Experiences of Upper Limb Somatosensory Retraining in Persons With Stroke: An Interpretative Phenomenological Analysis

Enhancing touch sensibility with sensory electrical stimulation and sensory retraining

A large proportion of stroke survivors suffer from sensory loss, negatively impacting their independence, quality of life, and neurorehabilitation prognosis. Despite the high prevalence of somatosensory impairments, our understanding of somatosensory interventions such as sensory electrical stimulation (SES) in neurorehabilitation is limited. We aimed to study the effectiveness of SES combined with a sensory discrimination task in a well-controlled virtual environment in healthy participants, setting a foundation for its potential application in stroke rehabilitation. We employed electroencephalography (EEG) to gain a better understanding of the underlying neural mechanisms and dynamics associated with sensory training and SES. We conducted a single-session experiment with 26 healthy participants who explored a set of three visually identical virtual textures-haptically rendered by a robotic device and that differed in their spatial period-while physically guided by the robot to identify the odd texture. The experiment consisted of three phases: pre-intervention, intervention, and post-intervention. Half the participants received subthreshold whole-hand SES during the intervention, while the other half received sham stimulation. We evaluated changes in task performance-assessed by the probability of correct responses-before and after intervention and between groups. We also evaluated differences in the exploration behavior, e.g., scanning speed. EEG was employed to examine the effects of the intervention on brain activity, particularly in the alpha frequency band (8-13 Hz) associated with sensory processing. We found that participants in the SES group improved their task performance after intervention and their scanning speed during and after intervention, while the sham group did not improve their task performance. However, the differences in task performance improvements between groups only approached significance. Furthermore, we found that alpha power was sensitive to the effects of SES; participants in the stimulation group exhibited enhanced brain signals associated with improved touch sensitivity likely due to the effects of SES on the central nervous system, while the increase in alpha power for the sham group was less pronounced. Our findings suggest that SES enhances texture discrimination after training and has a positive effect on sensory-related brain areas. Further research involving brain-injured patients is needed to confirm the potential benefit of our solution in neurorehabilitation.

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!

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.

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.

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.

Can body awareness training improve recovery following stroke: A study to assess feasibility and preliminary efficacy

BACKGROUND

Impairments in body awareness are common after stroke and are associated with decreased participation and performance in everyday activities.

OBJECTIVES

To explore the feasibility and safety of a body awareness program after stroke, and identify the preliminary efficacy of class-based lessons compared to home-based lessons on sensation, body awareness, motor impairment and quality of life.

METHODS

A two-armed pilot randomized controlled trial with a nested qualitative descriptive study was conducted. Individuals with a diagnosis of stroke (at least three months post injury) were randomized to either class-based face-to-face body awareness lessons or home-based individually performed body awareness lessons. Outcome measures were safety, feasibility, sensation, body awareness, motor impairment, self-efficacy and quality of life. Semi-structured interviews were used to allow greater exploration and understanding of participants' experience of the program.

RESULTS

Twenty participants were randomized, 16 participants completed the program. Feasibility was greater in the class-based group. No adverse events were detected. The class-based group led to improvement in body awareness (p = 0.002), quality of life (p = 0.002), and the arm (p = 0.025) and leg (p = 0.005) motor impairment scores. Qualitative data similarly indicated that the class-based group experienced a stronger sense of awareness, achievement and connection than the home-based group.

CONCLUSIONS

Body awareness training was safe, feasible and acceptable in people with stroke. Individuals in the class-based group showed greater benefit compared to those receiving home-based therapy.

[Proprioception - The Sixth Sense And Its Disorders]

Vision, hearing, smell, taste, touch - and the sixth sense, the perception of one's own body, allow for comprehensive interaction with our surroundings. This article provides an overview of physiological structures and diagnostic methods relevant for proprioception. In addition, the contribution of the proprioceptive function to the pathology of sensorimotoric disorders is described, and associated therapeutic approaches in neurorehabilitation are addressed.

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.