This study examined the validity of the Postrotary Nystagmus (PRN) test as a measure of vestibular functioning by examining the relations of scores from the PRN test with those from other variables measuring similar functions and through conducting a group comparison study. The PRN test is one of 17 tests included in the Sensory Integration and Praxis Tests (SIPT). Using SIPT scores from 575 children, sensory motor performance among children with depressed, average duration, and prolonged nystagmus was compared. The results indicated that children with low-duration postrotary nystagmus scored more poorly than children with average or prolonged postrotary nystagmus on other SIPT tests measuring aspects of vestibular function. Statistically significant, although weak correlation, coefficients were also obtained, demonstrating low-duration postrotary nystagmus may be associated with sensory motor deficits. The results of this study contribute to evidence supporting the PRN test's validity as a measure of some aspects of vestibular functioning.
