APSCI panel discussion I: imaging and surgical issues

[Present state of cochlear implant treatment in adults and children]

The technique of cochlear implantation was the first method which allowed replacement of a sense organ by a (partially) implantable electronic prosthesis. By this method the cells of the spiral ganglion of the cochlea are directly stimulated by the electrodes introduced into the cochlea, bypassing the functions of the outer and middle ear as well as the cochlea. Treatment with a cochlear implant (CI) has been established over the last 20-30 years as a reliable method for restoring hearing in adults and children with severe hearing disorders and is now a routine method in many centers. For optimal results in understanding speech and for children in the speech development phase, rehabilitation must be an integral part of the total treatment and follow soon after implantation. To achieve this early diagnosis of hearing difficulties or deafness is necessary, which is simplified by a consistent hearing screening of newborns, now a statutory procedure in Germany.

Magnetic resonance imaging in patients with meningitis induced hearing loss

The aim of this multicentre study was to compare T1 with T2 weighted MRI scans of the labyrinth after meningitis and to investigate whether waiting with scanning improved the reliability of diagnosing an ongoing process such as cochlear osteogenesis. Forty-five patients were included who suffered from meningitis induced hearing loss (radiological imaging <1 year after meningitis). Twenty-one gadolinium enhanced T1 and 45 T2 weighted MRI scans were scored by two radiologists regarding the condition of the labyrinth. These radiological observations were compared with the condition of the cochlea as described during cochlear implantation. A higher percentage of agreement with surgery was found for T2 (both radiologists 73%) than for T1 weighted MRI scans (radiologist 1: 62%, radiologist 2: 67%), but this difference is not significant. There was no significant difference between early (0–3 months) and late (>3 months) scanning, showing that radiological imaging soon after meningitis allows early diagnosis without suffering from a lower agreement with surgical findings.