To compare the frequency of abnormalities in epidermal nerve fiber density (ENFD) and quantitative sudomotor axon reflex (QSART) in patients with diabetic distal symmetric polyneuropathy (DSPN).
Nerve conduction studies, ENFD, and QSART data were obtained pre- and postexercise, in patients enrolled in a prospective diabetic neuropathy study. McNemar's test was applied to compare the yield of ENFD and QSART.
Eighteen patients (58 ± 4 years) were enrolled, with 36 data collection points. In diabetic DSPN and diabetic large fiber DSPN (DSPN-L), abnormal ENFD (77% and 100% respectively) is more frequent than abnormal QSART (39% and 35%, respectively) (P value = 0.001 in diabetic DSPN and P value = 0.0002 in diabetic DSPN-L), whereas in diabetic small fiber DSPN (DSPN-S), both tests have similar yields (47%).
ENFD has a high diagnostic yield in diabetic DSPN and DSPN-L. Including QSART data adds little to the sensitivity of EFND in DSPN-S.
*Department of Internal Medicine, Division of Neurology, King Abdulaziz University, Jeddah, Saudi Arabia;
Departments of †Physical Therapy and
‡Anatomy and Cell Biology, The University of Kansas Medical Center, Kansas City, KS;
§Clinical and Translational Science Unit, The University of Kansas Medical Center, Kansas City, KS; and
¶Department of Neurology, The University of Kansas Medical Center, Kansas City, KS.
Reprints: Mamatha Pasnoor, MD, Department of Neurology, The University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160 (e-mail: firstname.lastname@example.org).
R. J. Barohn has served as a consultant and received consulting fees from Baxter, CSL Behring, Genzyme, Grifols and NuFactor. He has received research grants from Biomarin, Cytokinetics, Eli Lilly, FDA/OPD, GSK, MDA, IONIS, NIH, NINDS, Novartis, PTC, Sanofi/Genzyme, and Teva. M. M. Dimachkie is on the speaker's bureau or is a consultant for Baxalta, Catalyst, CSL Behring, Mallinckrodt, Novartis and NuFactor. He has received grants from Alexion, Biomarin, Catalyst, CSL-Behring, FDA/OPD, GSK, MDA, NIH, Novartis and TMA. The remaining authors report no conflicts of interest.
Supported in part by the National Center for Research Resources, GrantM01 RR 02394 and the CTSA grant which is now at the National Center for Advancing Translational Sciences, Grant UL1RR033179. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. This study was also partially supported by the Ziegler Investigator grant (M.P.), and the Juvenile Diabetes Research Foundation and NIH RO1NS43314 (D.E.W).