Temporal bone fractures often cause loss of audiovestibular function. Those patients with bilateral profound sensorineural hearing losses secondary to temporal bone fractures become candidates for cochlear implantation. The authors present the histopathology of five temporal bone fractures in three patients, evaluating specifically the traumatic effects on the neural elements of the inner ear. Transverse fractures of the temporal bone result in severe loss of hair cells, ganglion cells, and other supporting cells in the inner ear. Occasionally labyrinthitis ossificans may occur as a consequence of trauma or infection. While longitudinal fractures do not violate the otic capsule, these same neural elements may be damaged by concussion.
"sub-category in this respect: transverse fractures may lead to loss of spiral ganglion cells, infection, intracochlear haemorrhage followed by neo-osteogenesis leading to labyrinth ossifi cation. Cochlear obliteration may then inhibit a successful electrode insertion (Morgan et al, 1994; Colletti et al, 2004), followed by unsatisfactory results (Camilleri et al, 1999; Moore & Cheshire, 1999). Another drawback is the possible facial nerve stimulation due to current leaks through the low resistive fracture line (Camilleri et al, 1999). "
[Show abstract][Hide abstract] ABSTRACT: In this clinical note we discuss the indications, feasibility, and outcomes of binaural simultaneous cochlear implantation (CI) following bilateral transverse temporal bone (TB) fractures. A 41-year-old male, totally deaf after a bilateral TB fracture, underwent an audiological, electrophysiological, and imaging investigation in order to assess the integrity of the VIIIth cranial nerves. Five months later he received a simultaneous bilateral CI. Speech perception tests were conducted at different time points. A significant advantage by dichotic listening was observed since the beginning of the habilitation program. The patient achieved a 100% word and sentences recognition in quiet at 12 months. His listening skills in noisy conditions were improved by the use of two implants. A CI in TB fractures is feasible if the VIII nerve is intact and the cochlea is spared by the fracture rim. The early timing of the procedure probably contributed to its success by preventing cochlear fibrosis and ossification.
International journal of audiology 10/2010; 49(10):788-93. DOI:10.3109/14992027.2010.497170 · 1.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Labyrinthitis ossificans results in part from the intense inflammatory response to Streptococcus pneumoniae cell wall components. Depletion of complement in Mongolian gerbils following induction of meningitis will reduce the degree of inflammation and subsequent cochlear fibrosis.
Random prospective study. Histological evaluations were performed with the researcher blinded to the experimental group
S. pneumoniae meningitis was induced in 10 control and 18 experimental Mongolian gerbils with an intrathecal injection of the bacteria. Both groups of animals received treatment with penicillin. The experimental group was also treated with cobra venom factor to deplete complement in the animals. Three months after the induction of meningitis, the animals' temporal bones were harvested for histological evaluation.
The decomplemented animals developed significantly less intracochlear fibrosis (P < .01). The mortality rate for the experimental group was 11% compared with 40% in the control group (P = .14).
Reduction of the intense inflammatory response to the S. pneumoniae cell wall components in suppurative labyrinthitis secondary to bacterial meningitis reduced the degree of labyrinthitis ossificans.
The Laryngoscope 11/1999; 109(10):1674-8. DOI:10.1097/00005537-199910000-00023 · 2.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We investigated whether methylprednisolone sodium succinate can ameliorate cochlear nerve degeneration following compression injury on the cerebellopontine angle portion of the cochlear nerve, using a quantitative animal experimental model that we have developed recently. In this model, cochlear nerve degeneration after compression could be quantitatively evaluated, while cochlear ischemia induced by the compression carefully maintained below the critical limit that causes irreversible damage to the cochlea. Eleven rats were treated with methylprednisolone during the pre- and post-compression period. Two weeks after compression, the numbers of SGC were compared between the rats that received the compression without and with methylprednisolone treatment. Methylprednisolone treatment improved the survival of SGC following cochlear nerve injury statistically highly significantly in the basal turn where the traumatic stress had been less than in the other cochlear turns in our experimental setting. Although it was not statistically significant, greater survival was also observed in the other cochlear turns. The results of this experimental study indicated that at least a portion of injured cochlear nerve had been potentially treatable, and that methylprednisolone might prevent such cochlear neurons from entering into the vicious process of irreversible damaging process.
Hearing Research 02/2001; 151(1-2):125-132. DOI:10.1016/S0378-5955(00)00219-7 · 2.97 Impact Factor
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