When caused by S1 irritation, the pain may radiate to the lateral aspect of the foot, while pain due to L5 radiculopathy may radiate to the dorsum of the foot and to the large toe. Anterior sciatica involves pain that radiates along the anterior aspect of the thigh into the anterior leg, and is due to L4 or L3 radiculopathy. Pain due to L2 radiculopathy is antero-medial in the thigh, and pain in the groin usually arises from an L1 lesion. Sciatica is almost invariably accompanied or preceded by back pain, and mobility is often affected (Koes 2007). Indicators for sciatica include unilateral leg pain that is greater than low back pain; pain radiating to the foot or toes, numbness and paraesthesia; increased pain on straight leg raising, and neurological symptoms limited to one nerve root (Waddell 1998).
The prevalence of lumbar radiculopathy is around 3% to 5%, and equally common in men and women (Tarulli 2007), and an estimated 5%-10% of patients with low back pain have sciatica (Health Council 1999). The annual prevalence of disc related sciatica in the general population is estimated at 2.2% (Younes 2006). In most patients, the prognosis is good, but up to 30% will have pain for one year or longer (Weber 1993, Vroomen 2000).
Conventional management includes advice to stay active and continue daily activities; exercise therapy; analgesics (e.g. paracetamol, NSAIDs, an opioid); muscle relaxants; corticosteroid spinal injections; and referral for consideration of surgery. However, there is a lack of strong evidence of effectiveness for most of these interventions (Hagen 2007, Luijsterburg 2007).
Hagen KB et al. The updated Cochrane review of bedrest for low back pain and sciatica. Spine
2005; 30: 542-6.
Health Council of the Netherlands: management of the lumbosacral radicular syndrome (sciatica): Health Council of the Netherlands, 1999; publication no. 1999/18.
Koes BW et al. Diagnosis and treatment of sciatica. BMJ 2007; 334: 1313-7.
Luijsterburg PAJ et al. Effectiveness of conservative treatments for the lumbosacral radicular syndrome: a systematic review. Eur Spine J 2007 Apr 6;(Epub ahead of print).
Tarulli AW, Raynor EM. Lumbosacral radiculopathy. Neurol Clin 2007; 25(2): 387-405.
Vroomen PCAJ et al. Conservative treatment of sciatica: a systematic review. J Spinal Dis 2000; 13: 463-9.
Weber H et al. The natural course of acute sciatica with nerve root symptoms in a double blind placebo-controlled trial of evaluating the effect of piroxicam (NSAID). Spine 1993; 18: 1433-8.
Waddell G. The back pain revolution. Edinburgh: Churchill Livingstone, 1998.
Younes M et al. Prevalence and risk factors of disc-related sciatica in an urban population in Tunisia. Joint Bone Spine 2006; 73: 538-42.
How acupuncture can help
There is substantial research to show that acupuncture is significantly better than no treatment and also at least as good, if not better than, standard medical care for back pain (Yuan 2008, Furlan 2008; see the Fact Sheet on Acupuncture and Back Pain). There is less specific research on acupuncture for sciatica, but there is evidence to suggest that it may provide some pain relief (Wang 2009, Chen 2009, Inoue 2008, Wang 2004). (see overleaf)
Acupuncture can help relieve back pain and sciatica by:
- stimulating nerves located in muscles and other tissues, which leads to release of endorphins and other neurohumoral factors, and changes the processing of pain in the brain and spinal cord (Pomeranz 1987, Zhao 2008).
- reducing inflammation, by promoting release of vascular and immunomodulatory factors (Kavoussi 2007, Zijlstra 2003).
- improving muscle stiffness and joint mobility by increasing local microcirculation (Komori 2009), which aids dispersal of swelling.
- causing a transient change in sciatic nerve blood flow, including circulation to the cauda equine and nerve root. This response is eliminated or attenuated by administration of atropine, indicating that it occurs mainly via cholinergic nerves (Inoue 2008).
- influencing the neurotrophic factor signalling system, which is important in neuropathic pain (Dong 2006).
- increasing levels of serotonin and noradrenaline, which can help reduce pain and speed nerve repair (Wang 2005).
- improving the conductive parameters of the sciatic nerve (Zhang 2005).
- promoting regeneration of the sciatic nerve (La 2005)
Reviews – low back pain
|Yuan J et al. Effectiveness of acupuncture for low back pain: a systematic review. Spine 2008; 33(23): E887-900.||Systematic review and meta-analysis of 23 trials involving 6,359 patients, which looked at acupuncture in the treatment of low back pain. It found moderate evidence that acupuncture is more effective than no treatment and strong evidence that acupuncture is a useful supplement to other forms of conventional therapy. The reviewers concluded that acupuncture should be advocated for the treatment of chronic low back pain.|
|Furlan AD et al. Acupuncture and dry-needling for low back pain. Cochrane Database Syst Rev 2005; (1): CD001351.||Systematic review and meta-analysis of 35 trials involving 2,861 patients, which assessed acupuncture for low back pain. The reviewers concluded that for chronic low back pain, acupuncture is more effective for pain relief and functional improvement than no treatment or sham treatment, and that acupuncture may be a useful adjunct to other therapies for chronic low back pain.|
|Ammendolia C et al. Evidence-informed management of chronic low back pain with needle acupuncture. Spine J 2008 Jan-Feb; 8(1): 160-72.||Review article on management of chronic low back pain with acupuncture, which explains theories on the mechanisms of action on pain with acupuncture. It concludes that the most consistent evidence is for the addition of acupuncture to other therapies.|
Clinical trials – sciatica
|Wang ZX. [Clinical observation on electroacupuncture at acupoints for treatment of senile radical sciatica].Zhongguo Zhenjiu 2009; 29(2): 126-8.|
|A randomised trial that compared therapeutic effects of electroacupuncture and TENS on radical sciatica in a total of 139 patients. At the end of the first course of treatment, the cure rate was greater (41.4%) in the electroacupuncture group than the TENS group (29.0%, p<0.05), and at the end of second course, was still greater (80.0% vs. 44.9%, p<0.005). The researchers concluded that the therapeutic effect of electroacupuncture on senile radical sciatica is significantly better than TENS.|
|Chen M-R et al. The warming acupuncture for treatment of sciatica in 30 cases. Journal of Traditional Chinese Medicine 2009; 29(1): 50-53.||A clinical study to observe the relationship between the pain threshold and the therapeutic effects of acupuncture for sciatica. Ninety sciatica patients were randomised to an acupuncture group (needles warmed with moxa), a western medicine group (nimesulide) or a point-injection group (anisodamine). Pain threshold was tested before treatment and after the first, second and third treatment courses. Acupuncture had better therapeutic effects than the other two groups, with significant differences in the change in pain threshold and the improvement of clinical symptoms and signs (p<0.01). The researchers concluded that acupuncture can relieve the symptoms of sciatica with an increase in pain threshold.|
|Inoue M et al. Acupuncture treatment for low back pain and lower limb symptoms – The relation between acupuncture or electroacupuncture stimulation and sciatic nerve blood flow.Evidence-based Complementary and Alternative Medicine 2008; 5(2): 133-43.|
|A clinical trial to investigate the efficacy of acupuncture for lumbar spinal canal stenosis and herniated lumbar disc, and an animal study to clarify the mechanisms of acupuncture on sciatic nerve blood flow. In the clinical trial, patients were divided into three treatment groups: needling of acupuncture points on either side of the spine, electroacupuncture on the pudendal nerve or electroacupuncture at the nerve root. Primary outcome measurements were pain and dysaesthesia [evaluated with a visual analogue scale (VAS)] and continuous walking distance. About half the patients in the spinal acupuncture points group had improvement in symptoms, while electroacupuncture on the pudendal nerve was effective for the symptoms that had not improved with that treatment. Considerable immediate and sustained relief was observed in patients who received electroacupuncture at the nerve root.|
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 anesthetised rats. Increase in sciatic nerve blood flow was observed in 56.9% of the animals given 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.
The researchers concluded that 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 flow, including circulation to the cauda equine and nerve root.
|Wang B-X, La J-L. Therapeutic effects of electro-acupuncture and diclofenac on herniation of lumbar intervertebral disc. Chinese Journal of Clinical Rehabilitation 2004; 8(17): 3413-5.||A randomised trial to compare the effects of electroacupuncture and diclofenac treatment in 40 patients with sciatica caused by herniation of an intervertebral disc. The main outcome measures were Laseque’s sign, and tenderness and numbness of the buttock, posterior side of the thigh, and the leg. After the treatment, the angle of Laseque’s sign in the acupuncture group was significantly greater than that in the medication group (p<0.05). Also, the mean score of buttock tenderness was significantly lower in the acupuncture group than in the medication group (p0.05). The researchers concluded that electro-acupuncture is more effective than diclofenac for increasing the Laseque’s sign angles and relieving tenderness at needled sites in patients with sciatica.|
|Inoue M et al. The effect of electrical stimulation of the pudendal nerve on sciatic nerve blood flow in animals. Acupuncture in Medicine 2008; 26(3): 145-8.|
|An animal study that investigated the mechanism of the clinical effect of electroacupuncture of the pudendal nerve on the lumbar and lower limb symptoms caused by lumbar spinal canal stenosis. Electrical stimulation of the pudendal nerve significantly increased blood flow in the sciatic nerve, transiently and without increasing heart rate and systemic blood pressure. The significant increase in the sciatic nerve blood flow disappeared after administration of atropine, indicating that it occurs mainly via cholinergic nerves.|
|Dong Z-Q et al. Down-regulation of GFRalpha-1 expression by antisense oligodeoxynucleotide attenuates electroacupuncture analgesia on heat hyperalgesia in a rat model of neuropathic pain. Brain Research Bulletin 2006; 69(1): 30-6.|
|An animal study that found the endogenous glial cell line-derived neurotrophic factor signalling system (important in neuropathic pain) is involved in the effects of electroacupuncture analgesia on neuropathic pain in rats.|
|Wang S et al. Effects of acupuncture on monoamine neurotransmitters in brain tissue of experimental rat models of sciatic nerve compression. Chinese Journal of Clinical Rehabilitation 2005; 9(33): 94-6.|
|An animal study that looked at the influence of acupuncture on the level of monoamine neurotransmitters in brain tissue of rat models of sciatic nerve compression, and how this affects analgesia and repair of nerve injury. Electroacupuncture resulted in significantly higher levels of serotonin and noradrenaline, which can help reduce pain and speed nerve repair.|
|Zhang W-G et al. Effect of acupuncture on the recovery of injured sciatic nerve in rats quantitatively evaluated with the changes of electrophysiological parameters. Chinese Journal of Clinical Rehabilitation 2005. 9(25): 140-1.|
|An animal study that observed the effect of acupuncture on injured sciatic nerves. It found that every conductive parameter of the sciatic nerve improved after acupuncture.|
|La J-L et al. Morphological studies on crushed sciatic nerve of rabbits with electroacupuncture or diclofenac sodium treatment. American Journal of Chinese Medicine 2005; 33(4): 663-9.|
|An animal study that compared the effects of electroacupuncture with diclofenac and a control on the regeneration of crushed sciatic nerves in rabbits. Electroacupuncture was found to promote nerve regeneration more effectively than diclofenac and the control (p<0.01 and p<0.001, respectively).|
|Komori M, Takada K, Tomizawa Y, Nishiyama K, Kondo I, Kawamata M, Ozaki M. Microcirculatory responses to acupuncture stimulation and phototherapy. Anesth Analg. 2009 Feb;108(2):635-40.|
|Experimental study on rabbits in which acupuncture stimulation was directly observed to increase diameter and blood flow velocity of peripheral arterioles, enhancing local microcirculation.|
General review articles of acupuncture
|Zhao ZQ. Neural mechanism underlying acupuncture analgesia. Prog Neurobiol 2008; 85(4): 355-75.||Review article that discusses the various peripheral and central nervous system components of acupuncture anaesthesia in detail.|
|Kavoussi B, Ross BE. The neuroimmune basis of anti-inflammatory acupuncture. Integr Cancer Ther 2007; 6(3): 251-7.|
|Review article that suggests the anti-inflammatory actions of traditional and electro-acupuncture are mediated by efferent vagus nerve activation and inflammatory macrophage deactivation.|
|Zijlstra FJ, van den Berg-de Lange I, Huygen FJ, Klein J. Anti-inflammatory actions of acupuncture. Mediators Inflamm. 2003 Apr;12(2):59-69.||An article that suggests a hypothesis for anti-inflammatory action of acupuncture: Insertion of acupuncture needles initially stimulates production of beta-endorphins, CGRP and substance P, leading to further stimulation of cytokines and NO. While high levels of CGRP have been shown to be pro-inflammatory, CGRP in low concentrations exerts potent anti-inflammatory actions. Therefore, a frequently applied ‘low-dose’ treatment of acupuncture could provoke a sustained release of CGRP with anti-inflammatory activity, without stimulation of pro-inflammatory cells.|
|Pomeranz B. Scientific basis of acupuncture. In: Stux G, Pomeranz B, eds. Acupuncture Textbook and Atlas. Heidelberg: Springer-Verlag; 1987:1-18.|
|Needle activation of A delta and C afferent nerve fibres in muscle sends signals to the spinal cord, where dynorphin and enkephalins are released. Afferent pathways continue to the the midbrain, triggering excitatory and inhibitory mediators in spinal cord. Ensuing release of serotonin and norepinephrine onto the spinal cord leads to pain transmission being inhibited both pre- and postsynaptically in the spinothalamic tract. Finally, these signals reach the hypothalamus and pituitary, triggering release of adrenocorticotropic hormones and beta-endorphin.|