Quantitative sudomotor axon reflex test (QSART) as a diagnostic tool of small fiber neuropathy

Abstract

Small fiber neuropathy is a painful neuropathy that cannot be assessed using nerve conduction studies. A skin biopsy and quantitative sensory testing (QST) are the gold standards for small fiber neuropathy diagnosis. However, a skin biopsy is invasive and commercially unavailable in Korea. QST is a method involving a thermal threshold, but its results can be affected by cognition as well as lesions of the central nervous system. Quantitative sudomotor axon reflex test (QSART) is a quantitative method of assessing sweat glands innervated by small fibers. In this review, we assessed the utility of QSART in evaluating small fiber neuropathy.