Characteristics of neuropathic pain in patients with spinal cord injury

Post-discharge follow-up of patients with spine trauma in the National Spinal Cord Injury Registry of Iran during the COVID-19 pandemic: Challenges and lessons learned

PURPOSE

The purpose of the National Spinal Cord Injury Registry of Iran (NSCIR-IR) is to create an infrastructure to assess the quality of care for spine trauma and in this study, we aim to investigate whether the NSCIR-IR successfully provides necessary post-discharge follow-up data for these patients.

METHODS

An observational prospective study was conducted from April 11, 2021 to April 22, 2022 in 8 centers enrolled in NSCIR-IR, respectively Arak, Rasht, Urmia, Shahroud, Yazd, Kashan, Tabriz, and Tehran. Patients were classified into 3 groups based on their need for care resources, respectively: (1) non-spinal cord injury (SCI) patients without surgery (group 1), (2) non-SCI patients with surgery (group 2), and (3) SCI patients (group 3). The assessment tool was a self-designed questionnaire to evaluate the care quality in 3 phases: pre-hospital, in-hospital, and post-hospital. The data from the first 2 phases were collected through the registry. The post-hospital data were collected by conducting follow-up assessments. Telephone follow-ups were conducted for groups 1 and 2 (non-SCI patients), while group 3 (SCI patients) had a face-to-face visit. This study took place during the COVID-19 pandemic. Data on age and time interval from injury to follow-up were expressed as mean ± standard deviation (SD) and response rate and follow-up loss as a percentage.

RESULTS

Altogether 1538 telephone follow-up records related to 1292 patients were registered in the NSCIR-IR. Of the total calls, 918 (71.05%) were related to successful follow-ups, but 38 cases died and thus were excluded from data analysis. In the end, post-hospital data from 880 patients alive were gathered. The success rate of follow-ups by telephone for groups 1 and 2 was 73.38% and 67.05% respectively, compared to 66.67% by face-to-face visits for group 3, which was very hard during the COVID-19 pandemic. The data completion rate after discharge ranged from 48% - 100%, 22% - 100% and 29% - 100% for groups 1 - 3.

CONCLUSIONS

To improve patient accessibility, NSCIR-IR should take measures during data gathering to increase the accuracy of registered contact information. Regarding the loss to follow-ups of SCI patients, NSCIR-IR should find strategies for remote assessment or motivate them to participate in follow-ups through, for example, providing transportation facilities or financial support.

Gut Microbiota Modulation and Its Implications on Neuropathic Pain: A Comprehensive Literature Review

Neuropathic pain (NP) is a chronic pain disorder arising from somatosensory nervous system impairment. Extensive evidence supports the notion that the gut microbiota (GM) is crucial in maintaining human health by performing vital tasks. At the same time, its disruption has been linked to the emergence and advancement of an expanding range of disorders, including NP, in which GM could play a role in its pathophysiology. The crosstalk between the nervous system and GM happens through immune mediators, metabolites, and nervous structures and involves both central and peripheral nervous systems. This literature review aims to thoroughly investigate the function of modulating GM in the treatment of NP. It will achieve this by integrating existing knowledge, identifying underlying mechanisms, and evaluating the possible clinical consequences of exploiting the gut-brain axis. We will cover the main therapeutic applications of the described GM-modulators, such as probiotics, faecal microbiota transplantation, dietary supplements and emotional support, to the main kinds of NP in which any evidence, even if only pre-clinical, has been unravelled in recent years. The explored NP areas include chemotherapy-induced peripheral neuropathy, diabetic neuropathy, trauma-induced neuropathic pain, trigeminal neuralgia, postherpetic neuralgia and low back pain.

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

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

The occurrence of neuropathic pain following surgery of brainstem cavernous malformations

BACKGROUND AND PURPOSE

This study aimed to assess the occurrence and significance of postoperative neuropathic pain (NP) in patients with surgically treated brainstem cavernous malformations (BSCMs).

METHODS

Seventy-four BSCM patients surgically treated between 2003 and 2019 were reviewed for the occurrence of postoperative NP and related treatment. The relevance of BSCM location, preoperative characteristics, influence on functional outcome, postoperative health-related quality of life (HRQOL) and life satisfaction was evaluated.

RESULTS

Six out of 74 patients (8%) suffered from NP. The Leeds Assessment of Neuropathic Symptoms and Signs scores ranged from 12 to 16 (mean 14.28 ± 1.6). Visual analog scale pain was 5.2 ± 2.0. NP had no effect on preoperative characteristics or functional outcome. Bodily pain (HRQOL) and vocational time (life satisfaction) were significantly decreased in NP compared to non-NP patients. Specific BSCM location (regarding brainstem nuclei involved in pain processing) and other preoperative patient- and BSCM-related parameters were not associated with the occurrence of postoperative NP. Three out of six patients were currently under NP-specific treatment. The proportion of patients suffering from postoperative NP (8%) was substantially higher compared to previously published studies. The pain affected the HRQOL of patients, most of whom were insufficiently treated and not satisfied with treatment results.

CONCLUSION

Our findings may help to raise awareness for postoperative NP in BSCM, which is essential to improve diagnosis and initiation of proper treatment, as well as preoperative informed consent of patients.

Synthesis and Evaluation of Novel α-Aminoamides Containing Benzoheterocyclic Moiety for the Treatment of Pain

Novel α-aminoamide derivatives containing different benzoheterocyclics moiety were synthesized and evaluated as voltage-gated sodium ion channels blocks the treatment of pain. Compounds 6a, 6e, and 6f containing the benzofuran group displayed more potent in vivo analgesic activity than ralfinamide in both the formalin test and the writhing assay. Interestingly, they also exhibited potent in vitro anti-Na_v1.7 and anti-Na_v1.8 activity in the patch-clamp electrophysiology assay. Therefore, compounds 6a, 6e, and 6f, which have inhibitory potency for two pain-related Na_v targets, could serve as new leads for the development of analgesic medicines.

Prevalence and Characteristics of Neuropathic Pain in Patients With Spinal Cord Injury Referred to a Rehabilitation Center

OBJECTIVE

To identify the prevalence and characteristics of neuropathic pain (NP) in patients with spinal cord injury (SCI) and to investigate associations between NP and demographic or disease-related variables.

METHODS

We retrospectively reviewed medical records of patients with SCI whose pain was classified according to the International Spinal Cord Injury Pain classifications at a single hospital. Multiple statistical analyses were employed. Patients aged <19 years, and patients with other neurological disorders and congenital conditions were excluded.

RESULTS

Of 366 patients, 253 patients (69.1%) with SCI had NP. Patients who were married or had traumatic injury or depressive mood had a higher prevalence rate. When other variables were controlled, marital status and depressive mood were found to be predictors of NP. There was no association between the prevalence of NP and other demographic or clinical variables. The mean Numeric Rating Scale (NRS) of NP was 4.52, and patients mainly described pain as tingling, squeezing, and painful cold. Females and those with below-level NP reported more intense pain. An NRS cut-off value of 4.5 was determined as the most appropriate value to discriminate between patients taking pain medication and those who did not.

CONCLUSION

In total, 69.1% of patients with SCI complained of NP, indicating that NP was a major complication. Treatment planning for patients with SCI and NP should consider that marital status, mood, sex, and pain subtype may affect NP, which should be actively managed in patients with an NRS ≥4.5.

Poly(lactic-co-glycolic acid) nanomaterial-based treatment options for pain management: a review

Neuropathic pain is one of the most intense types of chronic pain; it constitutes a pervasive complaint throughout the public health system. With few effective treatments, it remains a significant challenge. Commercially available drugs for neuropathic pain are still limited and have disappointing efficacy. Therefore, chronic neuropathic pain imposes a tremendous burden on patients' quality of life. Recently, the introduction and application of nanotechnology in multiple fields has accelerated the development of new drugs. This review highlights the application of poly(lactic-co-glycolic acid) nanomaterial-based vehicles for drug delivery and how they improve the therapeutic outcomes for neuropathic pain treatment. Finally, future developments for pain research and effective management are presented.

An unusual presentation of neuropathic pain following cervical spinal cord injury: a case report

Background

We report a patient with unusual occipital neuropathic pain (at-level neuropathic pain) due to a small central cervical spinal cord injury (SCI).

Case presentation

A 50-year-old man presented with severe bilateral occipital pain after falling from a height of 2 m, 2 weeks ago. The degree of pain was evaluated to be 9 out of 10 using the numeric rating scale (NRS). The nature of the pain was tingling, burning, and piercing, and hyperalgesia was present over the bilateral posterior head regions. Greater occipital nerve block with bupivacaine and dexamethasone was not effective. On axial T2-cervical magnetic resonance imaging (MRI), a focal high signal change was observed in the central portion of the spinal cord at the C2 level. We deliberated that the patient’s pain was due to the SCI observed on MRI, and after administration of oral medications, the NRS pain score reduced from 9 to 2.

Conclusions

Neuropathic pain caused by SCI varies according to the location and degree of injury of the pain-related neural tracts; therefore, clinicians should closely observe the pain patterns and findings on imaging in patients with SCI to determine the cause of pain accurately.

Regional Hyperexcitability and Chronic Neuropathic Pain Following Spinal Cord Injury

Spinal cord injury (SCI) causes maladaptive changes to nociceptive synaptic circuits within the injured spinal cord. Changes also occur at remote regions including the brain stem, limbic system, cortex, and dorsal root ganglia. These maladaptive nociceptive synaptic circuits frequently cause neuronal hyperexcitability in the entire nervous system and enhance nociceptive transmission, resulting in chronic central neuropathic pain following SCI. The underlying mechanism of chronic neuropathic pain depends on the neuroanatomical structures and electrochemical communication between pre- and postsynaptic neuronal membranes, and propagation of synaptic transmission in the ascending pain pathways. In the nervous system, neurons are the only cell type that transmits nociceptive signals from peripheral receptors to supraspinal systems due to their neuroanatomical and electrophysiological properties. However, the entire range of nociceptive signaling is not mediated by any single neuron. Current literature describes regional studies of electrophysiological or neurochemical mechanisms for enhanced nociceptive transmission post-SCI, but few studies report the electrophysiological, neurochemical, and neuroanatomical changes across the entire nervous system following a regional SCI. We, along with others, have continuously described the enhanced nociceptive transmission in the spinal dorsal horn, brain stem, thalamus, and cortex in SCI-induced chronic central neuropathic pain condition, respectively. Thus, this review summarizes the current understanding of SCI-induced neuronal hyperexcitability and maladaptive nociceptive transmission in the entire nervous system that contributes to chronic central neuropathic pain.

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.

Environmental control of microRNAs in the nervous system: Implications in plasticity and behavior

The discovery of microRNAs (miRNAs) a little over 20 years ago was revolutionary given that miRNAs are essential to numerous physiological and physiopathological processes. Currently, several aspects of the biogenic process of miRNAs and of the translational repression mechanism exerted on their targets mRNAs are known in detail. In fact, the development of bioinformatics tools for predicting miRNA targets has established that miRNAs have the potential to regulate almost all known biological processes. Therefore, the identification of the signals and molecular mechanisms that regulate miRNA function is relevant to understanding the role of miRNAs in both pathological and adaptive processes. Recently, a series of studies has focused on miRNA expression in the brain, establishing that their levels are altered in response to various environmental factors (EFs), such as light, sound, odorants, nutrients, drugs and stress. In this review, we discuss how exposure to various EFs modulates the expression and function of several miRNAs in the nervous system and how this control determines adaptation to their environment, behavior and disease state.

NT-3 attenuates the growth of human neuron cells through the ERK pathway

Spinal cord injury is a devastating health problem that affects thousands of individuals each year. The neurons were destroyed. NT-3 is a recently discovered neurotrophin. This study sought to understand the potential involvement of MAPKs in NT-3-mediated growth inhibition of human neurons. We applied different concentrations of NT-3 and observed the growth rate of the cells and the changes in the phosphorylation state of the MAPKs ERK1/2, JNK and p38. This study discovered that NT-3-induced HNC growth was promoted primarily by phosphorylated ERK1/2, and that this phosphorylation, as well p90(rsk)phosphorylation, was mediated by TrkC. The ERK1/2 pathway is known to play an essential role in the NT-3-mediated growth of human neurons. In conclusion, our study suggests that NT-3 promotes the growth of human neurons cells primarily through the TrkC/ERK pathway.