SFN-SIQ, SFNSL and skin biopsy of 55 cases with small fibre involvement

Abstract

ABSTRACTPurpose/aim of the study: To date, there are no validated screening scales for small fibre neuropathy. This study investigated the small-fibre neuropathy and the symptom inventory questionnaire as well as the small fibre neuropathy screening list for small fibre neuropathy diagnosis.Methods: Fifty-five patients were divided into small fibre neuropathy and mixed fibre damage groups. Relevant scales, nerve conduction studies and skin biopsies were performed. Relationships between the intraepidermal nerve fibre density and different scales as well as the diagnostic and cut-off values (score at which Youden's index is largest) were determined.Results: Compared with healthy Chinese participants, 20 patients were diagnosed with small fibre neuropathy. Intraepidermal nerve fibre density was moderately and highly correlated with the small fibre neuropathy–symptom inventory questionnaire and small fibre neuropathy screening list, respectively. The diagnostic values were moderate and high for the small fibre neuropathy–symptom inventory questionnaire (cut-off value = 5, sensitivity = 80%, specificity = 81.8%) and small fibre neuropathy screening list (cut-off value = 8, sensitivity = 94.1%, specificity = 90.9%), respectively. There were no significant differences in the visual analogue scale between the small fibre neuropathy group, mixed small and large fibre neuropathy group, pure large fibre neuropathy group and the normal group.Conclusion: Small fibre neuropathy–symptom inventory questionnaire and small fibre neuropathy screening list represent potential small fibre neuropathy screening tools.AbbreviationsEMGelectromyographyENAanti-extractable nuclear antigensESRerythrocyte sedimentation rateIENFDintraepidermal nerve fibre densityIGTimpaired glucose toleranceNCSnerve conduction studiesNDSneuropathy disability scoreOGTToral glucose tolerance testPGPprotein gene productPNperipheral neuropathyROCreceiver operating characteristic curveROC-AUCarea under the ROC curveSFNsmall fibre neuropathySFN–SIQsmall-fibre neuropathy and symptom inventory questionnaireSFNSLsmall fibre neuropathy screening listVASvisual analogue scaleWHOWorld Health Organization