Helping Dogs (and Humans) With Spinal Cord Injury Walk Again

Published: January 20, 2012  |  Source: medicalnewstoday.com
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On Wednesday, US researchers announced they are testing a new drug in dogs that has already proven effective in mice. The drug is designed to substantially reduce the hind limb paralysis that follows certain spinal cord injuries. There are currently no therapies that can do this. The researchers suggest if the drug succeeds in dogs, it could also work in humans.

Researchers from the University of California, San Francisco (UCSF) and Texas A&M College of Veterinary Medicine & Biomedical Sciences have teamed up to carry out the work, with the help of a three-year grant of some $750,000 from the US Department of Defense.

Dr Linda J. Noble-Haeusslein, a professor in the UCSF departments of Neurological Surgery and Physical Therapy and Rehabilitation Science, designed the intervention. She told the press that “it would be phenomenal if it works”.

“We are in a unique position of being able to treat a dog population where there are simply no current therapies that could effectively improve their hind limb function,” she explained.

The drug is not designed to regrow injured pathways in the spinal cord. Instead, the objective is to limit secondary damage to the spinal cord, where many types of injury trigger a chain of chemical reactions that damage nearby cells and pathways, and collectively reduce various functions, including that of the hind limbs.

UCSF has already shown that this works in mice, when a few years ago Noble and another colleague at UCSF, Dr Zena Werb, found that blocking the action of a protein helped the animals recover from spinal injuries.

The protein, which is found in the spinal cord, is called matrix metalloproteinase-9. It degrades pathways in the cord, causing local inflammation and cell death.

Now, it is up the Texas team to try the drug on dogs.

Other scientists have already established that if as little as 18 to 20% of the nerve fiber tracts in the spinal cord remain intact, then movement in the hind limbs can be preserved.

The Texas team will be testing it only on certain breeds of injured dogs: those that have short legs and long torsos, such as corgis, beagles and dachshunds. These breeds often suffer spinal injury when a disk in the spine ruptures spontaneously and causes damage to the underlying spinal cord.

The Small Animal Hospital at Texas A&M University sees about 120 dogs a year with such injuries, that lead to sudden onset hind limb paralysis. Currently, the best way to treat them is with a surgical procedure similar to that performed on humans.

Now, with their owners’ consent, the dogs will receive the experimental drug.

As well as being of benefit to dogs, if successful, the drug offers an opportunity to develop a treatment for humans, who can also suffer from a similar type of spinal injury for which there is no current treatment that significantly reduces paralysis.

Injuries to the spinal cord are among the most expensive to support: they can cost the health care system millions of dollars per patient over their lifetime. And this is in addition to the tragedy and devastation they cause, shattering and altering lives dramatically.

Many such injuries occur in young people with long lives ahead of them: most of the 12,000 Americans who suffer spinal cord injuries every year are between the ages of 16 and 30, according to the National Spinal Cord Injury Statistical Center, which is at the University of Alabama, Birmingham.

The National Statistics Center estimates around 265,000 people in the United States today are living with such injuries, including many wounded soldiers who have served in war zones.

Working alongside Noble in the new study will be Jonathan Levine, a doctor in veterinary medicine and an assistant professor neurology at Texas A&M University.

Levine will be giving the dogs the protein-blocking drug via injection. He will then take them through rehabilitation and assess their recovery.

In the meantime, at UCSF, they will be doing further work to refine the drug to optimize recovery.

Written by Catharine Paddock PhD
Copyright: Medical News Today