Sensory nerve conduction, evaluating

In axonal neuropathies, the velocity of action potential propagation in surviving axons is well maintained but the number of axons capable of conducting action potentials is diminished. Transcutaneous nerve stimulation and recording, the method routinely used for studying nerve conduction in the clinic, does not permit evaluation of the function of autonomic or unmyelinated sensory axons. These smaller, slow-conducting axons can be analyzed, in research studies, by intraneural recording with needle electrodes. 

Return of sensory function can be evaluated through sensory reflexes involving foot or tail withdrawal from noxious stimuli, or by changes in the conduction velocity of sensory nerves (De Koning et al., 1986 Gerristen van der Hoop et al., 1988 Van der Zee et al., 1988). 

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