Sensitivity and specificity of the head-shaking test for detecting vestibular system abnormalities.

The head-shaking nystagmus (HSN) test has been reported to be a sensitive screening test for the presence of peripheral and central vestibular system disease. Previous investigations have utilized few subjects who were drawn from well-defined patient populations. The purpose of the present investigation was twofold: first, to determine the prevalence of HSN in a large unselected population of dizzy patients seen in an otology and neurotology practice, and second, to determine the sensitivity and specificity of this evaluation in the detection of vestibular system abnormalities as reflected by results of electronystagmography and rotary chair testing. The results of the investigation have suggested that the HSN test has a 27% sensitivity and an 85% specificity. The HSN test yields an acceptable number of false positives (15%) and an unacceptably large number of false negatives (73%).