Abstract
Clinical effect of a canal plugging procedure was evaluated by positional nystagmus findings. A 61-year-old woman had complained of positional vertigo for the past 8 years. Vertigo was exacerbated when her head position was with the right side down. The positional nystagmus varied at every examination. They were direction-changing geotropic, or apogeotropic nystagmus, direction-changing rotatory nystagmus etc. Other neurootological tests were negative. From the findings of nystagmus, combined lesions involving the utricle, horizontal and posterior semicircular canals were suspected. Since her response to physical therapy was minimum, canal plugging surgery to the right horizontal canal was indicated. After surgery, all types of nystagmus as well as vertigo disappeared, suggesting an inhibitory effect of canal plugging on the whole vestibular organ.
