Clinical evaluation of a new device in the assessment of peripheral sensory neuropathy in diabetes

Abstract

Current National Institute for Health and Clinical Excellence guidelines state that patients with diabetes should have annual examination of their feet to exclude signs of sensory impairment. The VibraTip is a new disposable device producing a vibratory stimulus, which has been developed in order to screen for peripheral sensory neuropathy in diabetes. This study was designed to evaluate the device by assessing intra-rater reliability and comparing the ability of the VibraTip to detect or exclude peripheral sensory neuropathy with other bedside methods. One hundred and forty-one patients with diabetes (Type 1 or Type 2) were examined for diabetic peripheral sensory neuropathy using a Neurothesiometer, 10-g monofilament, a 128-Hz tuning fork, a Neurotip™ and a VibraTip. The failure to perceive the Neurosthesiometer stimulus at ≥ 25 V in either foot was considered the reference method for the presence of peripheral sensory neuropathy. Receiver operating characteristic curves were produced for each device and the sensitivity, specificity, predictive values and likelihood ratios for the diagnosis of peripheral sensory neuropathy were calculated. Repeat testing with the VibraTip was performed in 18 patients and intra-rater reliability assessed using Cronbach alpha. Analysis of the area under the receiver operating characteristic curves showed that the 10-g monofilament was significantly better than the 128-Hz tuning fork (P = 0.0056) and the Neurotip (P = 0.0022), but was no different from the VibraTip (P = 0.3214). The alpha coefficient for the VibraTip was calculated to be 0.882, indicating good reliability. The VibraTip is a device comparable with the 10-g monofilament and therefore could be considered a useful tool for screening for peripheral sensory neuropathy in diabetes.