Kris...

Even tho one has to consider some scary scenarios, it helps
to keep in perspective the odds...

The most frequent cause of neuropathies is diabetes.
Then comes drugs (my opinion) and nutrient deficiencies.
Then with your ankles, comes autoimmune disease (Rheumatoid arthritis, lupus, tendonitis, gluten issues, vasculitis, hypothyroidism with entrapment)
Then toxins like heavy metals, paint stripping solvents, formaldehyde, etc.
Paraneoplasia is further down the list. But it needs to be considered, because if it is the cause, catching any cancer at the early stage gives a more positive prognosis.
Hereditary types are also down the list, and poorly understood at this time.

here is a link that explains it:
http://www.aafp.org/afp/980215ap/poncelet.html

You just have to hang in there.