--the division into sensory, motor, and autonomic is one, based on function.

The other division neurologists tend to use is that between large and small-fiber; that division tends to overlap with the functionality distinction, but not quite.

Large fiber nerves (which can be further broken down by types of fibers) generally involve any nerve that has a myelin sheath--a fatty covering designed to improve signal conduction. Large fiber nerves in the body include motor nerves that send signals to muscle (all motor nerve are "large fiber", as they are all myelin sheathed), and the sensory nerves that subsume the sensations of position, vibration, and mechanical touch. Both sensory and motor nerves can be found in the same nerve trunk, though--think of a thick telephone cable with many wires in it. Some large nerves, like the sciatic (the widest nerve in the body) can have thousands of seperate fibers coming to and from various areas. In general, in these nerves, the sensory tracts are located more to the surface and the motor tracts deeper. So, depedning on the actual location of damage, one can get sensory disruption, motor disruption, or both.

By the way, neuros often talk of "demyelinating" neuropathy if the main damage is to the fatty myelin sheath--this tends t cause fairly distinctive signal abnormalities on EMG/NVC studies, but not signal block. Damage to the axon, or nerve fiber itself, is termed axonopathy. This tends to be more difficult to recover from--the body can restore myelin sheathing more readily than it can repair fibers (which happens VERY slowly, and only if whatever is damaging the nerves is somehow arrrested). Most difficult to recove from is neuronopathy, which refers to damage death to the cell body, where the functions of the cell are controlled. If the cell itself, as opposed to its axon, dies, that cell is gone. Its function may be taken up by other nearby cells, but that tends to be hit or miss. And the number of cell deaths becomes important in determining function.

The small fiber nerves are sensory and autonomic, and are so-called as they do not have myelin coverings. Thus, by definition, damage to a small fiber nerve is axonal or cell body oriented. Small fiber sensory nerves subsume the sensation of pain and temperature. Small-fiber autonomic nerves control our blood pressure, sweat, and urologic/genital/sexual response.

It's certainly possible to have a predominantly large-fiber syndrome, a predominantly small-fiber syndrome, or a mixed syndrome. If large fibers are involved, one can have a predominantly demyelinating syndrome with secondary axonal damage, a predominantly axonal syndrome with secondary demyelination, a neuronopathy with secondary damage, etc.