Comparison of a neurothesiometer and vibratron in measuring vibration perception thresholds and relationship to nerve conduction studies

OBJECTIVE - To compare vibration perception thresholds (VPTs) obtained with two different instruments, a neurothesiometer and a vibratron, and to characterize variability of repeat measures and correlation with sural nerve conduction parameters. RESEARCH DESIGN AND METHODS - A total of 152 patients with diabetic peripheral neuropathy received electrodiagnostic evaluation and quantitative VPT testing with the Vibratron II and the Horwell Neurothesiometer. Of the patients, 42 returned for repeat nerve conduction studies and VPT testing with both types of equipment on three separate occasions. RESULTS - The variability of repeat testing for the vibratron was 34 and 31% in the right and left first toes, respectively. Variability for the neurothesiometer was 8 and 6% for the right and left toes. This variability compares with that of sural nerve conduction velocity of 2% and that of sural nerve amplitude of 8% in this series of patients. CONCLUSIONS - We conclude that WT determined with the neurothesiometer is less variable than with the vibratron and more reflective of peripheral nerve function. Our results indicate that the neurothesiometer can be used reliably in clinical research trials.