Quantitative sensory testing examines thin nerve fibers, especially small unmyelinated C fibers and A delta fibers.

Quantitative sensory testing (QST) is a painless diagnostic method that measures the sensory functions of the nervous system. It is similar to EMG but completely painless.

Using various stimuli (e.g. heat, cold, vibration or pain), it assesses how a person perceives these sensations.

The goal is to detect sensory disturbances, especially in the peripheral nerves, and help diagnose conditions such as polyneuropathy or chronic pain.

QST can reveal what our pain threshold is and whether it is normal, too low, or elevated.

It can also reveal exactly which type of sensory nerve fibers are damaged.

This test is complementary to EMNG, and measures those aspects of sensation that EMNG cannot measure.