Sudomotor Testing of Diabetes Polyneuropathy

Sarah-Maria Krieger,Rocco Haase,Tjalf Ziemssen,Manja Reimann,Markolf Hanefeld,Elena Henkel

doi:10.3389/fneur.2018.00803

Abstract

Objective: The performance of the Sudoscan technology for diagnosing diabetic polyneuropathy (DPN) was evaluated against the quantitative sudomotor axon reflex test (QSART). Furthermore, the association of Sudoscan with two clinical neuropathy scoring systems was evaluated.Methods: Forty-seven patients with type 2 diabetes (20 without DPN, 27 with DPN) and 16 matched controls were examined for neuropathic symptoms and for the extent of sensory deficits. Sweat latency and volume by QSART and the skin electrochemical conductance (ESC) by Sudoscan were measured.Results: The feet and hand ESC was significantly lower in patients with DPN as compared to controls. Patients with DPN had also lower hand ESC than patients without DPN. Sensitivity and specificity of feet and hand ESC for detecting DPN were 70/85% and 53/50% respectively. QSART could not differentiate between the three groups. ESC was inversely related to neuropathic symptoms and sensory impairment. ESC was significantly correlated with sensory impairment and pain.Conclusions: Sudoscan shows a good performance in detecting subjects with DPN and it correlates well with clinical signs and symptoms of neuropathy.Significance: This study provides evidence that Sudoscan has high potential to be used as screening tool for DPN and possibly also for small fiber neuropathy in diabetic patients.HIGHLIGHTS - The sudomotor function test Sudoscan shows a good performance to detect diabetes peripheral neuropathy.- Sudoscan measures significantly correlate with clinical signs and symptoms of neuropathy.- The Sudoscan technology may help to secure clinical diagnosis of small fiber neuropathy.

Highlights

Diabetic neuropathy is the most common and disabling complication of diabetes mellitus accounting for the majority of non-traumatic amputations [1]
electrochemical skin conductance (ESC) was significantly correlated with sensory impairment and pain
Sudoscan shows a good performance in detecting subjects with diabetic peripheral neuropathy (DPN) and it correlates well with clinical signs and symptoms of neuropathy

Summary

Introduction

Diabetic neuropathy is the most common and disabling complication of diabetes mellitus accounting for the majority of non-traumatic amputations [1]. A proper diagnosis is often made when the disease has already caused irreversible damage to nerve fibers and significant function loss. Damage of small nerve fibers including unmyelinated C-fibers and myelinated Aδ-fibers can be observed at early stages of diabetic DPN. Typical symptoms of SFN are sensory impairment, neuropathic pain, burning and tingling in feet that become worse at night and allodynia [7, 8]. Those symptoms can be objectify in decreased pinprick test and temperature sensation, but neurological examination can be normal [9]. Available diagnostic tools are limited to detect damages to small nerve fibers. The quantitative sudomotor axon reflex test (QSART) is regarded as sensitive and reproducible test of sudomotor function but its application is extremely limited due to high costs, special equipment needed and highly timeconsuming nature [16]

Results

Discussion

Conclusion