SNAP

The acronym for Sensory Nerve Action Potential. The compound sensory nerve action potential (SNAP) is the result of phase summation and cancellation of single fiber potentials (SFAPs) with amplitudes that depend on fiber diameter, and the amplitude and shape of the SNAP is determined by the distribution of fiber diameters. Conduction velocities at different conduction distances are determined by summation of SFAPs of varying fiber diameters, and differ in this respect, also, from the compound muscle action potential (CMAP) for which conduction velocities are determined by the very fastest fibers in the nerve.

Essentially, SNAP is a measurement of how well a sensory nerve transmits a signal. This parameter is typically measured during a nerve conduction study that is performed in CMT.