Caloric Test Versus Rotational Sinusoidal Harmonic Acceleration and Step-Velocity Tests in Patients With and Without Suspected Peripheral Vestibulopathy

Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, U.S.A.Objective: To identify the predictive capabilities of caloric androtational testing to distinguish peripheral from nonperipheralvestibular causes of vertigo.Study Design: Retrospective case review.Setting: Academic tertiary care vestibular function test center.Patients: Two hundred dizzy patients (132 with and 68 withoutsuspected peripheral vestibular dizziness) evaluated withbithermal binaural caloric and sinusoidal and step-velocity ro-tary chair (RC) tests.Intervention: Caloric and RC tests.Main Outcome Measures: 1) Receiver operating characteristic(ROC) analysis of individual caloric and rotary parameters forarea under the curve (AUC) as indication of predictive value,and 2) logistic regression analysis of parameter combinationsfor identification of optimal test battery for predicting periph-eral vestibular dysfunctionResults: Analysisoftheindividualreceiveroperatingcharacter-istic (ROC) curves for each caloric and RC test parameter forprediction of peripheral vestibulopathy revealed that the bestoverall predictive parameterwaspercentageofcaloric weakness(CW; AUC-ROC, 0.73; 95% confidence interval, 0.66Y0.80).Using 29.5% as the optimal cutoff point for CW, a specificityof 84% and sensitivity of 55% were obtained. Because of thereduced AUC for the RC parameters, no optimal cutoff pointswere chosen. Using a logistic regression model in predictingpatients with peripheral vestibulopathy demonstrated that eithercomprehensive caloric and RC testing or the combination ofcaloricand0.025Hz,0.5Hz,andtime-constantrotationaltestingyielded the highest predictive value (AUC-ROC, 0.79)Conclusion: Calculation of CW was the most promising singlemarker for identifying peripheral from nonperipheral vestibulo-pathic patients. Individual RC parameters showed limited pre-dictive value to differentiate peripheral from nonperipheralvestibular dysfunction. However, the combination of subtestsyielded an AUC-ROC only slightly less than caloric testing.The combination of caloric and RC testing revealed the stron-gest predictive capabilities for identifying peripheral vestibularinjury. Furthermore, the combination of an abbreviated form ofRC testing with caloric testing yielded nearly identical resultsas full caloric and rotational testing.Key Words: CalorictestVPeripheral vestibulopathyVRotary chair testVRotationalstep velocity time constantVSinusoidal harmonic accelerationgain-phase-asymmetry.Otol Neurotol 30:800Y805, 2009.