Cochlear implantation after bacterial meningitis: the dangers of delay

Abstract

A case is described of a child of 2.6 years who developed total deafness after acute bacterial meningitis. Rapid obliteration of the cochleas due to osteoneogenesis led to limited cochlear implantation. The case is made for fast tracking these children to cochlear implant teams before neoossification becomes established.

The influence of post-meningitic obliteration and ossification of the cochlea on cochlear microphonics

“…Our data show that cochlear microphonics do not constitute a major criterion aiding diVerential diagnosis of a post-meningitic ossiWed or obliterated cochlea. It, therefore, remains necessary, prior to cochlear implantation, to obtain preoperative images of the temporal bone using computed tomography [9,15] and magnetic resonance tomography in order to spatially deWne any obliteration or ossiWcation [8,10] and, if necessary, consider use of a double-array electrode. The impact of other ossifying disorders of the cochlea, such as cochlear otosclerosis, may further clarify the signiWcance of cochlear microphonics in future studies.…”

“…In around one-third of these instances, the cochlea is also obliterated [9]. Obliteration is frequently followed by ossiWcation [8,10]. If either of these occurs, there is a potential physical/mechanical impact on the displacement behaviour of the remaining hair cells.…”

“…Meningitis may lead to deafness [7] in about 10% of cases [8]. In around one-third of these instances, the cochlea is also obliterated [9].…”

Hearing impairment in children following bacterial meningitis; assessed with brainstem auditory evoked response (BSAER)

“…This is important because late diagnosis may prevent optimal audiologic rehabilitation. Cochlear implantation, for example, can partially restore hearing in post meningitis deafness, but the procedure may be ineffective if not performed promptly (7,8). It may not be possible to do BSEAR of all the children following bacterial meningitis due to limited resources.…”

Aktuelle Entwicklung zum Cochlearimplantat

“…Tierstudien und (leidvolle) Erfahrungen mit Patienten belegen, dass nach stattgehabter bakterieller Meningitis innerhalb von 4-6 Wochen eine intrakochleäre ossäre Obliteration als Narbe nach Otitis acuta interna auftreten kann, die die reguläre Implantation verhindert [5,15].Trotz modifizierter Elektrodenträger oder aufwendiger Operationstechniken bleiben die Ergebnisse im Sprachverstehen bei nur partieller Insertion hinter dem Durchschnitt zurück [3,18].…”