A cross-sectional methodological study: evaluation of the examiner performance on the Dix-Hallpike test

The Dix-Hallpike test is recommended to diagnose Benign Paroxysmal Positional Vertigo (BPPV). This research aimed to quantify the movement of a healthy subject during the Dix-Hallpike test and determine what factors contribute to performance variation from the recommended head position with 20° cervical extension, 45° cervical rotation, and a brisk movement velocity.

Examiners performed the Dix-Hallpike test 10 times. The examinee's movement was recorded with Qualisys and processed with Visual3D. The proportion of variation in test performance within examiners, between examiners, and due to examiner position was calculated.

Thirteen participants, 54% male and mean age 40, performed 50 cranial and 77 lateral Dix-Hallpike tests. Head position differed significantly from the recommendations with the cranial tests for extension (mean difference [MD] = 11.6°, p < 0.001) and rotation (MD = 4.8°, p < 0.001) and with lateral tests for extension (MD = 13.3°, p < 0.001). The largest proportion of variation was between examiners (60-91%), followed by within-examiners (3-16%). The examiner position contributed to 20% of the variation in the cervical rotation achieved. Tests lasted, on average, 1.80 s.

Differences within and between examiners visually estimating the Dix-Hallpike test endpoints may impede BPPV diagnosis accuracy.