ID 390 – Association between intraepidermal nerve fiber density and quantitative sensory testing in the patients with possible small fiber neuropathy

Abstract

Objective To evaluate sensitivity of quantitative sensory testing (QST) and skin biopsy with assessment of intraepidermal nerve fiber density (IENFD) in patients with symptoms and clinical findings of small fiber neuropathy (SFN). Methods This is a retrospective study on 179 patients (age 48.7 ± 14.0 (8–82 years old), 64 men, 115 woman) examined from January 2012 to March 2015. All patients underwent nerve conduction studies (NCS), QST and skin biopsy for assessment of IENFD. Results NCS were normal in 85% of patients. Mean IENFD in the total patient group was 6.1 ± 2.7 fibers per mm (0.9–17.0). 94 patients (52%) had reduced IENFD. 82 patients (46%) had abnormalities on QST (in 2 and more parameters). However, only 43 patients (24%) had both abnormalities on QST and reduced IENFD. There were normal findings on both QST and IENFD in 29 patients (16%). Conclusions There is a rather lower concordance between the results of QST and IENFD. It remains unclear if diagnosis of SFN can be excluded in cases of normal findings both on QST and skin biopsy. Key message Both skin biopsy and QST should be performed in patients with suspected SFN.