Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New way to diagnose sciatica may point to a different cause

01.02.2005


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:
http://www.cshs.org
http://www.csmc.edu.

More articles from Health and Medicine:

nachricht Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center

nachricht Study advances gene therapy for glaucoma
17.01.2018 | University of Wisconsin-Madison

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: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials

17.01.2018 | Physics and Astronomy

Fraunhofer HHI receives AIS Technology Innovation Award 2018 for 3D Human Body Reconstruction

17.01.2018 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>