Active head rotation in benign positional paroxysmal vertigo

Aim

Study design

Materials and Method

Conclusion

Epley maneuver and the head autorotation test in benign paroxysmal positional vertigo

The head autorotation tests can be affected with the dynamic changes within the semicircular canals caused by benign paroxysmal positional vertigo (BPPV). The vestibular autorotation test is a method of examining the VOR (especially the VOR that develops at higher frequencies like those that occur in the everyday environment). Twenty patients who had been diagnosed as having posterior semicircular canal BPPV were evaluated with head autorotation tests before and after the treatment maneuver. The head autorotation tests were performed just before the use of the Epley maneuver and after the resolution of symptoms and the typical nystagmus pattern. The mean gain values for horizontal rotation tests during the pre-treatment period were 0.823, 0.844, and 0.840 for the frequencies 1, 2, and 3 Hz, respectively. The mean gain values increased by 0.095 (95% confidence interval) with Epley's maneuver. But this difference difference between the pre-treatment and post-treatment values was not statistically significant. All patients were also evaluated with vertical active tests. The differences between the pre-treatment and post-treatment values were not statistically significant in the vertical autorotation group. The phase values were within normal range in the horizontal and vertical rotation tests and remained so after the Epley maneuver. The stimulation of the VOR caused by BPPV did not affect gain and phase values to a statistically significant degree, and the values noted after the resolution of the patient's symptoms improved slightly but without statistical significance.

Evaluation of the vestibular autorotation test (VAT) for measuring vestibular oculomotor reflex in clinical research

BACKGROUND

A method is needed to measure parameters of vertigo and disequilibrium. Our objective was to ascertain whether the vestibular autorotation test (VAT) gives numerical data on the vestibular oculomotor reflex (VOR) that are useful for clinical research.

METHODS

A VAT was carried out on 17 healthy young volunteers twice, with an interval of 7 days (group A), and on a single occasion on another 17 volunteers of similar age and health (group B). The parameters studied were vertical and horizontal gains and phases and horizontal eye velocity symmetry. The resulting values were paired inter-session in the same individuals of group A, and between the first test of group A with the test in group B, chosen at random. Variances for the sets of numbers in each parameter as a whole and for each frequency of stimulation were calculated and statistical validity was determined.

RESULTS

No significant differences were found between the inter-session and inter-individual results. Variances of gain (horizontal and vertical) were small, but variances of phase and symmetry were large. An analysis of frequencies of stimulation revealed that variances increased with the elevation of frequency.

CONCLUSIONS

For clinical research and evaluation, the VAT affords sufficiently consistent figures for vertical and horizontal gain in the entire spectrum of frequencies tested (2-5.9 Hz) and for horizontal phases between 2-3.9 Hz. Vertical phases and horizontal asymmetry vary too greatly for our stated purpose.

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.