The term peripheral neuropathy encompasses many presentations.

When a nerve is entrapped or caught up in another process, it sends pain signals. When this becomes excessive then we say there is pathology in the nerve-- neuropathy. Since it is not in the CNS it is peripheral.

Many PNs start as sensory ones in the distal parts of the body.
(feet and hands), and may progress up toward the spinal cord.
This is the metabolic type, like I had and like diabetics have.
Numbness, tingling and pain follow, and includes many mixtures of all the symptoms. Then severe pain in the whole foot may result. (then sometimes total numbness, depending)

From your descriptions, you have pain in the ankles, and now coming to an arm? This anatomical difference suggests that "something" is causing your nerves in your ankles compression or inflammation. I know when my knee flares up, it compresses the meniscal nerve, this happened to me this week in fact.
So I slap on my Lidoderm patches for a few days in a row and then it quiets for me.

I also have a bad ankle...in my left foot. I get pain in the front of it sometimes, and I know that is related to two things.
A surgery I had when I was 12 to remove a tumor (cavernous hemangioma) on the top of my instep (a messy procedure because there were no lasers then) and a horrible spider bite I had about 6 yrs ago. Since that spider bite (which gave me pain for a good 3 months), that ankle is stiffer and will pain me if I ride a bike at the gym for more than 15 minutes. In fact I can only do 5 min sessions, with a rest inbetween, or else! So I think there is an adhesion in there, and when I tug or pull it with movement, it HURTS. When this happens I use Salonpas patches on it. (these are OTC and very good for
minor arthritis or minor inflammatory pain. I have been using these for years, since they came to US. They have been very popular in other countries for many years. Because they don't advertise on TV many people here don't know them. They are far better than the BenGay or IcyHot type we do see basketball players pitching lately.
http://salonpas.us/

I only use the ones with methyl salicylate in them (they make several types). I find these better for foot/ankle and toe arthritis than taking oral NSAIDs or Tylenol. I personally prefer keeping meds to a minimum if possible. So far I have been able to resist RX meds, and I have longstanding PN. I do not have progression from it, but I do have worsening arthritis which causes it own pain profile.(and that confuses the issue, when you are new to it...it is hard to filter them out from each other as which is causing the discomfort.) This is why I use both type of patch at times.

You will want to be careful with heat on those nerves. I would be doing an ice treatment for 20 minutes at least each day.
Keep a journal to show what triggers you. Activity? new shoes?
viral infections? certain foods? Don't get the flu shots.

You are the best advocate in the treatment of your pain. The doctors can only go so far, and offer what they know. Once you have a solid diagnosis (and many are not), you can proceed to feel better. You are in your body 24/7... the doctors cannot anticipate YOU and your perceptions. I have found that being observant and open, are your best tools.
And also patience, since healing takes a LONG time.

I'll sum up with a personal story. I have a friend from one of my jobs, (I work contingent mostly so I can have my summers off for our remote home in the far North). This gal has 3 kids.
Her 3rd was a later in life baby, she had him when she was almost 40. After his delivery, her ankles went out on her. She told me she had such pain, she was crawling on the floor...couldn't walk. It turns out the 3rd pregnancy set off an autoimmune Rheumatoid arthritis for her. It spread to her wrists also, and some in her neck. So she was put on methotrexate, and finally the injectable of it, plus Humira.
For pain she finds the old fashioned drug Salsalate (Dicalcid) most effective for daily pain. Her ankles remain swollen and she wears slip on shoes for them (no straps). She can work effectively and
with little discomfort. Sometimes she wears a wrist brace. Prior to this last pregnancy she had NO symptoms. So inflammatory arthritis is a sneaky thing.

So while you have those conduction studies and biopsies, think also that you may have either Rheumatoid arthritis or some inflammatory tendon thing going on there. Your pain is concentrated there, and is indicating "something". And sometimes it takes a while to understand the cause.