Why doctors can’t just remove the pain nerves in an area with chronic pain?



So, there are pain nerves, right? Different from the movement nerves. Normally you want to have functional pain nerves so they can alert your brain to an injury. If someone has, say, arthritis, or a bad joint or bone injury 30 years ago that has long since healed, those nerves are just sounding the alarm 24/7 even though there’s nothing to be done about it. So, since that pain isn’t giving you any new information you can use to help take care of your body, and is actively impeding your life, why not just remove the pain nerves, or cut them off from the nervous system? They are useless at that point for actually reporting things that would impede the mechanical function of that area, so getting rid of them would be a net benefit.

In: Biology

Because removing the pain doesn’t solve the problem. Take your arthritis example. Arthritis is literally deteriorating the joints. Taking the pain away doesn’t stop the deterioration. You have to treat the disease, not just make the pain go away.

Have you ever tried to stand up after your leg or foot falls asleep from lack of circulation?

This is a thing, its called nerve ablation. Its just not a common treatment.

The preferred treatment is called a nerve block and involves injecting a long lasting anesthetic into the nerve. Nerve block injections are cheap and can be done in an outpatient setting, regardless of what nerve is being targeted. On the other hand, nerve ablation is a reasonably complicated surgical procedure if its targeting a nerve in the peripheral nervous system and a very complicated, high risk procedure if its targeting a nerve in the central nervous system.

Ablating a nerve in the peripheral nervous system isn’t a permanent solution because the nerve will grow back after about a year. Nerve blocks don’t last that long, but again they’re much easier to do.

Because of the high cost/complexity/risk of nerve ablation, its very rarely done and only then in very severe cases where nerve blocks haven’t been effective.

Had ablation on the nerves in my lower lumbar after a bad car wreck. Literally a miracle cure for the pain!

I did have a portion of my nerve on my little toe removed along with a calcium build up. Night & day. I cannot feel anything in a small portion. This was over 20 years ago.

Other users have given great answers but they’ve all missed something significant: Substantial pain processing happens in the central nervous system as well (and we can’t remove that) AND that part of the nervous system becomes hyperactive, basically telling you that you’re in pain (often severe pain) even with little or even zero painful input.

An analogy might be stubbing your toe once; it probably hurts but it will go away. If you instead hit it with a hammer really hard 10 times over 10 days, you’ll probably really change your behavior to deal with that toe. On the 11th day, you’ll still be keenly aware of the damage done to your toe and it will still be extra sensitive, even if nothing happened to it that day. During long term chronic pain, your nervous system is constantly in that “11th day” pain state, where it’s super sensitive to any type of stimulation.

Source: I’m a chronic pain treatment researcher

I suffered knee trauma 20 years ago…and I asked why it never stopped hurting even though it’s long since healed. And they said something about nerves always firing signals…and there is nothing they can do. I just have to live with the pain.

Sometimes I feel like cutting off my leg would be the better option. If I ever do get rich enough…I will seriously try to get someone to make my knee stop hurting.

I mean, I’m used to the pain by now. But it feels…worse and worse as I age. And the weather changes make it such that some days my knee is soo stiff it’s hard to walk on it at all. It’d be nice to find some relief. But I’m already resolved to the fact that it’s always going to hurt.

I believe the nerves to sensation and movement are sometimes the same? I had surgery called selective peripheral denervation for cervical dystonia. ELI5 version: I have a movement disorder that causes my neck to turn right and muscles to contract when they shouldn’t. The doctors cut open my neck and removed large sections of certain nerves so that my neck wouldn’t turn right anymore.

As a result of the surgery, the right turning movement has stopped BUT I also have severely decreased sensation in the back of my head. This isn’t a complication of the surgery, it was a fully anticipated result of the surgery. So I’m assuming that the same nerves that caused the movement also provided sensation, or else they would have left the sensation nerves alone and just removed the movement nerves.

There’s 2 main reasons for this:

1) You can end up damaging/removing things you still need.

Think of nerves like power lines. There can be lots of stuff running along there: power cables, telephone lines, cable, internet, etc. Removing a nerve because it’s sending pain signals you don’t need is like chopping down the entire power line because you don’t need cable anymore. *Technically* it can do the trick, but unless you can guarantee the only thing running along the power line was the cable wire you can mess up a bunch of other important stuff.

2) You still aren’t addressing how the brain is interpreting pain signals.

A nerve’s job is to send electrical signals to the brain which then decides what those signals mean. Sometimes the problem isn’t always with the nerve, but the brain being extra sensitive to certain signals. Google something called “phantom limb syndrome”. The ELI5 for that one is that people who lose arms and legs still feel like those limbs “hurt” long after they’ve lost them.

I had this done when I was a kid. Chronic pain in my feet that still haven’t gone away. It has been 16ish years since I’ve had it done and never received relief.

A very simple answer here..
Simply if nerves are removed it can cause a whole new set of problems! Doctors are trained to take care of the problem at hand not to create new problems.

A Doctor’s Oath

Primum non nocere – First, Do no Harm!

Not to mention if nerves are removed this can cause harm because you can hurt yourself badly and in theory you may never know it. Until it’s to late that is..

Had a friend in university with what was then called [Reflex Sypathetic Dystrophy](https://en.wikipedia.org/wiki/Complex_regional_pain_syndrome) caused by having her foot crushed.

The pain started as a burning in her foot and moved up her leg. They cut the nerve chain in her knee and it stopped her being able to feel the burning, but her leg also lost the ability to cool itself – she stopped sweating below the cut.

Unfortunately it didn’t prevent the spread of the disease and a year later they cut the nerve chain in her groin. Same side effect – strange clammy not sweaty skin on that leg.

We didn’t stay in touch after university, but I heard she passed from it a couple years later. 🙁

The OPQ assumes that a foot pain starts in the foot. That isn’t always true.

I can’t give you a medical explanation for it, but my wife’s grandfather had his legs amputated just below the knees. He lived another 10 years but his feet hurt the rest of his life. Somewhere in his brain, he was still processing the pain that has existed before the amputation. That was 30 years ago and maybe the doctors have a solution now, but they did not then.