Based on your last post, it was recommended you go see your doctor for an MRI, at 34 you should have insurance that can cover this expenses. One of the possible causes of your neuropathy, was that you run 4mile per day, And exercising that much, and running is ultimately damaging to the body, especially the bone, muscle,nerves. Running everyday, doesnt allow your body to regenerate so you will eventually obtain complications from those issues.
paraneoplastic syndromes are different depending on what type of cancer you have. of cancer usually have other symptoms, but this is best done with an oncologist/hematologists.

Thanks

I've got insurance, a neurologist and a EMG scheduled for Monday

Sorry, mine is hereditary, CMT type 2, axonal degeneration. I repeat it so often i figure everyone gets tired of hearing it.
It is incredibly frustrating, but Mrs. D.'s advice is spot on. Many people never get a clear diagnosis. Lots of cases remain idiopathic, progressive, and untreatable. The push in the early days is to find out if your symptoms have a definite cause and treatment plan, the earlier the better the prognosis if you are one of the lucky ones.

Susanne, is your CMT type giving you issues with muscles as well as nerves? Since my issues seem to be with sensitive nerves (carpal and tarsal tunnel with widespread tinel sign) I wonder if I have HNPP.

http://ghr.nlm.nih.gov/condition/her...essure-palsies

Jumping in here. Yes, CMT is also known as Hereditary Motor Sensory Neuropathy (HMSN). It affects the muscles and the nerves. (That's just a simple explanation.) CMT is a complicated syndrome. There are over 70 types identified so far and the number is growing. It is inherited.

HNPP (Hereditary Neuropathy with Liability to Pressure Palsies) is the opposite of CMT1A. Here is the home site for it:

http://www.hnpp.org/

CMT1A is a mirror image. It has an extra copy of PMP22 whereas HNPP has a deletion.

The site explains it well. There is DNA blood testing available for HNPP.

anti hu, anti yo anti ri would be some of the blood tests used to look for paraneoplastic antibodies. a neurologist or any doctor could order those tests.

Yes, I have extensive muscle atrophy, with limited range of motion in arms and legs, completely unable to move toes, barely able to move ankles, and progressing. Neuro at Johns Hopkins suspected HNPP as well and I had the test done for it as he found pinched nerves everywhere he checked with EMG, but test was negative. Simple but expensive blood test will tell you.

I don't have any weakness or atrophy yet. When did you first notice the muscle weakness/atrophy as a symptom? Is there a chance the progression will slow/stop?

I may be wrong, but I don't see cancer or even B12 causes for 'sudden' PN. these seem to be more slowly progressing types.

You indicated in another thread that you haven't had an injury, so compression is likely out of the question and no antibiotics or other medications, so toxic shouldn't be a problem either. I'm still thinking you should be worked up for autoimmune more than cancer testing. Immune mediated PN is typically rapid onset like you've presented with. Have they done any work up for you in this regard?

Do you have any family history of autoimmune disorders?

No family history of autoimmune that I'm aware of. My primary care doc possibly with some communique from the neuro believe it's an immune response possibly from an infection.