Sciatica Research Today is a free monthly online journal that collates and summarizes the latest research about Sciatica, including details on treatment, prevention, medication.

Pain perception is altered by a nucleotide polymorphism in SCN9A.

Reimann F, Cox JJ, Belfer I, Diatchenko L, Zaykin DV, McHale DP, Drenth JP, Dai F, Wheeler J, Sanders F, Wood L, Wu TX, Karppinen J, Nikolajsen L, Männikkö M, Max MB, Kiselycznyk C, Poddar M, Te Morsche RH, Smith S, Gibson D, Kelempisioti A, Maixner W, Gribble FM, Woods CG

Department of Clinical Biochemistry, and Department of Medical Genetics, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge CB2 0XY, United Kingdom.

The gene SCN9A is responsible for three human pain disorders. Nonsense mutations cause a complete absence of pain, whereas activating mutations cause severe episodic pain in paroxysmal extreme pain disorder and primary erythermalgia. This led us to investigate whether single nucleotide polymorphisms (SNPs) in SCN9A were associated with differing pain perception in the general population. We first genotyped 27 SCN9A SNPs in 578 individuals with a radiographic diagnosis of osteoarthritis and a pain score assessment. A significant association was found between pain score and SNP rs6746030; the rarer A allele was associated with increased pain scores compared to the commoner G allele (P = 0.016). This SNP was then further genotyped in 195 pain-assessed people with sciatica, 100 amputees with phantom pain, 179 individuals after lumbar discectomy, and 205 individuals with pancreatitis. The combined P value for increased A allele pain was 0.0001 in the five cohorts tested (1277 people in total). The two alleles of the SNP rs6746030 alter the coding sequence of the sodium channel Nav1.7. Each was separately transfected into HEK293 cells and electrophysiologically assessed by patch-clamping. The two alleles showed a difference in the voltage-dependent slow inactivation (P = 0.042) where the A allele would be predicted to increase Nav1.7 activity. Finally, we genotyped 186 healthy females characterized by their responses to a diverse set of noxious stimuli. The A allele of rs6746030 was associated with an altered pain threshold and the effect mediated through C-fiber activation. We conclude that individuals experience differing amounts of pain, per nociceptive stimulus, on the basis of their SCN9A rs6746030 genotype.

Published 9 March 2010 in Proc Natl Acad Sci U S A.
Full-text of this article is available online (may require subscription).

Articles on Sciatica published 5 March 2010:

Plasma disc decompression compared with fluoroscopy-guided transforaminal epidural steroid injections for symptomatic contained lumbar disc herniation: a prospective, randomized, controlled trial.   J Neurosurg Spine.

Object Patients with radiculopathy, with or without back pain, often do not respond to conservative care and may be considered for epidural steroid injection therapy or a disc decompression procedure. Plasma disc decompression (PDD) using the Coblation SpineWand device is a percutaneous, minimally invasive interventional procedure. The purpose of this study was to evaluate clinical outcomes with PDD as compared with standard care using fluoroscopy-guided transforaminal epidural steroid ... [Abstract] [Full-text]

Articles on Sciatica published 3 March 2010:

Sciatica: what the rheumatologist needs to know.   Nat Rev Rheumatol, 6(3): 139-45.

Sciatica is a set of symptoms rather than a specific diagnosis, and is caused by a herniated lumbar disc in the vast majority of cases. The most important symptom is lower limb pain radiating below the knee and into the foot and toes. The clinical course of acute sciatica is generally favorable, with most pain and related disability improving within 2-4 weeks with or without treatment. Diagnosis mainly involves history taking and physical examination. Imaging is warranted if there is evidence ... [Abstract] [Full-text]

Sciatic hernia causing sciatica: MRI and MR neurography showing entrapment of sciatic nerve.   Br J Radiol, 83(987): e65-6.

Sciatic hernia is a rare condition with diverse clinical manifestations. We report a case of sciatic hernia causing sciatica, in which the diagnosis made on CT was subsequently confirmed on MRI including magnetic resonance neurography. The salient clinical and imaging features and a brief review are presented. [Abstract] [Full-text]

Articles on Sciatica published 26 February 2010:

Giant extradural sacral meningioma.   Acta Neurochir (Wien), 152(3): 485-8.

We present the first case of primary benign fibrous meningioma restricted to the sacrum with no sign of recurrence after a long follow-up duration. This occurred in a 36-year-old man who initially presented with a 3-month history of right-sided sciatica. The tumour was successfully resected after three surgical procedures due to its high vascularity and technical difficulties. Sacroiliac joint stability was not disrupted, and he is still doing well clinically at 8 years follow-up. [Abstract] [Full-text]

Effectiveness of manual therapies: the UK evidence report.   Chiropr Osteopat, 18(1): 3.

ABSTRACT: BACKGROUND: The purpose of this report is to provide a succinct but comprehensive summary of the scientific evidence regarding the effectiveness of manual treatment for the management of a variety of musculoskeletal and non-musculoskeletal conditions. METHODS: The conclusions are based on the results of systematic reviews of randomized clinical trials (RCTs), widely accepted and primarily UK and United States evidence-based clinical guidelines, plus the results of all RCTs not yet ... [Abstract] [Full-text]

Articles on Sciatica published 22 February 2010:

Diffuse large B-cell lymphoma presenting as piriformis syndrome.   Muscle Nerve, 41(3): 419-22.

Piriformis syndrome (PS) is a rare condition characterized by pain and paresthesia of the buttock, often radiating to the posterior thigh. A patient with sciatica that was clinically suspicious for PS, underwent diagnostic work-up. A diagnosis of diffuse large B-cell lymphoma with neurolymphomatosis (NL) was made. To our knowledge, this is the first report of NL presenting as PS. NL is a possible cause of secondary PS. [Abstract] [Full-text]

Articles on Sciatica published 18 February 2010:

Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain.   Cochrane Database Syst Rev, 2: CD007431.

BACKGROUND: Low-back pain with leg pain (sciatica) may be caused by a herniated intervertebral disc exerting pressure on the nerve root. Most patients will respond to conservative treatment, but in carefully selected patients, surgical discectomy may provide faster relief of symptoms. Primary care clinicians use patient history and physical examination to evaluate the likelihood of disc herniation and select patients for further imaging and possible surgery. OBJECTIVES: (1) To assess the ... [Abstract] [Full-text]

Articles on Sciatica published 16 February 2010:

The bothersomeness of sciatica: patients' self-report of paresthesia, weakness and leg pain.   Eur Spine J, 19(2): 263-9.

The objective of the study was to investigate how patients with sciatica due to disc herniation rate the bothersomeness of paresthesia and weakness as compared to leg pain, and how these symptoms are associated with socio-demographic and clinical characteristics. A cross-sectional study was conducted on 411 patients with clinical signs of radiculopathy. Items from the Sciatica Bothersomeness Index (0 = none to 6 = extremely) were used to establish values for paresthesia, weakness and leg pain. ... [Abstract] [Full-text]

© 2004-2010 Sciatica Research Today. All Rights Reserved.