What does it take to get a damaged nerve cell to repair itself? Scientists are still shaking their heads because we simply don’t know. Oh, a small injury to a single nerve takes time but it can regenerate. But the process is very slow and doesn’t always result in normal function.
Take that scenario and multiply it many times over with major nerve injuries. Add a stretch or traction injury to the nerve plexus and the outcome can be very poor indeed. The nerve plexus is an area where many nerves join together before separating and going to their individual destinations.
Multiple and/or major nerve injuries occur as a result of birth trauma, gunshot wounds, explosions, crush injuries, tumors, and motor vehicle accidents. Treatment may depend on the type of injury, severity, and location.
In some cases, time and support are all that can be offered patients. In patients with transected nerves (cut all the way across), surgery to stitch the ends back together or graft nerve (or other) tissue between the two ends may be necessary. But patients are warned ahead of time that they may only get partial control back.
Nerve transfers are another way to manage some major nerve injuries. A donor nerve taken from the same limb or another area is used to restore valuable function in the affected arm or leg. But nerves are very delicate and disturbing them to move them or surgically repair them has its own downfalls and complications.
Whether a patient is waiting for a return of function from nerve graft or nerve transfer, the process is slow. Many other factors can get in the way and prevent full functional repair.
For example, nutrition is a key factor. But even more important are the changes the tissues supplied by the damaged nerve are experiencing because of the loss of nerve impulses. Fat and fibrous scar tissue can get in the way of the regenerating nerve bridging the gap from one side to the other. And without the nerve signals, the muscles start to waste (atrophy) and get weaker and weaker.
The need to speed up nerve healing and recovery has led scientists to explore molecular and cell-based therapies. The body does have a protein called nerve growth factor. There’s just not enough of it to quickly or adequately repair a major nerve injury. So maybe there’s some way to use stem cells to grow more growth factor and thus stimulate faster nerve re-growth.
Other researchers are looking for ways to deal with the atrophy that occurs when nerve tissue is off-line. They are taking a look at the space between the nerve and muscle called the myoneural junction.
This space is where all the biochemical action takes place. Electrical signals passing down the length of the nerve turn into chemical signals that cross the gap between nerve and muscle and instruct the muscle to contract.
With a nerve injury, no messages are being sent down the nerve. No chemical changes occur in the junction. The muscle remains quiet. Perhaps there’s a way to artificially stabilize the neuromuscular junction and stimulate the muscle until the nerve can take over. This could possibly prevent the degeneration that occurs around the nerve cells and perhaps help prevent atrophy as the muscle waits for nerve signals to resume.
What does all this mean? Basically, that we need a breakthrough in our understanding of nerves in order to find better ways to treat nerve injuries. If scientists can break the code of the molecular biology involved in nerve injury and repair, it might be possible to find alternate ways to help the regenerative healing process along.
Until then, surgery remains inadequate and patients are at risk for a poor prognosis following major nerve injuries. That’s the bad news. But the good news is that scientists are indeed busily researching and investigating many different ways to approach this problem from all sides. It’s only a matter of time before we have the information needed to guide faster and more effective nerve regeneration.