Diagnostic accuracy of rotation testing vs. standard vestibular test battery--a long-term study.

Interpretation of vestibular test results derived from rotational and other electronystagmography studies often give confusing diagnostic and prognostic information. We have reviewed 90 consecutive patients seen in the Vestibular Clinic at the University of Texas Medical Branch comparing the accuracy of the damped torsion swing test (DTS) with a conventional vestibular test battery (VTB) to predict vestibular function abnormality (peripheral or central). These predictions were compared with vestibular diagnoses obtained by long-term follow-up (24-36 months). VTB and DTS results were evaluated in a double-blind study by two of the authors (W.C.L. and M.J.C.). Agreement of both VTB and DTS interpretation was uncommon (23/77) (30%); however, when present, it resulted in a 91% accuracy in predicting correct final diagnosis. Where VTB and DTS diagnoses differed, the DTS was more accurate in determining final vestibular system abnormality. In fact, while DTS testing correctly detected abnormality in 17 patients, the VTB was normal in 11. Rotation testing alone may provide a useful and accurate screening test prior to initiating further vestibular testing, particularly when central pathology is suspected.