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 Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>