Posts tagged nerves
Articles and news from the latest research reports.
Mystery disease unraveled by Stanford neurologist
At first, Marc Laderriere thought that his decreasing energy was just age catching up to him — he was about to be 50. But something about that explanation didn’t sit right.
"At one point, one of my doctors said, ‘This is definitely a little strange. I don’t know what you have, but it could be nerves,’" Laderriere recalled.
He was experiencing a set of symptoms that were unusual but did not strike him as significant: Hot weather sapped his strength and made him dizzy, but he was sweating less. In cool weather, he never got goose bumps.
As a young man growing up in France, Laderriere had always been active. “I did a lot of skiing, a lot of swimming,” he said. When he came to work in the United States, as a director of wine sales for the Vina Robles Winery & Vineyards in Paso Robles, he said he became a workaholic. “I completely accepted that way of life,” he said.
The more he traveled for his job, the less time and attention he paid to his health until he recognized, with some discomfort, that he was not in such great shape any more. He knew he should add exercise to his daily routine, but the fatigue he felt was overwhelming.
Laderriere, who lives in Paso Robles, started first with visits to local doctors. He had a variety of standard tests, with the thought that he might have developed diabetes. That was not the case. When one physician suggested it could be nerves, he went to see a local neurologist who sent him back to his original physician, still without a diagnosis. His symptoms continued and, finally, a local doctor suggested Stanford Hospital & Clinics.
During his first visit, he met with a group of physicians who asked him a lot questions,. “They were picking my brain,” he said, “asking me, ‘What’s wrong with this?’ I did not think to mention to them that I wasn’t sweating, but my wife was with me and she did. One of the doctors said, ‘Hmm, I think you may want to meet Dr. Jaradeh.’”
Step Forward in Effort to Regenerate Damaged Nerves
ScienceDaily (Feb. 21, 2012) — The carnage evident in disasters like car wrecks or wartime battles is oftentimes mirrored within the bodies of the people involved. A severe wound can leave blood vessels and nerves severed, bones broken, and cellular wreckage strewn throughout the body — a debris field within the body itself.
Thriving DRG cells. (Credit: Image courtesy of University of Rochester Medical Center)
It’s scenes like this that neurosurgeon Jason Huang, M.D., confronts every day. Severe damage to nerves is one of the most challenging wounds to treat for Huang and colleagues. It’s a type of wound suffered by people who are the victims of gunshots or stabbings, by those who have been involved in car accidents — or by soldiers injured on the battlefield, like those whom Huang treated in Iraq.
Now, back in his university laboratory, Huang and his team have taken a step forward toward the goal of repairing nerves in such patients more effectively. In a paper published in the journal PLoS ONE, Huang and colleagues at the University of Rochester Medical Center report that a surprising set of cells may hold potential for nerve transplants.
In a study in rats, Huang’s group found that dorsal root ganglion neurons, or DRG cells, help create thick, healthy nerves, without provoking unwanted attention from the immune system.
The finding is one step toward better treatment for the more than 350,000 patients each year in the United States who have serious injuries to their peripheral nerves. Huang’s laboratory is one of a handful developing new technologies to treat such wounds.
"These are very serious injuries, and patients really suffer, many for a very long time," said Huang, associate professor of Neurosurgery and chief of Neurosurgery at Highland Hospital, an affiliate of the University of Rochester Medical Center. "There are a variety of options, but none of them is ideal.
"Our long-term goal is to grow living nerves in the laboratory, then transplant them into patients and cut down the amount of time it takes for those nerves to work," added Huang, whose project was funded by the National Institute of Neurological Disorders and Stroke and by the University of Rochester Medical Center.
For a damaged nerve to repair itself, the two disconnected but healthy portions of the nerve must somehow find each other through a maze of tissue and connect together. This happens naturally for a very small wound — much like our skin grows back over a small cut — but for some nerve injuries, the gap is simply too large, and the nerve won’t grow back without intervention.
For surgeons like Huang, the preferred option is to transplant nerve tissue from elsewhere in the patient’s own body — for instance, a section of a nerve in the leg — into the wounded area. The transplanted nerve serves as scaffolding, a guide of sorts for a new nerve to grow and bridge the gap. Since the tissue comes from the patient, the body accepts the new nerve and doesn’t attack it.
But for many patients, this treatment isn’t an option. They might have severe wounds to other parts of the body, so that extra nerve tissue isn’t available. Alternatives can include a nerve transplant from a cadaver or an animal, but those bring other challenges, such as the lifelong need for powerful immunosuppressant drugs, and are rarely used.
One technology used by Huang and other neurosurgeons is the NeuraGen Nerve Guide, a hollow, absorbable collagen tube through which nerve fibers can grow and find each other. The technology is often used to repair nerve damage over short distances less than half an inch long.
In the PLoS One study, Huang’s team compared several methods to try to bridge a nerve gap of about half an inch in rats. The team transplanted nerve cells from a different type of rat into the wound site and compared results when the NeuraGen technology was was used alone or when it was paired with DRG cells or with other cells known as Schwann cells.
After four months, the team found that the tubes equipped with either DRG or Schwann cells helped bring about healthier nerves. In addition, the DRG cells provoked less unwanted attention from the immune system than the Schwann cells, which attracted twice as many macrophages and more of the immune compound interferon gamma.
While both Schwann and DRG cells are known players in nerve regeneration, Schwann cells have been considered more often as potential partners in the nerve transplantation process, even though they pose considerable challenges because of the immune system’s response to them.
"The conventional wisdom has been that Schwann cells play a critical role in the regenerative process," said Huang, who is a scientist in the Center for Neural Development and Disease. "While we know this is true, we have shown that DRG cells can play an important role also. We think DRG cells could be a rich resource for nerve regeneration."
In a related line of research, Huang along with colleagues in the laboratory of Douglas H. Smith, M.D. , at the University of Pennsylvania are creating DRG cells in the laboratory by stretching them, which coaxes them to grow about one inch every three weeks. The idea is to grow nerves several inches long in the laboratory, then transplant them into the patient, instead of waiting months after surgery for the nerve endings to travel that distance within the patient to ultimately hook up.
Source: Science Daily