be conducted after the last training session. Robotic-based performance indices and clinical assessments of upper limb functions after stroke will be used to acquire primary and secondary outcome measures respectively. This work will provide insights into the feasibility of such robot-assisted training clinically.

Discussion

The current work presents a study protocol to retrain upper-limb somatosensory and motor functions using robot-based rehabilitation for community-dwelling stroke survivors. The training promotes active use of the affected arm while at the same time enhances somatosensory input through augmented feedback. The outcomes of this study will provide preliminary data and help inform the clinicians on the feasibility and practicality of the proposed exercise.

Trial registration

ClinicalTrials.gov NCT04490655. Registered 29 July 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00948-3.

What is "usual care" in the rehabilitation of upper limb sensory loss after stroke? Results from a national audit and knowledge translation study

PURPOSE

To characterise the assessments and treatments that comprise "usual care" for stroke patients with somatosensory loss, and whether usual care has changed over time.

MATERIALS AND METHODS

Comparison of cross-sectional, observational data from (1) Stroke Foundation National Audit of Acute (2007-2019) and Rehabilitation (2010-2018) Stroke Services and (2) the SENSe Implement multi-site knowledge translation study with occupational therapists and physiotherapists (n = 115). Descriptive statistics, random effects logistic regression, and content analysis were used.

RESULTS

Acute hospitals (n = 172) contributed 24 996 cases across audits from 2007 to 2019 (median patient age 76 years, 54% male). Rehabilitation services (n = 134) contributed organisational survey data from 2010 to 2014, with 7165 cases (median 76 years, 55% male) across 2016-2018 clinical audits (n = 127 services). Somatoensory assessment protocol use increased from 53% (2007) to 86% (2019) (odds ratio 11.4, 95% CI 5.0-25.6). Reported use of sensory-specific retraining remained stable over time (90-93%). Therapist practice reports for n = 86 patients with somatosensory loss revealed 16% did not receive somatosensory rehabilitation. The most common treatment approaches were sensory rehabilitation using everyday activities (69%), sensory re-education (68%), and compensatory strategies (64%).

CONCLUSION

Sensory assessment protocol use has increased over time while sensory-specific training has remained stable. Sensory rehabilitation in the context of everyday activities is a common treatment approach. Clinical trial registration number: ACTRN12615000933550IMPLICATIONS FOR REHABILITATIONOnly a small proportion of upper limb assessments conducted with stroke patients focus specifically on sensation; increased use of standardised upper limb assessments for sensory loss is needed.Stroke patients assessed as having upper limb sensory loss frequently do not receive treatment for their deficits.Therapists typically use everyday activities to treat upper limb sensory loss and may require upskilling in sensory-specific retraining to benefit patients.

The effect of sensory discrimination training on sensorimotor performance in individuals with central neurological conditions: A systematic review

Objective

The aim of this systematic review was to investigate the efficacy of sensory discrimination training (SDT) on sensorimotor performance in individuals with a neurological condition affecting the central nervous system.

Methods

MEDLINE, CINAHL, EMBASE, AMED, CENTRAL, PsychINFO, Scopus, OT Seeker, PEDro, ETHOS, Web of Science and OpenGrey were systematically searched for appropriate randomised controlled trials (RCTs). Included studies were assessed for risk of bias, and the quality of the evidence was rated using the GRADE approach. The protocol was registered on PROSPERO (CRD42017055237).

Results

Six RCTs met the inclusion/exclusion criteria. All studies used manual tactile discrimination to retrain somatosensation. Somatosensory effect sizes (0.12–0.92) and motor function effect sizes (0.12–10.39) ranged from trivial to large with narrative analysis revealing some between-group difference in favour of the intervention group. However, the total sample size ( n = 220) was relatively small, and the quality of the included studies was low.

Conclusions

SDT may have potential to be an efficacious treatment option for improving sensorimotor performance in individuals with neurological disease. However, at present there is limited evidence on which to base any firm clinical recommendations.

SENSory re-learning of the UPPer limb (SENSUPP) after stroke: development and description of a novel intervention using the TIDieR checklist

Background

Sensorimotor impairments of upper limb (UL) are common after stroke, leading to difficulty to use the UL in daily life. Even though many have sensory impairments in the UL, specific sensory training is often lacking in stroke rehabilitation. Thus, the aim of this paper is to provide a detailed description of the novel intervention “SENSory re-learning of the UPPer limb after stroke (SENSUPP)” that we have developed to improve functioning in the UL in persons with mild to moderate impairments after stroke.

Methods

The SENSUPP protocol was designed using information from literature reviews, clinical experience and through consultation of experts in the field. The protocol integrates learning principles based on current neurobiological knowledge and includes repetitive intensive practice, difficulty graded exercises, attentive exploration of a stimulus with focus on the sensory component, and task-specific training in meaningful activities that includes feedback. For reporting the SENSUPP protocol, the Template for Intervention Description and Replication (TIDieR) checklist was used.

Results

The essential features of the SENSUPP intervention comprise four components: applying learning principles based on current neurobiological knowledge, sensory re-learning (exercises for touch discrimination, proprioception and tactile object recognition), task-specific training in meaningful activities, and home-training. The training is performed twice a week, in 2.5-h sessions for 5 weeks.

Conclusion

Since there is close interaction between the sensory and motor systems, the SENSUPP intervention may be a promising method to improve UL functioning after stroke. The TIDieR checklist has been very useful for reporting the procedure and development of the training.

Trial registration

ClinicalTrials.govNCT03336749. Registered on 8 November 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05375-6.

Brain connectivity alterations after additional sensorimotor or motor therapy for the upper limb in the early-phase post stroke: a randomized controlled trial

Somatosensory function plays an important role for upper limb motor learning. However, knowledge about underlying mechanisms of sensorimotor therapy is lacking. We aim to investigate differences in therapy-induced resting-state functional connectivity changes between additional sensorimotor compared with motor therapy in the early-phase post stroke. Thirty first-stroke patients with a sensorimotor impairment were included for an assessor-blinded multi-centre randomized controlled trial within 8 weeks post stroke [13 (43%) females; mean age: 67 ± 13 years; mean time post stroke: 43 ± 13 days]. Patients were randomly assigned to additional sensorimotor (n = 18) or motor (n = 12) therapy, receiving 16 h of additional therapy within 4 weeks. Sensorimotor evaluations and resting-state functional magnetic resonance imaging were performed at baseline (T1), post-intervention (T2) and after 4 weeks follow-up (T3). Resting-state functional magnetic resonance imaging was also performed in an age-matched healthy control group (n = 19) to identify patterns of aberrant connectivity in stroke patients between hemispheres, or within ipsilesional and contralesional hemispheres. Mixed model analysis investigated session and treatment effects between stroke therapy groups. Non-parametric partial correlations were used to investigate brain−behaviour associations with age and frame-wise displacement as nuisance regressors. Connections within the contralesional hemisphere that showed hypo-connectivity in subacute stroke patients (compared with healthy controls) showed a trend towards a more pronounced pre-to-post normalization (less hypo-connectivity) in the motor therapy group, compared with the sensorimotor therapy group (mean estimated difference = −0.155 ± 0.061; P = 0.02). Further, the motor therapy group also tended to show a further pre-to-post increase in functional connectivity strength among connections that already showed hyper-connectivity in the stroke patients at baseline versus healthy controls (mean estimated difference = −0.144 ± 0.072; P = 0.06). Notably, these observed increases in hyper-connectivity of the contralesional hemisphere were positively associated with improvements in functional activity (r = 0.48), providing indications that these patterns of hyper-connectivity are compensatory in nature. The sensorimotor and motor therapy group showed no significant differences in terms of pre-to-post changes in inter-hemispheric connectivity or ipsilesional intrahemispheric connectivity. While effects are only tentative within this preliminary sample, results suggest a possible stronger normalization of hypo-connectivity and a stronger pre-to-post increase in compensatory hyper-connectivity of the contralesional hemisphere after motor therapy compared with sensorimotor therapy. Future studies with larger patient samples are however recommended to confirm these trend-based preliminary findings.

Computational approach to understand temporal and spatial tactile transmission processes from mechanical stimuli of the index fingertip to the primary somatosensory cortex

Mechanisms of information transmission using tactile sense are one of major concerns in producing simulated experience in virtual or augmented reality as well as in compensating elderly or impaired people with diminished tactile sensory function. However, important mechanism of the difference of peak latency in the primary somatosensory cortex (SI) between electrical and mechanical stimulations of finger skin is not fully understood. We propose a computational approach to fuse a computational model to simulate temporal and spatial transmission processes from mechanical stimuli to the SI and experimental method using a magnetoencephalograph (MEG). In our model, a tactile model that combined a three-dimensional mechanical model of fingertip skin and a neurophysiological model of a slowly adapting type 1 (SA1) mechanoreceptor was integrated with a somatosensory evoked field (SEF) response model. Electrical and mechanical stimulations were applied to the same locations of the right or left index fingertips of three subjects using a MEG. By identifying parameters of the SEF response model using the electrical stimulation test data, predicted first peak latency due to a mechanical stimulus was identical to its average value obtained from the mechanical stimulation test data, while the spatial map predicted at the multiple SA1 receptors qualitatively corresponded to the MEG image map in the timings of peak latency. This suggests that mechanical change in the skin and neurophysiological responses generate the difference of peak latency in SI between electrical and mechanical stimulations. The computational approach has the potential for detailed investigation of mechanisms of tactile information transmission.

Lower Limb Sensorimotor Training (LoSenseT) for Children and Adolescents with Cerebral Palsy: A Brief Report of a Feasibility Randomized Protocol

Motor disorders in cerebral palsy (CP) are often accompanied by disturbances of sensation and impaired somatosensory functions have been reported in individuals with CP. To test the feasibility of a sensorimotor training protocol for lower limbs in children and adolescents with unilateral and bilateral CP, and to analyze the preliminary effects of this training on sensory and motor variables. This is a single-blind, prospective phase I feasibility randomized protocol. A total of twenty participants with uni or bilateral cerebral palsy, GMFCS level I-III, ages 5 to 20 years will be recruited. The LoSenseT protocol is composed of tactile and proprioceptive activities in a child-friendly format. An original qualitative feedback questionnaire was developed to assess the protocol feasibility. Additionally, proprioception, tactile discrimination, postural stability, and gait parameters will be assessed. The LoSenseT protocol can support the implementation of interventions targeting lower limbs somatosensory impairments in individuals with CP.

Factors influencing allied health professionals' implementation of upper limb sensory rehabilitation for stroke survivors: a qualitative study to inform knowledge translation

OBJECTIVES

Somatosensory loss is common after stroke with one-in-two individuals affected. Although clinical practice guidelines recommend providing somatosensory rehabilitation, this impairment often remains unassessed and untreated. To address the gap between guideline recommendations and clinical practice, this study sought to understand the factors influencing delivery of evidence-based upper limb sensory rehabilitation after stroke.

DESIGN

Qualitative study involving focus groups and interviews. Data analysis used an inductive approach (thematic analysis) and deductive analysis using implementation theory (the Theoretical Domains Framework and Normalisation Process Theory).

SETTING

Eight healthcare organisations in metropolitan and regional areas of Victoria and New South Wales, Australia.

PARTICIPANTS

Eighty-seven rehabilitation therapists (79% occupational therapists and 21% physiotherapists) were purposively sampled and participated in a knowledge translation study with staggered recruitment from 2014 to 2018.

RESULTS

Three types of factors influenced therapists' delivery of upper limb somatosensory rehabilitation: individual ('The uncertain, unskilled therapist'), patient ('Patient understanding and priorities') and organisational ('System pressures and resources'). Deductive analysis using implementation theory identified key determinants of practice change, such as opportunities to consolidate new skills, the anticipated benefits of upskilling as a therapy team and the work anticipated by therapists to incorporate a new somatosensory rehabilitation approach.

CONCLUSIONS

Occupational therapists and physiotherapists hold valuable insights towards practice change in somatosensory rehabilitation from the 'frontline'. Therapists experience barriers to change including a lack of knowledge and skills, lack of resources and organisational pressures. Facilitators for change were identified, including social support and therapists' perceived legitimacy in using new somatosensory rehabilitation approaches. Results will inform the design of a tailored implementation strategy to increase the use of evidence-based somatosensory rehabilitation in Australia.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12615000933550).

Effect of NEuroplasticity-Principles-based SEnsory-Rehabilitation (NEPSER) on sensori-motor recovery in stroke: study protocol for a randomized controlled trial

Introduction

Up to 2/3rd of the stroke subjects may experience impairment in any of the somatosensory modalities such as light touch, proprioception, and stereognosis. The sensory recovery is strongly associated with the level of motor recovery. Very negligible sensory-based interventions have been developed and found to be evident in enhancing the sensory deficit and associated motor recovery. The possible factor for the ineffectiveness of these sensory interventions could be lack of the neuroscientific basis in formulation of the program. Thus, the objective of the study is to determine the effectiveness of a neuralplasticity-principles-based sensory-rehabilitation protocol on motor and sensory recovery, and disability of the post-stroke hemiparetic subjects.

Methods

We propose to recruit 122 poststroke subjects in a randomized controlled, assessor blinded trial to be conducted in a rehabilitation-institute. The key eligibility criteria is age between 20 to 80 years, hemiparesis (right or left), ischemic or hemorrhagic stroke, 1 to 12 months poststroke, and impairment in any of the sensory modalities. The participants in the experimental group will receive NEuroplasticity-Principles-based SEnsory-Rehabilitation (NEPSER) protocol comprising active, repetitive, and meaningful training of the specific sensory modalities utilizing visuo-perceptual, cognitive, motor, and functional tasks will be imparted for 8 weeks, 5 sessions / week, each of 2 h. The control subjects will undergo only standard rehabilitation based on neurophysiological, biomechanical, and rehabilitative approaches. All the participants will be assessed for motor (Fugl-Meyer assessment, upper extremity section) and sensory recovery [Nottingham Sensory assessment (Erasmus MC modification of the revised version)] at baseline, 8-week, and 12-week follow-up. The Semmes weinstein monofilament, two-point discrimination test and modified rankin scale (disability) will be applied as secondary measures. A repeated-measures 2-way ANOVA will be used to estimate difference for the post intervention and follow-up scores between the groups.

Perspective

The proposed study will lead to development of a novel rehabilitation protocol that will not only enhance the sensory recovery but also the motor and functional recovery. This may reduce the impact of stroke disability and enhance the quality of life.

Trial registration

The trial has been registered under Clinical Trial Registry of India (CTRI) as CTRI/2019/09/021442 on 30th September 2019.

The tactile experience paired with vagus nerve stimulation determines the degree of sensory recovery after chronic nerve damage

Loss of sensory function is a common consequence of neurological injury. Recent clinical and preclinical evidence indicates vagus nerve stimulation (VNS) paired with tactile rehabilitation, consisting of delivery of a variety of mechanical stimuli to the hyposensitive skin surface, yields substantial and long-lasting recovery of somatosensory function after median and ulnar nerve transection and repair. Here, we tested the hypothesis that a specific component of the tactile rehabilitation paired with VNS is necessary for recovery of somatosensory function. In a second experiment in a separate cohort, we investigated whether VNS paired with tactile rehabilitation could improve skilled forelimb motor function. Elements of the study design, including planned sample size, assessments, and statistical comparisons, were preregistered prior to beginning data collection (https://osf.io/3tm8u/). Animals received a peripheral nerve injury (PNI) causing chronic sensory loss. Eight weeks after injury, animals were given a VNS implant followed by six weeks of tactile rehabilitation sessions consisting of repeated application of one of two distinct mechanical stimuli, a filament or a paintbrush, to the previously denervated forepaw. VNS paired with either filament indentation or brushing of the paw significantly improved recovery of forelimb withdrawal thresholds after PNI compared to tactile rehabilitation without VNS. The effect size was twice as large when VNS was paired with brushing compared to VNS paired with point indentation. An independent replication in a second cohort confirmed that VNS paired with brush restored forelimb withdrawal thresholds to normal. These rats displayed significant improvements in performance on a skilled forelimb task compared to rats that did not receive VNS. These findings support the utility of pairing VNS with tactile rehabilitation to improve recovery of somatosensory and motor function after neurological injury. Additionally, this study demonstrates that the sensory characteristics of the rehabilitation paired with VNS determine the degree of recovery.

Sensorimotor vs. Motor Upper Limb Therapy for Patients With Motor and Somatosensory Deficits: A Randomized Controlled Trial in the Early Rehabilitation Phase After Stroke

Background: Somatosensory function plays an important role in motor learning. More than half of the stroke patients have somatosensory impairments in the upper limb, which could hamper recovery. Question: Is sensorimotor upper limb (UL) therapy of more benefit for motor and somatosensory outcome than motor therapy? Design: Randomized assessor- blinded multicenter controlled trial with block randomization stratified for neglect, severity of motor impairment, and type of stroke. Participants: 40 first-ever stroke patients with UL sensorimotor impairments admitted to the rehabilitation center. Intervention: Both groups received 16 h of additional therapy over 4 weeks consisting of sensorimotor (N = 22) or motor (N = 18) UL therapy. Outcome measures: Action Research Arm test (ARAT) as primary outcome, and other motor and somatosensory measures were assessed at baseline, post-intervention and after 4 weeks follow-up. Results: No significant between-group differences were found for change scores in ARAT or any somatosensory measure between the three time points. For UL impairment (Fugl-Meyer assessment), a significant greater improvement was found for the motor group compared to the sensorimotor group from baseline to post-intervention [mean (SD) improvement 14.65 (2.19) vs. 5.99 (2.06); p = 0.01] and from baseline to follow-up [17.38 (2.37) vs. 6.75 (2.29); p = 0.003]. Conclusion: UL motor therapy may improve motor impairment more than UL sensorimotor therapy in patients with sensorimotor impairments in the early rehabilitation phase post stroke. For these patients, integrated sensorimotor therapy may not improve somatosensory function and may be less effective for motor recovery. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03236376.

Effect of neurocognitive rehabilitation on upper limb function in community-dwelling chronic stroke patients: A pilot study

Background: Although it has been reported that neurocognitive rehabilitation is effective for improving upper limb function in acute and subacute stroke patients, its effectiveness has not been clarified in community-dwelling chronic stroke patients.Objective: To examine the effect of neurocognitive rehabilitation on upper limb function in community-dwelling chronic stroke patients.Methods: Eight community-dwelling chronic stroke patients participated in the study. The mean period from the stroke onset to the start of the intervention was 425.3 days (approximately 14 months post-stroke). All patients received neurocognitive rehabilitation for 60 min, twice per week, for 3 months. Fugl-Meyer Assessments (FMA) were performed, and the amount of use (AOU) and quality of movement (QOM) of the Motor Activity Log (MAL) were measured before and after the intervention. We used the Wilcoxon signed-rank test to analyze the data.Results: The total, shoulder/elbow/forearm, and wrist scores of the FMA, MAL-AOU, and MAL-QOM significantly improved after the intervention compared to those before the intervention. However, significant improvement was not observed in the hand score of the FMA.Conclusion:Neurocognitive rehabilitation could be effective for improving upper limb function in community-dwelling chronic stroke patients.

Systematic Review of Sensory Stimulation Programs in the Rehabilitation of Acquired Brain Injury

Abstract. Acquired Brain Injury (ABI) can lead to sensory deficits and compromise functionality. However, most studies have been focused on motor stimulation in stroke and traumatic brain injury (TBI). Sensory stimulation in stroke and mild/moderate TBI has received reduced interest. The main objective of this review is to know the methodological characteristics and effects of sensory programs in ABI. Studies with the purpose of testing the efficacy of those programs were identified through a literature search, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Cochrane Collaboration Guidelines. Twenty-three studies were included in this review. The results show that in most studies sensory stimulation started within 12 months after injury and there is no consensus regarding frequency, duration and number of sessions, duration of intervention, and instruments used to assess outcomes. Most programs involved unisensory stimulation, and vision was the predominant target. The most used methods were compensation and somatosensory discrimination training. Most studies used a pre- and post-intervention assessment, with few studies comprising follow-up assessment. Regarding the studies revised, the interventions with positive outcomes in ABI are: compensation, cognitive training, vestibular intervention, somatosensory discrimination training, proprioceptive stimulation with muscle vibration, and sustained attention training with olfactory stimulation. Available findings suggest that sensory stimulation has positive results with immediate and long-term improvements in sensory functioning. This review provides useful information to improve rehabilitation and to design future investigation.

The Functional Tactile Object Recognition Test: A Unidimensional Measure With Excellent Internal Consistency for Haptic Sensing of Real Objects After Stroke

Introduction

Our hands, with their exquisite sensors, work in concert with our sensing brain to extract sensory attributes of objects as we engage in daily activities. One in two people with stroke experience impaired body sensation, with negative impact on hand use and return to previous valued activities. Valid, quantitative tools are critical to measure somatosensory impairment after stroke. The functional Tactile Object Recognition Test (fTORT) is a quantitative measure of tactile (haptic) object recognition designed to test one’s ability to recognize everyday objects across seven sensory attributes using 14 object sets. However, to date, knowledge of the nature of object recognition errors is limited, and the internal consistency of performance across item scores and dimensionality of the measure have not been established.

Objectives

To describe the original development and construction of the test, characterize the distribution and nature of performance errors after stroke, and to evaluate the internal consistency of item scores and dimensionality of the fTORT.

Method

Data from existing cohorts of stroke survivors (n = 115) who were assessed on the fTORT quantitative measure of sensory performance were extracted and pooled. Item and scale analyses were conducted on the raw item data. The distribution and type of errors were characterized.

Results

The 14 item sets of the fTORT form a well-behaved unidimensional scale and demonstrate excellent internal consistency (Cronbach alpha of 0.93). Deletion of any item failed to improve the Cronbach score. Most items displayed a bimodal score distribution, with function and attribute errors (score 0) or correct response (score 3) being most common. A smaller proportion of one- or two-attribute errors occurred. The total score range differentiated performance over a wide range of object recognition impairment.

Conclusion

Unidimensional scale and similar factor loadings across all items support simple addition of the 14 item scores on the fTORT. Therapists can use the fTORT to quantify impaired tactile object recognition in people with stroke based on the current set of items. New insights on the nature of haptic object recognition impairment after stroke are revealed.

Robotic Assessments of Proprioception and the Impact of Age

We examined different methods of robotic proprioception assessment and provided comparison with the wrist position sense test gold standard assessment. The aim is to determine which of the assessments are the most reliable and would be acceptable for clinical evaluation. 31 children between six and sixteen participated in a pilot assessment trial and completed all four of the assessments. The assessments included the manual and robotic versions of the wrist position sense test, the joint position matching assessment and the psychometric threshold determination assessment. There was not a significant difference between the manual and robotic wrist position sense tests but there were significant differences with the other assessments. The study also examined the effect of age on the different assessments and found that three of the assessments, excluding the joint position matching assessment, can differentiate between children of different ages. This study concludes that the significant differences between the assessments indicates that proprioception in the wrist is complex and multifaceted. Further studies will likely need to include multiple assessments to gain a more complete understanding of proprioception.

Neurocognitive robot-assisted rehabilitation of hand function: a randomized control trial on motor recovery in subacute stroke

Background

Hand function is often impaired after stroke, strongly affecting the ability to perform daily activities. Upper limb robotic devices have been developed to complement rehabilitation therapy offered to persons who suffered a stroke, but they rarely focus on the training of hand sensorimotor function. The primary goal of this study was to evaluate whether robot-assisted therapy of hand function following a neurocognitive approach (i.e., combining motor training with somatosensory and cognitive tasks) produces an equivalent decrease in upper limb motor impairment compared to dose-matched conventional neurocognitive therapy, when embedded in the rehabilitation program of inpatients in the subacute stage after stroke.

Methods

A parallel-group, randomized controlled trial was conducted on subjects with subacute stroke receiving either conventional or robot-assisted neurocognitive hand therapy using a haptic device. Therapy was provided for 15, 45-min sessions over four weeks, nested within the standard therapy program. Primary outcome was the change from baseline in the upper extremity part of the Fugl-Meyer Assessment (FMA-UE) after the intervention, which was compared between groups using equivalence testing. Secondary outcome measures included upper limb motor, sensory and cognitive assessments, delivered therapy dose, as well as questionnaires on user technology acceptance.

Results

Thirty-three participants with stroke were enrolled. 14 subjects in the robot-assisted and 13 subjects in the conventional therapy group completed the study. At the end of intervention, week 8 and week 32, the robot-assisted/conventional therapy group improved by 7.14/6.85, 7.79/7.31, and 8.64/8.08 points on the FMA-UE, respectively, establishing that motor recovery in the robot-assisted group is non-inferior to that in the control group.

Conclusions

Neurocognitive robot-assisted therapy of hand function allows for a non-inferior motor recovery compared to conventional dose-matched neurocognitive therapy when performed during inpatient rehabilitation in the subacute stage. This allows the early familiarization of subjects with stroke to the use of such technologies, as a first step towards minimal therapist supervision in the clinic, or directly at home after hospital discharge, to help increase the dose of hand therapy for persons with stroke.

Trial registration

EUDAMED database (CIV-13-02-009921), clinicaltrials.gov (NCT02096445). Registered 26 March 2014 – Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02096445

Synchrony Between Default-Mode and Sensorimotor Networks Facilitates Motor Function in Stroke Rehabilitation: A Pilot fMRI Study

Stroke is the most common cause of complex disability in Taiwan. After stroke onset, persistent physical practice or exercise in the rehabilitation procedure reorganizes neural assembly for reducing motor deficits, known as neuroplasticity. Neuroimaging literature showed rehabilitative effects specific to the brain networks of the sensorimotor network (SMN) and default-mode network (DMN). However, whether between-network interactions facilitate the neuroplasticity after stroke rehabilitation remains a mystery. Therefore, we conducted the longitudinal assessment protocol of stroke rehabilitation, including three types of clinical evaluations and two types of functional magnetic resonance imaging (fMRI) techniques (resting state and grasp task). Twelve chronic stroke patients completed the rehabilitation protocol for at least 24 h and finished the three-time assessments: before, after rehabilitation, and 1 month after the cessation of rehabilitation. For comparison, age-matched normal controls (NC) underwent the same fMRI evaluation once without repeated measure. Increasing scores of the Fugl–Meyer assessment (FMA) and upper extremity performance test reflected the enhanced motor performances after the stroke rehabilitation process. Analysis of covariance (ANCOVA) results showed that the connections between posterior cingulate cortex (PCC) and iM1 were persistently enhanced in contrast to the pre-rehabilitation condition. The interactions between PCC and SMN were positively associated with motor performances. The enhanced cross-network connectivity facilitates the motor recovery after stroke rehabilitation, but the cross-network interaction was low before the rehabilitation process, similar to the level of NCs. Our findings suggested that cross-network connectivity plays a facilitatory role following the stroke rehabilitation, which can serve as a neurorehabilitative biomarker for future intervention evaluations.

Restoration of Somatosensory Function by Pairing Vagus Nerve Stimulation with Tactile Rehabilitation

OBJECTIVE

Sensory dysfunction is a common consequence of many forms of neurological injury, including stroke and nerve damage. Rehabilitative paradigms that incorporate sensory retraining can provide modest benefits, but the majority of patients are left with lasting sensory loss. We have developed a novel strategy that uses closed-loop vagus nerve stimulation (VNS) paired with tactile rehabilitation to enhance synaptic plasticity and facilitate recovery of sensory function.

METHODS

A clinical case report provides initial evidence that a similar implementation of closed-loop VNS paired with a tactile rehabilitation regimen could improve recovery of somatosensory function. Here, we sought to build on these promising initial clinical data and rigorously evaluate the ability of VNS paired with tactile rehabilitation to improve recovery in an animal model of chronic sensory loss. The study design, including planned sample size, assessments, and statistical comparisons, was preregistered prior to beginning data collection (https://osf.io/xsnj5/).

RESULTS

VNS paired with tactile rehabilitation resulted in a significant and nearly complete recovery of mechanosensory withdrawal thresholds. Equivalent tactile rehabilitation without VNS failed to improve sensory function. This VNS-dependent restoration of sensory thresholds was maintained for several months after the cessation of stimulation, illustrating long-term benefits. Moreover, VNS paired with tactile rehabilitation resulted in significant generalized improvements in other measures of sensorimotor forepaw function.

INTERPRETATION

Given the safety and tolerability of VNS therapy, these findings suggest that incorporating VNS paired with sensory retraining into rehabilitative regimens may represent a fundamentally new method to increase recovery of sensory function after neurological injury. ANN NEUROL 2020;87:194-205.

A robot-assisted sensorimotor training program can improve proprioception and motor function in stroke survivors

Proprioceptive deficits are common among stroke survivors and are associated with slower motor recovery, poorer upper limb motor function, and decreased self-care ability. Somatosensory feedback augmenting proprioception should enhance motor control after stroke, but available evidence is inconclusive. This study evaluated the effects of a robot-aided, somatosensory-focused training on proprioceptive acuity and motor performance in individuals with sub-acute and chronic stroke. Twelve stroke survivors completed two training sessions on two consecutive days. During training, participants used a haptic robotic wrist exoskeleton and made continuous, goal-directed wrist ab/adduction movements to a visual target while receiving vibro-tactile feedback. Proprioceptive acuity and active movement errors were assessed before, immediately after, and two days after intervention. Results showed significantly improved proprioceptive acuity at posttest and retention. Motor accuracy measures showed improvements, however these were not statistically significant. This study demonstrates the feasibility of robot-aided somatosensory rehabilitation training in stroke survivors.

Neuromuscular electrical stimulation-enhanced rehabilitation is associated with not only motor but also somatosensory cortical plasticity in chronic stroke patients: an interventional study

Background:

Somatosensory function has been frequently overlooked in clinics and research in the field of chronic stroke. The effects of neurorehabilitation interventions on sensory processing have still to be investigated using electrophysiological means.

This study investigated the effect of hybrid assistive neuromuscular dynamic stimulation (HANDS) therapy utilizing closed-loop electromyography-controlled neuromuscular electrical stimulation (NMES), on sensory changes and cortical plasticity among patients with chronic stroke.

Methods:

This study was a prespecified analysis of 23 participants involved in an ongoing large interventional study. Patients with severe upper limb hemiplegia dues to chronic stroke underwent 3 weeks of inpatient HANDS therapy, where daily treatment consisted of 8 h of NMES combined with wrist splinting, 90 min of comprehensive occupational therapy, and the practice of bimanual activities of daily living. Somatosensory evoked potentials (SEPs) and functional sensory assessments, including the Semmes–Weinstein monofilament test (SWMT) and thumb localizing test (TLT), were compared pre and post-treatment.

Results:

While no significant recovery of tactile sensation was observed, significant improvements in proprioception and motor function were induced. The number of cortical peaks significantly increased in the median nerve, but not in the tibial nerve. A total of 9 out of 11 participants who initially lacked certain peaks responded to treatment. Further analysis revealed a significant improvement in latency and amplitude of SEP peaks.

Conclusions:

Our results suggest that NMES-based neurorehabilitation induces certain plastic changes in the primary sensory cortex and in cortices associated with sensorimotor processing in people with chronic stroke sequelae, which may explain the observed improvements in proprioception.