Comparison of Sum mat ing Potential in Menière's Disease between Trans- and Extratympanic Electrocochleography

Publisher Website
Google Scholar
Abstract
The summating potential (SP) recorded concurrently with transtympanic (TT) and extratympanic (ET) electrocochleography in Menière ears was compared with respect to polarity and amplitude. There was a difference in SP polarity and amplitude between the two methods. The incidence of the increase in the ratio of -SP amplitude to the amplitude of the auditory nerve action potential (AP) (-SP/AP ratio) at 80 dB nHL as a response to a click was higher with the ET than with the TT method. Most of the ears exhibiting an increased + SP/AP ratio with the TT method showed an increased -SP/AP ratio with the ET method. The incidence of increased SP/AP ratios including -SP/AP and + SP/AP ratios was similar with both methods. A + SP was recorded in 14 of 25 ears upon stimulation with an 8-kHz tone burst with the TT method, whereas no + SP was recorded in 25 ears with the ET method. Tone bursts of 1 and 2 kHz produced a -SP and similar waveforms with both methods. Comparison of -SP amplitude recorded with both methods revealed that the ratio of -SP amplitude with both methods is different across the stimulus frequencies. The present study suggests that the -SP elicited by tone bursts of mid to low frequencies is more stable in the diagnosis of Menière's disease than -SP elicited by a click because of the lesser influence of the electrode location and that the increase in the + SP recorded with the TT method may be of clinical significance in the diagnosis of Menière's disease.

This publication has 16 references indexed in Scilit: