Neuroprotective and anti-neuropathic actions of pulsed magnetic fields with low frequencies in rats with chronic peripheral neuropathic pain

Multilevel analysis of the central-peripheral-target organ pathway: contributing to recovery after peripheral nerve injury

Peripheral nerve injury is a common neurological condition that often leads to severe functional limitations and disabilities. Research on the pathogenesis of peripheral nerve injury has focused on pathological changes at individual injury sites, neglecting multilevel pathological analysis of the overall nervous system and target organs. This has led to restrictions on current therapeutic approaches. In this paper, we first summarize the potential mechanisms of peripheral nerve injury from a holistic perspective, covering the central nervous system, peripheral nervous system, and target organs. After peripheral nerve injury, the cortical plasticity of the brain is altered due to damage to and regeneration of peripheral nerves; changes such as neuronal apoptosis and axonal demyelination occur in the spinal cord. The nerve will undergo axonal regeneration, activation of Schwann cells, inflammatory response, and vascular system regeneration at the injury site. Corresponding damage to target organs can occur, including skeletal muscle atrophy and sensory receptor disruption. We then provide a brief review of the research advances in therapeutic approaches to peripheral nerve injury. The main current treatments are conducted passively and include physical factor rehabilitation, pharmacological treatments, cell-based therapies, and physical exercise. However, most treatments only partially address the problem and cannot complete the systematic recovery of the entire central nervous system-peripheral nervous system-target organ pathway. Therefore, we should further explore multilevel treatment options that produce effective, long-lasting results, perhaps requiring a combination of passive (traditional) and active (novel) treatment methods to stimulate rehabilitation at the central-peripheral-target organ levels to achieve better functional recovery.

Electromagnetic field stimulation for long-term mobility assessment after sciatic nerve injury

INTRODUCTION

Gauss (G) or miliTesla (mT) units measure electromagnetic field (EMF) stimulation. Tarlov Scale (TS) assesses motor impairment, Finger Abduction Scale (FAS) measures finger separation. The objective is to evaluate mobility using EMF in a Sciatic Nerve Injury (SNI) model.

MATERIALS & METHODS

SNI caused paresis in the right hind limb to observe motor changes in male Sprague-Dawley rats (372-529 g) (N = 30). Three groups of (n = 10) rats were created. Control Group (CG) was just injured. The experimental groups were EMF-treated two hours a day for four weeks (2/24, 5/7, 4/4), applying Gauss intensities: Low-Intensity (LIMF) 60-100 (6-10 mT) & High-Intensity (HIMF) 140-200 (14-20 mT). The mobility was measured each week with TS & FAS. Sciatic nerve & skeletal muscle histological slides were made with traditional staining technique to evaluate cellular inflammation. We used two-tailed repeated ANOVA measures & Bonferroni post hoc tests, with a significance p < 0.05 (α = 0.05) and β = 80%.

RESULTS

EMFs effectively treat SNI in rats, improving the mobility of the right hind limb in experimental groups. In the last week, TS scores were CG 3.5 (±1.35) p = 0.006, LIMF 4 (±0) p = 0.0001 & HIMF 4.3 (±0.82) p = 0.02. FAS scores were CG 0.2 (±0.42) p = 0.000001, LIMF 1.5 (±0.70) p = 0.05 & HIMF 1.8 (±0.42) p = 0.1. In histological findings, CG had inflammation in nerve & muscle, LIMF & HIMF diminished cellular activity.

DISCUSSION

TS & FAS helped to improve mobility in experimental groups using EMFs after SNI. The nerve repairing mechanism should be studied in future models.

Physical modulation and peripheral nerve regeneration: a literature review

Peripheral nerve injury (PNI) usually causes severe motor, sensory and autonomic dysfunction. In addition to direct surgical repair, rehabilitation exercises, and traditional physical stimuli, for example, electrical stimulation, have been applied in promoting the clinical recovery of PNI for a long time but showed low efficiency. Recently, significant progress has been made in new physical modulation to promote peripheral nerve regeneration. We hereby review current progress on the mechanism of peripheral nerve regeneration after injury and summarize the new findings and evidence for the application of physical modulation, including electrical stimulation, light, ultrasound, magnetic stimulation, and mechanical stretching in experimental studies and the clinical treatment of patients with PNI.

Nanomedicine in Neuroprotection, Neuroregeneration, and Blood-Brain Barrier Modulation: A Narrative Review

Nanomedicine is a newer, promising approach to promote neuroprotection, neuroregeneration, and modulation of the blood-brain barrier. This review includes the integration of various nanomaterials in neurological disorders. In addition, gelatin-based hydrogels, which have huge potential due to biocompatibility, maintenance of porosity, and enhanced neural process outgrowth, are reviewed. Chemical modification of these hydrogels, especially with guanidine moieties, has shown improved neuron viability and underscores tailored biomaterial design in neural applications. This review further discusses strategies to modulate the blood-brain barrier-a factor critically associated with the effective delivery of drugs to the central nervous system. These advances bring supportive solutions to the solving of neurological conditions and innovative therapies for their treatment. Nanomedicine, as applied to neuroscience, presents a significant leap forward in new therapeutic strategies that might help raise the treatment and management of neurological disorders to much better levels. Our aim was to summarize the current state-of-knowledge in this field.

Repetitive magnetic stimulation prevents dorsal root ganglion neuron death and enhances nerve regeneration in a sciatic nerve injury rat model

Peripheral nerve injury (PNI) often leads to retrograde cell death in the spinal cord and dorsal root ganglia (DRG), hindering nerve regeneration and functional recovery. Repetitive magnetic stimulation (rMS) promotes nerve regeneration following PNI. Therefore, this study aimed to investigate the effects of rMS on post-injury neuronal death and nerve regeneration. Seventy-two rats underwent autologous sciatic nerve grafting and were divided into two groups: the rMS group, which received rMS and the control (CON) group, which received no treatment. Motor neuron, DRG neuron, and caspase-3 positive DRG neuron counts, as well as DRG mRNA expression analyses, were conducted at 1-, 4-, and 8-weeks post-injury. Functional and axon regeneration analyses were performed at 8-weeks post-injury. The CON group demonstrated a decreased DRG neuron count starting from 1 week post-injury, whereas the rMS group exhibited significantly higher DRG neuron counts at 1- and 4-weeks post-injury. At 8-weeks post-injury, the rMS group demonstrated a significantly greater myelinated nerve fiber density in autografted nerves. Furthermore, functional analysis showed significant improvements in latency and toe angle in the rMS group. Overall, these results suggest that rMS can prevent DRG neuron death and enhance nerve regeneration and motor function recovery after PNI.

Comparison of the therapeutic efficacy of magneto-LED therapy and magnetostimulation applied as the adjuvant treatment of venous leg ulcers - preliminary study

PURPOSE

Venous leg ulcers are chronic wounds that are difficult to cure. The aim of the study was to compare the therapeutic efficacy of two methods of physical medicine - magneto-LED therapy and magnetostimulation, applied as adjuvant treatment in the treatment of venous leg ulcers.

METHODS

The study included 81 patients, 37 male (45.6%) and 44 female (54.3%) ones, age range between 45 and 90 years, with venous leg ulcers. The patients were assigned to two study groups: magneto-LED therapy (group 1) or magnetostimulation (group 2). In both groups, a total of 40 daily procedures were performed. Wound healing was evaluated using computerized planimetry and the pain intensity on numeric rating scale.

RESULTS

After treatment, the decrease in healing rate in group 1 was statistically significantly higher in comparison to group 2 (p < 0.001), while a statistically significant reduction in the surface area of ulcers was obtained, amounting on the average from 6.34 ± 1.29 cm2 to 2.31 ± 1.25 cm2 in group 1 (p < 0.001), and from 6.52 ± 1.20 cm2 to 4.79 ± 1.17 cm2 in group 2 (p < 0.001). The percentage changes of ulcers area in group 1 (64.21 ± 17.94%) were statistically significantly greater as compared to group 2 (25.87 ± 14.07%) (p < 0.001). After treatment, the decrease in pain relief in group 1 was statistically significantly higher in comparison to group 2 (p = 0.006), while pain intensity after treatment decreased statistically significantly in both compared groups of patients (p < 0.001).

CONCLUSIONS

Magneto-LED therapy and magnetostimulation caused significant reduction of surface area of the treated venous leg ulcers and pain intensity, yet magneto-LED therapy was more efficient. Both evaluated methods also significantly reduced pain intensity.

Autonomic Nervous System Dysfunction Is Related to Chronic Prostatitis/Chronic Pelvic Pain Syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common and non-lethal urological condition with painful symptoms. The complexity of CP/CPPS's pathogenesis and lack of efficient etiological diagnosis results in incomplete treatment and recurrent episodes, causing long-term mental and psychological suffering in patients. Recent findings indicate that the autonomic nervous system involves in CP/CPPS, including sensory, sympathetic, parasympathetic, and central nervous systems. Neuro-inflammation and sensitization of sensory nerves lead to persistent inflammation and pain. Sympathetic and parasympathetic alterations affect the cardiovascular and reproductive systems and the development of prostatitis. Central sensitization lowers pain thresholds and increases pelvic pain perception in chronic prostatitis. Therefore, this review summarized the detailed processes and mechanisms of the critical role of the autonomic nervous system in developing CP/CPPS. Furthermore, it describes the neurologically relevant substances and channels or receptors involved in this process, which provides new perspectives for new therapeutic approaches to CP/CPPS.

Advances in biotechnology and clinical therapy in the field of peripheral nerve regeneration based on magnetism

Peripheral nerve injury (PNI) is one of the most common neurological diseases. Recent studies on nerve cells have provided new ideas for the regeneration of peripheral nerves and treatment of physical trauma or degenerative disease-induced loss of sensory and motor neuron functions. Accumulating evidence suggested that magnetic fields might have a significant impact on the growth of nerve cells. Studies have investigated different magnetic field properties (static or pulsed magnetic field) and intensities, various magnetic nanoparticle-encapsulating cytokines based on superparamagnetism, magnetically functionalized nanofibers, and their relevant mechanisms and clinical applications. This review provides an overview of these aspects as well as their future developmental prospects in related fields.