CLINICAL AND VESTIBULOMETRIC STATUS FOLLOWING LABYRINTHECTOMY OR VESTIBULAR NERVE-SECTION FOR MENIERES-DISEASE

A clinical and vestibulometric comparison of 10 patients following labyrinthectomy, 5 following vestibular nerve section, and 10 control subjects was undertaken in order to evaluate the long-term effectiveness of these procedures. Testing was performed a mean of 8.5 years after surgery. Vestibulometry assessed time constants, gain, and phase advance of the vestibulo-ocular reflex (VOR) in both horizontal and vertical planes of head movement. Loss of the anticipated increase in phase advance in the vertical VOR of the labyrinthectomy group, significantly different from the vestibular nerve section group (P < 0.05 and P < 0.01 for each direction of rotation), suggests that posterior and superior semicircular canal function remains intact following per-meatal labyrinthectomy. Although stabilometry suggested that balance in the labyrinthectomy group was poorer than in the two other groups (P < 0.025 without optic fixation), clinical assessment demonstrated excellent functional results. Per-meatal labyrinthectomy remains a safe and effective procedure for the relief of vestibular symptoms, although vestibular nerve section may provide more complete removal of contributory end-organ function.