Influence of cochlear implantation on the vestibular function.

The aim of the present study was to examine the influence of cochlear implantation on vestibular function. The function of the horizontal semicircular canal, the saccular function, and the incidence of vestibular symptoms were assessed before and after cochlear implantation. Twenty unilaterally cochlear implant patients were evaluated preoperatively, 1 and 6 months postoperatively, with caloric testing with electronystagmography (ENG) recordings and vestibular evoked myogenic potentials (VEMP) testing. A medical history was taken from every subject, noting the presence or absence of vertigo before and after the operation. A possible correlation between the appearance of postoperative vertigo and age, sex, implant side, preoperative caloric results and VEMP status, and postoperatively recorded changes in caloric and VEMP testing was also investigated. A statistically significant difference was found in the percentages of canal paresis (p = 0.01) and the percentages of VEMP waveform absence (p = 0.002) between the repeated measurements in the implanted side, whereas in the non-implanted side no difference was (p > 0.05) found. Four patients complained of postoperative vestibular symptoms. In three of them the symptoms lasted less than 6 months postoperatively, but the fourth patient was still dizzy 6 months after cochlear implantation. No correlation was found between the above-mentioned factors and the occurrence of postoperative vertigo. In conclusion, although changes of the peripheral vestibular function of the implanted side were recorded in our patients, permanent vertigo was rare. Predictive factors for the occurrence of postoperative vestibular symptoms could not be identified.

CT scan versus surgery: how reliable is the preoperative radiological assessment in patients with chronic otitis media?

The objective of the study was to evaluate the accuracy of the preoperative radiological assessment regarding 10 different middle ear structures in patients with chronic otitis media (COM). The setting of the prospective study was in a Tertiary university hospital. Fifty patients scheduled for a primary operation for COM. All patients underwent preoperative temporal bone high-resolution CT-scan (HRCT). AC(1)-statistics between the radiological report and the intra-operative findings were calculated. There was no correlation between the radiological assessment and the surgical findings in the scutum, attic area, and oval window. There was a poor or fair agreement on the condition of the malleus-incus complex, the status of the tympanic cavity, and the round window. There was a moderately strong agreement regarding the status of the lateral semicircular canal (LSCC) and tegmen tympani. This agreement was primarily observed, when no erosion/exposure was present in the LSCC or the dura. There was a very strong agreement in the mastoid air-cell complex and the sigmoid sinus, especially when the former was abnormal and the latter had no pathology. There are significant difficulties in radiological imaging for reliably assessing the middle ear in patients with chronic otitis media, using HRCT. The preoperative CT scan generally underestimates the actual pathology found by the surgeon in certain middle ear areas. The decision for surgical intervention should not be based on the radiological interpretation of certain middle ear structures, and ENT surgeons should be prepared to encounter conditions which are not reported by the radiologist preoperatively, and modify the operating strategy accordingly. EBM level: 2c.