The amplitude ratio between the paretic and the normal side as determined by electroneuronography is used as a basis for estimating the prognosis of facial palsy. Several methods have been described of placing the surface electrodes and of finding the supramaximal impulse strength. We investigated 16 normal test persons with the aim (1) of optimizing the procedure of neuronography with regard to the possible variations of electrode placement and stimulus intensity and (2) of finding out the right/left difference in normal test subjects. Following our results, the best positions of the recording electrodes are the nasal alae. Even under these most favorable test conditions we found an average side difference of the bilaterally recorded electroneurograms of normal test persons of 22 %.

1028 ear operations which were performed by our department during the last few years are being analysed in the study. 649 of them were carried out to improve hearing, 245 to cure the middle ear; 120 were reoperations, and 14 could not be classified. The patients were diagnosed as follows: 280 with and 279 with other forms of cholesteatoma, 151 with otosclerosis, 20 with deformations, 89 with a trauma, and 20 with a tumour of the middle ear. Of these, only reoperations of cholesteatoma, chronic otitis media and tympanosclerosis were examined in further detail in this research. 54 (of a total of 280) patients diagnosed with cholesteatoma were surgically treated a second time. The reason for reoperation was recurrent cholesteatoma in 70% of the cases, and a planned second-look operation after one year in 30%. In second-look operations, ossicular chain reconstruction was performed in most cases, but in another 11%, recurrent cholesteatoma was found. The majority of recurrencies occurred either 2 to 4 years after primary operation or after 11 years. 44 of a total of 297 patients with chronic mesotympanic otitis media were re-operated on: 57% of them for recurrent inflammation, and 43% for ossicular chain reconstruction as a planned second-step operation. The majority of reoperations occurred within the first year after primary operation, continually decreasing for up to five years afterwards. The following conclusions can be drawn from these results: 1. Often the patients suffer from extended cholesteatoma, so that at first curative surgery is necessary, while the ossicular chain can be reconstructed by a second operation only.(ABSTRACT TRUNCATED AT 250 WORDS)