I know I've seen this article before, and thought it was already in the Stickies, but it wasn't, apparently. Thanks to Dahlek for pointing it out.

LizaJane is accurate--axonal neuorpathy means that the primary damage to the nerve is to the nerve fiber itself, whereas demyelinating neuropathy means the primary damage to the nerve is to the insulating surrounding myelin sheath. Both kinds have multiple causes, and the Washington University at St. Louis Neuromuscular website that LizaJane references is a good way to get a comprehensive list:

http://www.neuro.wustl.edu/neuromuscular/naltbrain.html

(This one I know I put in the Stickies.)

I say "primary" because it is entirely possible to have primary axonal damage and secondary problems with the myelin--when the axons degrade, myelin has less to adhere to, and deteriorates--and the reverse can also happen: primary myelin damage that gets severe enough to cause the now uncovered axonal fibers to also break down.

Experienced electrodiagnosticians can often tell by NCV/EMG testing results whether the damage is more one or the other, as each tends to leave somewhat characteristic fingerprints.

Small-fiber neuropathy is by definition axonal, as the fibers that subsume pain and temperature sensation, and many autonomic functions, are very thin and have very little or no myelin sheathing.

All motor fibers are myelinated, as are major sensory fibers underlying sensation of mechanical touch, vibaration, and kinesthetic feedback.

To get even more technical, one can have a neuronopathy or gangliopathy, in which the cell bodes in the dorsal root ganglia are actually attacked (which may cause axonal/myelin deterioration further down the nerve cell). This is quite common in Sjogren's and paraneoplastic syndromes. It's not technically either axonal or demyelinating, as it does not "first" involve some portion of the nerve fiber.

There's also the term "radiculopathy" referring to damage to the nerve roots on either side of the spinal cord--the first nerve "bundles" that connect to the cord. This is technically a peripheral neuropathy, as it is not central nervous system damage per se, but is often considered an adjunct to dysfunction of the spine.

Complicated, yes.