Efficacy of Fu's Subcutaneous Needling on Sciatic Nerve Pain: Behavioral and Electrophysiological Changes in a Chronic Constriction Injury Rat Model

This research investigates the analgesic effect of Fu's subcutaneous needle therapy and low-frequency electrotherapy in rats with chronic constriction injury and neuropathic pain. It explores non-pharmacological treatment options for neuropathic pain and examines the potential of FSN therapy as an effective intervention. The current experimental challenges include developing appropriate needle techniques to reduce discomfortable in rats during Fu's subcutaneous needling therapy, conducting needling procedures and the swaying movements without anesthesia, establishing a reliable and a reproducible chronical constrict injury model in rats, and accurately assessing behavior patterns and the electrophysiologic responses in neuropathic pain models.

The significant finding from this study include demonstrating the therapeutic effect of treatment on neuropathic pain in red chronic construction injury models, and the presenting a protocol for evaluating the therapeutic effect using SFI and the electrophysiological testing after Fu's over TENS treatment. The findings of this study will advance research in the field by providing a protocol for evaluating Fu's N treatment, bridging basic research and clinical application, improving patient's outcomes, and enhancing understanding of disease mechanisms for more effective treatments in neuropathic pain. In the future our laboratory aims to incorporate immunohistochemistry and the morphological aberration to validate the effectiveness of Fu's subcutaneous needling therapy in nerve compression related disease.

We strive to deepen our understanding of Fu's subcutaneous needling therapy, contribute to pain management, and advance rehabilitation strategies. Begin by wearing a surgical mask, disposable operating cap, and sterile gloves. Clean the surgical table surface with 70%ethanol and autoclave instruments, gauze, staples, and cotton swabs.

Position the anesthetized rat on the operating table, then shave its right hind leg hair. Now, disinfect the skin with povidone iodine solution and 75%ethanol three times. Make a 20 to 50 millimeter parallel skin incision about three to four millimeters below the femur.

Cut through the subcutaneous fat and superficial fascia layers using surgical scissors, and locate and expose the gluteus maximus and biceps femoris. Using blunt scissors, sever the connective tissue between the superficial gluteus and biceps femoris muscles. With the help of a retractor, expose the sciatic nerve by widening the gap between the two muscles.

Pick the sciatic nerve with a microneedle through a good light source, ensuring not to alter nerve morphology. Ligate the sciatic nerve twice using 3-0 chromic gut ligatures, positioning the ligature points approximately 1 millimeter apart between the two sutures. Create a loose loop for each ligature and grasp the ends of the ligature close to the loop.

Close the muscle with 4-0 suture lines, and then suture the skin layer. Begin by securing the rat from Fu's subcutaneous needling, or FSN treatment group, in the rodent restrained, exposing the affected limb laterally. Slowly and gradually extend the rat's hind limbs until stretched tight, without anesthesia.

Now, remove the protective sheath of the FSN needle. Insert the needle tip toward the tightened muscles near the gluteus maximus muscle on the lower back and rear. Position the needle flat, entering the skin at a 15 degree angle.

Push it cautiously and swiftly to avoid tension in the rat, ensuring full insertion of the needle and burying the soft tube under the skin. Begin the swaying movement by smoothly and softly fanning the FSN needle tip, using the thumb as the fulcrum and keeping the index, middle, and ring fingers aligned in a straight line. Hold the FSN needle between the middle finger and thumb, facing each other, and alternate the movement using the index and ring fingers.

Upon completing the manipulation, quickly withdraw the FSN needle. The sciatic function index or SFI in the constriction injury, FSN group, improved significantly compared to the injury group alone. The improvement was significant in the FSN group relative to the transcutaneous electrical nerve stimulator, or TENS group.

The SFI of the Sham, FSN, and TENS groups did not have any significant difference from each other, proving the safety of the treatment groups. The amplitude of CMAP, and the Latency peaks in the injury FSN treatment group improved significantly compared to the injury group alone. The CMAP and Latency peaks of the treatment groups did not differ significantly from each other.

The CMAP amplitudes and Latency of all three groups were statistically similar. Begin by fixing the rat from the transcutaneous electrical nerve stimulation, or TENS treatment group, in a rodent restraint, exposing the affected limb laterally. Administer a low frequency electrical stimulation with the electrode applied on the leg around the nerve, and to the Zu San Li and Sanyinjiao points using the TENS device, for 10 minutes.

The sciatic function index, or SFI in the injury with TENS group, improved significantly compared to the injury group alone. The improvement was significant in the FSN group relative to the TENS group. The SFI of the Sham, FSN, and TENS groups did not have any significant difference from each other, proving the safety of the treatment groups.

Improved amplitude of CMAP, relative to the injury alone group, was observed. Similar observations were observed with the Latency peak in the injury, with TENS treatment group. The CMAP and Latency peaks of the treatment groups did not differ significantly from each other.

The CMAP amplitudes and Latency of all three groups were statistically similar.