Influence of cochlear trauma and electrode array design on tinnitus burden, vertigo and speech perception

Introduction The aim of this prospective study is to investigate the rate of cochlear dislocation and the scalar position depending on the electrode array (EA) design and to compare their influence on postoperative speech perception, tinnitus development and burden and postoperative vertigo development.

Method 66 patients were evaluated preoperatively, 3 days, 4 weeks, 6 and 12 months after CI surgery. The scalar position, dislocation, insertion depth and angle in regard to cochlear morphology were recorded using digital volume tomography. Speech perception was evaluated using the Freiburg monosyllables. Tinnitus burden was assessed using a visual analogue scale (VAS) and the tinnitus questionnaire. Furthermore, subjective dizziness was tested using the dizziness handicap inventory and VAS and VNG, vKIT, c- and o-VEMPS were performed.

Results Speech perception was not significantly different in dislocated EA. The tinnitus burden is significantly reduced over the course of CI treatment. Cochleostomy showed no increased risk of dislocation or tinnitus exacerbation. The displacement of the EA and the cochleostomy showed a connection to postoperative vertigo due to damage to the sacculus with abnormal cVEMPS. However, this was already compensated for during the first adjustment.

Conclusion The round window insertion is preferable to the cochleostomy, since the cochleostomy carries the risk of saccular damage with postoperative symptoms of vertigo. Atraumatic insertion and slim, atraumatic EAs are preferable not only with regard to speech perception with CI, but also to reduce postoperative dizziness.

Publication History

Article published online:
12 May 2023