Evaluation of the VPT‐60 to measure peripheral nerve sensitivity

Abstract

The loss of peripheral nerve sensitivity can result in serious morbidity (including limb amputation) and mortality. Monitoring peripheral nerve sensitivity is important in avoiding these consequences.The purpose of this study was to evaluate the capability of an experimental VPT‐60 to accurately determine peripheral nerve sensitivity. Peripheral nerve sensitivity measurements from the VPT‐60 were compared to measurements of the two clinical reference standards, Semmes‐Weinstein monofilaments (SWM) and the Bio‐Thesiometer (BT).Peripheral nerve sensitivity and temperature of the index finger tip of 41 subjects, with ages ranging from 20–87 years, and mean SWM size range of 2.4–4.2 were measured. Finger tip temperature ranged from 71.4–88.2°F, and the force exerted by the finger on the vibrating probe ranged from <1.0 to 82 grams. Each subject's nerve sensitivity was measured 3 times with each of the 3 instruments.The correlation coefficient (r) of VPT‐60 and SWM was 0.75 and between the VPT‐60 and the BT was 0.86. The r between SWM and BT was only 0.51. As the nerve sensitivity decreased, the sensitivity of the VPT‐60 to detect changes increased. Reliability of the VPT‐60, SWM, and BT was 0.88, 0.78, and 0.74 respectively. In conclusion, this study indicates that the VPT‐60 provides results that are as capable as, if not more capable than, the gold standards in determining peripheral nerve sensitivity.