Abstract Conclusion: The distribution of abnormal results is not uniform between different canals in each patient; the most frequent gain reduction is obtained for the posterior canal. Gain reduction reflects the disease duration and amount of hearing loss.
To test the hypothesis that the vestibulo-ocular reflex (VOR) evoked after stimulation of each semicircular canal behaves in a different manner in patients with unilateral definite Ménière's disease.
We studied the VOR evoked by rapid head-impulses in the plane of the 6 semicircular canals in 36 patients. It was evaluated with a video system that analyzes the head and eye velocity and the gain was the objective measure.
In 12 (33.3%) patients the examination of both ears was normal for all the semicircular canals, in 12 patients the results from the affected ear were abnormal in at least 1 of the semicircular canals, in 11 (30.5%) patients the results were abnormal in at least 1 of the semicircular canals in both the affected and unaffected ears, and in 1 (2.9%) patient the results were abnormal only in the unaffected ear. The most frequent abnormal result was obtained from the posterior canal of the affected ear and from the coupled superior canal of the unaffected ear. The distribution of abnormal findings was dependent on the disease duration and hearing loss.