Comparison of sympathetic skin response with quantitative sudomotor axon reflex test in diabetic neuropathy

Muscle Nerve. 1989 May;12(5):420-3. doi: 10.1002/mus.880120513.


The sympathetic skin response (SSR), the quantitative sudomotor axon reflex test (Q-SART), and cardiac beat-to-beat variability with respiration as measured by the expiratory/inspiratory ratio (E/I ratio) were studied in 39 patients with diabetic neuropathy of whom 33 also had one or more symptoms of autonomic involvement. In the lower extremities 87% of the patients with an absent SSR had an abnormal Q-SART (P less than 0.001), and 81% of patients with the SSR present had a normal Q-SART (P less than 0.02). The E/I ratio was abnormal in all but one of 23 patients with an absent SSR in the foot, and a normal E/I ratio was present only in those patients (n = 7) with the SSR present in hand and foot, and in an eighth patient who had SSR absent in the foot and present in the hand. A similar correlation was found between the E/I ratio and the Q-SART in the foot, although 4 of 25 patients with an abnormal foot Q-SART had a normal E/I ratio. We conclude that the concordance of results of the SSR and Q-SART supports the combined use of these tests to uncover early distal sympathetic failure in diabetic neuropathy.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Diabetic Neuropathies / diagnosis
  • Diabetic Neuropathies / physiopathology*
  • Female
  • Galvanic Skin Response*
  • Humans
  • Male
  • Reflex / physiology
  • Sweat Glands / innervation
  • Sympathetic Nervous System / physiopathology*