Different Thumb Positions in the Tetraplegic Hand.

OBJECTIVE: To analyze factors associated with malposition that affects function of the thumb in individuals with tetraplegia. DESIGN: Retrospective cross-sectional study. SETTING: Rehabilitation Center for Spinal Cord Injury. PARTICIPANTS: Anonymized data from 82 individuals (68 men), mean age 52.9±20.2 (SD) with acute/subacute cervical spinal cord injury C2-C8 AIS A-D recorded during 2018-2020. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Motor point (MP) mapping and manual muscle test (MRC) of 3 extrinsic thumb muscles (flexor pollicis longus (FPL), extensor pollicis longus (EPL), and abductor pollicis longus (APL)). RESULTS: 159 hands in 82 patients with tetraplegia C2-C8 AIS A-D were analyzed and assigned to "key pinch" (40.3%), "slack thumb" (26.4%), and "thumb-in-palm" (7.5%) positions. There was a significant (P<.0001) difference between the 3 thumb positions depicted in lower motor neuron (LMN) integrity tested by MP mapping and muscle strength of the 3 muscles examined. All studied muscles showed a significantly different expression of MP and the MRC values (P<.0001) between the "slack thumb" and "key pinch" position. MRC of FPL was significantly greater in the group "thumb-in-palm" compared with "key pinch" position (P<.0001). CONCLUSIONS: Malposition of the thumb due to tetraplegia seems to be related to the integrity of LMN and voluntary muscle activity of the extrinsic thumb muscles. Assessments such as MP mapping and MRC of the 3 thumb muscles enable the identification of potential risk factors for the development of thumb malposition in individuals with tetraplegia.

Grasp Analysis in the Home Environment as a Measure of Hand Function After Cervical Spinal Cord Injury.

BACKGROUND: Following a spinal cord injury, regaining hand function is a top priority. Current hand assessments are conducted in clinics, which may not fully represent real-world hand function. Grasp strategies used in the home environment are an important consideration when examining the impact of rehabilitation interventions. OBJECTIVE: The main objective of this study is to investigate the relationship between grasp use at home and clinical scores. METHOD: We used a previously collected dataset in which 21 individuals with spinal cord injuries (SCI) recorded egocentric video while performing activities of daily living in their homes. We manually annotated 4432 hand-object interactions into power, precision, intermediate, and non-prehensile grasps. We examined the distributions of grasp types used and their relationships with clinical assessments. RESULTS: Moderate to strong correlations were obtained between reliance on power grasp and the Spinal Cord Independence Measure III (SCIM; P < .05), the upper extremity motor score (UEMS; P < .01), and the Graded Redefined Assessment of Strength Sensibility and Prehension (GRASSP) Prehension (P < .01) and Strength (P < .01). Negative correlations were observed between the proportion of non-prehensile grasping and SCIM (P < .05), UEMS (P < .05), and GRASSP Prehension (P < .01) and Strength (P < .01). CONCLUSION: The types of grasp types used in naturalistic activities at home are related to upper limb impairment after cervical SCI. This study provides the first direct demonstration of the importance of hand grasp analysis in the home environment.

Responsiveness of the International Spinal Cord Injury Quality of Life Basic Data Set V2.0: An international longitudinal study.

CONTEXT/OBJECTIVE: Examine the sensitivity of the International Spinal Cord Injury Quality of Life Basic Data Set V2.0 (QoL-BDS V2.0) to reflect changes in mobility and secondary health conditions (SHCs) between inpatient rehabilitation and one-year follow-up. DESIGN: International longitudinal study. Questionnaires were administered at baseline (Median 6 weeks, inter-quartile range 4-10 weeks post-onset) and after 12 months. SETTING: Spinal cord rehabilitation institutions in the US, Brazil, Australia and the Netherlands. PARTICIPANTS: : Individuals with recent onset of spinal cord injury or disease (SCI/SCD) admitted to inpatient rehabilitation. OUTCOME MEASURES: The QoL-BDS V2.0, comprises four items on satisfaction with 'life as a whole', 'physical health', 'psychological health', and 'social life'. Mobility level was measured with a single item and SHCs with the SCI Secondary Conditions Scale (SCI-SCS). RESULTS: Of the 160 participants, 61% had SCI, 48% had tetraplegia and 82% were wheelchair-users. Scores on 'life as a whole', 'physical health' and the total scale were significantly higher at follow-up compared to baseline in the total sample and the SCD subgroup, but not in the SCI subgroup. Increases in 'physical health', 'psychological health', 'social life' and the total score were significantly associated with improvements in the SCI-SCS or mobility scores. Participants with improved SCI-SCS and mobility at follow-up showed significantly more improvement in satisfaction with social life and the total score compared to participants without such favorable changes. CONCLUSION: The results of this study provide partial evidence of responsiveness of the QoL-BDS V2.0 total score as a measure of QoL among individuals with SCI/SCD.

Walking naturally after spinal cord injury using a brain-spine interface.

A spinal cord injury interrupts the communication between the brain and the region of the spinal cord that produces walking, leading to paralysis1,2. Here, we restored this communication with a digital bridge between the brain and spinal cord that enabled an individual with chronic tetraplegia to stand and walk naturally in community settings. This brain-spine interface (BSI) consists of fully implanted recording and stimulation systems that establish a direct link between cortical signals3 and the analogue modulation of epidural electrical stimulation targeting the spinal cord regions involved in the production of walking4-6. A highly reliable BSI is calibrated within a few minutes. This reliability has remained stable over one year, including during independent use at home. The participant reports that the BSI enables natural control over the movements of his legs to stand, walk, climb stairs and even traverse complex terrains. Moreover, neurorehabilitation supported by the BSI improved neurological recovery. The participant regained the ability to walk with crutches overground even when the BSI was switched off. This digital bridge establishes a framework to restore natural control of movement after paralysis.

The Berlin Bimanual Test for Tetraplegia (BeBiTT): development, psychometric properties, and sensitivity to change in assistive hand exoskeleton application.

BACKGROUND: Assistive hand exoskeletons are promising tools to restore hand function after cervical spinal cord injury (SCI) but assessing their specific impact on bimanual hand and arm function is limited due to lack of reliable and valid clinical tests. Here, we introduce the Berlin Bimanual Test for Tetraplegia (BeBiTT) and demonstrate its psychometric properties and sensitivity to assistive hand exoskeleton-related improvements in bimanual task performance. METHODS: Fourteen study participants with subacute cervical SCI performed the BeBiTT unassisted (baseline). Thereafter, participants repeated the BeBiTT while wearing a brain/neural hand exoskeleton (B/NHE) (intervention). Online control of the B/NHE was established via a hybrid sensorimotor rhythm-based brain-computer interface (BCI) translating electroencephalographic (EEG) and electrooculographic (EOG) signals into open/close commands. For reliability assessment, BeBiTT scores were obtained by four independent observers. Besides internal consistency analysis, construct validity was assessed by correlating baseline BeBiTT scores with the Spinal Cord Independence Measure III (SCIM III) and Quadriplegia Index of Function (QIF). Sensitivity to differences in bimanual task performance was assessed with a bootstrapped paired t-test. RESULTS: The BeBiTT showed excellent interrater reliability (intraclass correlation coefficients > 0.9) and internal consistency (α = 0.91). Validity of the BeBiTT was evidenced by strong correlations between BeBiTT scores and SCIM III as well as QIF. Wearing a B/NHE (intervention) improved the BeBiTT score significantly (p < 0.05) with high effect size (d = 1.063), documenting high sensitivity to intervention-related differences in bimanual task performance. CONCLUSION: The BeBiTT is a reliable and valid test for evaluating bimanual task performance in persons with tetraplegia, suitable to assess the impact of assistive hand exoskeletons on bimanual function.

Cardiometabolic risk profiling during spinal cord injury rehabilitation: A longitudinal analysis from the Swiss Spinal Cord Injury (SwiSCI) cohort.

BACKGROUND: Early screening is important in individuals with spinal cord injury (SCI) as they are deemed high risk for cardiometabolic diseases. Few studies explored changes in cardiometabolic risk profile in the early phase of the injury. Thus it remains unclear how early the cardiometabolic status deteriorates after injury. OBJECTIVE: To determine the longitudinal changes in the cardiometabolic risk profile and examine the association between injury characteristics and cardiometabolic status in subacute SCI. SETTING: Multicenter Swiss Spinal Cord Injury Cohort. PARTICIPANTS: Adults with traumatic SCI without a history of cardiovascular disease or type 2 diabetes. MAIN OUTCOME MEASURES: Blood pressure (BP), lipid profile, fasting glucose, waist circumference (WC), weight, body mass index (BMI), and Framingham risk score (FRS) were compared across time and according to the injury characteristics. RESULTS: We analyzed the data of 258 individuals with traumatic SCI (110 tetraplegia and 148 paraplegia, 122 motor complete, and 136 incomplete). The median age was 50 years (interquartile range [IQR] 32-60), with 76.4% (n = 197) of the population being male. The median rehabilitation duration was 5.5 months (IQR 3.2-7.1). At admission to rehabilitation, fully adjusted linear regression models showed higher baseline weight (ß 0.06, 95% confidence interval [CI] 0.005 to 0.11), systolic BP (ß 0.05, 95% CI 0.008 to 0.09), diastolic BP (ß 0.05, 95% CI 0.004 to 0.10), and triglycerides (ß 0.27, 95% CI 0.13 to 0.42) in paraplegia than tetraplegia. Systolic BP, diastolic BP, high-density lipoprotein cholesterol (HDL-C) levels were higher in incomplete than complete injury. In our main analysis, we observed an increase in cholesterol and HDL-C and lipid ratio when comparing the beginning and end of rehabilitation. Individuals with paraplegia had a higher increase in BMI than individuals with tetraplegia, whereas no differences in other cardiometabolic risk factors were detected when comparing motor incomplete and complete injury. Trajectories of each participant showed that the majority of individuals with SCI decreased FRS score at follow-up compared to baseline and no significant changes in the prevalence of cardiometabolic syndrome were observed. At discharge, one third of study participants were classified as moderate to high risk of cardiovascular disease (CVD), 64% were overweight, and 39.4% had cardiometabolic syndrome. CONCLUSION: We observed a modest improvement in lipid profile and FRS during the first inpatient rehabilitation hospitalization. Injury characteristics, such as level and completeness, were not associated with changes in cardiometabolic risk factors in the subacute phase of the injury. Despite this, a significant proportion of study participants remained at risk of cardiometabolic disease at discharge, suggesting that early cardiometabolic preventive strategies may be initiated as early as during the first inpatient rehabilitation hospitalization.

Surgery to restore upper extremity function in tetraplegia-Preferences for early and frequent access to information.

INTRODUCTION: People with cervical spinal cord injury (SCI) identify improving upper extremity (UE) function as a top priority. In addition to comprehensive rehabilitation, UE surgeries, including nerve and tendon transfers, enhance function. However, barriers exist to disseminating information about surgical options to enhance UE function. OBJECTIVE: To assess the experiences and preferences of people with cervical SCI and their caregivers in accessing information about surgery to enhance UE function. DESIGN: Prospective cohort study. Participants were followed up for 24 months and completed up to three interviews. SETTING: Tertiary care at academic and affiliated Veterans Administration Health Care Centers. PARTICIPANTS: Adults with cervical SCI (n = 35) ages 18 to 80 years with mid-cervical SCI American Spinal Injury Association Impairment Scale A, B, or C (at least 6 months post-injury) and their caregivers (n = 23) were eligible to participate. Participants were enrolled in three groups: nerve transfer, tendon transfer, or no UE reconstructive surgery. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Semi-structured interviews about surgical knowledge and experiences. RESULTS: Data were analyzed and three themes were identified. First, providing information about UE surgical options early post-injury was recommended. The acute or inpatient rehabilitation phases of recovery were the preferred times to receive surgical information. Second, challenges with information dissemination were identified. Participants learned about UE surgery through independent research, medical provider interactions, or peers. Third, peers were identified as valuable resources for SCI needs and surgical information. CONCLUSIONS: Following cervical SCI, information about UE reconstructive surgeries should be a standard component of education during rehabilitation. An increased understanding of the reconstructive options available to improve UE function is necessary to educate stakeholders. Future research is needed to support the development of strategies to effectively present surgical information to individuals with SCI and health care providers.

Developing guiding principles for technology-based rehabilitation program by engaging people with motor incomplete tetraplegia.

BACKGROUND: Technology-aided rehabilitation is well established in the field of neurologic rehabilitation. Despite the widespread availability, the development of technology-based interventions that incorporate perspectives of the people who will use them is lacking. OBJECTIVES: This qualitative study aims to understand how people with chronic motor incomplete cervical spinal cord injury view rehabilitation technology to improve upper extremity function and neuromuscular recovery to inform future intervention development. METHODS: Seven participants with chronic upper extremity impairment due to spinal cord injury/dysfunction trialed five rehabilitation technology devices. After a 30-45 min trial for each device, participants engaged in a semi-structured interview. Interviews were analyzed using a qualitative approach to explore the experience using and understand features that support motivation to use of rehabilitation technology. RESULTS: Qualitative analysis revealed three major themes: (1) devices must be flexible to meet diverse needs; (2) intervention protocols must be individualized to address unique needs and contexts of users; (3) intervention protocols should be developed and updated by a skilled clinician. These themes and subthemes were used to describe guiding principles to inform future intervention design. CONCLUSION: The experiences of people with cervical spinal cord injury can be elicited as part of the intervention design process to systematically develop protocols for future feasibility trials. The findings from this study can be used to inform the development of technology-aided rehabilitation programs to improve upper extremity function in people with chronic motor incomplete tetraplegia. CLINICAL TRIALS REGISTRATION NUMBER: NCT04000256.

Level of injury is an independent determining factor of gut dysbiosis in people with chronic spinal cord injury: A cross-sectional study.

STUDY DESIGN: A cross-sectional study. OBJECTIVE: To investigate the correlations between gut microbiota and metabolic parameters in people with different levels of chronic spinal cord injury (SCI). SETTING: An SCI-specialized rehabilitation facility in a university hospital. METHODS: Forty-three participants with chronic SCI were recruited. Blood samples of each participant were collected for analysis of metabolic parameters. Feces were collected after the bowel opening method the patient routinely uses to evaluate fecal bacterial microbiota using quantitative RT-PCR. Body composition was examined using dual-energy x-ray absorptiometry (DEXA). Data were analyzed to evaluate the correlations between gut microbiota and other parameters. RESULTS: Of the 43 participants, 31 people (72.1%) were paraplegic and 12 people (27.9%) tetraplegic. Thirty-two people (74.4%) were diagnosed with obesity using the percentage of body fat (% body fat) criteria. The mean (SD) ratio of Firmicutes:Bacteroides (F/B), which represents the degree of gut dysbiosis, was 18.3 (2.45). Using stepwise multivariable linear regression analysis, both having tetraplegia and being diagnosed with obesity from % body fat evaluated by DEXA were independent positively-correlating factors of F/B (p < 0.001 and p = 0.001, respectively), indicating more severe gut dysbiosis in people with tetraplegia than paraplegia. CONCLUSION: In people with chronic SCI, having tetraplegia and being diagnosed with obesity from % body fat evaluated by DEXA are independent positive-correlating factors of gut dysbiosis. These results indicate a significant association between gut microbiota and the characteristics of SCI as well as metabolic parameters.

Perceived Clinical Barriers to Employment for Males with Spinal Cord Injury in Saudi Arabia.

Return to work is a challenging aspect of community integration for individuals with disabilities. The reintegration of individuals with spinal cord injury (SCI) is multifactorial; hence, regional challenges need to be investigated in the context of their clinical attributes and perceptions. A total of 121 male participants above 18 years of age with diagnosis of SCI and living at home were included in this cross-sectional survey. The study was conducted at a tertiary care rehabilitation facility in Saudi Arabia. The most common reported clinical barriers to employment were mobility, bladder incontinence, spasticity, musculoskeletal pain, and neuropathic pain. Bladder incontinence and musculoskeletal pain were the most common perceived clinical barriers for individuals with paraplegia and tetraplegia, respectively. A significant difference was observed for bowel incontinence as a reported barrier (p = 0.024) among adults less than thirty years of age in comparison with those older than thirty years. Spasticity as a barrier was reported more among patients who were older than thirty years (54.0%) compared to those younger than thirty years of age (37.9%) (p = 0.077). Twenty-two (23.7%) participants with paraplegia reported transfers as a perceived barrier to employment, which was significant (p = 0.014), and it was also reported as a significant barrier (p = 0.001) in individuals with tetraplegia (56%). This study shows that clinical conditions associated with SCI are considered potential barriers to employment by individuals with SCI. In terms of priority, the perceived barriers between individuals with tetraplegia and paraplegia were mostly different. This shows the need to consider relevant secondary health care conditions in goal setting while planning for employment in individuals with SCI.

Controlling an effector with eye movements: The effect of entangled sensory and motor responsibilities.

Restoring arm and hand function has been indicated by individuals with tetraplegia as one of the most important factors for regaining independence. The overall goal of our research is to develop assistive technologies that allow individuals with tetraplegia to control functional reaching movements. This study served as an initial step toward our overall goal by assessing the feasibility of using eye movements to control the motion of an effector in an experimental environment. We aimed to understand how additional motor requirements placed on the eyes affected eye-hand coordination during functional reaching. We were particularly interested in how eye fixation error was affected when the sensory and motor functions of the eyes were entangled due to the additional motor responsibility. We recorded participants' eye and hand movements while they reached for targets on a monitor. We presented a cursor at the participant's point of gaze position which can be thought of as being similar to the control of an assistive robot arm. To measure eye fixation error, we used an offline filter to extract eye fixations from the raw eye movement data. We compared the fixations to the locations of the targets presented on the monitor. The results show that not only are humans able to use eye movements to direct the cursor to a desired location (1.04 ± 0.15 cm), but they can do so with error similar to that of the hand (0.84 ± 0.05 cm). In other words, despite the additional motor responsibility placed on the eyes during direct eye-movement control of an effector, the ability to coordinate functional reaching movements was unaffected. The outcomes of this study support the efficacy of using the eyes as a direct command input for controlling movement.

Guillain-Barre Syndrome After Two COVID-19 Vaccinations: Two Case Reports With Follow-up Electrodiagnostic Study.

Guillain-Barre syndrome (GBS) is an immune-mediated acute polyradiculoneuropathy and commonly occurs after a preceding infection or immunization sequalae. Following the severe acute respiratory syndrome-coronavirus-2 virus pandemic with co-introduction of massive vaccinations, several GBS cases associated with coronavirus disease 2019 (COVID-19) infection per se or after vaccination for COVID-19 were reported internationally. Herein, we report two cases of Korean GBS presenting with tetraplegia after two different COVID-19 vaccinations (42-year old man by AstraZeneca and 48-year woman by Pfizer vaccines) within four weeks after vaccination. The patients were diagnosed with clinical examination, serial electromyography, and compatible laboratory results and improved after comprehensive rehabilitative treatment and intravenous immunoglobulin therapy. Furthermore, we performed an electrodiagnostic follow-up study of each case to examine their unique characteristics.

Spinal Cord Injury-Functional Index/Capacity: Responsiveness to Change Over Time.

OBJECTIVE: To establish responsiveness of 3 Spinal Cord Injury-Functional Index/Capacity (SCI-FI/C) item banks in the first year after spinal cord injury (SCI). DESIGN: Longitudinal patient-reported outcomes assessment replicated through secondary analysis of an independent data set. SETTING: A total of 8 SCI Model Systems rehabilitation hospitals in the United States. PARTICIPANTS: Study 1 participants included 184 adults with recent (≤4 months) traumatic SCI and 221 community-dwelling adults (>1 year post injury) (N=405). Study 2 participants were 418 individuals with recent SCI (≤4 months) (N=418). INTERVENTIONS: In study 1, SCI-FI/C computer adaptive tests were presented in a standardized interview format either in person or by phone call at baseline and 6-month follow-up. Responsiveness was examined by comparing 6-month changes in SCI-FI scores within and across samples (recently injured vs community-dwelling) because only the recent injury sample was expected to exhibit change over time. Effect sizes were also computed. In study 2, the study 1 results were cross-validated in a second sample with recent SCI 1 year after baseline measurement. Study 2 also compared the SCI-FI/C measures' responsiveness to that of the Self-reported Functional Measure (SRFM) and stratified results by injury diagnosis and completeness. MAIN OUTCOME MEASURES: The SCI-FI Basic Mobility/C, Self-care/C and Fine Motor/C item banks (study 1 and study 2); Self-reported Functional Measure SRFM (study 2 only). RESULTS: In study 1, changes in SCI-FI/C scores between baseline and 6-month follow-up were statistically significant (P<.01) for recently injured individuals. SCI-FI Basic Mobility/C, Self-care/C, and Fine Motor/C item banks demonstrated small to medium effect sizes in the recently injured sample. In the community-dwelling sample, all SCI-FI/C effects were negligible (ie, effect size<0.08). Study 2 results were similar to study 1. As expected, SCI-FI Basic Mobility/C and Self-care/C were responsive to change for all individuals in study 2, whereas the SCI-FI Fine Motor/C was responsive only for individuals with tetraplegia and incomplete paraplegia. The SRFM demonstrated a medium effect size for responsiveness (effect size=0.65). CONCLUSIONS: The SCI-FI Basic Mobility/C and Self-care/C banks demonstrate adequate sensitivity to change at 6 months and 1 year for all individuals with SCI, while the SCI-FI/C Fine Motor item bank is sensitive to change in individuals with tetraplegia or incomplete paraplegia. All SCI-FI/C banks demonstrate stability in a sample not expected to change. Results provide support for the use of these measures for research or clinical use.

Effects of trunk muscle activation on trunk stability, arm power, blood pressure and performance in wheelchair rugby players with a spinal cord injury.

Objective: In wheelchair rugby (WR) athletes with tetraplegia, wheelchair performance may be impaired due to (partial) loss of innervation of upper extremity and trunk muscles, and low blood pressure (BP). The objective was to assess the effects of electrical stimulation (ES)-induced co-contraction of trunk muscles on trunk stability, arm force/power, BP, and WR performance.Design: Cross-sectional study.Setting: Rehabilitation research laboratory and WR court.Participants: Eleven WR athletes with tetraplegia.Interventions: ES was applied to the rectus abdominis, obliquus externus abdominis and erector spinae muscles. For every test, the ES condition was compared to the non-ES condition.Outcome measures: Stability was assessed with reaching tasks, arm force/power with an isokinetic test on a dynamometer, BP during an ES protocol and WR skill performance with the USA Wheelchair Rugby Skill Assessment.Results: Overall reaching distance (ES 14.6 ± 7.5 cm, non-ES 13.4 ± 8.2 cm), and BP showed a significant increase with ES. Arm force (ES 154 ± 106 N, non-ES 148 ± 102 N) and power (ES 37 ± 26 W, non-ES 36 ± 25 W), and WR skills were not significantly improved.Conclusion: ES-induced trunk muscle activation positively affects trunk stability and BP, but not arm force/power. No effects were found in WR skill performance, probably due to abdominal strapping. More research is needed to assess different ES (training) protocols and longitudinal effects.

Long-Term Follow-Up of Patients With Ventilator-Dependent High Tetraplegia Managed With Diaphragmatic Pacing Systems.

OBJECTIVE: To explore participants' experiences after implantation of a diaphragmatic pacing system (DPS). DESIGN: Cross-sectional, observational study using self-report questionnaires. SETTING: Participants were recruited from 6 Spinal Cord Injury Model System centers across the United States (Craig Hospital, CO; Jefferson/Magee Rehabilitation Hospital, PA; Kessler Rehabilitation Center, NJ; University of Miami, FL; The Shirly Ryan Ability Lab, IL; Shepherd Center, GA). INTERVENTIONS: Not applicable. PARTICIPANTS: Men and women (N=28) with tetraplegia were enrolled in the study between November 2012 and January 2015. MAIN OUTCOME MEASURES: Participants completed self-report questionnaires focused on their DPS usage and mechanical ventilation, as well as their experiences and satisfaction with the DPS. RESULTS: DPS is a well-tolerated and highly successful device to help individuals living with spinal cord injury who are dependent on ventilators achieve negative pressure, ventilator-free breathing. A small percentage of participants reported complications, including broken pacing wires and surgery to replace or reposition wires. CONCLUSIONS: This study provides insight into the usage patterns of DPS and both the potential negative and positive effects that DPS can have on the life of the user. Knowledge gained from this study can provide a foundation for further discussion about the benefits and potential risks of using a DPS to inform an individual's decision to pursue a DPS implant.

Sensing and decoding the neural drive to paralyzed muscles during attempted movements of a person with tetraplegia using a sleeve array.

Motor neurons convey information about motor intent that can be extracted and interpreted to control assistive devices. However, most methods for measuring the firing activity of single neurons rely on implanted microelectrodes. Although intracortical brain-computer interfaces (BCIs) have been shown to be safe and effective, the requirement for surgery poses a barrier to widespread use that can be mitigated by instead using noninvasive interfaces. The objective of this study was to evaluate the feasibility of deriving motor control signals from a wearable sensor that can detect residual motor unit activity in paralyzed muscles after chronic cervical spinal cord injury (SCI). Despite generating no observable hand movement, volitional recruitment of motor units below the level of injury was observed across attempted movements of individual fingers and overt wrist and elbow movements. Subgroups of motor units were coactive during flexion or extension phases of the task. Single digit movement intentions were classified offline from the electromyogram (EMG) power [root-mean-square (RMS)] or motor unit firing rates with median classification accuracies >75% in both cases. Simulated online control of a virtual hand was performed with a binary classifier to test feasibility of real-time extraction and decoding of motor units. The online decomposition algorithm extracted motor units in 1.2 ms, and the firing rates predicted the correct digit motion 88 ± 24% of the time. This study provides the first demonstration of a wearable interface for recording and decoding firing rates of motor units below the level of injury in a person with motor complete SCI.NEW & NOTEWORTHY A wearable electrode array and machine learning methods were used to record and decode myoelectric signals and motor unit firing in paralyzed muscles of a person with motor complete tetraplegia. The myoelectric activity and motor unit firing rates were task specific, even in the absence of visible motion, enabling accurate classification of attempted single-digit movements. This wearable system has the potential to enable people with tetraplegia to control assistive devices through movement intent.

Development and pilot testing of novel game-based respiratory rehabilitation exercise devices for patients with tetraplegia.

BACKGROUND: Individuals with spinal cord injuries (SCI) show restricted breathing patterns with reduced lung volumes and capacities. OBJECTIVE: To improve breathing in such individuals, we aimed to develop breathing exercise devices using a user-centered design (UCD) and then assess the effects of these devices on breathing. METHODS: Patients with SCI were involved in the device development. Preliminary online survey participants were recruited from the community, and interview and pilot test participants were recruited from a patient self-help group. The four UCD phases were repeatedly performed. Users required fun, easy, multi-player, and safe exercise devices. RESULTS: Seven breathing exercise devices were developed, and 10 different game-based exercises were performed. Two individuals participated in a pilot test involving a respiratory rehabilitation exercise program conducted twice weekly for 60 min/session over 8 weeks. Lung function was assessed using a spirometer. Forced vital capacity, forced expiratory volume in 1 s, and vital capacity showed minimal changes, whereas maximum inspiratory and expiratory pressures improved. Participants reported that the exercises were entertaining and that the competitive nature of the game-like exercises encouraged further participation. CONCLUSION: Breathing exercise programs using our developed devices can improve breathing and positively affect the psychological states and sociability of users.

Locked-In Syndrome: Practical Rehabilitation Management.

Locked-in syndrome is a rare and devastating condition that results in tetraplegia, lower cranial nerve paralysis, and anarthria with preserved cognition, vertical gaze, and upper eyelid movements. Although acute management is much like that of any severe stroke, rehabilitation and recovery of these patients have not been previously described. Challenges relevant to this population include blood pressure management and orthostasis, timing and appropriateness of reinstating oral feeding, ventilatory support, decannulation after tracheostomy, bowel and bladder management, vestibular dysfunction, and eye care. Targeted rehabilitation of head, neck, and trunk stability to improve function, and proper fit in an appropriate wheelchair are essential to assist with mobility. Rehabilitation interventions should include a focus on distal motor control and upright tolerance training followed by balance and mobility exercises. In addition, special considerations must be given to developing early methods of communication through use of augmentative systems to call for help and express needs. These systems along with additional technology provide the basis to promote connectivity to family and friends through the use of social media and the internet. Establishment of communication, mobility, and connectivity is essential in promoting independence, autonomy, and improving quality of life. Overall, with specialized rehabilitative care and access to the proper equipment, long-term outcomes and quality of life in these patients can be favorable.

Predictive Value of Midsagittal Tissue Bridges on Functional Recovery After Spinal Cord Injury.

BACKGROUND: The majority of patients with spinal cord injury (SCI) have anatomically incomplete lesions and present with preserved tissue bridges, yet their outcomes vary. OBJECTIVE: To assess the predictive value of the anatomical location (ventral/dorsal) and width of preserved midsagittal tissue bridges for American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade conversion and SCI patient stratification into recovery-specific subgroups. METHODS: This retrospective longitudinal study includes 70 patients (56 men, age: 52.36 ± 18.58 years) with subacute (ie, 1 month) SCI (45 tetraplegics, 25 paraplegics), 1-month neuroimaging data, and 1-month and 12-month clinical data. One-month midsagittal T2-weighted scans were used to determine the location and width of tissue bridges. Their associations with functional outcomes were assessed using partial correlation and unbiased recursive partitioning conditional inference tree (URP-CTREE). RESULTS: Fifty-seven (81.4%) of 70 patients had tissue bridges (2.53 ± 2.04 mm) at 1-month post-SCI. Larger ventral (P = .001, r = 0.511) and dorsal (P < .001, r = 0.546) tissue bridges were associated with higher AIS conversion rates 12 months post-SCI (n = 39). URP-CTREE analysis identified 1-month ventral tissue bridges as predictors of 12-month total motor scores (0.4 mm cutoff, P = .008), recovery of upper extremity motor scores at 12 months (1.82 mm cutoff, P = .002), 12-month pin-prick scores (1.4 mm cutoff, P = .018), and dorsal tissue bridges at 1 month as predictors of 12-month Spinal Cord Independence Measure scores (0.5 mm cutoff, P = .003). CONCLUSIONS: Midsagittal tissue bridges add predictive value to baseline clinical measures for post-SCI recovery. Based on tissue bridges' width, patients can be classified into subgroups of clinical recovery profiles. Midsagittal tissue bridges provide means to optimize patient stratification in clinical trials.

Active proportional electromyogram controlled functional electrical stimulation system.

Neurophysiological theories and past studies suggest that intention driven functional electrical stimulation (FES) could be effective in motor neurorehabilitation. Proportional control of FES using voluntary EMG may be used for this purpose. Electrical artefact contamination of voluntary electromyogram (EMG) during FES application makes the technique difficult to implement. Previous attempts to date either poorly extract the voluntary EMG from the artefacts, require a special hardware or are unsuitable for online application. Here we show an implementation of an entirely software-based solution that resolves the current problems in real-time using an adaptive filtering technique with an optional comb filter to extract voluntary EMG from muscles under FES. We demonstrated that unlike the classic comb filter approach, the signal extracted with the present technique was coherent with its noise-free version. Active FES, the resulting EMG-FES system was validated in a typical use case among fifteen patients with tetraplegia. Results showed that FES intensity modulated by the Active FES system was proportional to intentional movement. The Active FES system may inspire further research in neurorehabilitation and assistive technology.