Pain profiles in a community dwelling population following spinal cord injury: a national survey

Prevalence of opioid use in adults with spinal cord injury: A systematic review and meta-analysis

OBJECTIVE

To determine the prevalence, reported harms and factors associated with opioid use among adults with spinal cord injury (SCI) living in the community.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Comprehensive literature searches were conducted in PubMed (MEDLINE), EMBASE, CINAHL, Web of Science and Scopus for articles published between 2000 and 2023. Risk of bias was assessed using a prevalence-specific tool. Random-effects meta-analyses were conducted to pool prevalence data for any context of opioids. Sensitivity and subgroup analyses were also performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the study protocol was registered via Prospero (CRD42022350768).

RESULTS

Of the 4969 potential studies, 38 were included in the review. Fifty-three percent of studies had a low risk of bias, with a high risk of bias in 5% of studies. The pooled prevalence for the 38 studies included in the meta-analysis (total cohort size of 50,473) across any opioid context was 39% (95% confidence interval [CI], 32-47). High heterogeneity was evident, with a prediction interval twice as wide as the 95% CI (prediction interval, 7-84%). Mean or median opioid dose was unreported in 95% of studies. Opioid dose and factors related to opioids were also rarely explored in the SCI populations.

CONCLUSIONS

Results should be interpreted with caution based on the high heterogeneity and imprecise pooled prevalence of opioids. Contextual details including pain, cohort-specific injury characteristics and opioid dosage were inconsistently reported, indicating a clear need for additional studies in a population at greater risk of experiencing opioid-related adverse effects.

Administration of anti-GFAP antibodies increases CGRP expression and increases pain hypersensitivity in spinal cord injured animals

BACKGROUND

Spinal cord injury (SCI) results in a multitude of cellular and pathological changes including neuronal loss, axonal damage, gliosis, and loss of motor and sensory function. In 40%-70% of patients, SCI can also trigger the development of neuropathic pain. Our previous study demonstrated that SCI patients who developed autoantibodies to glial fibrillary acidic protein (GFAP) were at increased risk for the subsequent development of neuropathic pain. However, whether GFAP autoantibodies (GFAPab) contribute to the development of neuropathic pain after SCI had yet to be examined.

OBJECTIVE

Using a mid-thoracic contusion model of SCI in male Sprague-Dawley rats, we examined the effect of exogenous anti-GFAP antibodies on SCI pathology, pain-associated molecular changes, and behavior.

METHODS

Anti-GFAP or IgG was administered at 7- and 14-days post-injury. Immunohistochemistry was performed to measure the relative levels of calcitonin gene-related peptide (CGRP), and inflammatory proteins in dorsal horn tissue. To assess the development of neuropathic pain, the von Frey test and the Mechanical Conflict-Avoidance Paradigm (MCAP) were performed.

RESULTS

CGRP immunoreactivity was significantly higher in the anti-GFAP-treated injured rats compared to control SCI IgG-treated rats. As anticipated, SCI rats had a lower pain threshold at 1- and 2-months post-injury compared to laminectomy-only controls. However, pain withdrawal threshold was not significantly affected by post-injury administration of the anti-GFAP. Operant testing revealed that SCI rats treated with the anti-GFAP had a trending increase in pain sensitivity.

CONCLUSION

Taken together, these data suggest that autoantibodies to GFAP following SCI may contribute to developing pain states following SCI.

The influence of pain on community reintegration after spinal cord injury

BACKGROUND

Community reintegration is an important goal for people living with a spinal cord injury (SCI), and pain is suspected to limit reintegration due to its limitations in daily functioning, mood, and sleep.

OBJECTIVES

To determine the influence of pain on community reintegration in manual wheelchair users with SCI.

METHODS

The Reintegration to Normal Living Index was used to determine community reintegration, while the DN4 and the Wheelchair User's Shoulder Pain Index were used to determine the presence of neuropathic and shoulder pain respectively. Associations and differences between the pain variables and participants with and without pain were analyzed with Spearman correlations and Mann-Whitney U-tests using SPSS v27 at 0.05 significance level and 95% confidence interval.

RESULTS

Of the 122 participants, 85.2% reported current pain, with a 77.7% median for community reintegration. Neuropathic pain (53.3%) was more common and severe than nociceptive shoulder pain (14.8%). There was no significant difference in community reintegration between participants with and without pain, nor any correlation between the overall presence of pain and community reintegration. The severity of pain, particularly shoulder pain, was negatively associated with taking trips out of town (p < 0.01), and overall community reintegration (p < 0.05).

CONCLUSION

It is not the mere presence of pain that influences community reintegration, but rather the severity and the location of pain. Shoulder care and pain management need to be included in the rehabilitation program, as these are important considerations when rehabilitating people with SCI back into their communities.

Exoskeleton Training for Spinal Cord Injury Neuropathic Pain (ExSCIP): Protocol for a Phase 2 Feasibility Randomised Trial

Background

Following Spinal Cord Injury (SCI), 53% of people develop neuropathic pain (NP). NP can be more debilitating than other consequences of SCI, and a persistent health issue. Pharmacotherapies are commonly recommended for NP management in SCI, although severe pain often remains refractory to these treatments in many sufferers. Furthermore, poor medication adherence exists, stemming from unacceptable side-effects and fear of dependency.Sensorimotor stimulation using active walking with robotic assistance has not been well studied in NP after SCI, despite convincing locomotor-based pre-clinical studies, identifying prevention and reversal of NP.Our primary aim is to assess the impact of exoskeleton-based walking on NP intensity and interference after SCI and examine feasibility outcomes for progression to a definitive trial.

Methods

This is a phase 2 single-blinded, randomised feasibility study. It will test the feasibility and acceptability of exoskeleton-based walking 3 times per week for 12 weeks (intervention), as a mechanistic-based intervention for NP after SCI. The comparator will be an equally dosed, blended relaxation programme devoid of motor imagery prompts. 40 participants with moderate-to-severe NP post SCI will be recruited and randomised to intervention and comparator groups.The primary outcomes are feasibility outcomes for progression to definitive trial which include recruitment and retention rates, adverse events and acceptability of the intervention.Secondary outcomes explore changes in NP intensity and interference as measured by the International Spinal Cord Injury Pain Basic Data Set 3.0 (ISCIPBDS) at baseline, post-intervention (week 13) and at 6-month follow-up.

Conclusions

There is a need to explore non-pharmacological management of NP after SCI. The findings of this feasibility trial will inform the development of a future multicentre, international RCT.

Trial Registration

NCT06463418, 08/07/2024, https://clinicaltrials.gov/study/NCT06463418.

Perceived stress and pain interference in acute rehabilitation following spinal cord injury: Resilience as a moderator

PURPOSE/OBJECTIVE

Higher levels of resilience is associated with improved pain outcomes in chronic pain and other neurological populations, but the role of resilience in pain following spinal cord injury (SCI) remains unclear. This study examined resilience as a moderator in the relationship between perceived stress and both pain intensity and interference during acute rehabilitation for SCI.

RESEARCH METHOD/DESIGN

Individuals admitted to inpatient rehabilitation acutely following SCI (N = 57) completed measures of perceived stress, resilience, pain intensity, and interference. The Johnson-Neyman procedure was used to examine significance of conditional relationships that emerged.

RESULTS

Resilience was found to moderate the relationship between perceived stress and pain interference, but not pain intensity, during inpatient rehabilitation.

CONCLUSIONS/IMPLICATIONS

When resilience is low, perceived stress has a more profound and adverse impact on pain interference during inpatient rehabilitation, suggesting therapeutic strategies that build components of resilience are needed during acute rehabilitation following SCI. The relationship between stress, resilience, and pain may differ postinpatient rehabilitation for SCI and warrants further investigation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Differential relationships between physical activity and pain phenotypes in individuals with spinal cord injury

BACKGROUND

Chronic pain affects 70% of individuals with spinal cord injury (SCI) and leads to declines in health and quality of life. Neuropathic and nociceptive pain are phenotypes derived from different mechanisms that contribute to pain perception. The objective of this research was to investigate differential pain responses to moderate-to-vigorous physical activity (MVPA) in two chronic pain phenotypes: neuropathic and nociceptive pain.

METHODS

Community-based physical activity levels were collected for one week in 17 individuals with SCI using a wrist-worn accelerometer, and daily pain ratings were assessed and categorized by phenotype. Physical activity levels were summarized to calculate minutes of MVPA. Correlational analyses were conducted to compare relationships between pain intensity and MVPA across individual participants and between pain phenotype groups.

RESULTS

The neuropathic pain group revealed significant negative correlation between MVPA and pain intensity. In the nociceptive pain group, there was no significant correlation between MVPA and pain intensity. Further analysis revealed two subgroups of positive (N = 4) and negative (N = 3) correlations between MVPA and pain intensity. Pain location differed between the subgroups of nociceptive pain. Individuals with negative correlation experienced neck and upper back pain, whereas individuals with positive correlation experienced unilateral upper extremity pain.

CONCLUSION

Differential relationships exist between pain phenotypes and MVPA in individuals with SCI. Pain location differed between the subgroups of nociceptive pain, which we presume may indicate the presence of nociplastic pain in some individuals. These results may contribute to the advancement of personalized pain management by targeting non-pharmacological interventions for specific pain phenotypes.Trial registration: ClinicalTrials.gov identifier: NCT05236933..

Pain in the Context of Sensory Deafferentation

Pain that accompanies deafferentation is one of the most mysterious and misunderstood medical conditions. Prevalence rates for the assorted conditions vary considerably but the most reliable estimates are greater than 50% for strokes involving the somatosensory system, brachial plexus avulsions, spinal cord injury, and limb amputation, with controversy surrounding the mechanistic contributions of deafferentation to ensuing neuropathic pain syndromes. Deafferentation pain has also been described for loss of other body parts (e.g., eyes and breasts) and may contribute to between 10% and upwards of 30% of neuropathic symptoms in peripheral neuropathies. There is no pathognomonic test or sign to identify deafferentation pain, and part of the controversy surrounding it stems from the prodigious challenges in differentiating cause and effect. For example, it is unknown whether cortical reorganization causes pain or is a byproduct of pathoanatomical changes accompanying injury, including pain. Similarly, ascertaining whether deafferentation contributes to neuropathic pain, or whether concomitant injury to nerve fibers transmitting pain and touch sensation leads to a deafferentation-like phenotype can be clinically difficult, although a detailed neurologic examination, functional imaging, and psychophysical tests may provide clues. Due in part to the concurrent morbidities, the physical, psychologic, and by extension socioeconomic costs of disorders associated with deafferentation are higher than for other chronic pain conditions. Treatment is symptom-based, with evidence supporting first-line antineuropathic medications such as gabapentinoids and antidepressants. Studies examining noninvasive neuromodulation and virtual reality have yielded mixed results.

Omega-conotoxin MVIIA reduces neuropathic pain after spinal cord injury by inhibiting N-type voltage-dependent calcium channels on spinal dorsal horn

Spinal cord injury (SCI) leads to the development of neuropathic pain. Although a multitude of pathological processes contribute to SCI-induced pain, excessive intracellular calcium accumulation and voltage-gated calcium-channel upregulation play critical roles in SCI-induced pain. However, the role of calcium-channel blockers in SCI-induced pain is unknown. Omega-conotoxin MVIIA (MVIIA) is a calcium-channel blocker that selectively inhibits N-type voltage-dependent calcium channels and demonstrates neuroprotective effects. Therefore, we investigated spinal analgesic actions and cellular mechanisms underlying the analgesic effects of MVIIA in SCI. We used SCI-induced pain model rats and conducted behavioral tests, immunohistochemical analyses, and electrophysiological experiments (in vitro whole-cell patch-clamp recording and in vivo extracellular recording). A behavior study suggested intrathecal MVIIA administration in the acute phase after SCI induced analgesia for mechanical allodynia. Immunohistochemical experiments and in vivo extracellular recordings suggested that MVIIA induces analgesia in SCI-induced pain by directly inhibiting neuronal activity in the superficial spinal dorsal horn. In vitro whole-cell patch-clamp recording showed that MVIIA inhibits presynaptic N-type voltage-dependent calcium channels expressed on primary afferent Aδ-and C-fiber terminals and suppresses the presynaptic glutamate release from substantia gelatinosa in the spinal dorsal horn. In conclusion, MVIIA administration in the acute phase after SCI may induce analgesia in SCI-induced pain by inhibiting N-type voltage-dependent calcium channels on Aδ-and C-fiber terminals in the spinal dorsal horn, resulting in decreased neuronal excitability enhanced by SCI-induced pain.

Spinal cord injury-induced neurogenic bowel: A role for host-microbiome interactions in bowel pain and dysfunction

Background and aims

Spinal cord injury (SCI) affects roughly 300,000 Americans with 17,000 new cases added annually. In addition to paralysis, 60% of people with SCI develop neurogenic bowel (NB), a syndrome characterized by slow colonic transit, constipation, and chronic abdominal pain. The knowledge gap surrounding NB mechanisms after SCI means that interventions are primarily symptom-focused and largely ineffective. The goal of the present studies was to identify mechanism(s) that initiate and maintain NB after SCI as a critical first step in the development of evidence-based, novel therapeutic treatment options.

Methods

Following spinal contusion injury at T9, we observed alterations in bowel structure and function reflecting key clinical features of NB. We then leveraged tissue-specific whole transcriptome analyses (RNAseq) and fecal 16S rRNA amplicon sequencing in combination with histological, molecular, and functional (Ca2+ imaging) approaches to identify potential mechanism(s) underlying the generation of the NB phenotype.

Results

In agreement with prior reports focused on SCI-induced changes in the skin, we observed a rapid and persistent increase in expression of calcitonin gene-related peptide (CGRP) expression in the colon. This is suggestive of a neurogenic inflammation-like process engaged by antidromic activity of below-level primary afferents following SCI. CGRP has been shown to disrupt colon homeostasis and negatively affect peristalsis and colon function. As predicted, contusion SCI resulted in increased colonic transit time, expansion of lymphatic nodules, colonic structural and genomic damage, and disruption of the inner, sterile intestinal mucus layer corresponding to increased CGRP expression in the colon. Gut microbiome colonization significantly shifted over 28 days leading to the increase in Anaeroplasma, a pathogenic, gram-negative microbe. Moreover, colon specific vagal afferents and enteric neurons were hyperresponsive after SCI to different agonists including fecal supernatants.

Conclusions

Our data suggest that SCI results in overexpression of colonic CGRP which could alter colon structure and function. Neurogenic inflammatory-like processes and gut microbiome dysbiosis can also sensitize vagal afferents, providing a mechanism for visceral pain despite the loss of normal sensation post-SCI. These data may shed light on novel therapeutic interventions targeting this process to prevent NB development in patients.

Chronic pain among Lebanese individuals with spinal cord injury: Pain interference and impact on quality of life

Background: Chronic pain is one of the most disabling consequences of spinal cord injury (SCI). Although studies have identified a link between chronic pain and decreased quality of life (QOL) among this population, few studies have looked into the experience of chronic pain in Lebanese individuals with SCI and the impact of pain characteristics on QOL. Thus, the present study evaluated the chronic pain experience and its associated factors among Lebanese individuals with SCI in order to determine the impact of pain on QOL. Methods: A cross-sectional study was conducted on 81 Lebanese individual with SCI between August 1st and October 31, 2022. The collected information included sociodemographic characteristics, SCI-related information, pain-related variables, and the 12-item Short Form Health Survey (SF-12). Factors associated with pain interference were evaluated using a linear regression model. One-way ANOVA and independent sample t-test were used to evaluate the association of different baseline and pain characteristics with QOL. Results: In the present study, 81.5% of participants reported chronic pain with the majority of them having neuropathic pain type. Employment status (P = 0.034), type of pain (P = 0.009), and pain severity (P = 0.028) were significantly associated with pain interference. Unemployed participants and those with severe chronic pain, particularly neuropathic pain, had lower QOL. Conclusion: Chronic pain was found to be highly prevalent among Lebanese patients with SCI. Pain interference and QOL were significantly affected by employment status and pain type. Therefore, targeting chronic pain and its associated factors in rehabilitation practice is warranted.

The international spinal cord injury pain basic data set (version 3.0)

STUDY DESIGN

Expert opinion, feedback, revisions, and final consensus.

OBJECTIVES

To update the International Spinal Cord Injury Pain Basic Data Set (ISCIPBDS version 2.0) and incorporate suggestions from the SCI pain clinical and research community with respect to overall utility.

SETTING

International.

METHODS

The ISCIPBDS working group evaluated these suggestions and made modifications. The revised ISCIPBDS (Version 3.0) was then reviewed by members of the International SCI Data Sets Committee, the American Spinal Injury Association (ASIA) Board, the International Spinal Cord Society (ISCoS) Executive and Scientific Committees, individual reviewers and societies, and posted on the ASIA and ISCoS websites for 1 month to elicit comments before final approval by ASIA and ISCoS.

RESULTS

The ISCIPBDS (Version 3.0) was updated to make the dataset more flexible and useful: 1. The assessment can be based on the patient's perception of several of his/her "worst" pain(s) or based on the International SCI Pain (ISCIP) Classification-defined or other pain types, depending on the specific research questions or clinical needs. 2. Pain interference should usually be rated for overall pain but may also be used for specific pain problems if needed. 3. An optional pain drawing was added to complement the check box documentation of pain location. 4. Data categories consistent with the Extended Pain Dataset list of current treatments were added. 5. Several new training cases were added.

Pain and pain management experiences following spinal cord injury - a mixed methods study of Australian community-dwelling adults

PURPOSE

There is a high prevalence of persistent pain following SCI yet insights into its impact and the quality of pain care are limited. We aimed to explore, in-depth, the problem of persistent pain in Australian community-dwelling adults with a spinal cord injury (SCI). Our objectives were to investigate (i) how individuals experience persistent pain, (ii) how they experience pain care and (iii) the concordance between clinical practice guidelines for managing pain and reported care practices.

METHODS

We conducted a mixed-methods convergent parallel study. Adults with SCI and persistent pain completed a survey (n = 43); a subset of participants completed interviews (n = 10). We analysed the data from each method separately and then integrated the findings.

RESULTS

Results indicated that the life impact of persistent pain is variable but it can be more disabling than physical impairments and compound a sense of isolation and despair. Community-based management was reported to predominantly have a pharmacological focus, with occurrences of opioid misuse apparent in the data. Access to expert, comprehensive and individualised care was frequently reported as inadequate.

CONCLUSION

While some people with SCI and persistent pain can effectively self-manage their pain, for others the impact on quality of life is profound and complex care needs are commonly unmet.IMPLICATIONS FOR REHABILITATIONPersistent pain is a common consequence of SCI and profoundly impacts quality of life.Complex pain care needs are commonly unmet.Individuals require regular, comprehensive, biopsychosocial assessment.The effectiveness of pain management strategies must be monitored on an ongoing basis.Opportunities for personal self-management support must be available long-term.

Pharmacological and non-pharmacological therapeutic interventions for the treatment of spinal cord injury-induced pain

Spinal cord injury (SCI) is a complex neurophysiological disorder, which can result in many long-term complications including changes in mobility, bowel and bladder function, cardiovascular function, and metabolism. In addition, most individuals with SCI experience some form of chronic pain, with one-third of these individuals rating their pain as severe and unrelenting. SCI-induced chronic pain is considered to be "high impact" and broadly affects a number of outcome measures, including daily activity, physical and cognitive function, mood, sleep, and overall quality of life. The majority of SCI pain patients suffer from pain that emanates from regions located below the level of injury. This pain is often rated as the most severe and the underlying mechanisms involve injury-induced plasticity along the entire neuraxis and within the peripheral nervous system. Unfortunately, current therapies for SCI-induced chronic pain lack universal efficacy. Pharmacological treatments, such as opioids, anticonvulsants, and antidepressants, have been shown to have limited success in promoting pain relief. In addition, these treatments are accompanied by many adverse events and safety issues that compound existing functional deficits in the spinally injured, such as gastrointestinal motility and respiration. Non-pharmacological treatments are safer alternatives that can be specifically tailored to the individual and used in tandem with pharmacological therapies if needed. This review describes existing non-pharmacological therapies that have been used to treat SCI-induced pain in both preclinical models and clinical populations. These include physical (i.e., exercise, acupuncture, and hyper- or hypothermia treatments), psychological (i.e., meditation and cognitive behavioral therapy), and dietary interventions (i.e., ketogenic and anti-inflammatory diet). Findings on the effectiveness of these interventions in reducing SCI-induced pain and improving quality of life are discussed. Overall, although studies suggest non-pharmacological treatments could be beneficial in reducing SCI-induced chronic pain, further research is needed. Additionally, because chronic pain, including SCI pain, is complex and has both emotional and physiological components, treatment should be multidisciplinary in nature and ideally tailored specifically to the patient.

Prevalence and impact of neuropathic and non-neuropathic pain in chronic spinal cord injury

OBJECTIVE

Compare prevalence, intensity ratings, and interference ratings of neuropathic pain (NeuP) and nociceptive pain in people with chronic spinal cord injury (SCI) DESIGN: Cross-sectional survey SETTING: Six SCI Model System centers in the US PARTICIPANTS: Convenience sample of 391 individuals with traumatic SCI, aged 18 years or older, 81% male, 57% white INTERVENTIONS: Not applicable MAIN OUTCOME MEASURES: Survey based on the International Spinal Cord Injury Pain Basic Data Set (ISCIPBDS) and the Spinal Cord Injury Pain Instrument (SCIPI), including 0-10 numerical ratings of pain intensity and pain interference with daily activities, mood, and sleep RESULTS: 80% of those surveyed reported having at least one pain problem; 58% reported two or more pain problems; 56% had probable NeuP; and 49% had non-NeuP. When comparing ratings for all pains (n=354 for NeuP, n=290 for non-NeuP) across subjects, probable NeuPs were significantly more intense (6.9 vs. 5.7) and interfered more with activities (5.2 vs. 3.7), mood (4.9 vs. 3.2), and sleep (5.4 vs. 3.6) than non-NeuPs (all p<0.001). However, when comparing ratings for probable NeuPs and non-NeuPs within subjects, for the subgroup of 94 participants with both pain types, only ratings for sleep interference were found to be significantly different between the pain types . Additionally, we found significantly greater prevalence of NeuP and non-NeuP for women compared to men, and of NeuP for those with paraplegia compared to those with tetraplegia.

CONCLUSIONS

Independent assessment of the pain conditions experienced by an individual with SCI is useful in understanding the differential impact that pain type has on quality of life. This is particularly important with regard to sleep interference and should be kept in mind when determining treatment strategies for meeting patient-centered outcome goals.

Pain characteristics in Italian people with spinal cord injury: a multicentre study

STUDY DESIGN

Multicentre cross-sectional study.

OBJECTIVE

The objective of this study is to evaluate prevalence, location and characteristics of pain in hospital inpatients people with spinal cord injury (SCI).

SETTING

Ten Italian rehabilitation centres specialized in spinal injury care, where inpatients are admitted both after the acute lesion and for late complications (time since injury, median [IQR]: 0.8 [0.2-8.2] years).

METHODS

All the persons were submitted to AIS scale assessment [1] and modified Ashworth scale [2]; personal data and anamnesis were recorded; any pain within 1 week was investigated and the International Spinal Cord Injury Pain Basic Data Set (ISCIPBDS) Italian version [3] was administered by physicians expert in type of pain definition.

RESULTS

Of 385 included persons, 275 (72%) suffered pain, with the score value median [IQR]: 6 [4-8]. The worst pain of the person was nociceptive in 52% and neuropathic in 48% of the cases; 46% of nociceptive pain was located in the neck-shoulder region, whereas 67% of neuropathic pain was located in the sublesional part of the body. In 48% of the whole population, spasticity was observed but only 74% of them had pain. Being old and female are associated with high pain development, OR (95% CI): 1.24 (1.01-1.04) and 1.83 (1.05-3.20), respectively.

CONCLUSIONS

A high prevalence of pain is confirmed in persons with SCI, with both nociceptive and neuropathic pain characteristics. Only old age and female sex resulted as variables highly associated with pain.

Systemic gene expression profiles according to pain types in individuals with chronic spinal cord injury

Pain affects most individuals with traumatic spinal cord injury (SCI). Major pain types after SCI are neuropathic or nociceptive, often experienced concurrently. Pain after SCI may be refractory to treatments and negatively affects quality of life. Previously, we analyzed whole blood gene expression in individuals with chronic SCI compared to able-bodied (AB) individuals. Most participants with SCI reported pain (N = 19/28). Here, we examined gene expression of participants with SCI by pain status. Compared to AB, participants with SCI with pain had 468 differentially expressed (DE) genes; participants without pain had 564 DE genes (FDR < 0.05). Among DE genes distinct to participants with SCI with pain, Gene Ontology Biological Process (GOBP) analysis showed upregulated genes were enriched in categories related to T cell activation or inflammation; downregulated genes were enriched in categories related to protein proteolysis and catabolism. Although most participants with pain reported multiple pain types concurrently, we performed a preliminary comparison of gene expression by worst pain problem type. Compared to AB, participants with SCI who ranked neuropathic (N = 9) as worst had one distinct DE gene (TMEM156); participants who ranked nociceptive (N = 10) as worst had 61 distinct DE genes (FDR < 0.05). In the nociceptive group, the GOBP category with the lowest P-value identified among upregulated genes was “positive regulation of T cell activation”; among downregulated genes it was “receptor tyrosine kinase binding”. An exploratory comparison of pain groups by principal components analysis also showed that the nociceptive group was enriched in T-cell related genes. A correlation analysis identified genes significantly correlated with pain intensity in the neuropathic or nociceptive groups (N = 145, 65, respectively, Pearson’s correlation r > 0.8). While this pilot study highlights challenges of identifying gene expression profiles that correlate with specific types of pain in individuals with SCI, it suggests that T-cell signaling should be further investigated in this context.

Interrelationship of Neurogenic Obesity and Chronic Neuropathic Pain in Persons With Spinal Cord Injury

The prevalence of obesity and of neuropathic pain are both estimated at above 50% in the population of people with chronic spinal cord injury (SCI). These secondary consequences of SCI have significant negative impact on physical functioning, activities of daily living, and quality of life. Investigations of relationships between weight or body composition and chronic neuropathic pain in people with SCI are lacking, but investigations in non-SCI cohorts suggest an association between obesity and the presence and severity of neuropathic pain conditions. In the present article, we present a review of the literature linking obesity and neuropathic pain and summarize findings suggesting that metabolic syndrome and chronic, systemic inflammation due to excess adiposity increase the risk for neuropathic pain after an SCI.

An internet-delivered cognitive behavioural therapy pain management programme for spinal cord injury pain: A randomized controlled trial

BACKGROUND

Chronic pain is common after spinal cord injury (SCI) and dedicated SCI cognitive behavioural therapy pain management programmes (CBT-PMPs) have a growing evidence base to support their uptake clinically. The development of internet-delivered treatment options may overcome barriers to the access and uptake of centre-based programmes. This study examines such an approach on quality of lie (QoL), pain, mood and sleep.

METHODS

Adults with SCI pain (>3 months) were recruited and randomly assigned to the intervention or control group. The intervention comprised a six module CBT-PMP delivered once weekly. A blinded assessor determined changes in self-reported outcome measures post-intervention and at 3 months. Linear mixed models and effect sizes based on changes between groups were reported. Significance was set p < 0.05.

RESULTS

The recruitment rate was 32% (intervention n = 35, control n = 34), and the drop-out rate at 3 months was 26%. On average, participants accessed three (SD 2.1) of six modules. While no difference in QoL was reported, a significant group*time interaction was found for NRS of current pain (χ2  = 8.22, p = 0.016), worst pain (χ2  = 11.20, p = 0.004), and Brief Pain Inventory (interference) (χ2  = 6.924, p = 0.031). Moderate to large effect sizes favouring the intervention were demonstrated at each time point for the pain metrics (Cohen's d: 0.38-0.84). At 3-month follow-up, 48% of the intervention group rated themselves improved or very much improved (p < 0.05).

CONCLUSIONS

This study demonstrates the potential of an internet-delivered SCI specific CBT-PMP in reporting significant statistical and clinical benefit in pain intensity and interference. Strategies to improve engagement are needed.

Assessment of pain symptoms and quality of life using the International Spinal Cord Injury Data Sets in persons with chronic spinal cord injury

Introduction

Traumatic spinal cord injury (SCI) triggers complex changes that can negatively impact health and quality of life. The International SCI Data Sets were developed to enable more comparable data collection on the complex sequelae of SCI across studies. This should facilitate progress in mechanistic understanding and improving treatments of SCI.

Study design

Prospective observational pilot study.

Objectives

To collect data on pain symptoms and quality of life (QoL) in adults living with chronic SCI.

Setting

Academic medical center, New York, USA.

Methods

The International SCI Basic Pain and Qol Data Sets were used to collect data from participants with chronic SCI (N = 31) at 2 study visits held 6 months apart. The QoL Data Set was also used to collect data from able-bodied persons of similar age and gender distribution (N = 28).

Results

Most participants with SCI had multiple types and locations of pain problems at both study visits, despite reported being treated for pain. At both visits, the worst pain problem type was nociceptive, followed by neuropathic, which was typically rated of higher intensity. QoL scores were significantly lower across all domains of the data set in persons with SCI than able-bodied persons. Persons with pain tended to have lower QoL scores, although this trend was not significant.

Conclusions

This study demonstrates the presence, complexity and stability of pain symptoms refractory to treatment and lower quality of life ratings in persons with chronic SCI.

Sponsorship

Grants from the Craig H. Neilsen Foundation, New York Empire Clinical Research Program, New York State Spinal Cord Injury Research Board.

Moderate Fluid Shear Stress Could Regulate the Cytoskeleton of Nucleus Pulposus and Surrounding Inflammatory Mediators by Activating the FAK-MEK5-ERK5-cFos-AP1 Signaling Pathway

We first applied moderate fluid shear stress to nucleus pulposus cells. The correlation of AP-1 with type II collagen, proteoglycan, Cytokeratin 8 protein, MAP-1, MAP-2, and MAP-4 and the correlation of AP-1 with IL-1β, TNF-α, IL-6, IL-8, MIP-1, MCP-1, and NO were detected. Our results document that moderate fluid shear stress could activate the FAK-MEK5-ERK5-cFos-AP1 signaling pathway. AP1 could downregulate the construct factors of cytoskeleton such as type II collagen, proteoglycan, Cytokeratin 8 protein, MAP-1, MAP-2, and MAP-4 in nucleus pulposus cell after the fluid shear stress was loaded. AP1 could upregulate the inflammatory factors such as IL-1β, TNF-α, IL-6, IL-8, MIP-1, MCP-1, and NO in nucleus pulposus cell after the fluid shear stress was loaded. Taken together, our data suggested that moderate fluid shear stress may play an important role in the cytoskeleton of nucleus pulposus and surrounding inflammatory mediators by activating the FAK-MEK5-ERK5-cFos-AP1 signaling pathway, thereby affecting cell degeneration.