--probably the best specialty centers for neuropathy--many of these have done extensive research into diagnostics/causes/treatments--are Johns Hopkins in Baltimore, Jacksonville Shands in Florida, Massachusetts General Hospital in Boston, the Washington University Neuromuscular Center in St. Louis, the Cornell Weill Center for Peripheral Neuropathy in New York City, and the Jack Miller Center in Chicago.

Others can probably add in a few more, but these, in my experience, are the most dedicated to the condition.

As to treatments, things very much depend on what is causing the neuropathy, if that can be found. Good blood sugar control is essential for those with diabetic neuropathies. Supplementation may prove helpful for those with this and other metabolic neuropathies, and for toxic neuropathies (including those caused by chemotherapy). Of course, in toxic cases stopping exposure to the toxin is important (if that's doable). In certain autoimmune neuropathies, immune modulating treatments such as IvIg may be important.

It really is very individualized.