The summating potential in ultrasonic labyrinthectomy for Menière's disorder.

This paper reports SP changes pre- and post-operatively in a series of 12 patients who have undergone ultrasonic labyrinthectomy for Menière's disorder. The unoperated ear in 7 of these patients also had pre- and post- operative ECochG. The SP in the operated ear was reduced in amplitude and duration in 50 per cent and 66 per cent of ears respectively. However, the SP was also reduced in the unoperated ears by similar proportions. Statistical analysis showed no significant difference in SP change between the two sets of ears. It is concluded that the value of the SP in prediction or assessment of results of treatment in Menière's disorder is not at present proven, and that future investigations require the use of controls.