Evaluation of pressure threshold prior to foot ulceration - One- versus two-point static touch

A prospective study of 29 patients with diabetic neuropathy and 47 nondiabe tic patients with tarsal tunnel syndrome were evaluated with computer-assis ted neurosensory testing at three sites on the foot. The sensitivity and sp ecificity of one-point static touch thresholds for identifying the presence of large fiber axonal loss was done using the calculated thresholds for mo nofilaments derived from their markings. The sensitivity for one-point stat ic touch in identifying axonal loss was 33% for the 5.07, 38% for the 4.93, 50% for the 4.17, and 60% for the 4.08 monofilament-equivalent, with a spe cificity of 100% at each level. Therefore, one-point static touch testing, even using monofilaments thinner than 5.07, has a high percentage of false- negative results in identifying patients with axonal loss.