Neuromodulation Through Magnetic Fields Irradiation with AT-04 Improves Hyperalgesia in a Rat Model of Neuropathic Pain via Descending Pain Modulatory Systems and Opioid Analgesia

Effects of magnetic field therapy (AT-04) on pain reduction during arteriovenous fistula puncture in hemodialysis

BACKGROUND

Pain from arteriovenous fistula puncture significantly affects the quality of life of patients undergoing hemodialysis. AT-04 was designed to alleviate this pain using magnetic stimulation, which is anticipated to be beneficial for managing pain across different conditions. However, limited research exists on the effectiveness of AT-04 in diminishing the pain related to arteriovenous fistula puncture in hemodialysis patients.

METHODS

Between July and August 2024, we enrolled 14 outpatient maintenance hemodialysis patients at Tokyu Hospital who had given informed consent. AT-04 was administered before arteriovenous fistula puncture. We assessed the pain intensity of the puncture using the Visual Analog Scale (VAS) before the application of AT-04, as well as at one and four weeks afterward. We observed changes in puncture pain levels before and after the AT-04 application.

RESULTS

The participants had an average age of 80 years (IQR, 74-85) and a mean dialysis duration of 5.8 years (IQR, 1.0-8.9). Lidocaine tape was utilized by 71.4% of participants, painkillers by 7.1%, and 28.6% used sleeping pills, with none taking antidepressants. The median VAS score before starting AT-04 was 40.5 (IQR, 23.5-55.5). One week after starting AT-04, the median VAS score dropped to 27.0 (IQR, 4.5-32.8), and four weeks later, it further decreased to 16.5 (IQR, 5.0-38.8). These decreases were statistically significant compared to the pre-treatment VAS score (one week after p = 0.0057, four weeks after p = 0.0076).

CONCLUSION

The AT-04 device, which uses alternating magnetic field therapy, significantly alleviated pain from arteriovenous fistula puncture in hemodialysis patients.

Endogenous opiates and behavior: 2023

This paper is the forty-sixth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2023 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug and alcohol abuse (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

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.

Analgesic effect of neuromodulation using the AT-04 portable magnetic field-generating device in a patient with neuropathic pain: a case report

BACKGROUND

Neuromodulation by magnetic field through the AT-04 (ait® (AT-04); Peace of Mind Co., Ltd., Kumamoto, Japan) has improved allodynia in neuropathic pain model rats. This report focuses on neuromodulation through magnetic field exposure using the AT-04 that provided an analgesic effect in a patient with neuropathic pain.

CASE PRESENTATION

A 47-year-old man presented with flaccid paralysis and extensive neuropathic pain and scored 7 on the 11-point Numerical Rating Scale (NRS) for his left upper limb. The patient was treated with neuromodulation by magnetic field exposure using the AT-04. Baseline NRS scores were obtained three times daily during the baseline period (days 1-5). Magnetic field exposure was then performed for 30 min three times daily (morning, noon, and evening) at home for 36 days, which was termed the intervention period (days 6-41). During the baseline period, the median NRS score was 7 and the baseline NRS score for calculating the percentage of nonoverlap data (PND) was 6. During the intervention period, the median NRS score was 4 and the PND value of the NRS score was 77.8% (28/36). Neuromodulation by magnetic field exposure using the AT-04 effectively decreased the patient's NRS score. The patient had no adverse effects during the intervention period.

CONCLUSIONS

Neuromodulation by magnetic field exposure using the AT-04 was effective in decreasing the NRS score in a patient with neuropathic pain. The AT-04 portable magnetic field-generating device shows potential as a therapeutic option for refractory neuropathic pain.

Efficacy and safety of a novel pain management device, AT-04, for endometriosis-related pain: study protocol for a phase III randomized controlled trial

BACKGROUND

Endometriosis-related pain encompassing dysmenorrhea, dyspareunia, and chronic pelvic pain, reduces the quality of life in premenopausal women. Although treatment options for endometriosis alleviate this pain, approximately one-third of women still experience pain even after receiving treatment, indicating the need for novel approaches to pain relief in those women. The Angel Touch device (AT-04) is a portable magnetic fields irradiation device that incorporates a combination of mixed alternative magnetic fields at 2 kHz and 83.3 MHz. A phase III trial confirmed the efficacy and safety of AT-02, a prototype of AT-04, for pain relief in patients with fibromyalgia.

METHODS

This is a phase III, multicenter, prospective, randomized, sham device-controlled, double-blind, parallel study. The participants will be premenopausal women aged > 18 years who have endometriosis-related pain with at least moderate severity. Considering dropouts, 50 participants have been deemed appropriate. Eligible women will be centrally registered, and the data center will randomly allocate them in a 1:1 ratio to the intervention and control groups. Women in the intervention group will receive electromagnetic wave irradiation generated by AT-04 and those who in the control group will wear a sham device for 16 weeks, and both groups will wear AT-04 for another 4 weeks. The primary outcome measure is the change in the Numeric Rating Scale score at 16 weeks compared with the baseline. Secondary outcome measures are efficacy for pelvic pain including dysmenorrhea and non-menstrual pain, and chronic pelvic pain not related to menstruation, dysmenorrhea, and dyspareunia, and improvement of quality of life during the study period. Safety will be evaluated by device defects and the frequency of adverse events. The study protocol has been approved by the Clinical Study Review Board of Chiba University Hospital, Chiba, Japan, and will be conducted in accordance with the principles of the Declaration of Helsinki and the Japanese Clinical Trials Act and relevant notifications.

DISCUSSION

This study aims to develop a novel method of managing endometriosis-related pain. The AT-04 is an ultralow-invasive device that can be used without inhibiting ovulation, suggesting potential benefits to women of reproductive-age. Trial registration number Japan Registry of Clinical Trials (jRCTs032230278).