Abstract
1. In evaluating the diagnostic significance of the polarity of summating potentials (SP) or the SP/AP ratio in Meniere's disease, the following should be studied :
1) the electrode positions in the tympanic cavity;2) the interval of sound stimulations; and 3) the method of recording, whether it is by transtympanic or extra-tympanic recording.
2. When a double electrode recording is made via the transtympanic route, the polarity of the SP, whether it is positive or negative, depends on the electrode positions.
3. Abnormal SP's were not very closely related to the time elapsed since the onset of vertigo, audiometric pattern, or the findings of the glycerol test.
4. It is difficult to differentiate Meniere's disease from sudden deafness on the basis of large SP/AP ratios alone, which are frequently found in both diseases.5. Recovery or progression of hearing impairment was not always related to the findings of the SP.6. Positive SP's were seen in Ménière's disease at a higher incidence than in other sensorineural hearing loss.
