Sensory perception threshold measurement: an evaluation of semiobjective testing devices

Five semiobjective devices for testing sensory perception thresholds were concomitantly used on 36 normal subjects to determine normal threshold values, intersubject variability, and their correlation with age. The five devices include the Semmes-Weinstein monofilament (touch); three-point esthesiometer (two-point discrimination); Pfizer thermal tester (temperature); biothesiometer (vibration); and Optacon tactile tester (vibration). Each subject was tested at 12 upper extremity (UE) and ten lower extremity (LE) sites. The threshold was determined by the two-alternative forced choice method. Results showed that the mean threshold for each sensory perception modality in the UE sites was significantly lower than in the LE sites. The means of distally located sites for two-point discrimination and vibration thresholds were significantly lower than the means of the proximal sites in the UE. In the LE, touch perception threshold was significantly higher distally than proximally. Distally located nerves (median and ulnar) showed lower mean threshold values than proximally located nerves for two-point discrimination. There were also similar findings for the other sensory modalities in the UE and LE. The mean threshold of dermatomes showed significant variation across the trials for two-point discrimination and vibration sensation. Distally located dermatomes showed lower threshold values than those located proximally. The means of most sites tested for each sensory modality (except vibration tested by the Optacon) showed correlation with age. There was no difference in threshold values between men and women for any sensory modality. The mean values of standard deviation were provided for each peripheral sensory nerve and dermatome.(ABSTRACT TRUNCATED AT 250 WORDS)