Manual rotational testing of the vestibule-ocular reflex

Objectives/Hypothesis: Manual whole-body and head-on-body rotational testin g of the vestibulo-ocular reflex (VOR) is comparable to conventional rotary chair methods with and without visual fixation from 0.025 to 1 Hz, Study D esign: Summary of four previously published trials from our laboratory(1-4) and a fifth prospective blinded study comparing whole-body and head-on-bod y rotation with rotational chair results from 0.025 to 1 Hz in 10 patients with bilateral vestibular dysfunction. Methods: Subjects were fitted with s tandard electro-oculogram (EOG) electrodes and placed in the rotary chair f or testing at 0.025, 0.05, 0.1, 0.25, 0.5, and 1 Hz in the dark (VOR) and i n the light with a stationary target (VVOR), They were then placed in an ot olaryngology examination, chair where an adjustable headband containing the velocity sensor and an opaque visor were placed on the forehead. Whole-bod y rotational trials from 0.025 to 1 Hz and both passive and active head-on- body trials from 0.25 to 1 Hz were performed with and without visual fixati on, Data from each frequency were analyzed cycle-by-cycle and averaged for gain, phase, and asymmetry. These values were then compared to the results obtained during rotational chair testing, Results: Throughout the five stud ies, no systematic differences were noted between the manual rotational met hods and the rotary chair results. Specifically, no consistent effect of vo lition or cervico ocular reflex (COR) enhancement was demonstrated Conclusi ons: Manual rotational testing is a reliable technique for measuring the VO R up to 1 ID as compared with standard rotary chair methods. Advantages to this technique include portability, lower equipment costs, and potential ap plication up to 6 Hz using head-on-body rotation.