Acupuncture Treatment for Low Back Pain and Lower Limb Symptoms—The Relation between Acupuncture or Electroacupuncture Stimulation and Sciatic Nerve Blood Flow

Abstract

To investigate the clinical efficacy of acupuncture treatment for lumbar spinal canal stenosis and herniated lumbar disc and to clarify the mechanisms in an animal experiment that evaluated acupuncture on sciatic nerve blood flow. In the clinical trial, patients with lumbar spinal canal stenosis or herniated lumbar disc were divided into three treatment groups; (i) Ex-B2 (at the disordered level), (ii) electrical acupuncture (EA) on the pudendal nerve and (iii) EA at the nerve root. Primary outcome measurements were pain and dysesthesia [evaluated with a visual analogue scale (VAS)] and continuous walking distance. In the animal study, sciatic nerve blood flow was measured with laser-Doppler flowmetry at, before and during three kinds of stimulation (manual acupuncture on lumber muscle, electrical stimulation on the pudendal nerve and electrical stimulation on the sciatic nerve) in anesthetized rats. For the clinical trial, approximately half of the patients who received Ex-B2 revealed amelioration of the symptoms. EA on the pudendal nerve was effective for the symptoms which had not improved by Ex-B2. Considerable immediate and sustained relief was observed in patients who received EA at the nerve root. For the animal study, increase in sciatic nerve blood flow was observed in 56.9% of the trial with lumber muscle acupuncture, 100% with pudendal nerve stimulation and 100% with sciatic nerve stimulation. Sciatic nerve stimulation sustained the increase longer than pudendal nerve stimulation. One mechanism of action of acupuncture and electrical acupuncture stimulation could be that, in addition to its influence on the pain inhibitory system, it participates in causing a transient change in sciatic nerve blood blow, including circulation to the cauda equine and nerve root.

Efficacy of Acupuncture for the Treatment of Sciatica: A Systematic Review and Meta-Analysis

“…Acupuncture is thought to stimulate inhibitory nerve fibers for a short period, reducing transmission of pain signal to the brain [33]. Acupuncture treatment activates endogenous analgesic mechanisms [34], causing secretion of endorphin which is an endogenous opioid [35] and triggering release of adenosine [36], producing a rapidly effective analgesic action on radicular sciatica. Extensive research has shown that acupuncture analgesia may be initiated by stimulation of high-threshold, small-diameter nerves in the muscles [37].…”

Clinical Effect of Acupuncture on Cervical Spondylotic Radiculopathy: Results of a Case Series

“…For lower extremity symptoms originating from lumbar spine disease, in an investigation similar to the present study our research group has already reported on a clinical effect in about half of the patients given acupuncture treatment to the lumbar paraspinal region. 10 In addition, in animal experiments it was found that application of acupuncture to the lumbar paraspinal region increased the sciatic nerve blood flow in approximately 60% of animals. 11 It is possible that such a change would also occur in the cervical spine, which is very similar to the lumbar spine in terms of structure and innervation.…”

Changes in Blood Fluidity Caused by Electroacupuncture Stimulation

“…The ability to control blood fluidity by using acupuncture showed that the acupuncture signal initiated at the acupoints was transferred to the brain through the afferent nervous pathway; therefore, it modulated the function of neurotransmitter systems such as the cardiovascular center. Output signaling cascades may improve blood fluidity through efferent neural regulation, such as that by the sympathetic nervous system [25].…”