Featured Research

from universities, journals, and other organizations

Nerves Controlling Muscles Are Best Repaired With Similar Nerves

Date:
May 12, 2007
Source:
Washington University School of Medicine
Summary:
When repairing severed or damaged motor nerves with a donor nerve graft, surgeons have traditionally used a sensory nerve from another area of the patient's body. However, these patients often do not fully regain function in the injured area. But now a team of surgeons has found that repairing a motor nerve in rats with an intact motor nerve yields better results than using a sensory nerve.

Surgeon Gregory Borschel has found that larger nerve fibers of motor nerves are better for regeneration than smaller sensory nerve fibers.
Credit: Image courtesy of Washington University School of Medicine

When repairing severed or damaged motor nerves with a donor nerve graft, surgeons have traditionally used a sensory nerve from another area of the patient's body. However, these patients often do not fully regain function in the injured area.

But now a team of surgeons at Washington University School of Medicine in St. Louis and Barnes-Jewish Hospital has found that repairing a motor nerve in rats with an intact motor nerve yields better results than using a sensory nerve. The research appeared in the March issue of the journal Microsurgery.

Motor nerves control movement in the muscles, while sensory nerves receive sensory stimuli, such as pain. A significant difference between the two types of nerves is that motor nerves have much larger axons, the thread-like extensions of the nerve cell that carry nerve impulses throughout the body.

The researchers, led by Gregory H. Borschel, M.D., a plastic and reconstructive surgeon at the School of Medicine and senior author of the paper, defines the question of this work as seeking to determine why motor nerves were regenerating more successfully than sensory nerves. Was it because of the nerve's own structure, or architecture, or because supporting cells such as Schwann cells were boosting the regeneration"

To find an answer, the researchers broke down the nerve architecture by chopping up motor, sensory and mixed nerves. They divided the minced nerves into groups by type, inserted the mush into tiny silicone tubes and encouraged severed motor nerves to regenerate through the mixtures in the tubes.

The researchers found that disrupting the nerve's architecture by mincing it abolished the benefit of repairing a motor nerve with an intact motor nerve. "It turned out there was no difference in regeneration using motor versus sensory nerves through the chopped-nerve tissue," Borschel said.

Several factors contributed to the results, he said. "We know that the axons, or nerve fibers, in the motor nerves are bigger, while the sensory nerve fibers are smaller," he said. "When the nerves are trying to regenerate using a motor nerve as a graft, it's easier for them to use the larger axons of another motor nerve, although the reason why is not clear."

The results could eventually translate into improved treatment for humans who have nerve damage from industrial, recreational or auto accidents.

"The research data is very compelling," Borschel said. "The evidence presented through this study could represent a paradigm shift from what we currently do in the operating room. The current standard of treatment for fixing a gap in a motor nerve is to use a sensory nerve, but we believe that if you use a motor nerve instead of a sensory nerve, then the outcome would be better."

The surgeons in the Division of Plastic and Reconstructive Surgery have begun using motor nerves grafts in limited patient cases with good results, Borschel said, but to clearly demonstrate the difference between motor nerve grafting and sensory nerve grafting in humans, much more study is needed.

One obstacle to the use of more motor nerve grafts is that the human body has a limited number of expendable motor nerves. Currently, surgeons are able to use the nerve from the gracilis muscle along the inner thigh or the latissimus dorsi along the side of the torso.

"This study, in conjunction with other related work from our laboratory, will likely result in a shift away from the use of traditional sensory nerve grafts to the much more permissive motor nerve grafts for reconstruction of injury," said Susan E. Mackinnon, M.D., the Sydney M., Jr. and Robert H. Shoenberg Professor and Head of the Division of Plastic and Reconstructive Surgery at the School of Medicine.

Lloyd BM, Luginbuhl RD, Brenner MJ, Rocque BG, Tung TH, Myckatyn TM, Hunter DA, Mackinnon SE, Borschel GH. Use of motor nerve material in peripheral nerve repair with conduits. Microsurgery, Volume 27, Issue 2.

Funding from the National Institutes of Health supported this research.


Story Source:

The above story is based on materials provided by Washington University School of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Washington University School of Medicine. "Nerves Controlling Muscles Are Best Repaired With Similar Nerves." ScienceDaily. ScienceDaily, 12 May 2007. <www.sciencedaily.com/releases/2007/05/070511203204.htm>.
Washington University School of Medicine. (2007, May 12). Nerves Controlling Muscles Are Best Repaired With Similar Nerves. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2007/05/070511203204.htm
Washington University School of Medicine. "Nerves Controlling Muscles Are Best Repaired With Similar Nerves." ScienceDaily. www.sciencedaily.com/releases/2007/05/070511203204.htm (accessed October 23, 2014).

Share This



More Health & Medicine News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
US to Track Everyone Coming from Ebola Nations

US to Track Everyone Coming from Ebola Nations

AP (Oct. 22, 2014) Stepping up their vigilance against Ebola, federal authorities said Wednesday that everyone traveling into the US from Ebola-stricken nations will be monitored for symptoms for 21 days. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Doctors Help Paralysed Man Walk Again, Patient in Disbelief

Doctors Help Paralysed Man Walk Again, Patient in Disbelief

AFP (Oct. 22, 2014) Polish doctors describe how they helped a paralysed man walk again, with the patient in disbelief at the return of sensation to his legs. Duration: 1:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins