Systematic Review of Pharmacologic Treatments of Pain After Spinal Cord Injury: An Update

A home-based self-directed EEG neurofeedback intervention for people with chronic neuropathic pain following spinal cord injury (the StoPain Trial): description of the intervention

STUDY DESIGN

Randomised controlled trial.

OBJECTIVES

The objective is to describe an electroencephalography (EEG) neurofeedback intervention that will be provided in a randomised controlled trial for people with neuropathic pain following spinal cord injury (SCI): the StoPain Trial. In this trial, participants in the treatment group will implement an EEG neurofeedback system as an analgesic intervention at home, while participants in the control group will continue with the treatments available to them in the community.

SETTING

University-based study in Sydney, Australia.

METHODS/RESULTS

This manuscript describes the rationale and components of the EEG neurofeedback intervention designed for individuals with SCI neuropathic pain and intended for home-based implementation. Our report is based on the criteria of the Template for Intervention Description and Replication (TIDieR) checklist, and includes why the efficacy of EEG neurofeedback will be investigated, what will be provided, who will administer it, and how, where, when, and how much the EEG neurofeedback intervention will be administered.

CONCLUSIONS

This manuscript provides a detailed description of a complex intervention used in a randomised controlled trial. This description will facilitate the subsequent interpretation of the trial results and allow for the replication of the intervention in clinical practice and future trials.

SPONSORSHIP

Australian Government Medical Research Future Fund (2020 Rare Cancers Rare Diseases and Unmet Needs Scheme: 2006020).

Choosing non-pharmacological treatments for neuropathic pain in spinal cord injury: a qualitative study

PURPOSE

The aims of this study were to explore (1) the considerations of people with spinal cord injury (SCI) in choosing to use non-pharmacological treatments (N-PTs) for neuropathic pain (NP), (2) which factors influence their decision and who is involved in this choice.

MATERIALS AND METHODS

Eleven individuals with SCI and NP were interviewed. Interviews were transcribed verbatim, transcripts were analysed through thematic coding, following an inductive content analysis approach.

RESULTS

A journey towards finding and choosing N-PTs emerged. Key phases in this journey were: motives, strategy and practical considerations. Pain and its impact on their life led participants to consider N-PTs. Motives were participants' negative attitudes towards regular medication, willingness to try everything and disappointment and frustration with the guidance from their health care provider (HCP). The search strategies often involved third parties and the internet. This led them to choose a specific N-PT. The journey was influenced by one's attitude, previous personal experience, experience of HCPs, financial considerations, availability and convenience of the treatment.

CONCLUSIONS

The journey individuals with SCI and NP go through to find N-PTs to manage pain is difficult and often lonely. Findings highlight the importance of HCPs accompanying people with SCI in finding N-PTs.

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.

Cortical Mechanisms Underlying Immersive Interactive Virtual Walking Treatment for Amelioration of Neuropathic Pain after Spinal Cord Injury: Findings from a Preliminary Investigation of Thalamic Inhibitory Function

BACKGROUND

Neuropathic pain following spinal cord injury (SCI) affects approximately 60% of individuals with SCI. Effective pharmacological and non-pharmacological treatments remain elusive. We recently demonstrated that our immersive virtual reality walking intervention (VRWalk) may be effective for SCI NP. Additionally, we found that SCI NP may result from a decrease in thalamic γ-aminobutyric-acid (GABA), which disturbs central sensorimotor processing.

OBJECTIVE

While we identified GABAergic changes associated with SCI NP, a critical outstanding question is whether a decrease in SCI NP generated by our VRWalk intervention causes GABA content to rise.

METHOD

A subset of participants (n = 7) of our VRWalk trial underwent magnetic resonance spectroscopy pre- and post-VRWalk intervention to determine if the decrease in SCI NP is associated with an increase in thalamic GABA.

RESULTS

The findings revealed a significant increase in thalamic GABA content from pre- to post-VRWalk treatment.

CONCLUSION

While the current findings are preliminary and should be interpreted with caution, pre- to post-VRWalk reductions in SCI NP may be mediated by pre- to post-treatment increases in thalamic GABA by targeting and normalizing maladaptive sensorimotor cortex reorganization. Understanding the underlying mechanisms of pain recovery can serve to validate the efficacy of home-based VR walking treatment as a means of managing pain following SCI. Neuromodulatory interventions aimed at increasing thalamic inhibitory function may provide more effective pain relief than currently available treatments.

Could conditioned medium be used instead of stem cell transplantation to repair spinal cord injury in animal models? Identifying knowledge gaps

The drawbacks of stem cell (SC) therapies have led to investigations of SC conditioned medium (CM) instead of SC transplantation in the repair of spinal cord injury (SCI). However, the effectiveness of CM in comparison with cell transplantation in SCI models remain an open and intriguing question. The focus of this review was to survey existing publications addressing this comparison. The review included articles from electronic databases Medline, Embase, Scopus, and Web of Science that included comparisons of the effects of CM versus SC transplantation and versus controls on locomotion after SCI. The search yielded 5 studies and 6 experiments. The results indicated that there was insufficient evidence to conclude that treatment with CM and source cells were equally effective (SMD = 0.12; 95% CI = -0.36 to 0.59; p = 0.07). Regarding investigations of separate effects of SCs versus CM, there currently is limited evidence on efficacy in SCI models. This highlights a notable concern affecting this field. Thus, we identified critical knowledge gaps concerning comparisons of the efficacy of therapeutic application of SC and their derived CM on functional recovery following SCI.

A Systematic Review of the Interventions for Management of Pain in Patients After Spinal Cord Injury

Chronic pain is a very common problem in patients with spinal cord injury (SCI) as it affects 80% of these patients, which negatively affects their quality of life. Despite many advantages that exist in the management of any type of pain (neuropathic, nociceptive, mixed) in these patients, there is no cure, and the analgesic effect of some treatments is inadequate. This study aims to conduct an evidence-based systematic review regarding the various interventions used for the management of pain after SCI. The PubMed, Physiotherapy Evidence Database (PEDro), and Cochrane Library databases were searched from 1969 to 2023. The risk of bias was assessed using the PEDro scoring system. A total of 57 studies met the inclusion criteria and were included in this systematic review. Among the different interventions at present, 18 studies examined the role of oral medications, 11 studies examined the role of minimally invasive methods (injection and infusion), 16 studies investigated physiotherapy and alternative treatments, and 12 studies examined the role of repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), and cranial electrotherapy stimulation (CES) in the management of pain in patients after SCI. Gabapentin and pregabalin are very effective in managing chronic neuropathic pain after SCI, and pregabalin also seems to reduce anxiety and sleep disturbances in the patients. It is noteworthy that lamotrigine, valproate, and carbamazepine do not have an analgesic effect, but mirogabalin is a novel and promising drug. Antidepressants (selective serotonin reuptake inhibitors and serotonin and noradrenaline reuptake inhibitors) did not reduce the pain of the patients, although some studies showed an efficacy of amitriptyline especially in depressed patients and tramadol should be considered short-term with caution. Also, tDCS and rTMS reduced pain. Moreover, botulinum toxin type A, lidocaine, ketamine, and intrathecal baclofen significantly reduced pain intensity, although the sample of the studies was small. Physiotherapy and alternative treatments seem to relieve pain, and transcutaneous electrical nerve stimulation had the greatest reduction of pain intensity. In conclusion, several pharmaceutical and non-pharmaceutical methods exist, which can reduce pain in patients after SCI. The type of intervention can be considered by the physician depending on the patients' preference, age, medical history, type of pain, and associated symptoms. However, more studies with greater samples and with better methodological quality should be conducted.

Differential target multiplexed spinal cord stimulation using a paddle-type lead placed at the appropriate site for neuropathic pain after spinal cord injury in patients with past spinal surgical histories: study protocol for an exploratory clinical trial

BACKGROUND

Neuropathic pain after spinal cord injury (SCI), both traumatic and non-traumatic, is refractory to various treatments. Spinal cord stimulation (SCS) is one of the neuromodulation therapies for neuropathic pain, although SCS has insufficient efficacy for neuropathic pain after SCI. The reasons are presumed to be inappropriate locations of SCS leads and conventional tonic stimulation itself does not have a sufficient analgesic effect for the pain. In patients with past spinal surgical histories, the cylinder-type leads are likely to be placed on the caudal side of the SCI because of surgical adhesions. Differential target multiplexed (DTM) stimulation is one of the latest new stimulation patterns that is superior to conventional stimulation.

METHODS

A single-center, open-label, randomized, two-way crossover trial is planned to investigate the efficacy of SCS using DTM stimulation placing a paddle lead at the appropriate site for neuropathic pain after SCI in patients with spinal surgical histories. The paddle-type lead delivers energy more efficiently than a cylinder-type lead. This study consists of two steps: SCS trial (first step) and SCS system implantation (second step). The primary outcome is rates of achieving pain improvement with more than 33% reduction 3 months after SCS system implantation. The secondary outcomes are to be evaluated as follows: (1) effectiveness of DTM and tonic stimulations during the SCS trial; (2) changes of assessment items from 1 to 24 months; (3) relationships between the result of the SCS trial and the effects 3 months after SCS system implantation; (4) preoperative factors associated with a long-term effect, defined as continuing for more than 12 months; and (5) whether gait function improves from 1 to 24 months.

DISCUSSION

A paddle-type lead placed on the rostral side of SCI and using DTM stimulation may provide significant pain relief for patients with intractable neuropathic pain after SCI in patients with past spinal surgical histories.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (jRCT) jRCT 1042220093. Registered on 21 November 2022, and last modified on 6 January 2023. jRCT is approved as a member of the Primary Registry Network of WHO ICTRP.

Prevalence and Determinants of Pain in Spinal Cord Injury During Initial Inpatient Rehabilitation: Data From the Dutch Spinal Cord Injury Database

OBJECTIVE

To describe the prevalence and characteristics of spinal cord injury (SCI)-related pain during initial inpatient rehabilitation and to investigate relationships with demographic and lesion characteristics.

DESIGN

Cohort during inpatient rehabilitation.

SETTING

Eight specialized SCI rehabilitation centers in the Netherlands.

PARTICIPANTS

Patients with newly acquired SCI admitted for inpatient rehabilitation between November 2013 and August 2019 (N=1432).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Presence of pain at admission and discharge. Logistic regression analyses were used to study the prevalence of pain related to sex, age, etiology, completeness, and level of injury.

RESULTS

Data from 1432 patients were available. Of these patients 64.6% were male, mean age was 56.8 years, 59.9% had a nontraumatic SCI, 63.9% were classified as American Spinal Cord Injury Association Impairment Scale (AIS) D and 56.5% had paraplegia. Prevalence of pain was 61.2% at admission (40.6% nociceptive pain [NocP], 30.2% neuropathic pain [NeuP], 5.4% other pain) and 51.5% at discharge (26.0% NocP, 31.4% NeuP, 5.7% other pain). Having NocP at admission was associated with traumatic SCI. AIS B had a lower risk of NocP than AIS D at admission. Having NocP at discharge was associated with female sex and traumatic SCI. AIS C had a lower risk of NocP at discharge than AIS D. Having NeuP at admission was associated with female sex. Having NeuP at discharge was associated with female sex, age younger than 65 years vs age older than 75 years and tetraplegia.

CONCLUSIONS

SCI-related pain is highly prevalent during inpatient rehabilitation. Prevalence of NocP decreased during inpatient rehabilitation, and prevalence of NeuP stayed the same. Different patient and lesion characteristics were related to the presence of SCI-related pain. Healthcare professionals should be aware of these differences in screening patients on presence and development of pain during inpatient rehabilitation.

Spinal Cord Stimulation for Neuropathic Pain following a Spinal Cord Lesion with Past Spinal Surgical Histories Using a Paddle Lead Placed on the Rostral Side of the Lesion: Report of Three Cases

Spinal cord parenchymal lesions may induce intractable neuropathic pain. However, the efficacy of conventional spinal cord stimulation for the neuropathic pain following spinal cord lesions remains to be controversial. In this study, we present three cases of spinal cord stimulation using a paddle lead at the rostral side of the spinal lesion causing pain symptoms. Good pain reductions were achieved using conventional stimulation in one case and using differential target multiplexed stimulation in two cases. Case 1: A 55-year-old man presented with neuropathic pain affecting his bilateral upper extremities due to a traumatic cervical spinal cord injury. Conventional stimulation via a paddle-type electrode was able to reduce the pain from 8 to 4 via a visual analog scale. Case 2: A 67-year-old man had undergone three spinal surgeries. He presented with pain and numbness of bilateral lower extremities due to a spinal cord lesion by thoracic disc herniation. Differential target multiplexed stimulation via a paddle-type electrode achieved excellent pain reduction, that is, from 9 to 2 on the visual analog scale. Case 3: An 80-year-old man presented with pain in his bilateral upper extremities due to a cervical spinal cord lesion caused by compression and spinal canal stenosis. Posterior cervical decompression and paddle-type electrode placement were performed simultaneously. Differential target multiplexed stimulation was able to achieve excellent pain reduction, from 7 to 2 on the visual analog scale. Spinal cord stimulation using a paddle lead at the rostral side of the spinal lesion and differential target multiplexed stimulation may provide significant opportunities for patients with intractable neuropathic pain following spinal cord lesions.

Pilot clinical trial of a clinical meditation and imagery intervention for chronic pain after spinal cord injury

OBJECTIVE

To assess the feasibility and potential benefits of clinical meditation and imagery (CMI) for people with chronic spinal cord injury (SCI) and chronic pain.

DESIGN

Pilot randomized, controlled trial.

SETTING

Outpatients with SCI in the United States.

PARTICIPANTS

24 adults with chronic SCI (>1 year) and a >3 month history of pain rated ≥4/10 on average over the last week.

INTERVENTIONS

4-week program of once-weekly 2-hour group classes, offered in-person and online. CMI group participants were taught mindfulness, mantra meditation, and guided imagery practices. Control group participants received education on topics related to health and function after SCI.

OUTCOME MEASURES

Pain interference (primary outcome), pain cognitions, pain intensity/unpleasantness, depressive symptomology, perceived stress.

RESULTS

Pain interference decreased to a greater extent in the control group at both Day 42 and Day 70, with a large effect size (d > 1.0). Several secondary outcome measures showed changes consistent with more favorable outcomes in the CMI group at both Day 42 and Day 70, with a large effect size d > 0.80, including worst pain intensity over the last week, depressive symptomology, belief in pain as a sign of harm and perceived control over pain. Perceived stress improved to a greater extent in the control group (d = 1.16 at Day 42, d = .20 at Day 70).

CONCLUSION

CMI is feasible and acceptable to implement with people with SCI and chronic pain. Further study is warranted to assess potential benefits for pain-related outcomes.

Non-opioid pharmacologic treatment of chronic spinal cord injury-related pain

Purpose: Spinal cord injury-related pain is often a severe debilitating condition that adversely affects the patient's physical health, psychological wellbeing and quality of life. Opioid medications have historically been prescribed to this population with great frequency. As opioid abuse disorder becomes an ever-worsening public health issue, more attention must be placed upon non-opioid options. This paper reviews non-opioid medications to be considered when treating spinal cord injury-related pain. The pertinent literature is reviewed, and the advantages and pitfalls of various medication options are discussed in the complicated context of the individual with a spinal cord injury.Methods: Peer-reviewed journal articles and medication package insert data are reviewed.Results:. The non-opioid medications with the greatest evidence for efficacy in the treatment of chronic spinal cord injury-related pain are drawn from the antiepileptic drug and antidepressant categories though the specific selection must be nuanced to the particular individual patient. More research is required to understand the role of calcitonin, lithium, and marijuana in treating spinal cord injury-related pain.Conclusions: The complex clinical situation of each individual patient must be weighed against the risks and benefits of each medication, as reviewed in this paper, to determine the ideal treatment strategy for chronic spinal cord injury-related pain.

From acute to long-term alterations in pain processing and modulation after spinal cord injury: mechanisms related to chronification of central neuropathic pain

ABSTRACT

A severe and debilitating consequence of a spinal cord injury (SCI) is central neuropathic pain (CNP). Our aim was to investigate the processes leading to CNP emergence and chronification by analyzing causal relationship over time between spinothalamic function, pain excitability, and pain inhibition after SCI. This longitudinal follow-up study included 53 patients with acute SCI and 20 healthy controls. Spinothalamic, pain excitability, and intrasegmental and extrasegmental pain inhibition indices were repeatedly evaluated at 1.5, 3, and 6 months post-SCI. Between- and within-group analyses were conducted among those patients who eventually developed CNP and those who did not. Healthy controls were evaluated twice for repeatability analysis. Patients who developed CNP, compared with those who did not, exhibited increased thermal thresholds (P < 0.05), reduced pain adaptation (P < 0.01), and conditioned pain modulation (P < 0.05), early post-injury, and the CNP group's manifestations remained worse throughout the follow-up. By contrast, allodynia frequency was initially similar across SCI groups, but gradually increased in the subacute phase onward only among the CNP group (P < 0.001), along with CNP emergence. Early worse spinothalamic and pain inhibition preceded CNP and predicted its occurrence, and early worse pain inhibition mediated the link between spinothalamic function and CNP. Crossover associations were observed between early and late pain inhibition and excitability. Inefficient intrasegmental and extrasegmental inhibition, possibly resulting from spinothalamic deafferentation, seems to ignite CNP chronification. Pain excitability probably contributes to CNP maintenance, possibly via further exhaustion of the inhibitory control. Preemptive treatment promoting antinociception early post-SCI may mitigate or prevent CNP.

Microglial deactivation by adeno-associated virus expressing small-hairpin GCH1 has protective effects against neuropathic pain development in a spinothalamic tract-lesion model

AIMS

Neuropathic pain after spinal cord injury is one of the most difficult clinical problems after the loss of mobility, and pharmacological or neuromodulation therapy showed limited efficacy. In this study, we examine the possibility of pain modulation by a recombinant adeno-associated virus (rAAV) encoding small-hairpin RNA against GCH1 (rAAV-shGCH1) in a spinal cord injury model in which neuropathic pain was induced by a spinothalamic tract (STT) lesion.

METHODS

Micro-electric lesioning was used to damage the left STT in rats (n = 32), and either rAAV-shGCH1 (n = 19) or rAAV control (n = 6) was injected into the dorsal horn of the rats at the same time. On postoperative days 3, 7, and 14, we evaluated neuropathic pain using a behavioral test and microglial activation by immunohistochemical staining.

RESULTS

A pain modulation effect of shGCH1 was observed from postoperative days 3 to 14. The mechanical withdrawal threshold was 13.0 ± 0.95 in the shGCH1 group, 4.3 ± 1.37 in the control group, and 3.49 ± 0.85 in sham on postoperative day 3 (p < 0.0001) and continued to postoperative day 14 (shGCH1 vs. control: 11.4 ± 1.1 vs. 2.05 ± 0.60, p < 0.001 and shGCH1 vs. sham: 11.4 ± 1.1 vs. 1.43 ± 0.54, p < 0.001). Immunohistochemical staining of the spinal cord dorsal horn showed deactivation of microglia in the shGCH1 group without any change of delayed pattern of astrocyte activation as in STT model.

CONCLUSIONS

Neuropathic pain after spinal cord injury can be modulated bilaterally by deactivating microglial activation after a unilateral injection of rAAV-shGCH1 into the dorsal horn of a STT lesion spinal cord pain model. This new attempt would be another therapeutic approach for NP after SCI, which once happens; there is no clear curative options still now.

Extracorporeal shockwave therapy in spinal cord injury, early to advance to clinical trials? A systematic review and meta-analysis on animal studies

BACKGROUND

As there is no consensus over the efficacy of extracorporeal shockwave therapy in the management of spinal cord injury complications, the current meta-analysis aims to investigate preclinical evidence on the matter.

METHODS

The search strategy was developed based on keywords related to 'spinal cord injury' and 'extracorporeal shockwave therapy'. A primary search was conducted in Medline, Embase, Scopus and Web of Science until the end of 2020. Studies which administered extracorporeal shockwave therapy on spinal cord injury animal models and evaluated motor function and/or histological findings were included. The standardised mean difference with a 95% confidence interval (CI) were calculated.

RESULTS

Seven articles were included. Locomotion was significantly improved in the extracorporeal shockwave therapy treated group (standardised mean difference 1.68, 95% CI 1.05-2.31, P=0.032). It seems that the efficacy of extracorporeal shockwave therapy with an energy flux density of 0.1 mJ/mm² is higher than 0.04 mJ/mm² (P=0.044). Shockwave therapy was found to increase axonal sprouting (standardised mean difference 1.31, 95% CI 0.65, 1.96), vascular endothelial growth factor tissue levels (standardised mean difference 1.36, 95% CI 0.54, 2.18) and cell survival (standardised mean difference 2.49, 95% CI 0.93, 4.04). It also significantly prevents axonal degeneration (standardised mean difference 2.25, 95% CI 1.47, 3.02).

CONCLUSION

Extracorporeal shockwave therapy significantly improves locomotor recovery in spinal cord injury animal models through neural tissue regeneration. Nonetheless, in spite of the promising results and clinical application of extracorporeal shockwave therapy in various conditions, current evidence implies that designing clinical trials on extracorporeal shockwave therapy in the management of spinal cord injury may not be soon. Hence, further preclinical studies with the effort to reach the safest and the most efficient treatment protocol are needed.

Cannabinoids, cannabis, and cannabis-based medicines for pain management: an overview of systematic reviews

ABSTRACT

Cannabinoids, cannabis, and cannabis-based medicines (CBM) are increasingly used to manage pain, with limited understanding of their efficacy and safety. We assessed methodological quality, scope, and results of systematic reviews of randomised controlled trials of these treatments. Several search strategies sought self-declared systematic reviews. Methodological quality was assessed using both AMSTAR-2 and techniques important for bias reduction in pain studies. Of the 106 articles read, 57 were self-declared systematic reviews, most published since 2010. They included any type of cannabinoid, cannabis, or CBM, at any dose, however administered, in a broad range of pain conditions. No review examined the effects of a particular cannabinoid, at a particular dose, using a particular route of administration, for a particular pain condition, reporting a particular analgesic outcome. Confidence in the results in the systematic reviews using AMSTAR-2 definitions was critically low (41), low (8), moderate (6), or high (2). Few used criteria important for bias reduction in pain. Cochrane reviews typically provided higher confidence; all industry-conflicted reviews provided critically low confidence. Meta-analyses typically pooled widely disparate studies, and, where assessable, were subject to potential publication bias. Systematic reviews with positive or negative recommendation for use of cannabinoids, cannabis, or CBM in pain typically rated critically low or low (24/25 [96%] positive; 10/12 [83%] negative). Current reviews are mostly lacking in quality and cannot provide a basis for decision-making. A new high-quality systematic review of randomised controlled trials is needed to critically assess the clinical evidence for cannabinoids, cannabis, or CBM in pain.

On the therapeutic targets and pharmacological treatments for pain relief following spinal cord injury: A mechanistic review

Spinal cord injury (SCI) is globally considered as one of the most debilitating disorders, which interferes with daily activities and life of the affected patients. Despite many developments in related recognizing and treating procedures, post-SCI neuropathic pain (NP) is still a clinical challenge for clinicians with no distinct treatments. Accordingly, a comprehensive search was conducted in PubMed, Medline, Scopus, Web of Science, and national database (SID and Irandoc). The relevant articles regarding signaling pathways, therapeutic targets and pharmacotherapy of post-SCI pain were also reviewed. Data were collected with no time limitation until November 2020. The present study provides the findings on molecular mechanisms and therapeutic targets, as well as developing the critical signaling pathways to introduce novel neuroprotective treatments of post-SCI pain. From the pathophysiological mechanistic point of view, post-SCI inflammation activates the innate immune system, in which the immune cells elicit secondary injuries. So, targeting the critical signaling pathways for pain management in the SCI population has significant importance in providing new treatments. Indeed, several receptors, ion channels, excitatory neurotransmitters, enzymes, and key signaling pathways could be used as therapeutic targets, with a pivotal role of n-methyl-D-aspartate, gamma-aminobutyric acid, and inflammatory mediators. The current review focuses on conventional therapies, as well as crucial signaling pathways and promising therapeutic targets for post-SCI pain to provide new insights into the clinical treatment of post-SCI pain. The need to develop innovative delivery systems to treat SCI is also considered.

The Efficacy, Adverse Events & Withdrawal Rates of the Pharmacological Management of Chronic Spinal Cord Injury Pain: A Systematic Review & Meta-Analysis

OBJECTIVE

To establish the efficacy of medications, incidence of adverse events (AE) and withdrawal rates (WR) of the pharmacological management of chronic spinal cord injury (SCI) pain.

METHODOLOGY

PubMed, MEDLINE, Embase, CINAHL, Web of Science, CENTRAL and PsycINFO were searched (November 2017) and updated (January 2020). Two independent review authors screened and identified papers for inclusion.

RESULTS

Twenty-one studies met inclusion for efficacy analysis and 17 for AEs and WR analysis; no additional paper were included from the up dated 2020 search. Treatments were divided into 6 categories: anticonvulsants (n = 6), antidepressants (n = 3), analgesics (n = 8), anti-spasticity (n = 2), cannabinoids (n = 1) and other (n = 2). Trials of anticonvulsants, antidepressants, and cannabinoids included long-term follow-up trials (2 weeks- 4 months), and analgesics, anti-spasticity, among others were short term trials (0-2 days). Effectiveness for NP was found for Pregabalin (3/3 studies) and Lidocaine (2/3 studies). Studies using Ketamine also reported effectiveness (2/2) but the quality of these papers was rated as poor. Most frequently reported AEs included dizziness, dry mouth, nausea and constipation. Pregabalin had a higher risk of somnolence (RR 3.15, 95% CI 2.00-4.98) and dizziness (RR 2.9, 95% CI 1.58-5.30). Ketamine had a higher risk of reduced vision (RR 9.00, 95% CI 0.05-146.11), dizziness (RR 8.33, 95% CI 1.73-40.10) and somnolence (RR 7.00, 95% CI 1.73-40.1). WRs ranged from: 18.4% (antidepressants), 0-30% (anticonvulsants), 0-10% (anti-spasticity), 0-48% (analgesics), 28.6% (cannabinoids) and 0-22.2% (other).

CONCLUSION

Pregabalin was found to be effective for NP versus placebo. Cannabinoids was ineffective for NP. AEs are a common cause for withdrawal. The nature of AEs was poorly reported and should be improved in future RCT's.

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.

Adeno-associated virus packaged TRPC5 gene therapy alleviated spinal cord ischemic reperfusion injury in rats

Spinal cord injury (SCI) is a devastating disease with few effective treatments. This study mainly explored the mechanism of TRPC5 gene in the treatment of spinal cord ischemia reperfusion injury from the perspective of angiogenesis. Western blot, immunohistochemistry, hematoxylin and eosin, ELISA, and reverse transcription-PCR (RT-PCR) were used to detect the expression levels of related angiogenic proteins such as von Willebrend factor (vWF), vascular endothelial growth factor (VEGF), CD31, and HIF-1α. The results showed that compared with the IR group, the Basso, Beattie, and Bresnahan scores of IR + adeno-associated virus (AAV) + TRPC5 group were higher with significant difference. And compared with ischemia/reperfusion (I/R) group, RT-PCR and ELISA results showed that inflammatory factors such as IL-6, IL-1β, and TNF-α were significantly reduced in IR + AAV + TRPC5 group. In addition, the expression of vascular related proteins such as vWF, VEGF, and CD31 in spinal cord tissue were all increased. Taken together the results, we suggest that TRPC5 could significantly increase the expression of angiogenic protein and slow down the occurrence of inflammatory response to repair the SCI.

The gut-brain axis and beyond: Microbiome control of spinal cord injury pain in humans and rodents

Spinal cord injury (SCI) is a devastating injury to the central nervous system in which 60 to 80% of patients experience chronic pain. Unfortunately, this pain is notoriously difficult to treat, with few effective options currently available. Patients are also commonly faced with various compounding injuries and medical challenges, often requiring frequent hospitalization and antibiotic treatment. Change in the gut microbiome from the "normal" state to one of imbalance, referred to as gut dysbiosis, has been found in both patients and rodent models following SCI. Similarities exist in the bacterial changes observed after SCI and other diseases with chronic pain as an outcome. These changes cause a shift in the regulation of inflammation, causing immune cell activation and secretion of inflammatory mediators that likely contribute to the generation/maintenance of SCI pain. Therefore, correcting gut dysbiosis may be used as a tool towards providing patients with effective pain management and improved quality of life.

Opioid Use Among Individuals With Spinal Cord Injury: Prevalence Estimates Based on State Prescription Drug Monitoring Program Data

OBJECTIVE

To identify the prevalence of opioid use in individuals with chronic spinal cord injury (SCI) living in South Carolina.

DESIGN

Cohort study.

SETTING

Data from 2 statewide population-based databases, an SCI Registry and the state prescription drug monitoring program, were linked and analyzed.

PARTICIPANTS

The study included individuals (N=503) with chronic (>1y) SCI who were injured between 2013 and 2014 in South Carolina and who survived at least 3 years postinjury.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Filled opioid prescriptions over a 2-year period (months 13-36 after injury). The main outcomes were total number of days with an opioid prescription over the 2-year period, length of coverage period [(final day of prescription coverage+the days supplied)-first day of prescription coverage], average daily morphine milligram equivalents (MME) over the coverage period, and concurrent days covered by an opioid and a prescription for benzodiazepines, sedatives, or hypnotics.

RESULTS

A total of 53.5% of the cohort (269 individuals) filled at least 1 opioid prescription during their second or third year after SCI. In total, there were 3386 opioid fills during the 2-year study. On average, the total number of opioid prescription days was 293±367. The average coverage period was 389±290 days, and the average daily MME during the coverage period was 41±70 MME. Of those who filled an opioid prescription, 23% had high-risk fills (>50 MME), and 38% had concurrent prescriptions for benzodiazepines, sedatives, or hypnotics.

CONCLUSIONS

The prevalence of opioid use was high among individuals with chronic SCI, exceeding rates observed in the general population. Also concerning were the rates of high-risk fills, based on average daily MME and concurrent benzodiazepine, sedative, or hypnotic prescriptions. These findings, taken together with those of earlier studies, should be used by providers to assess and monitor opioid use, decrease concurrent high-risk medication use, and attenuate the risk of adverse outcomes.

Neuropathic pain in spinal cord injury: topical analgesics as a possible treatment

STUDY DESIGN

Review of the literature and semi-structured interviews.

OBJECTIVE

To explore the possible use of topical analgesics for the treatment of neuropathic pain (NP) in spinal cord injury (SCI).

SETTING

Institute for Neuropathic Pain, Soest, The Netherlands.

METHODS

A review was performed of studies on topical analgesics for SCI-related NP published up to May 2019. In addition, eight persons with SCI-related NP who were treated with topical analgesics were interviewed in a semi-structured interview on their experience with topical analgesics.

RESULTS

Seven studies (five case reports and two case series) were found that evaluated the use of topical analgesics for SCI-related NP. None of the studies used a control treatment. Topical analgesics included baclofen, ketamine, lidocaine, capsaicin, and isosorbide dinitrate. All studies reported a decrease in NP over time. Persons interviewed were 49-72 years of age and all but one had an incomplete SCI. They used topical agents containing phenytoin, amitriptyline, baclofen, ketamine or loperamide. All showed a decrease in pain of at least 3 points on the 11-point numeric rating scale during this treatment.

DISCUSSION/CONCLUSIONS

Evidence on the use of topical analgesics in SCI is scarce. Case reports, case series and interviews suggest that the use of topical analgesics can be beneficial in treating SCI-related NP. Placebo-controlled studies are required to investigate the effect of topical analgesics on SCI-related NP.

French recommendations for the management of patients with spinal cord injury or at risk of spinal cord injury

OBJECTIVES

To update the French guidelines on the management of trauma patients with spinal cord injury or suspected spinal cord injury.

DESIGN

A consensus committee of 27 experts was formed. A formal conflict-of-interest (COI) policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e. pharmaceutical, medical devices). The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised.

METHODS

The committee studied twelve questions: (1) What are the indications and arrangements for spinal immobilisation? (2) What are the arrangements for pre-hospital orotracheal intubation? (3) What are the objectives of haemodynamic resuscitation during the lesion assessment, and during the first few days in hospital? (4) What is the best way to manage these patients to improve their long-term prognosis? (5) What is the place of corticosteroid therapy in the initial phase? (6) What are the indications for magnetic resonance imaging in the lesion assessment phase? (7) What is the optimal time for surgical management? (8) What are the best arrangements for orotracheal intubation in the hospital environment? (9) What are the specific conditions for weaning these patients from mechanical ventilation for? (10) What are the procedures for analgesic treatment of these patients? (11) What are the specific arrangements for installing and mobilising these patients? (12) What is the place of early intermittent bladder sampling in these patients? Each question was formulated in a PICO (Patients, Intervention, Comparison, Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® Methodology.

RESULTS

The experts' work synthesis and the application of the GRADE method resulted in 19 recommendations. Among the recommendations formalised, 2 have a high level of evidence (GRADE 1+/-) and 12 have a low level of evidence (GRADE 2+/-). For 5 recommendations, the GRADE method could not be applied, resulting in expert advice. After two rounds of scoring and one amendment, strong agreement was reached on all the recommendations.

CONCLUSIONS

There was significant agreement among experts on strong recommendations to improve practices for the management of patients with spinal cord injury.

Therapeutic use of cannabis and cannabinoids: an evidence mapping and appraisal of systematic reviews

BACKGROUND

Although cannabis and cannabinoids are widely used with therapeutic purposes, their claimed efficacy is highly controversial. For this reason, medical cannabis use is a broad field of research that is rapidly expanding. Our objectives are to identify, characterize, appraise, and organize the current available evidence surrounding therapeutic use of cannabis and cannabinoids, using evidence maps.

METHODS

We searched PubMed, EMBASE, The Cochrane Library and CINAHL, to identify systematic reviews (SRs) published from their inception up to December 2017. Two authors assessed eligibility and extracted data independently. We assessed methodological quality of the included SRs using the AMSTAR tool. To illustrate the extent of use of medical cannabis, we organized the results according to identified PICO questions using bubble plots corresponding to different clinical scenarios.

RESULTS

A total of 44 SRs published between 2001 and 2017 were included in this evidence mapping with data from 158 individual studies. We extracted 96 PICO questions in the following medical conditions: multiple sclerosis, movement disorders (e.g. Tourette Syndrome, Parkinson Disease), psychiatry conditions, Alzheimer disease, epilepsy, acute and chronic pain, cancer, neuropathic pain, symptoms related to cancer (e.g. emesis and anorexia related with chemotherapy), rheumatic disorders, HIV-related symptoms, glaucoma, and COPD. The evidence about these conditions is heterogeneous regarding the conclusions and the quality of the individual primary studies. The quality of the SRs was moderate to high according to AMSTAR scores.

CONCLUSIONS

Evidence on medical uses of cannabis is broad. However, due to methodological limitations, conclusions were weak in most of the assessed comparisons. Evidence mapping methodology is useful to perform an overview of available research, since it is possible to systematically describe the extent and distribution of evidence, and to organize scattered data.

Benefits and harms of medical cannabis: a scoping review of systematic reviews

BACKGROUND

There has been increased interest in the role of cannabis for treating medical conditions. The availability of different cannabis-based products can make the side effects of exposure unpredictable. We sought to conduct a scoping review of systematic reviews assessing benefits and harms of cannabis-based medicines for any condition.

METHODS

A protocol was followed throughout the conduct of this scoping review. A protocol-guided scoping review conduct. Searches of bibliographic databases (e.g., MEDLINE®, Embase, PsycINFO, the Cochrane Library) and gray literature were performed. Two people selected and charted data from systematic reviews. Categorizations emerged during data synthesis. The reporting of results from systematic reviews was performed at a high level appropriate for a scoping review.

RESULTS

After screening 1975 citations, 72 systematic reviews were included. The reviews covered many conditions, the most common being pain management. Several reviews focused on management of pain as a symptom of conditions such as multiple sclerosis (MS), injury, and cancer. After pain, the most common symptoms treated were spasticity in MS, movement disturbances, nausea/vomiting, and mental health symptoms. An assessment of review findings lends to the understanding that, although in a small number of reviews results showed a benefit for reducing pain, the analysis approach and reporting in other reviews was sub-optimal, making it difficult to know how consistent findings are when considering pain in general. Adverse effects were reported in most reviews comparing cannabis with placebo (49/59, 83%) and in 20/24 (83%) of the reviews comparing cannabis to active drugs. Minor adverse effects (e.g., drowsiness, dizziness) were common and reported in over half of the reviews. Serious harms were not as common, but were reported in 21/59 (36%) reviews that reported on adverse effects. Overall, safety data was generally reported study-by-study, with few reviews synthesizing data. Only one review was rated as high quality, while the remaining were rated of moderate (n = 36) or low/critically low (n = 35) quality.

CONCLUSIONS

Results from the included reviews were mixed, with most reporting an inability to draw conclusions due to inconsistent findings and a lack of rigorous evidence. Mild harms were frequently reported, and it is possible the harms of cannabis-based medicines may outweigh benefits.

SYSTEMATIC REVIEW REGISTRATION

The protocol for this scoping review was posted in the Open Access (https://ruor.uottawa.ca/handle/10393/37247).

Effect of vitamins C and E on recovery of motor function after spinal cord injury: systematic review and meta-analysis of animal studies

Context

Many animal studies have evaluated the role of vitamins in the recovery of motor function after spinal cord injury, but their results have been contradictory and no consensus has been reached.

Objective

This meta-analysis aimed to investigate the effects of vitamin C and vitamin E on recovery of motor function after spinal cord injury in animal models.

Data Sources

Two authors independently collected the records of relevant articles published in MEDLINE, Embase, Scopus, and Web of Science through November 2018.

Study Selection

All studies conducted in animal models to evaluate the therapeutic effects of vitamin C or vitamin E or both on recovery of motor function after spinal cord injury were included. Studies that lacked a control group or a standard treatment, lacked an assessment of motor function, included genetically modified/engineered animals, included animals pretreated with vitamin C or vitamin E, or combined vitamin treatment with other methods, such as cell therapies, were excluded.

Data Extraction

Data from 10 articles met the inclusion criteria for meta-analysis, conducted in accordance with PRISMA guidelines.

Results

Daily supplementation with vitamin C (P &lt; 0.0001) and vitamin E (P &lt; 0.0001) significantly improved the recovery of motor function in animals affected by spinal cord injury. Vitamin C supplementation is effective only when administered intraperitoneally (P &lt; 0.0001). Concurrent supplementation with both vitamins does not show better efficacy than treatment with either one alone.

Conclusion

Administration of vitamin C and vitamin E in animal models of spinal cord injury significantly improves the recovery of motor function.

Management of pain in individuals with spinal cord injury: Guideline of the German-Speaking Medical Society for Spinal Cord Injury

Introduction: Pain is a prominent complication in spinal cord injury (SCI). It can either occur as a direct or as an indirect consequence of SCI and it often heavily influences the quality of life of affected individuals. In SCI, nociceptive and neuropathic pain can equally emerge at the same time above or below the level of injury. Thus, classification and grading of pain is frequently difficult. Effective treatment of SCI-related pain in general and of neuropathic pain in particular is challenging. Current treatment options are sparse and their evidence is considered to be limited. Considering these aspects, a clinical practice guideline was developed as basis for an optimized, comprehensive and standardized pain management in SCI-related pain.

Methods: The German-Speaking Medical Society for Spinal Cord Injury (Deutschsprachige Medizinische Gesellschaft für Paraplegiologie – DMGP) developed a clinical practice guideline that received consensus from seven further German-speaking medical societies and one patient organization. The evidence base from clinical trials and meta-analyses was summarized and subjected to a structured consensus-process in accordance with the regulations of the Association of Scientific Medical Societies in Germany (AWMF) and the methodological requirements of the “German instrument for methodological guideline appraisal”.

Results: This consensus-based guideline (S2k classification according to the AWMF guidance manual and rules) resulted in seven on-topic statements and 17 specific recommendations relevant to the classification, assessment and therapy of pain directly or indirectly caused by SCI. Recommended therapeutic approaches comprise pharmacological (e.g. nonsteroidal anti-inflammatory drugs or anticonvulsants) and non-pharmacological (e.g. physical activity or psychotherapeutic techniques) strategies for both nociceptive and neuropathic pain.

Discussion: Assessment of SCI-related pain is standardized and respective methods in terms of examination, classification and grading of pain are already in use and validated in German language. In contrast, valid, evidence-based and efficient therapeutic options are limited and ask for further clinical studies, ideally randomized controlled trials and meta-analyses.

Medicate or Meditate? Greater Pain Acceptance is Related to Lower Pain Medication Use in Persons With Chronic Pain and Spinal Cord Injury

OBJECTIVES

There is little information about whether use of pain self-management skills that are common targets of psychosocial interventions for pain are associated with reduced reliance on pain medications. The aim of this study was to test whether higher chronic pain acceptance, which is a readily modified pain self-management approach, is related to lower use of pain medications (eg, opioid medications, and gabapentinoids) in a sample with chronic pain and spinal cord injury (SCI).

MATERIALS AND METHODS

This is a cross-sectional survey study of pain medication use, pain severity and distribution (Brief Pain Inventory [BPI]), depressive symptoms (Patient Health Questionnaire-9 [PHQ-9]), and chronic pain acceptance (Chronic Pain Acceptance Questionnaire [CPAQ]) administered to a sample of 120 adults with chronic pain and SCI.

RESULTS

Regression results indicated that, above and beyond the effects of pain intensity, pain distribution, and depressive symptoms, higher pain acceptance was related to lower use of all types of pain medications, and lower odds of using opioid medications or gabapentinoids. Pain intensity was not related to pain medication use, but greater pain distribution was related to using more pain medications in general and to greater odds of using gabapentinoids.

DISCUSSION

Findings from this study indicate that those with chronic pain and SCI who have a more accepting orientation to pain are less reliant on pain medications, and thereby experience lower risks associated with medication consumption. Longitudinal, daily process, and clinical trial studies are needed to better understand the association between pain acceptance and pain medication consumption.

Pilot study of feasibility and effect of anodal transcutaneous spinal direct current stimulation on chronic neuropathic pain after spinal cord injury

STUDY DESIGN

A single-blind crossover study.

OBJECTIVES

This study aimed to evaluate neuropathic pain in persons with spinal cord injury (SCI) after the application of transcutaneous spinal direct current stimulation (tsDCS).

SETTING

Outpatient Clinic of the Rehabilitation Department, Seoul National University Hospital.

METHODS

The effect of single sessions of both anodal and sham tsDCS (2 mA, 20 min) on chronic neuropathic pain in ten volunteers with complete motor cervical SCI was assessed. The active electrode was placed over the spinal process of the tenth thoracic vertebra and the reference electrode, at the top of the head. Pre- to post-tsDCS intervention changes in pain intensity (numeric rating scale, NRS), patient global assessment, and present pain intensity (PPI) were assessed before and after the tsDCS session (immediately post stimulation, and at 1 and 2 h post stimulation).

RESULTS

All participants underwent the stimulation procedure without dropout. Our results showed no significant pre- to post-treatment difference in pain intensity between the active and sham tsDCS groups. Only in the sham tsDCS stimulation, NRS and PPI scores were reduced after the stimulation session. Furthermore, in the mixed effect model analysis, the response in the second period appeared to be more favorable.

CONCLUSION

The results suggest that a single session of anodal tsDCS with the montage used in this study is feasible but does not have a significant analgesic effect in individuals with chronic cervical SCI.

SPONSORSHIP

The study was funded by Seoul National University Hospital (No. 0420160470) and Korea Workers' Compensation & Welfare Service.

Spinal Cord Stimulation for Pain Treatment After Spinal Cord Injury

In addition to restoration of bladder, bowel, and motor functions, alleviating the accompanying debilitating pain is equally important for improving the quality of life of patients with spinal cord injury (SCI). Currently, however, the treatment of chronic pain after SCI remains a largely unmet need. Electrical spinal cord stimulation (SCS) has been used to manage a variety of chronic pain conditions that are refractory to pharmacotherapy. Yet, its efficacy, benefit profiles, and mechanisms of action in SCI pain remain elusive, due to limited research, methodological weaknesses in previous clinical studies, and a lack of mechanistic exploration of SCS for SCI pain control. We aim to review recent studies and outline the therapeutic potential of different SCS paradigms for traumatic SCI pain. We begin with an overview of its manifestations, classification, potential underlying etiology, and current challenges for its treatment. The clinical evidence for using SCS in SCI pain is then reviewed. Finally, future perspectives of pre-clinical research and clinical study of SCS for SCI pain treatment are discussed.

The level of evidence of medical marijuana use for treating disabilities: a scoping review

Purpose: Twenty-nine states have bypassed federal regulations by legalizing marijuana (MJ) either medicinally, recreationally or both. The FDA states that there is no empirical evidence that MJ is effective to treat these disorders. With over a billion individuals living with a disability across the globe, it is crucial to fully research the efficaciousness and safety of medical MJ to treat this population. The purpose to present the results of a scoping review of studies focused on the levels of evidence currently available on medical MJ's efficacy in treatment across a large range of disabilities.Methods: Databases were searched for research articles on the current level of evidence to support medical MJ use among people with disabilities.Results: Forty-one peer reviewed articles met the inclusion criteria. Articles focused on attention deficit hyperactivity disorder, post-traumatic stress disorder, depression, schizophrenia, spinal cord injury, multiple sclerosis/movement disorders, fibromyalgia, epilepsy, with some that focused on multiple disabilities.Conclusions: The level of evidence for the use of medical MJ among people with disabilities varies greatly, and has a clear lack of methodologically sound studies. Overall, medical MJ does not improve the level of functioning, but it may improve the overall quality of life for people with disabilities.Implications for RehabilitationEpilepsy can be a disabling chronic disorder which not only impacts physically but can restricts quality of life.Quality of life is diminished even more with treatment resistant epilepsy.Chronic pain is the leading cause of disability and is the most common cause of long-term disability.There is sufficient evidence that medical marijuana is effective in treating epileptic seizures and chronic pain.Medical marijuana may improve the level of functioning and quality of life for individuals with certain disabilities.

Synchrotron Radiation Imaging Reveals the Role of Estrogen in Promoting Angiogenesis After Acute Spinal Cord Injury in Rats

STUDY DESIGN

The efficacy of estrogen on vessel angiogenesis in acute spinal cord injury (SCI) in a rat model was evaluated by synchrotron radiation.

OBJECTIVE

Here, we investigate the change in injured spinal cord vessels and used the synchrotron radiation to investigate the effect of estrogen on vessel angiogenesis and functional recovery in a rat model of SCI.

SUMMARY OF BACKGROUND DATA

The promotion of angiogenesis after SCI may be a therapeutic target in the treatment of SCI. Estrogen has been reported to improve locomotor recovery after SCI. However, how estrogen regulates angiogenesis in acute SCI and enhances neurological functional recovery has not been fully characterized.

METHODS

Synchrotron radiation imaging combined with histological methods was used to image angiogenesis in acute spinal cord treatment with estrogen in rats.

RESULTS

Synchrotron radiation imaging vividly demonstrated three-dimensional vessel changes in the spinal cord after injury. The imaging showed that vessel number, vessel volume fraction, and vessel connectivity value in the groups treated with estrogen after SCI were significantly increased compared to control groups (P < 0.05). Vessel angiogenesis increased in groups treated with estrogen compared with control rats, which was confirmed with histological staining. Estrogen treatment also attenuated the injury-induced lesion area compared with control groups and improved locomotor functional recovery after SCI.

CONCLUSION

The results indicated that synchrotron radiation is a powerful imaging tool for visualizing angiogenesis after acute SCI. Estrogen treatment exerted a neuroprotective effect on acute SCI treatment by promoting angiogenesis and reducing the injury-induced lesion area could be recommended as a potential preclinical treatment approach for acute SCI.

LEVEL OF EVIDENCE

N/A.

The reliability of end of day and ecological momentary assessments of pain and pain interference in individuals with spinal cord injury

PURPOSE

This study investigated the most efficient means of measuring pain intensity and pain interference comparing ecological momentary assessment (EMA) to end of day (EOD) data, with the highest level of measurement reliability as examined in individuals with spinal cord injury.

METHODS

EMA (five times throughout the day) and EOD ratings of pain and pain interference were collected over a 7-day period. Multilevel models were used to examine the reliability for both EOD and EMA assessments in order to determine the amount of variability in these assessments over the course of a week or the day, and a multilevel version of the Spearman-Brown Prophecy formula was used to estimate values for reliability.

RESULTS

Findings indicate the minimum of number of EOD and EMA assessments needed to achieve different levels of reliability ("adequate" > 0.70, "good" > 0.80 and excellent > 0.90). In addition, the time of day (either morning, midday or evening) did not impact the estimated reliability for the EMA assessments.

CONCLUSIONS

These findings can help researchers and clinician balance the cost/benefit tradeoffs of these different types of assessments by providing specific cutoffs for the numbers of each type of assessment that are needed to achieve excellent reliability.

Opioids should not be prescribed for chronic pain after spinal cord injury

Most people with spinal cord injury (SCI) have chronic pain and effective treatments have not been identified. Within the first two decades of the 21st century, opioids have been commonly prescribed in an attempt to manage pain after SCI, however, the risks and absence of benefit of opioids have become more apparent as opioid crises have developed around the world. This perspective is an argument for why opioids should no longer be prescribed to treat chronic pain after SCI.

Severe chronic pain following spinal cord damage: a pragmatic perspective for prescribing opioids

The controversial issue of prescribing opioids to people with spinal cord damage who have severe pain is discussed in this paper. The reasons for concern regarding the increase in opioid prescription over recent years are outlined, along with a summary of the major potential adverse outcomes associated with opioids, such as falls, respiratory suppression, adverse endocrine effects, cognitive impairment, and the potential for opioid abuse, addiction and death. Situations when opioids are more appropriate are considered to be in the immediate post-trauma or post-operative periods. More controversial is the use of opioids in chronic non-cancer pain. A brief review of the evidence regarding opioids in chronic non-cancer pain is presented, and strategies outlined for reducing the risk of adverse consequences from opioid use in chronic non-cancer pain. These strategies include considerations before starting opioids, during initiation, monitoring activities and the cessation process. A vital consideration before starting opioids includes ensuring that all alternatives to opioids have been fully considered and trialled. Finally, some pragmatic proposals for prescribing opioids in people with SCD are suggested. It is recommended that before opioids are commenced, that the informed consent process should be complimented by a treatment agreement, with an initial 4-week trial period, and close monitoring of established goals.

Spinal Cord Injury: How Could Acupuncture Help?

Spinal cord injury (SCI) is one of the most common causes of death and disability worldwide, and it can result in both permanent disability and serial complications in patients. Research shows that patients with SCI complications are often interested in acupuncture for symptomatic relief. Therefore, the issue of physicians advising their patients regarding the use of acupuncture to alleviate SCI complications becomes pertinent. We review and summarize two types of relevant publications: (1) literature concerning acupuncture for SCI and its complications and (2) underlying mechanisms of acupuncture therapy for SCI. Clinical trials and reviews have suggested that acupuncture effectively manages a range of post-SCI complications, including motor and sensory dysfunction, pain, neurogenic bowel and bladder, pressure ulcers, spasticity, and osteoporosis. The effect of acupuncture on post-SCI orthostatic hypotension and sexual dysfunction remains unclear. Decreased oxidative stress, inhibition of inflammation and neuronal apoptosis, regulation of the expression and activity of endogenous biological mediators, and increased regenerative stem cell production are the possible mechanisms of acupuncture therapy for SCI. Although many limitations have been reported in previous studies, given the evidence for the efficacy of acupuncture, we recommend that physicians should support the use of acupuncture therapy for SCI complications.

TRPA1 polymorphisms in chronic and complete spinal cord injury patients with neuropathic pain: a pilot study

Study design

Pilot study.

Objectives

Single-nucleotide polymorphisms (SNPs) in TRPA1 gene are related to the etiology of chronic pain. The study is a pilot study with the primary objective of analyzing these SNPs in Spanish patients with chronic and complete spinal cord injury (SCI) and neuropathic pain (NPP).

Setting

Asepeyo Hospital Department of Chronic and Complete SCI.

Methods

Twelve patients with chronic and complete SCI and NPP, and 12 patients with chronic and complete SCI with no pain were reviewed. International Spinal Cord Injury Pain Classification (LANSS) and visual analog score (VAS) were chosen to classify pain syndrome. SNPs were identified by melting analysis after DNA amplification with real-time fluorescence PCR.

Results

There were differences in rs11988795 variant: GG homozygous (p = 0.01) and G allele (p = 0.001) were more frequent in SCI patients with no pain. There were differences in rs13255063 variant: TT homozygous were prevalent (p = 0.03) in patients with NPP.

Conclusions

Until now this is the first study to show a description of TRPA1 SNPs in Spanish patients with chronic and complete SCI and NPP. These results suggest that GG genotype in rs11988795 variant and G allele could be protective factors against NPP. TT genotype in rs13255063 variant could be a risk factor for NPP. Neuropathic pain after spinal cord injuries may have genetic contributions.

Transplantation of olfactory ensheathing cells on functional recovery and neuropathic pain after spinal cord injury; systematic review and meta-analysis

There are considerable disagreements on the application of olfactory ensheathing cells (OEC) for spinal cord injury (SCI) rehabilitation. The present meta-analysis was designed to investigate the efficacy of OEC transplantation on motor function recovery and neuropathic pain alleviation in SCI animal models. Accordingly, all related studies were identified and included. Two independent researchers assessed the quality of the articles and summarized them by calculating standardized mean differences (SMD). OEC transplantation was shown to significantly improve functional recovery (SMD = 1.36; 95% confidence interval: 1.05–1.68; p < 0.001). The efficacy of this method was higher in thoracic injuries (SMD = 1.41; 95% confidence interval: 1.08–1.74; p < 0.001) and allogeneic transplants (SMD = 1.53; 95% confidence interval: 1.15–1.90; p < 0.001). OEC transplantation had no considerable effects on the improvement of hyperalgesia (SMD = −0.095; 95% confidence interval: −0.42–0.23; p = 0.57) but when the analyses were limited to studies with follow-up ≥8 weeks, it was associated with increased hyperalgesia (SMD = −0.66; 95% confidence interval: −1.28–0.04; p = 0.04). OEC transplantation did not affect SCI-induced allodynia (SMD = 0.54; 95% confidence interval: −0.80–1.87; p = 0.43). Our findings showed that OEC transplantation can significantly improve motor function post-SCI, but it has no effect on allodynia and might lead to relative aggravation of hyperalgesia.

Success with neurotropin in treating pediatric lower extremity pain induced by spinal cord injury after epidural anesthesia

Spinal cord injury (SCI) complicated by epidural anesthesia, though rare, can result in neuropathic pain. However, the treatment for this kind of life-altering injury remains a challenge. A 7-year-old girl was referred with dyskinesia and severe pain in her right lower extremity due to an accidental SCI following lumbar puncture. After treatment with analgesics such as gabapentin, mecobalamin, and dexamethasone/methylprednisolone for 1 week, the myodynamia had improved, but progressive pain persisted. After treatment with neurotropin, a gradual decrease in visual analog scale score from 7 to 0 was observed. We herein first describe that neurotropin produced sustained relief of pain induced by SCI. This case suggests that neurotropin might be a promising drug in treating pediatric neuropathic pain caused by SCI.

Exploring acute-to-chronic neuropathic pain in rats after contusion spinal cord injury

Spinal cord injury (SCI) causes chronic pain in 65% of individuals. Unfortunately, current pain management is inadequate for many SCI patients. Rodent models could help identify how SCI pain develops, explore new treatment strategies, and reveal whether acute post-SCI morphine worsens chronic pain. However, few studies explore or compare SCI-elicited neuropathic pain in rats. Here, we sought to determine how different clinically relevant contusion SCIs in male and female rats affect neuropathic pain, and whether acute morphine worsens later chronic SCI pain. First, female rats received sham surgery, or 150kDyn or 200kDyn midline T9 contusion SCI. These rats displayed modest mechanical allodynia and long-lasting thermal hyperalgesia. Next, a 150kDyn (1s dwell) midline contusion SCI was performed in male and female rats. Interestingly, males, but not females showed SCI-elicited mechanical allodynia; rats of both sexes had thermal hyperalgesia. In this model, acute morphine treatment had no significant effect on chronic neuropathic pain symptoms. Unilateral SCIs can also elicit neuropathic pain that could be exacerbated by morphine, so male rats received unilateral T13 contusion SCI (100kDyn). These rats exhibited significant, transient mechanical allodynia, but not thermal hyperalgesia. Acute morphine did not exacerbate chronic pain. Our data show that specific rat contusion SCI models cause neuropathic pain. Further, chronic neuropathic pain elicited by these contusion SCIs was not amplified by our course of early post-trauma morphine. Using clinically relevant rat models of SCI could help identify novel pain management strategies.

Lipoxin A4 inhibits microglial activation and reduces neuroinflammation and neuropathic pain after spinal cord hemisection

BACKGROUND

Spinal cord injury (SCI) is a severe neurological disorder with many disabling consequences, including persistent neuropathic pain, which develops in about 40 % of SCI patients and is induced and sustained by excessive and uncontrolled spinal neuroinflammation. Here, we have evaluated the effects of lipoxin A4 (LXA4), a member of a unique class of endogenous lipid mediators with both anti-inflammatory and analgesic properties, on spinal neuroinflammation and chronic pain in an experimental model of SCI.

METHODS

Spinal hemisection at T10 was carried out in adult male CD1 mice and Wistar rats. To test if LXA4 can reduce neuroinflammation and neuropathic pain, each animal received two intrathecal injections of LXA4 (300 pmol) or vehicle at 4 and 24 h after SCI. Sensitivity to mechanical stimulation of the hind paws was evaluated using von Frey monofilaments, and neuroinflammation was tested by measuring the mRNA and/or protein expression levels of glial markers and cytokines in the spinal cord samples after SCI. Also, microglia cultures prepared from murine cortical tissue were used to assess the direct effects of LXA4 on microglial activation and release of pro-inflammatory TNF-α.

RESULTS

LXA4 treatment caused significant reductions in the intensity of mechanical pain hypersensitivity and spinal expression levels of microglial markers and pro-inflammatory cytokines induced by SCI, when compared to rodents receiving control vehicle injections. Notably, the increased expressions of the microglial marker IBA-1 and of the pro-inflammatory cytokine TNF-α were the most affected by the LXA4 treatment. Furthermore, cortical microglial cultures expressed ALX/FPR2 receptors for LXA4 and displayed potentially anti-inflammatory responses upon challenge with LXA4.

CONCLUSIONS

Collectively, our results suggest that LXA4 can effectively modulate microglial activation and TNF-α release through ALX/FPR2 receptors, ultimately reducing neuropathic pain in rodents after spinal cord hemisection. The dual anti-inflammatory and analgesic properties of LXA4, allied to its endogenous nature and safety profile, may render this lipid mediator as new therapeutic approach for treating various neuroinflammatory disorders and chronic pain with only limited side effects.