NORMAL-DISTRIBUTIONS OF THERMAL AND VIBRATION SENSORY THRESHOLDS

The distributions of sensory thresholds were estimated in a healthy po pulation while controlling for potential covariates. Using the method of levels and the two-alternative forced choice, thermal and vibration thresholds respectively were measured in the hand and foot of 148 sub jects. Age was uniformly distributed between 20 and 86 years. Independ ent effects of age, gender, height, and skin temperature were estimate d using multiple linear regression. Parametric and nonparametric metho ds were used to estimate the distributions of interest. Significant ag e-related increases were observed for all vibration thresholds (P < 0. 0001), and for thermal thresholds in the foot (P < 0.0002). Percentile s were estimated for thermal thresholds in the hand and age-adjusted c ontinuous distributions were calculated for all other thresholds. Heig ht was positively associated with vibration thresholds in the foot (P < 0.003), and appropriate corrections were made. Our results provide r eference values for thermal and vibration sensory thresholds in a heal thy population, allowing for the accurate diagnosis of disordered sens ory function. (C) 1998 John Wiley & Sons, Inc.