Purdue News

May 17, 1989 Purdue Paralysis Study Expands After Year of Promising Results West Lafayette, Ind. – Purdue University researchers studying the effects of electrical stimulation on paralyzed dogs say they're both frustrated and encouraged by the results so far of their study, which one day may help humans with spinal-cord injuries. "We simply need more dogs," says Professor Richard B. Borgens, director of the Center for Paralysis Research in the School of Veterinary Medicine. "We're now accepting dogs that are paralyzed as a result of spinal fractures, in addition to those we've been taking with disc herniations." So far 39 dogs are in the study, which began last year and is funded by the Spinal Cord Society, Fergus Falls, Minn. Borgens says he'd like to have 60 to 80 dogs total to complete the first study. The research involves electrically stimulating nerves near the spinal-cord injury. The same technique applied to laboratory guinea pigs with spinal injuries resulted in nerve regeneration within the spinal cord and recovery of certain neurological functions, Borgen explains. "We want to know if this is clinically meaningful and have moved the tests to naturally occurring paraplegia in dogs," says Borgens, associate professor of developmental anatomy. Dogs accepted for the study are implanted surgically with either an active miniature electrical stimulator or with a sham unit. Neither the Purdue researchers nor the owners know which type of unit is put in any particular dog because the information is kept in a code. At the end of six months, when the dog comes in for its final checkup, the code is broken and the status of the battery unit revealed. If the dog had an inactive unit, it's given an active one if the owner wants it. The animal is then re-checked six months later. Dr. James P. Toombs, who does most of the surgeries, says 20 of the 39 dogs in the study have improved, mostly in better bladder control. Of the 20, 11 had active units. Nine of the 20 dogs that improved are now walking. Five of them had active units, two had shams and the six-month waiting period for the last two has not been reached, Toombs says. However, Toombs and Borgens both caution that it's still too early to know if the electrical stimulation is working. For one thing, Toombs says, each dog is operated on to decompress, or relieve swelling in, the damaged spine. Also, some of the dogs now are being given a drug that can restore function to damaged but intact nerve fibers. "The results are interesting but also frustrating because we don't have enough dogs to draw any real conclusions," says Toombs, assistant professor of small-animal orthopedics and neurosurgery. Raven, a six-year-old Welsh corgi owned by William and Christine Shriner of Bloomington, Ind., ruptured a disc in early 1988. The Shriners were thinking of having the dog put to sleep when their veterinarian suggested the Purdue program. Last summer Raven got a sham unit, which was replaced this past February with an active one. "Before the surgery, Raven had learned to get around by sort of hopping, and I would 'tail-walk' her," says Christine Shriner. "Then, after getting the active unit, she really took off walking in March." Edelweiss, a miniature dachshund owned by Andrea and Mark Schultz of New Palestine, Ind., first got a sham unit in April 1988. For the first six months that she had the inactive unit, the dog got around using a little wheeled cart that supported her hind legs. Eventually, Edelweiss was able to do without the cart and run somewhat, although she dragged her back legs, Andrea Schultz says. This past fall the Schultzes had an active unit implanted in their pet, whose mobility has improved gradually, they say. "We've really noticed it with her running," says Mark Schultz. "Since the second implant, she runs on all four legs, though it's somewhat jerky. "Also, she now can go up a step we have at home. Before the active unit was put in, her hind legs just couldn't push her up it." Borgens says dogs can be recommended either by owners or veterinarians, who should call the following persons: Ellen Adams, Center for Paralysis Research, 317-494-8587, or Drs. James Toombs or Michael Bauer, Purdue School of Veterinary Medicine, 317-494-1107. Each dog that is a candidate first will undergo, at no charge, neurological and other tests to determine the extent of the loss of function, Borgens says. If the animal is accepted, the only costs to the owner will be travel and lodging; Purdue will pay all medical and surgical costs. Purdue News Service: (765) 494-2096; purduenews@purdue.edu To the Purdue News and Photos Page