Paralyzed Dogs Walk Again
Before you read any further, take a look at this video. Note the captions that appear at the bottom of the frame. In order, they read Dog 7 (his name is Jasper, by the way) – preintervention; One month post OEC transplantation; Three months post OEC transplantation; and Six months post OEC transplantation.
You’re back? Good. What did you think? What if I told you that before these videos were taken Jasper had severely injured his back, and after months of treatment he had neither recovered the ability to use his hind legs nor could sense what should have been a severely painful stimulus to his hind legs. This is the type of injury that dachshunds (and other long-backed, short-legged breeds) are prone to as a result of severe intervertebral disk disease. Unfortunately, the vast majority of dogs that have failed to show significant signs of improvement soon after their injuries never recover meaningful function in their hind legs.
You must be wondering what was different in this case. Jasper was part of a study that looked into whether transplanting cells derived from the mucosa of the dogs’ own noses (olfactory ensheathing cells or OEC) into the injured part of their spinal cords could help them regain function. The answer was a resounding, "yes."
Thirty-four dogs were included in the study. Twenty-three received injections of olfactory ensheathing cells (after isolation and multiplication in culture), and eleven were given injections of the cell transport medium but no cells. The paper’s authors found the following:
Recipients of olfactory mucosal cell transplants gained significantly better fore–hind coordination than those dogs receiving cell transport medium alone. There were no significant differences in outcome between treatment groups in measures of long tract functionality. We conclude that intraspinal olfactory mucosal cell transplantation improves communication across the damaged region of the injured spinal cord, even in chronically injured individuals.
As cool as the results of this research is, there are a few drawbacks. First of all, this procedure is not exactly available at your local veterinary clinic, and I expect that even if it ever does become clinically-accessible, its cost would make it untenable for most clients. However, the study was not really aimed at veterinary patients. The dogs were a stand-in (no pun intended) for people who have experienced serious spinal injuries, and as the paper states:
The conclusion drawn from this approach is that olfactory mucosa-derived cell transplants can mediate substantial change in function in a clinical spinal cord injury model. However, the effects are likely to be on local intraspinal circuitry [in other words, reflexes] rather than on long tract function [that is important for the recovery of functions important to human patients, like motor control of the hands], which leads us to conclude that this intervention alone is unlikely to have appreciable benefits in the treatment of human spinal cord injury but, nonetheless, may form a useful component of a multi-faceted approach.
Even with its limitations, I think this study is pretty impressive and suspect that Jasper and his owners agree. The paper is available in its entirety on the Brain website.
Dr. Jennifer Coates