Sharika Rajan1, Marta Campagnolo1, Brian Callaghan1, Christopher H Gibbons2. 1. Beth Israel Deaconess Medical Center, 185 Pilgrim Rd, Palmer 111, Boston, MA, USA. 2. Beth Israel Deaconess Medical Center, 185 Pilgrim Rd, Palmer 111, Boston, MA, USA. cgibbons@bidmc.harvard.edu.
Abstract
OBJECTIVE: Electrochemical skin conductance (ESC) is a non-invasive test of sweat function developed as a potential marker of small fiber neuropathy. Here we systematically review the evolution of this device and the data obtained from studies of ESC across different diseases. METHODS: Electronic databases, including MEDLINE, and Google Scholar were searched through to February 2018. The search strategy included the following terms: "electrochemical skin conductance," "EZSCAN," and "Sudoscan." The data values provided by each paper were extracted, where available, and input into tabular and figure data for direct comparison. RESULTS: Thirty-seven studies were included this systematic review. ESC did not change by age or gender, and there was significant variability in ESC values between diseases, some of which exceeded control values. Longitudinal studies of disease demonstrated changes in ESC that were not biologically plausible. Of the 37 studies assessed, 25 received support from the device manufacturer. The extracted data did not agree with other published normative values. Prior studies do not support claims that ESC is a measure of small fiber sensory function or autonomic function. CONCLUSIONS: Although many papers report significant differences in ESC values between disease and control subjects, the compiled data assessed in this review raises questions about the technique. Many of the published results violate biologic plausibility. A single funding source with a vested interest in the study outcomes has supported most of the studies. Normative values are inconsistent across publications, and large combined data sets do not support a high sensitivity and specificity. Finally, there is insufficient evidence supporting the claim that Sudoscan tests sudomotor or sensory nerve fiber function.
OBJECTIVE: Electrochemical skin conductance (ESC) is a non-invasive test of sweat function developed as a potential marker of small fiber neuropathy. Here we systematically review the evolution of this device and the data obtained from studies of ESC across different diseases. METHODS: Electronic databases, including MEDLINE, and Google Scholar were searched through to February 2018. The search strategy included the following terms: "electrochemical skin conductance," "EZSCAN," and "Sudoscan." The data values provided by each paper were extracted, where available, and input into tabular and figure data for direct comparison. RESULTS: Thirty-seven studies were included this systematic review. ESC did not change by age or gender, and there was significant variability in ESC values between diseases, some of which exceeded control values. Longitudinal studies of disease demonstrated changes in ESC that were not biologically plausible. Of the 37 studies assessed, 25 received support from the device manufacturer. The extracted data did not agree with other published normative values. Prior studies do not support claims that ESC is a measure of small fiber sensory function or autonomic function. CONCLUSIONS: Although many papers report significant differences in ESC values between disease and control subjects, the compiled data assessed in this review raises questions about the technique. Many of the published results violate biologic plausibility. A single funding source with a vested interest in the study outcomes has supported most of the studies. Normative values are inconsistent across publications, and large combined data sets do not support a high sensitivity and specificity. Finally, there is insufficient evidence supporting the claim that Sudoscan tests sudomotor or sensory nerve fiber function.
Authors: Aaron I Vinik; A Gordon Smith; J Robinson Singleton; Brian Callaghan; Barry I Freedman; Jaakko Tuomilehto; Lyse Bordier; Bernard Bauduceau; Frederic Roche Journal: Diabetes Technol Ther Date: 2016-04-08 Impact factor: 6.118
Authors: Beat P Müller-Stich; Adrian T Billeter; Thomas Fleming; Lars Fischer; Markus W Büchler; Peter P Nawroth Journal: Surg Obes Relat Dis Date: 2014-12-16 Impact factor: 4.734
Authors: Barry I Freedman; Donald W Bowden; Susan Carrie Smith; Jianzhao Xu; Jasmin Divers Journal: J Diabetes Complications Date: 2013-10-17 Impact factor: 2.852
Authors: Brian C Callaghan; Rong Xia; Evan Reynolds; Mousumi Banerjee; Charles Burant; Amy Rothberg; Rodica Pop-Busui; Emily Villegas-Umana; Eva L Feldman Journal: Clin Neurophysiol Date: 2018-01-16 Impact factor: 3.708
Authors: Jamie Burgess; Bernhard Frank; Andrew Marshall; Rashaad S Khalil; Georgios Ponirakis; Ioannis N Petropoulos; Daniel J Cuthbertson; Rayaz A Malik; Uazman Alam Journal: Diagnostics (Basel) Date: 2021-01-24