Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New way to diagnose sciatica may point to a different cause


Many cases of sciatica not relieved by current treatments may now be successfully diagnosed and treated using new nerve imaging technology

For the last 70 years, a damaged disc in the lower back has been widely accepted as the most common cause of sciatica – a condition where the sciatic nerve is pinched, causing pain to radiate down the leg. As a result, treatment for sciatica is based on diagnosis of a damaged disc, despite the fact that nerves cannot be viewed with routine imaging tests. Consequently, over one million patients each year undergo magnetic resonance imaging scans (MRI) for sciatica and many are told there is no obvious cause for their pain.

Now, researchers at Cedars-Sinai Medical Center, the University of California, Los Angeles, and the Institute for Nerve Medicine in Los Angeles, have found that new nerve imaging technology called Magnetic Resonance neurography was effective to reveal that a pinched-nerve in the pelvis called piriformis syndrome caused sciatic leg pain in the majority of patients who had failed diagnosis with an MRI scan and/or who were not treated successfully with surgery. The study, published in the February issue of the Journal of Neurosurgery: Spine, may lead to a better way to diagnose and treat sciatica – a condition that affects nearly 40 percent of adults at some point during their lifetime.

"Our study not only found that we can use MR neurography to accurately image the sciatic nerve, but also shows that we can effectively diagnose and treat sciatic pain that is not caused by a herniated or damaged disc," said Aaron Filler, M.D., Ph.D., lead author of the study and a neurosurgeon at the Cedars-Sinai Institute of Spinal Disorders. "When a damaged disc is not causing sciatica, patients should talk to their doctors about special imaging for nerves with MR neurography."

Sciatica occurs when the sciatic nerve is pinched or irritated, causing pain to travel from the buttocks and down the back of the thigh and calf, sometimes extending into the foot. Today, when a patient experiences painful and persistent sciatica, physicians typically perform a physical exam and ultimately rely on MRI scans to show the extent to which a disc or discs may be damaged. But, of the 1.5 million MRI scans performed each year, only about 20 percent show a herniated disc serious enough to be treated with surgery. And, of those patients treated with surgery, about one-third do not experience relief from their sciatica. (Statistics derived from the American Academy of Orthopaedic Surgeons, Radiological Society of North America and the American Association of Neurological Surgeons.)

One possible cause of non-disc related sciatic pain is a condition called piriformis muscle syndrome. The syndrome is caused by a narrow muscle located deep in the buttocks that irritates or pinches the sciatic nerve, causing pain to radiate down the leg and into the foot. However, diagnosing piriformis syndrome is difficult, as there has been no effective means to diagnose and treat the condition. For example, MRI scans cannot reliably image nerves. Further, physicians usually perform a physical exam requiring patients to raise their leg straight up to determine whether a damaged disc may be causing their sciatica. But one large study found that the test was negative in up to 85 percent of patients experiencing chronic back pain and sciatica.

MR neurography, which was developed by Filler, however, uses MRI technology coupled with special software and hardware upgrades that generate detailed images of just about any nerve in the body. However, the technology is not widely used and is only available on a limited basis, despite several recent studies demonstrating its effectiveness.

To find out whether MR neurography could effectively identify the cause of sciatica, the researchers evaluated 239 patients whose symptoms had not improved after diagnosis or treatment for a herniated or damaged disc. All patients received a detailed neurological exam and had a thorough review of all previous scans and treatment history to rule out any condition that might have been missed. Patients without adequate scan information within the last 12 months underwent additional X-ray and MRI scanning. The investigators found that seven patients had torn disc related conditions (annular tears) and were subsequently treated successfully with spine surgery.

The remaining 232 patients then underwent MR neurography to evaluate the sciatic nerve. They found that 162 (69 percent) of patients had piriformis syndrome, while the remaining 31 percent had 15 other nerve, muscle or joint conditions at various locations not seen in standard MRI scans. Piriformis syndrome was also confirmed and/or treated by using Open MRI guided imaging, a procedure in which a specially designed MRI scanner guides deep injections of pain medication into the spine, muscles, or near nerves.

"For the last 70 years, sciatica has been thought to be caused by a herniated disc and treated as such," said Dr. J. Patrick Johnson, M.D., senior author of the study and the director of the Cedars-Sinai Institute for Spinal Disorders. "But our study shows that it is time for a major reassessment of how patients will be evaluated and treated for sciatica in the future – particularly in those patients with no obvious disc damage who previously failed treatment."

Following their diagnoses with MR neurography, all patients received treatment that included spinal surgery, nerve or muscle surgery, open MR guided injections, or non-interventional pain management that included physical therapy and exercise. Among the 62 patients who needed surgery to correct piriformis syndrome, 82 percent had a good or excellent outcome, based on patients’ responses to a standardized outcome questionnaire over a six-year period.

"Although sciatica is the most common condition treated by neurosurgeons, piriformis syndrome is not even mentioned in the majority of neurosurgery textbooks and no more than a handful of surgeons in the U.S. are trained to treat it," said Filler. "The use of optimum diagnostic technology and formal outcomes assessment is essential to identify this large number of patients who have sciatica caused by piriformis syndrome. Although MR neurography is only available at limited locations nationwide, patients who fail diagnosis or treatment should talk to their physician about nerve imaging with MR neurography."

Kelli Hanley | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht NIH scientists describe potential antibody treatment for multidrug-resistant K. pneumoniae
14.03.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht Researchers identify key step in viral replication
13.03.2018 | University of Pittsburgh Schools of the Health Sciences

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Natural enemies reduce pesticide use

21.03.2018 | Life Sciences

Make way for the mini flying machines

21.03.2018 | Life Sciences

Taming chaos: Calculating probability in complex systems

21.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>