Labyrinthine Ossification after Meningitis: Its Implications for Cochlear Implantation

Abstract

Labyrinthine ossification can be found in a high percentage of patients with profound deafness resulting from bacterial meningitis. Radiographic evidence of ossification can be found as early as 2 months after the acute infection, indicating that the intracochlear process probably begins much earlier. If long, intracochlear cochlear implants are to be most successfully used in these patients, an aggressive approach to clinical management following the meningitis should be taken. Illustrative case reports and suggested guidelines for evaluation and treatment are given.

Meningitis resulting in hearing loss and labyrinthitis ossificans - does the causative organism matter?

“…There are papers that demonstrate that ossifi cation can occur as early as 2 months after meningitis (Novak et al, 1990) on computed tomographic scans. There are also animal studies (Nabili et al, 1999) demonstrating that ossifi cation occurs within the cochlea as early as 3 weeks after intrathecal injection of Streptococcus pneumoniae.…”

“…Eisenberg et al (1984) produced evidence that Streptococcus pneumoniae may be associated with greater degrees of labyrinthine ossifi cation on radiological and surgical reports but more recently Axon et al (1998) did not demonstrate any difference in severity of ossifi cation between aetiological agents. Severe ossifi cation may occlude the cochlear lumen, making full insertion of the implant diffi cult or impossible, therefore early cochlear implantation is advocated in patients with profound hearing loss secondary to meningitis to allow surgery prior to the development of extensive ossifi cation (Novak et al, 1990).…”

Diagnostic challenges and safety considerations in cochlear implantation under the age of 12 months

“…Situations such as postmeningitic cochlear obliteration on the other hand, may push otologists to intervene earlier. This condition may be detected on MRI scans as early as 2 months after the infection, and can make cochlear implantation an urgent procedure in order to avoid the ossification, which makes full electrode insertion difficult or impossible [48,65,66].…”

Differential diagnosis and prognosis of T1-weighted post-gadolinium intralabyrinthine hyperintensities

“…On the contrary, the substantial decrease in fluid signal could correspond to the loss of the normal fluid viscosity that would evolve to fibrosis and even to ossification in 60% of cases. This criterion could be interesting for the selection of patients with the aim of early cochlear implantation [7,27,28]: in the case of labyrinthitis, patients with a substantial loss of fluid signal on 3D HRT2 associated with considerable deafness without improvement after a few weeks should be candidates for an early cochlear implantation, in particular in cases of bilateral labyrinthitis [29]. However, these data have to be confirmed in larger series.…”