Early detection of nerve damage and repair in diabetic neuropathy

This Practice Point commentary discusses the results of a study that employed thermal threshold testing and quantification of intraepidermal nerve fiber (IENF) density in patients with diabetes who had normal electrophysiology findings. The study showed that a significant proportion of these patients had abnormalities in small-fiber function, as quantified by thermal thresholds, and structure, as quantified by IENF density. Interestingly, patients who showed symptoms of diabetic neuropathy had reduced IENF densities but no difference in thermal thresholds compared with diabetic patients lacking these symptoms. This study highlights the importance of establishing which tests should be used to detect the earliest nerve damage in diabetic neuropathy, and which tests should be used as end points in clinical trials relating to this condition.