Patients in the diabetic neuropathy groups (DN and DNU) all had a clinical diagnosis of peripheral diabetic neuropathy. The inclusion criteria for both neuropathic groups were diabetes (type 1 or 2) with more than five years since onset and a score higher than six on the Michigan Neuropathy Screening Instrument questionnaire (MNSI-q) for symptoms related to the diabetic neuropathy.Additionally, subjects were required to have a minimum of two areas where they did not feel a 10 g monofilament.