Brian's Breakthrough: Repairing Paralyzed Nerves--In-Depth Doctor's Interview
Justin Brown, M.D., Neurosurgeon, Director of the Neurosurgery Peripheral Nerve Program and Co-Director of the Center for Neurophysiology and Restorative Neurology at UCSD, talks about nerve grafting and nerve transfers.
Tell me a little bit about Brian, when you first saw him, what happened?
Dr. Brown: Brian had an injury to his knee. He was doing a track and field event and he took a jump and when he fell he apparently injured his knee. There’s a nerve that runs right past the knee called perineal nerve which causes you to be able to lift your foot and your toes and when he injured his knee he completely lost function of that nerve and had impaired ability to walk.
So there’s this healthy kid who was up for a scholarship to play football, then he could barely walk?
Dr. Brown: Yes. He could walk but it required a brace.
He was in a wheelchair for about three months, right?
Dr. Brown: That probably was post op, it was his knee repair and that sort of thing. If all of this had gone wrong with his nerve and his nerve had never recovered he would have required a brace and could not have played sports any more.
So it was basically his nerve that was making him so he couldn’t walk very well?
Dr. Brown: Right, his nerve was not functioning any more.
Can you explain again to me what was happening to his nerve?
Dr. Brown: In his case, his nerve was entrapped in scar tissue. It was completely compressed. You can imagine a garden hose -- if you pinch it off it can’t bring water from one end to the other. The nerve is the same way. If they have enough pressure on them they can’t conduct signals from one end to the other. So his had enough pressure on it that it could not conduct, and left in that condition he would never have played again.
Did that happen overnight, did it happen when the injury happened, did it happen as they repaired his knee?
Dr. Brown: It’s hard to know the sequence of events exactly. Certainly the nerve was injured at the event, it was probably stretched badly. Maybe without the buildup of scar tissue it would have recovered on its own. But the scar tissue from the initial injury, the scar tissue from the surgery that followed all of those probably added to this nerve being compressed in addition to the initial injury.
So before what was there to help him?
Dr. Brown: Well this isn’t actually an innovative procedure like the nerve transfers we’ll talk about later. This is a relatively traditional procedure.
What did you do?
Dr. Brown: We decompressed the nerve. We identified the nerve, the healthy part above the injury and the healthy part below the injury, and then what we did is just dissect the scar tissue off the nerve. For Brian it looked very much like initially we would have to cut the nerve out and graft it to give it something to grow through. But as we began to work our way through the scar tissue we found out that there was healthy nerve underneath that, it was just extremely compressed. We just dissected all the way out of the scar tissue from one end to the other until we had healthy nerve uncovered.
And will the nerve re-grow?
Dr. Brown: The nerve re-grows.
How long from that surgery until he’s back up and well again?
Dr. Brown: It was probably about four or five months before we started to see him move his foot.
When you decompress the nerve, do you have to wait until it re-grows to move his foot? Is that how that works?
Dr. Brown: That’s usually how that works. There are degrees of injury. You can have a type of injury where it’s just not getting the blood flow and as soon as the blood flow comes back things work. You can have the type where the myelin or the insulation has been crushed and that needs to grow back and that can take two to three months. Or you can have it where the wires, the axons inside of it are completely cut and they need to grow from the point of cut all the way down the nerve until they reach a muscle and that’s about a millimeter a day. He had primarily that type of injury.
What is a millimeter a day to a normal person? What kind of growth is that? Can you even see a millimeter a day?
Dr. Brown: About an inch a month.
There’s that type of surgery and then we’re talking about a different type of nerve surgery, correct?
Dr. Brown: Right. So there are several different types of surgery to recover nerves when they’re not working like that. Obviously the simplest is just to get pressure off and let it recover. If the nerve itself is so badly damaged, I talk to patients about the train on the train tracks. If the train tracks are so badly damaged that you can’t get the axons on the train from one end to the other then it requires some way of repairing that. And there’s two basic ways of repairing. One is to essentially build a new train track, find a nerve somewhere else in the body you can do without cutting a piece of that and building a bridge across where that damaged part of the nerve used to be.
Where are nerves that you can do without, where do you usually find those?
Dr. Brown: The one that is most commonly used is called the sural nerve and it does a patch of skin on the outside of the foot. We love it because it’s like thirty centimeters long in adults. A very long, thin nerve, you can take it from the back of the knee all the way down to the ankle and use that. And the only deficit you get is a patch about so big on the side of the foot.
So you’re taking people who are somewhat paralyzed and giving them the ability to walk again?
Dr. Brown: Right.
Why is that? What is helping these people?
Dr. Brown: If you have that kind of damage there’s no way the nerve comes back on its own without you doing some rebuilding type of procedures. So there’s that part called grafting and the other is called nerve transfers. If you have two nerves running right next to each other one of which works perfectly well but is less important and one that is out that’s very important you can imagine cutting and splicing one in to the other so that now the less important nerve runs the more important function.
Is grafting, kind of the concept?
Dr. Brown: That is exactly the concept. So one of the ones that works the best with that is the patient who has had an injury to the nerves where they can’t flex at the elbow and if you have a perfectly good hand those nerves have to run past the elbow all the way to the hand. We can take a portion of that nerve and move it over to the biceps. And what used to help run their hand now becomes biceps function.
What is the most extreme case that you’ve seen in someone?
Dr. Brown: The most extreme case we’ve seen is a patient with their entire arm paralyzed, limp and numb. It’s usually a stage procedure. We see them in a matter of a couple of years recover the ability to flex the arm, maybe have some basic hand grasp function and get sensation back in the fingers.
Are these trauma accidents?
Dr. Brown: They’re generally trauma.
Like car accidents?
Dr. Brown: Motorcycle accidents are most common, car accidents, gunshot wounds, knives to the neck, even difficult birth, difficult delivery. I mean if they child’s head is pulled away from his shoulder during delivery, sometimes that will rip all the nerves in the neck.
And for a child like that can you get them back to normal?
Dr. Brown: Same operation. You have to do the nerve transfers or the nerve graft. We have to open up find the damaged area cut it out and lay new nerve graft in.
How long have you been doing this?
Dr. Brown: I’ve been doing this about seven years now.
Are there some patients that it just doesn’t work in?
Dr. Brown: Yes, every once in a while an operation like that will fail?
Dr. Brown: We don’t know, we wonder after surgery if they pull the nerves apart. Sometimes there are issues with patients coming too late. We know that after a year of waiting, after a year from the time of injury if we try to do these operations they don’t work as well. Sometimes the injury to the nerve extends over a very large area of the nerve, the longer the graft is the less well it works. So a lot of factors you have to consider.
Is there anyone you wouldn’t do this on besides the people after a year of trauma?
Dr. Brown: I think it’s very important the patients have realistic expectations of what they’re going to get. If there’s one or two muscles missing we can give them a wonderful arm. If the entire arm or entire leg is paralyzed we can give them only very basic function in the arm. I want patients to have realistic expectations. We need them to be highly motivated. It requires someone to really work hard to learn how to retrain their arm to work once again.
This is for people with nerve damage and not paralysis, or anyone with spine damage or anything like that, right?
Dr. Brown: We’re using it for that now as well.
And how does that work? That seems huge.
Dr. Brown: It is huge. In the spinal cord injury for example you have the area where the spinal cord is damaged and everything above that is normal. So you can imagine a person who has broken their neck and their shoulders work fine and their biceps work fine but their hands are paralyzed and then everything below that is paralyzed. If you have a nerve nearby that works in that condition, the biceps works perfectly fine but the hand doesn’t. You could imagine doing the same kind of rewiring or grafting as you talked about from the muscles that work from the biceps in to the nerve that causes the hand to close or the nerve that causes the hand to open.
Now how long have you been doing that?
Dr. Brown: I’ve been doing this for three years.
How rewarding when you give back someone who has been told, sorry you’re paralyzed?
Dr. Brown: It’s very exciting and particularly since it’s an area where there were no answers before and now these patients are coming and finding out that there are things that we can do. In fact, in a lot of nerve injuries a lot of doctors out there will tell you there’s nothing that can be done. Most of these patients in fact find us on their own. They get on the internet and they search and they discover something can be done and they seek you out themselves.
So you can make someone’s hands move. Would that transfer to their legs if they’re paralyzed?
Dr. Brown: The basic rule of thumb is if there is something in that limb we can probably give it something else. Patients whose spinal cord injury is cut right in the middle of their chest, it’s going to be hard to get their legs to go. But somebody who has at least the ability to flex at the hip or extend the knee, we can give the more.
How much more can they expect, could they walk?
Dr. Brown: I would hope that they could walk yes, particularly if it’s one leg.
Would this have an effect for stroke patients as well?
Dr. Brown: Stroke patients are a little bit more complicated. They’re like the incomplete spinal cord injury patients where instead of having muscles that work perfectly and muscles that don’t work at all there’s a whole spectrum of muscles that work. Too much, too little, turn on too early turn off too late. So for that, we have a special way of doing nerve studies where we test all the muscles within the arm or within the leg when they try to do a particular activity and find out which ones are antagonizing the activity, which ones are assisting the activity, what’s getting in the way and what’s helping.
Do you want to talk a little more about how important timing is when you sustain an injury like this? Let’s say you get a life threatening injury and you’re in the hospital for a month and then you’re in rehab. It’s like six or eight months then, right?
Dr. Brown: It should be about three months by the time you get done with all that. Rehab doesn’t usually last that long. If they get to a doctor at that point of time they’re not getting bad information and they’re doing just fine. But a lot of them are told, sorry nothing can be done, that’s it. And then they may in a year start looking in to things. Where a lot of times they’re told, wait it will probably come back within a year. So they’ve waited for the year and now the year is up and they have nothing and then they start looking. The window applies to nerve injuries. The spinal cord injuries you talked about you can usually do things to them several years out. Strokes and brain injuries the same thing, many years out. But the nerves when there’s no connection to the muscle that muscle begins to degenerate and that degeneration after about a year is difficult to reverse.
I understand that Brian’s condition was called foot drop, can you explain that?
Dr. Brown: Sure. What Brian had by injuring the perineal nerve is what’s called foot drop. Foot drop means that you cannot pull the foot up. It pushes down and he will stand on his toes but when it comes time to walk he will catch his toes on something, his foot will drag behind him and it’s very difficult to walk around.
That happens a lot to stroke patients too, right?
Dr. Brown: It does. Stoke patients spinal cord injury is actually one of the more sensitive nerves or muscles in the body.
You talked about the nerve on the back of the leg, what does it look like?
Dr. Brown: The sural nerve, the one we use for graft, looks a bit like a capellini noodle and sort of the consistency after it’s cooked as well. It’s about a millimeter and a half in diameter, it runs about thirty centimeters in length.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
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Justin Brown, M.D., Neurosurgeon
To read the full report, Brian's Breakthrough: Repairing Paralyzed Nerves, click here.