Neuropathic Pain Intensity, Unpleasantness, Coping Strategies, and Psychosocial Factors after Spinal Cord Injury: An Exploratory Longitudinal Study During the First Year

Predicting chronic pain two years following a spinal cord injury: Longitudinal study on the reciprocal role of acute pain and PTSD symptoms

OBJECTIVES

To examine a) the development of PTSD symptoms and pain over five months post-spinal cord injury (SCI); b) the directional effects of PTSD symptoms and pain across five months post-SCI; and c) the prediction of chronic pain two-years post-SCI by PTSD symptoms and pain severity in the first five months post-SCI.

STUDY DESIGN

Two-year longitudinal study.

SETTING

: Individuals with an SCI admitted to the Department of Neurological Rehabilitation (N = 65).

OUTCOME MEASURES

: PTSD symptoms and pain were evaluated at 1.5 months (T1), three months (T2), and five months (T3) post-SCI. Chronic pain was evaluated at 24 months post-SCI (follow-up).

RESULTS

Seventy-five percent of participants reported chronic pain at follow-up. Pain severity at T1 and T2 predicted PTSD symptoms at T2 and T3, respectively. PTSD symptoms at T2 predicted pain severity at T3. Individuals with chronic pain at follow-up had reported more PTSD symptoms at T1, T2, and T3 than those without pain. A multivariate model yielded two significant indirect paths: a) PTSD symptoms at T1 predicted chronic pain severity at follow-up through PTSD symptoms at T2 and T3, and b) pain severity at T1 predicted chronic pain severity at follow-up through pain severity at T2 and T3.

CONCLUSIONS

Both pain and PTSD in the acute post-SCI phase are markers for chronic pain two years later. PTSD and chronic pain exhibit a complex, reciprocal relationship across time that contributes to pain chronicity. Identifying individuals at risk and implementing interventions targeting both pain and PTSD symptoms during the acute phase may prevent their chronification.

Neuropathic pain in burn patients - A common problem with little literature: A systematic review

BACKGROUND

The prevalence of neuropathic pain (NP) in burn patients is reported in the literature to be as high as 80%1. Given the complexity of NP in burn patients and the wide range of treatments available, a systematic review of the literature is warranted to summarize our current understanding of management and treatment of NP in this population.

METHODS

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The following databases were queried to identify relevant articles: PubMed, Cochrane, Embase, Scopus, Ovid, and Web of Science. The main outcome measures were incidence and management of NP. Secondary outcomes included risk factors for NP.

RESULTS

Included articles presented findings from 11 different countries, capturing outcomes for 4366 patients. Risk factors for neuropathic pain in burn patients were identified, including older age, alcohol and substance abuse, current daily smoking, greater % total body surface area burns (TBSA), and longer hospitalizations. Pharmacologic treatments included gabapentin/pregabalin (n = 7), ascorbic acid (n = 1), and lidocaine (n = 1). Overall, the studies showed varied results regarding the efficacy of pharmacological treatments. While certain studies demonstrated gabapentanoids to be effective in reducing neuropathic symptoms, others found conflicting results. With regards to non-pharmacologic treatments, electroconvulsive therapy (n = 1), electropuncture (n = 1), nerve release/reconstruction (n = 2), and somatosensory feedback rehabilitation (n = 1) were used and demonstrated promise in reducing pain intensity and improving functionality.

CONCLUSIONS

Despite NP afflicting the majority of burn patients long after their injury, this systematic review demonstrates insufficient evidence on the pathophysiology, outcomes, and risk factors in NP, as well as the efficacy of various therapies. Future prospective and randomized studies evaluating the etiology of these factors can substantially improve our treatment strategies. This can allow for the development of well-delineated and evidence-based protocols in NP management in hopes of improving quality of life and both psychological and physical function in burn patients.

A Case Study of Hypnosis Enhanced Cognitive Therapy for Pain in a Ventilator Dependent Patient during Inpatient Rehabilitation for Spinal Cord Injury

Early, acute pain following spinal cord injury (SCI) is common, can negatively impact SCI rehabilitation, and is frequently not responsive to biomedical treatment. Nonpharmacological interventions show promise in reducing pain for individuals with SCI. However, most psychological interventions rely heavily on verbal interaction between the individual being treated and the clinician, making them inaccessible for individuals with impaired verbal output due to mechanical ventilation. This case study aims to describe the adaptation and implementation of hypnotic cognitive therapy (HYP-CT) intervention for early SCI pain in the context of mechanical ventilation dependence and weaning. The participant was a 54-year-old male with C2 AIS A SCI requiring mechanical ventilation. Four sessions of HYP-CT were provided during inpatient rehabilitation with assessment prior to intervention, after the intervention sessions, and prior to discharge. The participant reported immediate reductions in pain intensity following each intervention session. Overall, he reported increases in self-efficacy and pain acceptance. He did not report any negative treatment effects and thought the intervention provided support during mechanical ventilation weaning. During treatment, he discontinued opioid pain medications and reported actively using intervention strategies. Our results support the potential for early, hypnotic cognitive therapy for individuals with SCI experiencing pain or distress while dependent on mechanical ventilation.

Identifying Discomplete Spinal Lesions: New Evidence from Pain-Autonomic Interaction in Spinal Cord Injury

The clinical evaluation of spinal afferents is an important diagnostic and prognostic marker for neurological and functional recovery after spinal cord injury (SCI). Particularly important regarding neuropathic pain following SCI is the function of the spinothalamic tract (STT) conveying nociceptive and temperature information. Here, we investigated the added value of neurophysiological methods revealing discomplete STT lesions; that is, residual axonal sparing in clinically complete STT lesions. Specifically, clinical pinprick testing and thermal thresholds were compared with objective contact heat-evoked potentials (CHEPs) and a novel measure of pain-autonomic interaction employing heat-induced sympathetic skin responses (SSR). The test stimuli (i.e., contact heat, pinprick) were applied below the lesion level in 32 subjects with thoracic SCI while corresponding heat-evoked responses (i.e., CHEPs and SSR) were recorded above the lesion (i.e., scalp and hand, respectively). Readouts of STT function were related to neuropathic pain characteristics. In subjects with abolished pinprick sensation, measures of thermosensation (10%), CHEPs (33%), and SSR (48%) revealed residual STT function. Importantly, SSRs can be used as an objective readout and when abolished, no other proxy indicated residual STT function. No relationship was found between STT function readouts and spontaneous neuropathic pain intensity and extent. However, subjects with clinically preserved STT function presented more often with allodynia (54%) than subjects with discomplete (13%) or complete STT lesions (18%). In individuals with absent pinprick sensation, discomplete STT lesions can be revealed employing pain-autonomic measures. The improved sensitivity to discerning STT lesion completeness might support the investigation of its association with neuropathic pain following SCI.

Biomarkers for predicting central neuropathic pain occurrence and severity after spinal cord injury: results of a long-term longitudinal study

Central neuropathic pain (CNP) after spinal cord injury (SCI) is debilitating and immensely impacts the individual. Central neuropathic pain is relatively resistant to treatment administered after it develops, perhaps owing to irreversible pathological processes. Although preemptive treatment may overcome this shortcoming, its administration necessitates screening patients with clinically relevant biomarkers that could predict CNP early post-SCI. The aim was to search for such biomarkers by measuring pronociceptive and for the first time, antinociceptive indices early post-SCI. Participants were 47 patients with acute SCI and 20 healthy controls. Pain adaptation, conditioned pain modulation (CPM), pain temporal summation, wind-up pain, and allodynia were measured above, at, and below the injury level, at 1.5 months after SCI. Healthy control were tested at corresponding regions. Spinal cord injury patients were monitored for CNP emergence and characteristics at 3 to 4, 6 to 7, and 24 months post-SCI. Central neuropathic pain prevalence was 57.4%. Central neuropathic pain severity, quality, and aggravating factors but not location somewhat changed over 24 months. Spinal cord injury patients who eventually developed CNP exhibited early, reduced at-level pain adaptation and CPM magnitudes than those who did not. The best predictor for CNP emergence at 3 to 4 and 7 to 8 months was at-level pain adaptation with odds ratios of 3.17 and 2.83, respectively (∼77% probability) and a cutoff value with 90% sensitivity. Allodynia and at-level CPM predicted CNP severity at 3 to 4 and 24 months, respectively. Reduced pain inhibition capacity precedes, and may lead to CNP. At-level pain adaptation is an early CNP biomarker with which individuals at risk can be identified to initiate preemptive treatment.

Self-management of pain and depression in adults with spinal cord injury: A scoping review

Context: Pain and depression are two prevalent secondary complications associated with spinal cord injury (SCI) that negatively impact health and well-being. Self-management strategies are growing in popularity for helping people with SCI to cope with their pain and depression. However, there is still a lack of research on which approaches are best suited for this population.Objective: The aim of this scoping review was to determine what is known about the self-management of pain and depression through the use of pharmacological and non-pharmacological therapies in adults with SCI.Methods: Seven electronic databases were searched for articles published between January 1, 1990 and June 13, 2017. Grey literature was searched and additional articles were identified by manually searching the reference lists of included articles.Results: Overall, forty-two articles met the inclusion criteria; with the majority reporting on the self-management of pain, rather than on depression or on both complications. Non-pharmacological interventions were more likely to include self-management strategies than pharmacological interventions. A limited number of studies included all of the core self-management tasks and skills.Conclusions: There are significant knowledge gaps on effective self-management interventions for pain and depression post-SCI. There is a need to develop interventions that are multi-faceted, which include both pharmacological and non-pharmacological therapies to address multimorbidity.

A cohort study of the association between psychosocial factors and pain in patients with Spinal Cord Injury and Stroke

PURPOSE

To explore associations between psychosocial factors and pain intensity and pain interference in a population with a new neurological injury on admission to rehabilitation, and after six months.

MATERIALS AND METHODS

A longitudinal, prospective cohort study with participants with stroke or Spinal Cord Injury (SCI) completing questionnaires for pain intensity and interference, mental health, pain coping strategies and pain attitudes and beliefs within two weeks of admission to inpatient rehabilitation. After six months, participants completed measures of pain intensity and pain interference only.

RESULTS

In all 32 participants completed the questionnaires at baseline and 19 after six months. Several associations between a person's mental health and certain beliefs were associated with pain outcomes. Additionally, poorer baseline mental health was associated with greater pain intensity and pain interference after six months, and a stronger belief in a medical cure for pain at baseline was associated with less pain intensity and pain interference after six months.

CONCLUSIONS

Psychosocial factors are associated with pain early after stroke and SCI. Psychosocial factors are also associated with pain outcomes several months after stroke and SCI. This highlights the importance of psychosocial factors in both of these populations and their relationship with pain outcomes.

"My friend, the pain": does altered body awareness affect the valence of pain descriptors?

Background: Pain is a marker of bodily status, that despite being aversive under most conditions, may also be perceived as a positive experience. However, how bodily states represent, define, and interpret pain signals, and how these processes might be reflected in common language, remains unclear.

Methods: Qualitative and quantitative methods were used to explore the relationship between bodily awareness, pain reactions, and descriptions. A list of pain-related terms was generated from open-ended interviews with persons with spinal cord injury (SCI), and 138 participants (persons with SCI, health professionals, and a healthy control group) rated each descriptor as representative of pain on a gradated scale. A lexical decision task was used to test the strength of the automatic association of the word “pain” with positive and negative concepts. The behavioral results were related to body awareness, experience of pain, and exposure to pain, by comparing the three groups.

Results: Higher positive and lower negative pain descriptors, as well as slower response times when categorizing pain as an unpleasant experience were found in the SCI group. The effect was not modulated by either the time since the injury or the present pain intensity, but it was linked to the level of subjective bodily awareness. Compared with the SCI group, health experts and non-experts both associated more quickly the word “pain” and unpleasant in the lexical decision task. However, while health professionals attributed positive linguistic qualities to pain, pain was exclusively associated with negative descriptors in healthy controls group.

Conclusions: These findings are discussed in terms of their theoretical and clinical implications. An awareness of bodily signals prominently affects both the sensory and linguistic responses in persons with SCI. Pain should be evaluated more broadly to understand and, by extension, to manage, experiences beyond its adverse side.

Beyond the Diagnosis: Lived Experiences of Persons with Spinal Cord Injury in a Selected Town in Ghana

Background

Although several studies have been conducted on the lived experiences of persons with spinal cord injury (SCI) in high income countries, there is no published data on such experiences in Ghana. The purpose of this study was to explore the lived experiences of persons with SCI in the Tamale Metropolis of the Northern Region of Ghana.

Material and Methods

A qualitative descriptive design involving thirteen participants was conducted at the Tamale Metropolis-Ghana. A purposive sampling technique was used to recruit participants, using the Neurosurgical Unit of the Tamale Teaching Hospital as an outlet for recruitment of the sample. Data was gathered mainly through face-to-face in-depth interviews. The data was analyzed concurrently with data collection, using thematic content analysis. Ethical approval was obtained for the study from the Noguchi Memorial Institute for Medical Research and the research unit of the Tamale Teaching Hospital.

Results

The three main themes that emerged from the data during analysis were “physical effects,” “psychological effects,” and “social issues.” Conclusion. The findings from the study suggest that SCI is a life threatening condition and that persons with SCI grapple with a myriad of physical symptoms that range from chronic pain and paralysis of lower and/or upper limbs, to bladder and bowel incontinence. These physical symptoms have significant psychological and social effects on the functioning of the affected persons.

Measuring pain phenomena after spinal cord injury: Development and psychometric properties of the SCI-QOL Pain Interference and Pain Behavior assessment tools

OBJECTIVE

To develop modern patient-reported outcome measures that assess pain interference and pain behavior after spinal cord injury (SCI).

DESIGN

Grounded-theory based qualitative item development; large-scale item calibration field-testing; confirmatory factor analyses; graded response model item response theory analyses; statistical linking techniques to transform scores to the Patient Reported Outcome Measurement Information System (PROMIS) metric.

SETTING

Five SCI Model Systems centers and one Department of Veterans Affairs medical center in the United States.

PARTICIPANTS

Adults with traumatic SCI.

INTERVENTIONS

N/A.

OUTCOME MEASURES

Spinal Cord Injury - Quality of Life (SCI-QOL) Pain Interference item bank, SCI-QOL Pain Interference short form, and SCI-QOL Pain Behavior scale.

RESULTS

Seven hundred fifty-seven individuals with traumatic SCI completed 58 items addressing various aspects of pain. Items were then separated by whether they assessed pain interference or pain behavior, and poorly functioning items were removed. Confirmatory factor analyses confirmed that each set of items was unidimensional, and item response theory analyses were used to estimate slopes and thresholds for the items. Ultimately, 7 items (4 from PROMIS) comprised the Pain Behavior scale and 25 items (18 from PROMIS) comprised the Pain Interference item bank. Ten of these 25 items were selected to form the Pain Interference short form.

CONCLUSIONS

The SCI-QOL Pain Interference item bank and the SCI-QOL Pain Behavior scale demonstrated robust psychometric properties. The Pain Interference item bank is available as a computer adaptive test or short form for research and clinical applications, and scores are transformed to the PROMIS metric.

Treatment with albumin-hydroxyoleic acid complex restores sensorimotor function in rats with spinal cord injury: Efficacy and gene expression regulation

Sensorimotor dysfunction following incomplete spinal cord injury (SCI) is often characterized by paralysis, spasticity and pain. Previously, we showed that intrathecal (i.t.) administration of the albumin-oleic acid (A-OA) complex in rats with SCI produced partial improvement of these symptoms and that oral 2-hydroxyoleic acid (HOA, a non-hydrolyzable OA analogue), was efficacious in the modulation and treatment of nociception and pain-related anxiety, respectively. Here we observed that intrathecal treatment with the complex albumin-HOA (A-HOA) every 3 days following T9 spinal contusion injury improved locomotor function assessed with the Rotarod and inhibited TA noxious reflex activity in Wistar rats. To investigate the mechanism of action of A-HOA, microarray analysis was carried out in the spinal cord lesion area. Representative genes involved in pain and neuroregeneration were selected to validate the changes observed in the microarray analysis by quantitative real-time RT-PCR. Comparison of the expression between healthy rats, SCI rats, and SCI treated with A-HOA rats revealed relevant changes in the expression of genes associated with neuronal morphogenesis and growth, neuronal survival, pain and inflammation. Thus, treatment with A-HOA not only induced a significant overexpression of growth and differentiation factor 10 (GDF10), tenascin C (TNC), aspirin (ASPN) and sushi-repeat-containing X-linked 2 (SRPX2), but also a significant reduction in the expression of prostaglandin E synthase (PTGES) and phospholipases A1 and A2 (PLA1/2). Currently, SCI has very important unmet clinical needs. A-HOA downregulated genes involved with inflammation and upregulated genes involved in neuronal growth, and may serve to promote recovery of function after experimental SCI.

Increased psychological distress among individuals with spinal cord injury is associated with central neuropathic pain rather than the injury characteristics

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

Central neuropathic pain (CNP) is common after spinal cord injury (SCI). The psychological impact of CNP is not clear. Previous studies reported depression and pain catastrophizing among patients with SCI and CNP; however, the lack of control groups prevented discerning whether these were attributed to CNP or to the SCI itself. The aim was to examine the psychological distress among individuals with SCI with and without CNP and controls to evaluate its impact and possible source.

SETTING

Outpatient clinic of a large rehabilitation center.

METHODS

Individuals with SCI and CNP (n = 27) and without CNP (n = 23), and able-bodied controls (n = 20) participated. Data collection included sociodemographics, SCI characteristics, and level of post-traumatic stress disorder (PTSD), anxiety, stress, depression, and pain catastrophizing. The sensory, affective, and cognitive dimensions of CNP were analyzed.

RESULTS

Individuals with SCI and CNP exhibited elevated levels of PTSD, anxiety, stress, depression, and pain catastrophizing compared to the two control groups, which presented similar levels. The psychological variables among the CNP group correlated positively only with the affective dimension of CNP. Neither CNP nor the psychological variables correlated with SCI characteristics.

CONCLUSIONS

Irrespective of CNP intensity, the affective dimension (suffering) is associated with increased psychological distress. Perhaps individual differences in the response to SCI and/or individual traits rather than the mere exposure to SCI may have a role in the emergence of CNP and psychological distress/mood dysfunction. Rehabilitation programs should prioritize stress management and prevention among individuals with SCI and CNP.

Neuropathic Pain and Spinal Cord Injury: Phenotypes and Pharmacological Management

Chronic neuropathic pain is a complicated condition after a spinal cord injury (SCI) that often has a lifelong and significant negative impact on life after the injury; therefore, improved pain management is considered a significant and unmet need. Neuropathic pain mechanisms are heterogeneous and the difficulty in determining their individual contribution to specific pain types may contribute to poor treatment outcomes in this population. Thus, identifying human neuropathic pain phenotypes based on pain symptoms, somatosensory changes, or cognitive and psychosocial factors that reflect specific spinal cord or brain mechanisms of neuropathic pain is an important goal. Once a pain phenotype can be reliably replicated, its relationship with biomarkers and clinical treatment outcomes can be analyzed, and thereby facilitate translational research and further the mechanistic understanding of individual differences in the pain experience and in clinical trial outcomes. The present article will discuss clinical aspects of SCI-related neuropathic pain, neuropathic pain phenotypes, pain mechanisms, potential biomarkers and pharmacological interventions, and progress regarding how defining neuropathic pain phenotypes may lead to more targeted treatments for these difficult pain conditions.

The role of Omega-3 and Omega-9 fatty acids for the treatment of neuropathic pain after neurotrauma

Omega-3 polyunsaturated fatty acids (PUFAs), such as docosaexaenoic acid (DHA) and eicosapentaenoic acid (EPA), mediate neuroactive effects in experimental models of traumatic peripheral nerve and spinal cord injury. Cellular mechanisms of PUFAs include reduced neuroinflammation and oxidative stress, enhanced neurotrophic support, and activation of cell survival pathways. Bioactive Omega-9 monounsaturated fatty acids, such as oleic acid (OA) and 2-hydroxy oleic acid (2-OHOA), also show therapeutic effects in neurotrauma models. These FAs reduces noxious hyperreflexia and pain-related anxiety behavior following peripheral nerve injury and improves sensorimotor function following spinal cord injury (SCI), including facilitation of descending inhibitory antinociception. The relative safe profile of neuroactive fatty acids (FAs) holds promise for the future clinical development of these molecules as analgesic agents. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.

Evaluation of a specialized yoga program for persons with a spinal cord injury: a pilot randomized controlled trial

Objectives

The purpose of this randomized controlled trial was to evaluate the effects of a specialized yoga program for individuals with a spinal cord injury (SCI) on pain, psychological, and mindfulness variables.

Materials and methods

Participants with SCI (n=23) were outpatients or community members affiliated with a rehabilitation hospital. Participants were randomized to an Iyengar yoga (IY; n=11) group or to a 6-week wait-list control (WLC; n=12) group. The IY group participated in a twice-weekly 6-week seated IY program; the WLC group participated in the same yoga program, after the IY group’s yoga program had ended. Pain, psychological, and mindfulness measures were collected at two time points for both groups (within 1–2 weeks before and after program 1 and at a third time point for the WLC group (within 1 week after program 2).

Results

Linear mixed-effect growth models were conducted to evaluate the main effects of group at T2 (postintervention), controlling for T1 (preintervention) scores. T2 depression scores were lower (F_1,18=6.1, P<0.05) and T2 self-compassion scores higher (F_1,18=6.57, P< 0.05) in the IY group compared to the WLC group. To increase sample size and power, the two groups were combined and analyzed across time by comparing pre- and postintervention scores. Main effects of time were found for depression scores, (F_1,14.83=6.62, P<0.05), self-compassion, (F_1,16.6=4.49, P<0.05), mindfulness (F_1,16.79=5.42, P<0.05), mindful observing (F_1,19.82=5.06, P<0.05), and mindful nonreactivity, (F_1,16.53=4.92, P<0.05), all showing improvement after the intervention.

Discussion

The results indicated that a specialized 6-week yoga intervention reduced depressive symptoms and increased self-compassion in individuals with SCI, and may also have fostered greater mindfulness.

Psychosocial aspects of spinal cord injury pain: a meta-analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVES

Although the association between modifiable psychosocial factors and spinal cord injury (SCI) pain has been identified, the full range of psychological and social difficulties for those who experience acute and/or persistent pain remains unclear. This meta-analysis consolidates the available evidence, using the International Classification of Functioning, Disability and Health (ICF) as a reference framework.

METHODS

Nineteen studies that examined persistent neuropathic, nociceptive or mixed pain subtypes in adults with a SCI (newly acquired and chronic; Nparticipants=2934) were identified from electronic database searches. Standardised mean differences between SCI pain and no-pain groups on self-reported psychosocial outcomes were calculated, along with 95% confidence intervals, fail-safe Ns and heterogeneity statistics.

RESULTS

Twenty individual outcomes were grouped into nine ICF-related categories. Emotional functions were the most frequent (100%) psychosocial outcomes assessed, with pain contributing to heightened stress (d=-0.85), depression (d=-2.49) anxiety (d range=-0.85 to -1.45), poor self-efficacy (d=-0.77), lowered wellbeing (d range=-0.67 to -1.02) and decreased use of adaptive coping, such as illness acceptance (d=-0.85). Activity limitations and participation restriction were examined by seven studies (43%), although these findings were largely characterised by single studies.

CONCLUSIONS

Multicomponent treatments that target mood disturbance and foster community connections are important in SCI pain management. However, to improve the comparability of future studies, SCI pain research must adopt definitions of pain consistent with the International Spinal Cord Injury Pain Classification along with validated outcomes that map onto the ICF framework.

Deficient conditioned pain modulation after spinal cord injury correlates with clinical spontaneous pain measures

The contribution of endogenous pain modulation dysfunction to clinical and sensory measures of neuropathic pain (NP) has not been fully explored. Habituation, temporal summation, and heterotopic noxious conditioning stimulus-induced modulation of tonic heat pain intensity were examined in healthy noninjured subjects (n = 10), and above the level of spinal cord injury (SCI) in individuals without (SCI-noNP, n = 10) and with NP (SCI-NP, n = 10). Thermoalgesic thresholds, Cz/AFz contact heat evoked potentials (CHEPs), and phasic or tonic (30 seconds) heat pain intensity were assessed within the C6 dermatome. Although habituation to tonic heat pain intensity (0-10) was reported by the noninjured (10 s: 3.5 ± 0.3 vs 30 s: 2.2 ± 0.5 numerical rating scale; P = 0.003), loss of habituation was identified in both the SCI-noNP (3.8 ± 0.3 vs 3.6 ± 0.5) and SCI-NP group (4.2 ± 0.4 vs 4.9 ± 0.8). Significant temporal summation of tonic heat pain intensity was not observed in the 3 groups. Inhibition of tonic heat pain intensity induced by heterotopic noxious conditioning stimulus was identified in the noninjured (-29.7% ± 9.7%) and SCI-noNP groups (-19.6% ± 7.0%), but not in subjects with SCI-NP (+1.1% ± 8.0%; P < 0.05). Additionally, the mean conditioned pain modulation response correlated positively with Cz/AFz CHEP amplitude (ρ = 0.8; P = 0.015) and evoked heat pain intensity (ρ = 0.8; P = 0.007) in the SCI-NP group. Stepwise regression analysis revealed that the mean conditioned pain modulation (R = 0.72) correlated with pain severity and pressing spontaneous pain in the SCI-NP group. Comprehensive assessment of sensory dysfunction above the level of injury with tonic thermal test and conditioning stimuli revealed less-efficient endogenous pain modulation in subjects with SCI-NP.

Cross-cultural adaptation of the spinal cord lesion-related coping strategies questionnaire for use in Iran

INTRODUCTION

This study examined the validity and reliability of the Iranian version of the spinal cord lesion-related coping strategies questionnaire (SCL CSQ-I) in persons with spinal cord injury (SCI).

METHODS

Consecutive patients with SCI (n=220) were recruited into the study. A standard forward-backward translation procedure was used to translate the SCL CSQ from English into Persian. Participants also completed the Short Form Health Survey (SF-12), Hospital Anxiety and Depression Scale (HADS), Spinal Cord Independence Measure (SCIM III), Community Integration Questionnaire (CIQ), and SCL CSQ-I. Psychometric properties examined were internal consistency, test-retest reliability, convergent validity, discriminant validity, and construct validity.

RESULTS

Cronbach alphas for the SCL CSQ-I subscales ranged from 0.68 to 0.89, indicating acceptable internal reliability, and intraclass correlation coefficients ranged from 0.74 to 0.89, indicating good test-retest reliability. The SCL CSQ-I subscales significantly correlated with scores on the SF-12, HADS, SCIM III and CIQ, indicating solid convergent validity. Each item of the SCL CSQ-I within a hypothesized dimension correlated strongly with the total score for that dimension. Exploratory and confirmatory factor analyses identified a three-factor model. The SCL CSQ-I subscales correlated significantly with clinical and socio-demographic characteristics.

CONCLUSION

The Iranian version of the SCL CSQ is a reliable and valid tool for measuring coping strategies in persons with SCI.

Oral administration of the p38α MAPK inhibitor, UR13870, inhibits affective pain behavior after spinal cord injury

The p38α mitogenous activated protein kinase (MAPK) cell signaling pathway is a key mechanism of microglia activation and has been studied as a target for neuropathic pain. The effect of UR13870, a p38α MAPK inhibitor, on microglia expression in the anterior cingulate cortex (ACC) and spinal dorsal horn was addressed after T9 contusion spinal cord injury (SCI) in the rat, in addition to behavioral testing of pain-related aversion and anxiety. Administration of intravenous UR13870 (1mg/kg i.v.) and pregabalin (30 mg/kg i.v.) reduced place escape avoidance paradigm (PEAP) but did not affect open-field anxiety behavior 42 days after SCI. PEAP behavior was also reduced in animals administered daily with oral UR13870 (10mg/kg p.o.) and preserved spinal tissue 28 days after SCI. Although UR13870 (10mg/kg p.o.) failed to reduce OX-42 and glial fibrillar acid protein immunoreactivity within the spinal dorsal horn, a reduction toward the control level was observed close to the SCI site. In the anterior cingulate cortex (ACC), a significant increase in OX-42 immunoreactivity was identified after SCI. UR13870 (10mg/kg p.o.) treatment significantly reduced OX-42, metabotropic glutamate type 5 receptor (mGluR5), and NMDA (N-methyl-d-aspartate) 2B subunit receptor (NR2B) expression in the ACC after SCI. To conclude, oral treatment with a p38α MAPK inhibitor reduces the affective behavioral component of pain after SCI in association with a reduction of microglia and specific glutamate receptors within the ACC. Nevertheless the role of neuroinflammatory processes within the vicinity of the SCI site in the development of affective neuropathic pain cannot be excluded.