Sciatica, more accurately termed lumbar radiculopathy, is a syndrome involving nerve root impingement and/or inflammation that has progressed enough to cause neurological symptoms (e.g. pain, numbness, paraesthesia) in the areas that are supplied by the affected nerve root(s) (Tarulli 2007). Posterior sciatica involves pain that radiates along the posterior thigh and the posterolateral aspect of the leg, and is due to an S1 or L5 radiculopathy.
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).
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).
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)
- Hagen KB et al. The updated Cochrane review of bedrest for low back pain and sciatica. Spine
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- 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.