Topographic analysis of inner ear lesions in profoundly deafened patients with tympanogenic and meningogenic labyrinthitis using three-dimensional magnetic resonance imaging.

OBJECTIVE

High-resolution magnetic resonance imaging (MRI) provided clear images of three-dimensional (3D) reconstruction of the inner ear in candidates for cochlear implantation. In this study. semiquantitative analysis of the 3D MRI findings was performed to investigate topographic lesions of the inner ear caused by tympanogenic and meningogenic labyrinthitis.

STUDY DESIGN

This was an observational study.

SETTING

The study was performed in an academic, comprehensive, multispecialty group practice.

PATIENTS

Postlingual deafened patients with cochlear implantation. The cause of deafness was tympanogenic or meningogenic labyrinthitis.

INTERVENTION

High-resolution 3D MRI and postoperative speech recognition tests were used.

RESULTS

Abnormal findings in the inner ear detected with MRI were found before surgery in 58.3% of the patients with meningogenic labyrinthitis, although the incidence was lower in patients with tympanogenic labyrinthitis. Abnormal MRI findings were frequently observed in the cochlear basal turn and semicircular canals more than in the middle and apical turn in cases with meningogenic etiology. Patients with tympanogenic labyrinthitis suffered less with a vestibular apparatus than did those patients with meningogenic labyrinthitis. Regarding the analysis of the inner ear lesions at the implanted side, the postoperative speech recognition ability did not correlate to the extent of abnormal MRI findings of the implanted ear.

CONCLUSION

Improvement in 3D MRI technology provided an accurate preoperative picture of the inner ear apparatus. In cochlear implant patients with infectious labyrinthitis, the extent of the inner ear lesion detected with 3D MRI was different among etiologies of deafness.