Purpose: To demonstrate thermal features of the foot in diabetic subjects without known peripheral neuropathy.
Background: Assessment of thermoregulation of the foot in patients diagnosed with diabetes identifies those predisposed to foot ulcer and amputation.
Methods: The clinical study of the thermoregulation of the microvascular processes of the plantar foot included 100 subjects with diabetes ages 35 to 76. Subjects underwent a complete clinical exam and nerve conduction study. Thermal imaging with a portable device followed a standard procedure for cooling of the plantar foot, followed by video imaging of the plantar surface during re-warming. The reference standard for neuropathy was a nerve conduction study. Features included: Initial temperature; temperature after cold provocation; and recovery temperatures.
Results: The figure shows the 6 standard regions studied. The temperature after cooling for the normal subject was 16 deg C with a recovery temperature of 6 to 8 deg C after 400 s. For the subject with neuropathy the temperature after cooling dropped only to 18 deg C and recovered 2 to 4 deg C. Using these features, the sensitivity was 85% sensitivity and 70% specificity.
Conclusion: Quantification of thermoregulation of the foot provides a new and non-invasive assessment of diabetic peripheral neuropathy in patients with diabetes. Identification of these at-risk patients may prevent amputation.
P.Soliz: None. E.Duran-valdez: None. A.P.Bancroft: None. G.Tang: None. D.S.Schade: Consultant; AbbVie Inc. J.Vijayamohanan: None.