Age-dependent Reliability of Semmes-Weinstein and 2-Point Discrimination Tests in Children

Objective sensory testing is a critical component of the physical examination in children as they may be unable to communicate whether or not numbness is present. The purpose of this study was to determine at what age objective sensory tests could reliably be performed.

Normal, uninjured participants aged 2 to 17 years were enrolled in the study. Monofilament and static/moving 2-point discrimination tests were performed bilaterally assessing the median, ulnar, and radial nerves. Performance scores were recorded using the monofilament size and 2-point discrimination distance. Statistical analysis was performed utilizing univariable linear regression, 1-way ANOVA, and Welch t test.

A total of 396 hands were tested utilizing the Semmes-Weinstein monofilament and static/moving 2-point discrimination tests. For the monofilament test, 27% of 3-year-olds, 83% of 4-year-olds, and all participants 5 years of age and older were capable of performing the monofilament test. The average monofilament scores were 2.874, 2.868, and 3.043 for the ulnar, median, and radial nerves, respectively, with no correlation with advancing age present. The ulnar and median nerve distributions were more sensitive than the radial nerve distribution (P<0.001).For 2-point discrimination tests, 33% of 4-year-olds, 61% of 5-year-olds, 88% of 6-year-olds, 95% of 7- and 8-year-olds, and all participants 9 years and older were capable of performing the static/moving 2-point discrimination tests. The average static 2-point discrimination scores were 3.348, 2.806, and 9.637 mm for the ulnar, median, and radial nerves, respectively. The average moving 2-point discrimination scores were 2.977, 2.483, and 8.506 mm for the ulnar, median, and radial nerves, respectively. There was no correlation between advancing age and performance scores. Children are the most sensitive in the median, then ulnar, and then radial nerve distribution (P<0.001). Better discrimination is present between 2 moving points than static points (P<0.001).

Objective threshold testing utilizing a monofilament can reliably be performed in the vast majority of children aged 4 years and above, whereas density testing utilizing 2-point discrimination can reliably be performed in the vast majority of children aged 6 years and above.

Level II.