Vestibular autorotation testing in patients with benign paroxysmal positional vertigo.

OBJECTIVES: The current gold standard for diagnosis of benign paroxysmal positional vertigo (BPPV) is the Dix-Hallpike maneuver. However, because of fatigability, the Dix-Hallpike is often falsely normal. The objective of this study was to evaluate the utility of vestibular autorotation testing in the diagnosis of BPPV.

METHODS: The charts of 210 patients at a tertiary referral center for vertiginous disorders were reviewed. All patients underwent clinical evaluation, Dix-Hallpike testing, audiometry, electronystagmography, and vestibular autorotation testing. The vestibular autorotation results of patients with BPPV were compared with the findings in patients with non-BPPV vestibular disorders. The sensitivity and specificity of vestibular autorotation testing in diagnosing BPPV were calculated.

RESULTS: Ninety-one patients (42.9%) had BPPV, 76 patients (36.2%) had vertigo of uncertain cause, 28 (13.3%) had unilateral vestibular hypofunction, 9 patients (4.3%) had Meniere's disease, and 2 patients (1.0%) had perilymphatic fistula. Patients with BPPV were 3.32 times more likely to have a normal horizontal gain (95% CI = 1.54-7.19). A normal horizontal gain is 85% sensitive but only 36% specific for BPPV. Patients with BPPV were 1.9 times more likely to have vertical phase lead (95% CI = 0.95-3.93). Patients with BPPV were 2.20 times more likely to have both normal horizontal gain and vertical phase lead (95% CI = 1.03-4.69) The sensitivity of the combination of normal horizontal gain and vertical phase lead on vestibular autorotation testing is 87% specific but only 25% sensitive in the diagnosis of BPPV.

CONCLUSION: A normal horizontal gain or vertical phase lead on vestibular autorotation testing in a vertiginous patient is suggestive of but not exclusive to a diagnosis of BPPV. The combination of a normal horizontal gain and vertical phase lead on vestibular autorotation testing is highly suggestive of the diagnosis of BPPV. Adjuvant use of these parameters in vestibular autorotation testing may prove to be helpful in the diagnosis of BPPV.