Future Treatment of Neuropathic Pain in Spinal Cord Injury: The Challenges of Nanomedicine, Supplements or Opportunities?

Unveiling the effects of Rosa canina oligosaccharide liposome on neuropathic pain and motor dysfunction following spinal cord injury in rats: relevance to its antioxidative effects

Background

Spinal cord injury (SCI) is a leading cause of sensorimotor disorders, impacting millions of people globally. The absence of effective treatments and the side effects of existing medications highlight the need for innovative research into new therapeutic compounds.

Purpose

Given the critical role of oxidative stress in the development of SCI and the antioxidant properties of oligosaccharides in other neurological disorders, this study focuses on the role of oxidative stress in SCI and explores the potential of a novel oligosaccharide nanoformulation derived from Rosa canina (Oligo-L).

Materials and methods

Oligo-L was formulated using soy lecithin as the phospholipid and the characterization included size, zeta potential, morphology, and drug loading efficiency. Then 35 Wistar male rats were divided into five groups of Sham, SCI, and Oligo-L (10 μL intrathecal injection of 15, 30, and 45 mg/mL). An aneurysm clip was used to induce compression injury of the SCI and Oligo-L groups. Sensory-motor functions were evaluated weekly for 4 weeks using tests such as the BBB scale, inclined plane, acetone drop, hot plate, von Frey, and monitoring of weight changes. Additionally, oxidative stress markers and histological changes were examined to evaluate changes in nitrite, glutathione, catalase, and neuronal survival.

Results and discussion

The findings indicated that Oligo-L treatment led to significant improvements in neuropathic pain, and motor function performance and weight of the animals from the first week post-SCI. Oligo-L also enhanced catalase and glutathione levels while reducing serum nitrite levels, contributing to neuronal preservation. Additionally, Oligo-L increased neuronal survival in the both ventral (motor neurons) and dorsal (sensory neurons) horns of the spinal cord.

Conclusion

Overall, Oligo-L, characterized by its beneficial physicochemical properties, showed promising potential as a neuroprotective agent and facilitated the recovery of sensory and motor functions after SCI.

Effects of Percutaneous Electrical Stimulation on Chronic Neuropathic Pain: A Retrospective Observational Study

INTRODUCTION

Chronic pain affects millions worldwide, with 15% to 25% being neuropathic due to conditions like diabetic neuropathy and radiculopathy. Neuropathic pain, often described as burning or shooting, includes symptoms like allodynia, significantly impacting the quality of life and posing high economic costs. While pharmacological treatments are common, many patients require more invasive, costly interventions such as spinal cord stimulation. As an alternative, percutaneous electrical nerve stimulation (PENS) therapy (PT) offers a less invasive, cost-effective approach that can be administered outpatient, reducing hospitalization costs and providing psychological benefits like anxiety and stress relief.

AIM

This study aimed to compare the efficacy of PT in the short, medium, and long term in patients affected by chronic neuropathic pain, resistant to conventional pharmacological therapies, using a single active PT probe.

METHODS

A total of 100 patients were enrolled for the first PT procedure, and 190 procedures were performed from 2021 to 2023. Excluding those for whom pain could not be detected during follow-up, 41 patients were enrolled, to whom only one PT procedure was performed (Group I). Fourteen patients were enrolled, to whom two PT treatments were performed (Group II), and finally, eight patients were enrolled, to whom three or more PT treatments were performed (Group III). Therefore, a total of 63 patients were enrolled, and 106 PT procedures were performed with pain detected according to the Numeric Pain Scale (NRS) during the entire follow-up period. All patients who presented a trigger point and a specific nevus path or who presented a specific allodynic area caused by a surgical scar were treated.

RESULTS

The group of patients who showed a greater decrease in pain from T0 (baseline) to T1 (three hours after PT) were those who underwent two PT sessions (-52.7%, p = .001). The greatest percentage decrease between before the procedure and seven days after the PT was obtained in the group of patients who underwent three or more PT sessions (T0 4.9 vs. T2 2.9, -40.8%, p < .001). The same group of patients also showed the greatest decrease in pain four weeks after the PT (T0 4.9 vs. T3 3.1, -36.7%, p < .001).

CONCLUSION

PT appears to be an alternative therapy to pharmacological and infiltrative therapy against chronic neuropathic pain.

The Therapeutic Potential of MicroRNA-21 in the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) involves complex pathological processes that often result in significant and long-term neurological deficits. Increasingly, research has identified microRNA-21 (miR-21) as a pivotal regulator in SCI, with studies focusing on its roles in inflammation, apoptosis, and tissue repair. This review synthesizes current findings on miR-21's involvement in post-injury molecular events, emphasizing its interactions with regulatory targets such as Phosphatase and Tensin Homolog (PTEN) and Programmed Cell Death Protein 4 (PDCD4), as well as its broader effects on inflammatory and apoptotic signaling pathways. Evidence from both in vitro and in vivo studies suggests that modulating miR-21 influences lesion size, cellular dynamics, and functional recovery, highlighting its potential as a therapeutic target for SCI. Nonetheless, the clinical translation of miR-21-based therapies poses significant challenges, including the need to optimize dosages, delivery mechanisms, and long-term safety profiles. Further research is crucial to fully delineate miR-21's therapeutic potential and determine its feasibility for integration into SCI treatment protocols. This review aims to provide a comprehensive overview of miR-21's roles in SCI pathology, offering insights into the molecular mechanisms underlying recovery and the emerging potential of miR-21 in SCI management to enhance outcomes and quality of life for affected patients.

Comparative outcomes of microsurgical dorsal root entry zone lesioning (DREZotomy) for intractable neuropathic pain in spinal cord and cauda equina injuries

Treatment of neuropathic pain in patients with spinal cord injury (SCI) and cauda equina injury (CEI) remains challenging. Dorsal root entry zone lesioning (DREZL) or DREZotomy is a viable surgical option for refractory cases. This study aimed to compare DREZL surgical outcomes between patients with SCI and those with CEI and to identify predictors of postoperative pain relief. We retrospectively analyzed 12 patients (6 with SCI and 6 with CEI) with intractable neuropathic pain who underwent DREZL. The data collected were demographic characteristics, pain distribution, and outcomes assessed by numeric pain rating scores. Variables and percentages of pain improvement at 1 year and long-term were statistically compared between the SCI and CEI groups. The demographic characteristics and percentage of patients who experienced pain improvement at 1 year postoperatively did not differ between the groups. Compared with the SCI group, the CEI group presented significantly better long-term pain reduction (p = 0.020) and favorable operative outcomes (p = 0.015). Patients with border zone pain had significantly better long-term pain relief and outcomes than did those with diffuse pain (p = 0.008 and p = 0.010, respectively). Recurrent pain after DREZL occurred in the SCI group but not in the CEI group. DREZL provided superior pain relief in patients with CEI. The presence of border zone pain predicted favorable outcomes. CEI patients or SCI patients with border zone pain are good surgical candidates for DREZL, whereas SCI patients with below-injury diffuse pain are poor candidates.

To Be in Pain: Pain Multidimensional Questionnaire as Reliable Tool to Evaluate Multifaceted Aspects of Pain

Background/Objectives: Pain is a multidimensional experience influenced by sensory, emotional, and cognitive factors. Traditional pain assessments often fail to capture this complexity. This study aimed to develop and validate the Pain Multidimensional Questionnaire (Pa-M-QU), a new self-report tool designed to assess pain catastrophizing, sensitivity, and coping strategies. Methods: Two independent samples of Italian-speaking participants, aged 18 and above, were recruited online. The first sample (n = 392; mean age = 29.36) was used for exploratory factor analysis (EFA), and the second sample (n = 123; mean age = 28.0) for confirmatory factor analysis (CFA). Pearson's correlations and convergent validity analyses were conducted. Results: From an initial pool of 59 items identified through focus group discussions, 35 items were removed based on reliability analysis. The final 24-item Pa-M-QU features a three-factor structure: catastrophizing, pain sensitivity, and coping with pain. Conclusions: The Pa-M-QU offers a rapid, non-invasive assessment that captures the multidimensional nature of pain. It is a starting point to develop tools for both clinical and research settings, aiding in evaluating pain in healthy individuals and predicting acute and chronic pain disorders. Future research should focus on refining the Pa-M-QU for broader clinical applications and exploring its potential to complement or replace traditional pain assessments, thereby advancing pain management and research.

A cutting-edge new framework for the pain management in children: nanotechnology

Pain is a subjective concept which is ever-present in the medical field. Health professionals are confronted with a variety of pain types and sources, as well as the challenge of managing a patient with acute or chronic suffering. An even bigger challenge is presented in the pediatric population, which often cannot quantify pain in a numerical scale like adults. Infants and small children especially show their discomfort through behavioral and physiological indicators, leaving the health provider with the task of rating the pain. Depending on the pathophysiology of it, pain can be classified as neuropathic or nociceptive, with the first being defined by an irregular signal processing in the nervous system and the second appearing in cases of direct tissue damage or prolonged contact with a certain stimulant. The approach is generally either pharmacological or non-pharmacological and it can vary from using NSAIDs, local anesthetics, opiates to physical and psychological routes. Unfortunately, some pathologies involve either intense or chronic pain that cannot be managed with traditional methods. Recent studies have involved nanoparticles with special characteristics such as small dimension and large surface area that can facilitate carrying treatments to tissues and even offer intrinsic analgesic properties. Pediatrics has benefited significantly from the application of nanotechnology, which has enabled the development of novel strategies for drug delivery, disease diagnosis, and tissue engineering. This narrative review aims to evaluate the role of nanotechnology in current pain therapy, with emphasis on pain in children.

Long-term outcome and predictors of neurological recovery in cervical spinal cord injury: a population-based cohort study

This retrospective study analyzed prognostic factors for neurological improvement and ambulation in 194 adult patients (≥ 15 years) with traumatic cervical spinal cord injuries treated at the neurological SCI unit (SCIU) at the Karolinska University Hospital Stockholm, Sweden, between 2010 and 2020. The primary outcome was American spinal injury association impairment scale (AIS) improvement, with secondary focus on ambulation restoration. Results showed 41% experienced AIS improvement, with 51% regaining ambulation over a median follow-up of 3.7 years. Significant AIS improvement (p < 0.001) and reduced bladder/bowel dysfunction (p < 0.001) were noted. Multivariable analysis identified initial AIS C-D (< 0.001), central cord syndrome (p = 0.016), and C0-C3 injury (p = 0.017) as positive AIS improvement predictors, while lower extremity motor score (LEMS) (p < 0.001) and longer ICU stays (p < 0.001) were negative predictors. Patients with initial AIS C-D (p < 0.001) and higher LEMS (p < 0.001) were more likely to regain ambulation. Finally, older age was a negative prognostic factor (p = 0.003). In conclusion, initial injury severity significantly predicted neurological improvement and ambulation. Recovery was observed even in severe cases, emphasizing the importance of tailored rehabilitation for improved outcomes.

Improved Recovery of Complete Spinal Cord Transection by a Plasma-Modified Fibrillar Scaffold

Complete spinal cord injury causes an irreversible disruption in the central nervous system, leading to motor, sensory, and autonomic function loss, and a secondary injury that constitutes a physical barrier preventing tissue repair. Tissue engineering scaffolds are presented as a permissive platform for cell migration and the reconnection of spared tissue. Iodine-doped plasma pyrrole polymer (pPPy-I), a neuroprotective material, was applied to polylactic acid (PLA) fibers and implanted in a rat complete spinal cord transection injury model to evaluate whether the resulting composite implants provided structural and functional recovery, using magnetic resonance (MR) imaging, diffusion tensor imaging and tractography, magnetic resonance spectroscopy, locomotion analysis, histology, and immunofluorescence. In vivo, MR studies evidenced a tissue response to the implant, demonstrating that the fibrillar composite scaffold moderated the structural effects of secondary damage by providing mechanical stability to the lesion core, tissue reconstruction, and significant motor recovery. Histologic analyses demonstrated that the composite scaffold provided a permissive environment for cell attachment and neural tissue guidance over the fibers, reducing cyst formation. These results supply evidence that pPPy-I enhanced the properties of PLA fibrillar scaffolds as a promising treatment for spinal cord injury recovery.

The Pharmacological Treatment of Neuropathic Pain in Children

The International Association for the Study of Pain (IASP) defines neuropathic pain as pain caused by a lesion or disease of the somatosensory nervous system. It is characterized as a clinical condition in which diagnostic studies reveal an underlying cause of an abnormality in the peripheral or central nervous system. Many common causes of neuropathic pain in adults are rare in children. The purpose of this focused narrative review is, to 1) provide an overview of neuropathic pain in children, 2) highlight unique considerations related to the diagnosis and mechanisms of neuropathic pain in children, and 3) perform a comprehensive analysis of the pharmacological treatments available. We emphasize that data for routine use of pharmacological agents in children with neuropathic pain are largely inferred from adult literature with little research performed on pediatric populations, yet have clear evidence of harms to pediatric patients. Based on these findings, we propose risk mitigation strategies such as utilizing topical treatments whenever possible, assessing pain phenotyping to guide drug class choice, and considering pharmaceuticals in the broader context of the multidisciplinary treatment of pediatric pain. Furthermore, we highlight important directions for future research on pediatric neuropathic pain treatment.

Feasibility of using remotely delivered Spring Forest Qigong to reduce neuropathic pain in adults with spinal cord injury: a pilot study

Introduction: Approximately 69% of 299,000 Americans with spinal cord injury (SCI) suffer debilitating chronic neuropathic pain, which is intractable to treatment. The aim of this study is to determine feasibility, as the primary objective, and estimates of efficacy of a remotely delivered Qigong intervention in adults with SCI-related neuropathic pain, as the secondary objective. Methods: We recruited adults with SCI-related neuropathic pain, with SCI ≥3 months, with complete or incomplete SCI, and highest neuropathic pain level of >3 on the Numeric Pain Rating Scale (NPRS), using nationwide volunteer sampling. Using a non-randomized controlled trial design, participants practiced Spring Forest Qigong's "Five Element Qigong Healing Movements" (online video) by combining movement to the best of their ability with kinesthetic imagery, at least 3x/week for 12 weeks. Adherence was automatically tracked through the Spring Forest Qigong website. Outcomes of neuropathic pain intensity (NPRS) were assessed weekly, and SCI-related symptoms were assessed at baseline, 6, and 12 weeks of Qigong practice and at 6-week and 1-year follow-ups. Results: We recruited 23 adults with chronic SCI (7/2021-2/2023). In total, 18 participants started the study and completed all study components, including the 6-week follow-up. Twelve participants completed the 1-year follow-up assessment. Feasibility was demonstrated through participants' willingness to participate, adherence, and acceptability of the study. Mean age of the 18 participants was 60 ± 12 years, and they were 15 ± 11 years post-SCI with the highest baseline neuropathic pain of 7.94 ± 2.33, which was reduced to 4.17 ± 3.07 after 12 weeks of Qigong practice (Cohen's d = 1.75). This pain relief remained at 6-week and 1-year follow-ups. Participants reported reduced spasm frequency (change score 1.17 ± 1.20, d = 0.98) and severity (0.72 ± 1.02, d = 0.71), reduced interference of neuropathic pain on mood (3.44 ± 2.53, d = 1.36), sleep (3.39 ± 2.40, d = 1.41), daily activities (3.17 ± 2.77, d = 1.14), greater ability to perform functional activities (6.68 ± 3.07, d = 2.18), and improved mood (2.33 ± 3.31, d = 0.70) after Qigong. Discussion: Remote Spring Forest Qigong's "Five Element Qigong Healing Movements" practice is feasible in adults with SCI-related neuropathic pain, with promising prolonged results of neuropathic pain relief and improvement in SCI-related symptoms after Qigong practice. Clinical trial registration: https://www.clinicaltrials.gov/ct2/show/NCT04917107, identifier NCT04917107.

Integrated Neuroregenerative Techniques for Plasticity of the Injured Spinal Cord

On the slow path to improving the life expectancy and quality of life of patients post spinal cord injury (SCI), recovery remains controversial. The potential role of the regenerative capacity of the nervous system has led to numerous attempts to stimulate the SCI to re-establish the interrupted sensorimotor loop and to understand its potential in the recovery process. Numerous resources are now available, from pharmacological to biomolecular approaches and from neuromodulation to sensorimotor rehabilitation interventions based on the use of various neural interfaces, exoskeletons, and virtual reality applications. The integration of existing resources seems to be a promising field of research, especially from the perspective of improving living conditions in the short to medium term. Goals such as reducing chronic forms of neuropathic pain, regaining control over certain physiological activities, and enhancing residual abilities are often more urgent than complete functional recovery. In this perspective article, we provide an overview of the latest interventions for the treatment of SCI through broad phases of injury rehabilitation. The underlying intention of this work is to introduce a spinal cord neuroplasticity-based multimodal approach to promote functional recovery and improve quality of life after SCI. Nonetheless, when used separately, biomolecular therapeutic approaches have been shown to have modest outcomes.