Table 1. Summary of methods for the diagnosis of diabetic peripheral neuropathy.

Examination name	Examination type	Advantages	Disadvantages
Clinical symptoms & signs	DN4, LANSS, NPQ, MNSI, DNS, TCNS, NDS, UENS	Relevant to the patient, easy to use, inexpensive	Limited sensitivity, high variability
Quantitative sensory testing	CASE IV (WR Medical Electronics), Biothesiometer, Thermoaesthesiometer, TSA Neurosensory Analyser (Medoc Ltd.)	Easy to perform, rapid, non-invasive, evaluates large and small nerve fibers	Variable, subjective, requires special equipment
Sudomotor function	Neuropad (Skyrocket Phytopharma), Sudoscan (Impeto Medical), QSART, sympathetic skin response	Fast, objective, easy to perform, simple, reproducible	Moderate sensitivity, uncertain interpretation
Neurophysiology	NCS of motor and sensory nerves	Objective, widely available	Only assesses large fibers, moderate reproducibility, requires special equipment
Skin punch biopsy	IENFD	Objective, gold standard to assess small fibers	Costly, time-consuming, risk of infections requires specialist equipment and personnel to quantify IENFD
Corneal confocal microscopy	HRT III RCM	Objective, rapid, reproducible, assesses small fibers	Costly, requires specialist equipment

DN4, Douleur Neuropathique en 4; LANSS, Leeds Assessment of Neuropathic Symptoms and Signs; NPQ, Neuropathic Pain Questionnaire; MNSI, Michigan Neuropathy Screening Instrument; DNS, Diabetic Neuropathy Symptom; TCNS, Toronto Clinical Neuropathy Score; NDS, neuropathy disability score; UENS, Utah Early Neuropathy Scale; QSART, Quantitative Sudomotor Axon Reflex Test; NCS, nerve conduction studies; IENFD, intra-epidermal nerve fiber density; HRT III RCM, Heidelberg Retina Tomograph III Rostock Corneal Module.