Characterizing the Experience of Spasticity after Spinal Cord Injury: A National Survey Project of the Spinal Cord Injury Model Systems Centers

Multi-session transcutaneous spinal cord stimulation prevents chloride homeostasis imbalance and the development of hyperreflexia after spinal cord injury in rat

Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects. Despite its popularity, the neuroplasticity induced by tSCS also remains widely unexplored, particularly due to the lack of suitable animal models to investigate this intervention. Thus, the basis of this work was to use tSCS over multiple sessions (multi-session tSCS) in a rat model to target spasticity after SCI and identify the long-term physiological improvements and anatomical neuroplasticity occurring in the spinal cord. Here, we show that multi-session tSCS in rats with an incomplete (severe T9 contusion) SCI (1) decreases hyperreflexia, (2) increases the low frequency-dependent modulation of the H-reflex, (3) prevents potassium-chloride cotransporter isoform 2 (KCC2) membrane downregulation in lumbar motoneurons, and (4) generally augments motor output, i.e., EMG amplitude in response to single pulses of tSCS, particularly in extensor muscles. Together, this work displays that multi-session tSCS can target and diminish spasticity after SCI as an alternative to pharmacological interventions and begins to highlight the underlying neuroplasticity contributing to its success in improving functional recovery.

Optimizing assessment of low frequency H-reflex depression in persons with spinal cord injury

Considering the growing interest in clinical applications of neuromodulation, assessing effects of various modulatory approaches is increasingly important. Monosynaptic spinal reflexes undergo depression following repeated activation, offering a means to quantify neuromodulatory influences. Following spinal cord injury (SCI), changes in reflex modulation are associated with spasticity and impaired motor control. To assess disrupted reflex modulation, low-frequency depression (LFD) of Hoffman (H)-reflex excitability is examined, wherein the amplitudes of conditioned reflexes are compared to an unconditioned control reflex. Alternatively, some studies utilize paired-pulse depression (PPD) in place of the extended LFD train. While both protocols induce similar amounts of H-reflex depression in neurologically intact individuals, this may not be the case for persons with neuropathology. We compared the H-reflex depression elicited by PPD and by trains of 3-10 pulses to an 11-pulse LFD protocol in persons with incomplete SCI. The amount of depression produced by PPD was less than an 11-pulse train (mean difference = 0.137). When compared to the 11-pulse train, the 5-pulse train had a Pearson's correlation coefficient (R) of 0.905 and a coefficient of determination (R2) of 0.818. Therefore, a 5-pulse train for assessing LFD elicits modulation similar to the 11-pulse train and thus we recommend its use in lieu of longer trains.

Intensive support does not improve positive-airway pressure use in spinal cord injury/disease: a randomized clinical trial

STUDY OBJECTIVE

Treatment of sleep-disordered breathing (SDB) with positive airway pressure (PAP) therapy has unique clinical challenges in individuals living with spinal cord injuries and diseases (spinal cord injury [SCI]/D). Interventions focused on increasing PAP use have not been studied in this population. We aimed to evaluate the benefits of a program to increase PAP use among Veterans with SCI/D and SDB.

METHODS

Randomized controlled trial comparing a behavioral Intervention (n = 32) and educational control (n = 31), both including one face-to-face and five telephone sessions over 3 months. The intervention included education about SDB and PAP, goal setting, troubleshooting, and motivational enhancement. The control arm included non-directive sleep education only.

RESULTS

Primary outcomes were objective PAP use (nights ≥4 hours used within 90 days) and sleep quality (Pittsburgh Sleep Quality Index [PSQI] at 3 months). These did not differ between intervention and control (main outcome timepoint; mean difference 3.5 [-9.0, 15.9] nights/week for PAP use; p = .578; -1.1 [-2.8, 0.6] points for PSQI; p = .219). Secondary outcomes included fatigue, depression, function, and quality of life. Only fatigue improved significantly more in the intervention versus the control group (p = .025). Across groups, more PAP use was associated with larger improvements in sleep quality, insomnia, sleepiness, fatigue, and depression at some time points.

CONCLUSIONS

PAP use in Veterans with SCI/D and SDB is low, and a 3-month supportive/behavioral program did not show significant benefit compared to education alone. Overall, more PAP use was associated with improved symptoms suggesting more intensive support, such as in-home assistance, may be required to increase PAP use in these patients.

CLINICAL TRIALS INFORMATION

Title: "Treatment of Sleep Disordered Breathing in Patients with SCI." Registration number: NCT02830074. Website: https://clinicaltrials.gov/study/NCT02830074?cond=Sleep%20Apnea&term=badr&rank=5.

Management of acute cervical spinal cord injury in the non-specialist intensive care unit: a narrative review of current evidence

Each year approximately one million people suffer spinal cord injury, which has significant physical, psychosocial and economic impacts on patients and their families. Spinal cord rehabilitation centres are a well-established part of the care pathway for patients with spinal cord injury and facilitate improvements in functional independence and reductions in healthcare costs. Within the UK, however, there are a limited number of spinal cord injury centres, which delays admission. Patients and their families often perceive that they are not receiving specialist care while being treated in non-specialist units. This review aimed to provide clinicians who work in non-specialist spinal injury centres with a summary of contemporary studies relevant to the critical care management of patients with cervical spinal cord injury. We undertook a targeted literature review including guidelines, systematic reviews, meta-analyses, clinical trials and randomised controlled trials published in English between 1 June 2017 and 1 June 2023. Studies involving key clinical management strategies published before this time, but which have not been updated or repeated, were also included. We then summarised the key management themes: acute critical care management approaches (including ventilation strategies, blood pressure management and tracheostomy insertion); respiratory weaning techniques; management of pain and autonomic dysreflexia; and rehabilitation.

Stretching is not essential for managing MS spasticity: A randomized controlled trial

BACKGROUND

Clinical practice, expert opinion, and evidence-based guidelines recommend daily stretching as first-line treatment for multiple sclerosis (MS) spasticity, but this has not been evaluated by fully powered clinical trials.

OBJECTIVE

To determine whether MS Spasticity: Take Control (STC), a guideline-based program of spasticity education and stretching exercises has different effects on the impact of spasticity than a control program of different spasticity education and range of motion (ROM) exercises.

METHODS

Ambulatory people with self-reported MS spasticity were randomly assigned to STC or ROM, delivered in same duration, facilitator-led, group classes, face-to-face (F2F) initially and later virtually, due to coronavirus disease 2019 (COVID-19). Multiple Sclerosis Spasticity Scale (MSSS) scores were compared between groups at 1 (primary outcome) and 6 months after interventions.

RESULTS

A total of 231 people enrolled. There was no significant difference in MSSS scores between STC and ROM at 1 month (mean difference = 0.28, 95% (confidence interval (CI)) = [-9.45 to 10.01], p = 0.955). There were significant group mean improvements in MSSS scores and most other outcomes at 1 and 6 months.

CONCLUSION

Education with stretching exercises, the first-line recommended treatment for MS spasticity, and education with ROM exercises may both improve MS spasticity to a similar degree. This study debunks the belief that stretching is essential to managing MS spasticity.

Multi-session transcutaneous spinal cord stimulation prevents chloridehomeostasis imbalance and the development of spasticity after spinal cordinjury in rat

Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects. Despite its popularity, the neuroplasticity induced by tSCS also remains widely unexplored, particularly due to the lack of suitable animal models to investigate this intervention. Thus, the basis of this work was to use tSCS over multiple sessions (multi-session tSCS) in a rat model to target spasticity after SCI and identify the long-term physiological improvements and anatomical neuroplasticity occurring in the spinal cord. Here, we show that multi-session tSCS in rats with an incomplete (severe T9 contusion) SCI (1) decreases hyperreflexia, (2) increases the low frequency-dependent modulation of the H-reflex, (3) prevents potassium-chloride cotransporter isoform 2 (KCC2) membrane downregulation in lumbar motoneurons, and (4) generally augments motor output, i.e., EMG amplitude in response to single pulses of tSCS, particularly in extensor muscles. Together, this work displays that multi-session tSCS can target and diminish spasticity after SCI as an alternative to pharmacological interventions and begins to highlight the underlying neuroplasticity contributing to its success in improving functional recovery.

Transcutaneous spinal stimulation in patients with intrathecal baclofen pump delivery system: A preliminary safety study

Objective

To determine the effect of transcutaneous spinal stimulation (TSS) on an implanted intrathecal baclofen (ITB) pump in persons with traumatic spinal cord injury (SCI).

Design

Prospective clinical trial.

Participants

Five individuals with chronic traumatic SCI, >18 years of age, and an anteriorly implanted Medtronic SynchroMed™ II ITB pump delivery system.

Intervention

Transcutaneous spinal stimulation trials with cathode at T11/12, with pump interrogation before, during and after stimulation.

Results

There was no evidence of any effect of the TSS in regards to disruption of the ITB pump delivery mechanism. Communication interference with the interrogator to the pump occurred often during stimulation for log transmission most likely secondary to the electromagnetic interference from the stimulation. One individual had elevated blood pressure at the end of the trial, suspected to be unrelated to the spinal stimulation.

Conclusion

Based upon this pilot study, further TSS studies including persons with an implanted Medtronic SynchroMed™ II ITB pump can be considered when stimulating at the low thoracic spine, although communication with the programmer during the stimulation may be affected.

Limb accelerations during sleep are related to measures of strength, sensation, and spasticity among individuals with spinal cord injury

BACKGROUND

To evaluate the relationship between measures of neuromuscular impairment and limb accelerations (LA) collected during sleep among individuals with chronic spinal cord injury (SCI) to provide evidence of construct and concurrent validity for LA as a clinically meaningful measure.

METHODS

The strength (lower extremity motor score), sensation (summed lower limb light touch scores), and spasticity (categorized lower limb Modified Ashworth Scale) were measured from 40 adults with chronic (≥ 1 year) SCI. Demographics, pain, sleep quality, and other covariate or confounding factors were measured using self-report questionnaires. Each participant then wore ActiGraph GT9X Link accelerometers on their ankles and wrist continuously for 1-5 days to measure LA from movements during sleep. Regression models with built-in feature selection were used to determine the most relevant LA features and the association to each measure of impairment.

RESULTS

LA features were related to measures of impairment with models explaining 69% and 73% of the variance (R²) in strength and sensation, respectively, and correctly classifying 81.6% (F1-score = 0.814) of the participants into spasticity categories. The most commonly selected LA features included measures of power and frequency (frequency domain), movement direction (correlation between axes), consistency between movements (relation to recent movements), and wavelet energy (signal characteristics). Rolling speed (change in angle of inclination) and movement smoothness (median crossings) were uniquely associated with strength. When LA features were included, an increase of 72% and 222% of the variance was explained for strength and sensation scores, respectively, and there was a 34% increase in spasticity classification accuracy compared to models containing only covariate features such as demographics, sleep quality, and pain.

CONCLUSION

LA features have shown evidence of having construct and concurrent validity, thus demonstrating that LA are a clinically-relevant measure related to lower limb strength, sensation, and spasticity after SCI. LA may be useful as a more detailed measure of impairment for applications such as clinical prediction models for ambulation.

Accuracy of self-reported severity and level of spinal cord injury

Study design

Observational.

Objectives

To assess accuracy of self-reported level of injury (LOI) and severity in individuals with chronic spinal cord injury (SCI) as compared with clinical examination.

Setting

An SCI Model System Hospital.

Methods

A 20-item survey evaluated demographics, physical abilities, and self-reported injury level and severity. A decision tree algorithm used responses to categorize participants into injury severity groups. Following the survey, participants underwent clinical examination to determine current injury level and severity. Participants were later asked three questions regarding S1 sparing. Chart abstraction was utilized to obtain initial injury level and severity. Injury level and severity from self-report, decision tree, clinical exam, and chart abstraction were compared.

Results

Twenty-eight individuals participated. Ninety-three percent correctly self-reported anatomical region of injury (ROI). Self-report of specific LOI matched current clinical LOI for 25% of participants, but matched initial LOI for 61%. Self-report of ASIA Impairment Scale (AIS) matched clinical AIS for 36%, but matched initial AIS for 46%. The injury severity decision tree was 75% accurate without, but 79% accurate with additional S1 questions. Self-report of deep anal pressure (DAP) was correct for 86% of participants, while self-report of voluntary anal contraction (VAC) was correct for 82%.

Conclusion

Individuals with SCI are more accurate reporting ROI than specific LOI. Self-reported injury level and severity align more closely with initial clinical examination results than current exam results. Using aggregate data from multiple questions can categorize injury severity more reliably than self-report. Using this type of decision tree may improve injury severity classification in large survey studies.

Combined selective peripheral neurotomy in the treatment of spastic lower limbs of spinal cord injury patients

Objective

To explore the therapeutic effect of combined selective peripheral neurotomy (cSPN) on the spasm of the lower limbs after spinal cord injury.

Methods

A prospective intervention (before-after trial) with an observational design was conducted in 14 spinal cord injury patients with severe lower limbs spasticity by cSPN. Given the severe spasm of hip adductor, triceps surae, and hamstring muscles in these patients, a total of 26 obturator nerve branches, 26 tibia nerve branches, and 4 sciatic nerve branches partial neurotomy were performed. The modified Ashworth scale, composite spasticity scale, surface electromyography, gait analysis, functional ambulation category, spinal cord independence measure, and modified spinal cord injury–spasticity evaluation tool were used before and after surgery.

Results

Compared with preoperative, the spasm of the hip adductor, triceps surae, and hamstrings of the lower limbs in the postoperative patients decreased significantly. The abnormal gait of knee flexion and varus in the standing stage were significantly reduced. The grading of walking ability and activities of daily living were significantly improved.

Conclusions

Combined selective peripheral neurotomy can significantly reduce the spasm of lower limbs post spinal cord injury, improve abnormal gait, and improve motor function and activities of daily living.

Trial registration

ChiCTR1800019003 (2018–10-20).

Acceptability and impact on spasticity of a single session of upper extremity vibration in individuals with tetraplegia

STUDY DESIGN

Pre-post design; before and after vibration intervention.

OBJECTIVES

To explore effect of a focal, self-applied upper extremity (UE) vibration intervention on UE spasticity for individuals with tetraplegia. The secondary objectives were to explore the acceptability and ease of use of this intervention.

SETTING

Specialty rehabilitation center in Georgia, USA.

METHODS

Eleven participants each completed one session of focal, self-applied vibration to the UEs. UE spasticity was measured using the Modified Ashworth Scale (MAS). UE function was measured using the Box & Block (B&B) test which measures the effectiveness of grasp, transport, and release. These measurements were taken pre-intervention, immediately post-intervention, and 20 min post-intervention. Participants also self-reported the acceptability and usability of the intervention, their perception of change in their spasticity and completed the Qualities of Spasticity Questionnaire.

RESULTS

In the full group analysis of the spasticity measures, no significant effects were found. Subgroup analysis, however, indicated participants with higher spasticity demonstrated significantly more change on the MAS than the lower spasticity group. Analysis did not reveal any impact of the intervention on UE function as measured by the B&B. Ten out of eleven participants indicated that they agreed or strongly agreed that the intervention would be valuable to have at home.

CONCLUSIONS

Participants with higher spasticity demonstrated decreased spasticity after focal UE vibration, although there was no clear effect on grasp, transport and release function. Participants were satisfied with the intervention; most were able to use it independently and indicated it would be a valuable home intervention.

Noninvasive neuromodulation and rehabilitation to promote functional restoration in persons with spinal cord injury

PURPOSE OF REVIEW

This review will focus on the use of clinically accessible neuromodulatory approaches for functional restoration in persons with spinal cord injury (SCI).

RECENT FINDINGS

Functional restoration is a primary rehabilitation priority for individuals with SCI. High-tech neuromodulatory modalities have been used in laboratory settings to improve hand and walking function as well as to reduce spasticity and pain in persons with SCI. However, the cost, limited accessibility, and required expertise are prohibitive for clinical applicability of these high-tech modalities. Recent literature indicates that noninvasive and clinically accessible approaches targeting supraspinal, spinal, and peripheral neural structures can modulate neural excitability. Although a limited number of studies have examined the use of these approaches for functional restoration and amelioration of secondary complications in SCI, early evidence investigating their efficacy when combined with training is encouraging.

SUMMARY

Larger sample studies addressing both biomarker identification and dosing are crucial next steps in the field of neurorehabilitation research before novel noninvasive stimulation approaches can be incorporated into standard clinical practice.

Efficacy of Transcutaneous Spinal Stimulation versus Whole Body Vibration for Spasticity Reduction in Persons with Spinal Cord Injury

Transcutaneous spinal stimulation (TSS) and whole-body vibration (WBV) each have a robust ability to activate spinal afferents. Both forms of stimulation have been shown to influence spasticity in persons with spinal cord injury (SCI), and may be viable non-pharmacological approaches to spasticity management. In thirty-two individuals with motor-incomplete SCI, we used a randomized crossover design to compare single-session effects of TSS versus WBV on quadriceps spasticity, as measured by the pendulum test. TSS (50 Hz, 400 μs, 15 min) was delivered in supine through a cathode placed over the thoracic spine (T11-T12) and an anode over the abdomen. WBV (50 Hz; eight 45-s bouts) was delivered with the participants standing on a vibration platform. Pendulum test first swing excursion (FSE) was measured at baseline, immediately post-intervention, and 15 and 45 min post-intervention. In the whole-group analysis, there were no between- or within-group differences of TSS and WBV in the change from baseline FSE to any post-intervention timepoints. Significant correlations between baseline FSE and change in FSE were associated with TSS at all timepoints. In the subgroup analysis, participants with more pronounced spasticity showed significant decreases in spasticity immediately post-TSS and 45 min post-TSS. TSS and WBV are feasible physical therapeutic interventions for the reduction of spasticity, with persistent effects.