--to determine, by electron microscopy, your intraepidermal small-fiber density and condition, is the current "godl standard" for determining small-fiber damage. The small, unmyelinated fibers that subsume the sensation of pain and temperature simply are too thin to be accessed through nerve conduction studies or electromyography--this is why its possible to have normal NCV/EMG studies and still have extensive neuropathy symptoms.

The skin biopsy is MUCH less invasive than nerve biopsy, and no where near as uncomfortable as EMG/NCV. A few 3mm skin circles will be taken from you for analysis after a topical anesthetic is first injected. The injection is the worst part, and it's not bad at all, and over is seconds.

Once the samples are taken, a few band aids are all that's needed for you to walk out minutes later.

Take a look at:

http://www.medscape.com/viewarticle/563262_3