The Byl-Cheney-Boczai Sensory Discriminator: reliability, validity, and responsiveness for testing stereognosis

This study evaluated reliability, validity, and responsiveness of a new test of stereognosis (Byl-Cheney-Boczai Sensory Discriminator Test [BCBI]). Participants included 38 controls, 29 subjects with hand problems, and 3 raters. With eyes closed, after sweeping the digit over a design (10 mm x 10 mm) embedded in a plastic cube (13 mm x 13 mm), subjects matched the design palpated with a design on an answer sheet (10 trials/digits 2 and 4). The intra-class correlation coefficients were 0.997 and 0.994 for intra-rater and inter-rater reliability. No significant performance differences were found by gender or side. Accuracy was significantly higher for digit 2 versus digit 4, younger subjects versus older subjects, and controls versus subjects with pathology. There were significant (1) positive correlations (+0.41 to +0.53) between the BCBI and tests of stereognosis and graphesthesia; (2) negative correlations (-0.44 to -0.51) between the BCBI and the Purdue and digital reaction time; and (3) gains on the BCBI and function with therapy. The BCBI seems to be a reliable, valid, and responsive test of stereognosis that can be administered in 15 minutes in the cinic.