Effect on brainstem auditory evoked responses of posterior semicircular canal occlusion in guinea pigs.

The site of origin of benign paroxysmal positional vertigo is the posterior semicircular canal and when persistent, the condition is known as cupulolithiasis. Singular neurectomy is the current procedure of choice for the treatment of incapacitating cupulolithiasis. The neurectomy is difficult to learn and carries a significant risk of hearing loss. An alternative procedure, whereby the posterior canal is occluded, is discussed. This was performed on 11 guinea pigs and the effect on hearing was measured using brainstem evoked audiometry. Eight animals showed no hearing loss while the other three had a mild to moderate loss of hearing due to intra-operative complications. The effect of canal plugging on hearing compares favorably with the hearing results obtained with singular neurectomy. Posterior semicircular canal occlusion is suggested as a safer and technically easier treatment for incapacitating cupulolithiasis.