First, I received a referral to a neuro who specializes in peripheral neuropathy. (The neurologist I see for migraines, for example, would not have been the right person.) Second, I kept pushing for a diagnosis. (A large fraction of us are diagnosed as "idiopathic", which makes it difficult to understand whether treatments that target causes rather than symptoms might be helpful. Also makes it difficult to qualify for clinical trials.) Third, after running through all the normal tests, I pressed them for low-probability possibilities, and they proposed a blood test, pretty much to get me off their hands, I think. Fourth, the blood test came out positive, which got me a referral to another specialist. Fifth, the blood test turned out to be a false positive, but the new specialist turned out to be the right person to diagnose the problem anyway, so I landed on an answer that makes sense. (I have drug-induced peripheral neuropathy, but from a drug where the symptom is really, really rare.)

So at the end of the day, I just kept persisting until I lucked into an answer. In the meantime, I had started ramping down on the problematic drug, which halted the progression although it didn't reverse it (that pattern was part of what led to the diagnosis), and I hunted through this and other sources to find ways to accommodate and tolerate the symptoms.

In my case, it's very likely that the damage is permanent. On the positive side, I don't (yet) have pain, and I've found that once I landed on a suite of things that help minimize the symptoms (shoes, socks, warmth, etc), I started going for longer and longer periods during which I am mostly unaware of the symptoms -- that is, if I think about them, I'm aware they are constant, but much of the time, I'm just not conscious of them.

This is how, for example, floaters in the eye work. When I first started getting floaters, they were really annoying and disturbing. Discussed them with my eye doctor, learned when I should worry and when I shouldn't, and over time, my brain stopped noticing them. They are still there, but most of the time, my brain just sees past them, so they are effectively invisible.

To make that work in my case, I need to be at peace with the symptoms, not worried about them, and moving on with my life. That means it doesn't work as well for pain, although it does work for pain to some degree -- one of the best solutions I've found for chronic pain is mental distraction, which is why mine often did better when I had a full engagement of my mind at work to distract me. The migraine drugs are much more effective for me when combined with the need to pay attention to something else. Cognitive behavioral therapy for pain works on this same principle, I believe.

Sorry for the long essay, and hope something in it helps!