TY - JOUR
T1 - The pathologic basis of facial nerve stimulation in otosclerosis and multi-channel cochlear implantation
AU - Seyyedi, Mohammad
AU - Herrmann, Barbara S.
AU - Eddington, Donald K.
AU - Nadol, Joseph B.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2013
Y1 - 2013
N2 - Hypothesis: Unintentional electrical stimulation of the facial nerve by cochlear implants occurs when advanced otosclerosis invades the endosteum of both the upper basal turn of the cochlea (UBTC) and the facial nerve canal (FNC) and all the bone between these 2 structures. Background: A complication of cochlear implantation is facial nerve stimulation (FNS) known to be more common in otosclerosis. Otosclerotic involvement of the enchondral bone of the otic capsule results in areas of bone resorption, new bone formation, vascular proliferation, and a connective tissue stroma. This may reduce impedance, shunting current to the facial nerve. The cause of FNS has not been fully elucidated, and remarkable differences in FNS rates have been reported using different types of electrode arrays. Methods: Thirteen implanted temporal bones from 11 patients with otosclerosis, 10 with straight, and 3 with perimodiolar electrodes, were histologically processed after death. The data were analyzed using Fisher's exact test. Results: In the straight electrode group (n = 10), only those subjects with temporal bones showing involvement by otosclerosis of the UBTC and of FNC endosteum and the bone between these 2 structures (n = 4; 40%) showed FNS during life (p = 0.005), which was consistent with the location of problematic electrodes during life. None of the cases in the perimodiolar group had FNS even with endosteal involvement by otosclerosis. Conclusion: FNS is a common complication of cochlear implantation in patients with otosclerosis and occurs most commonly with straight electrode implants where the endosteum of both UBTC and FNC and the intervening bone are otosclerotic.
AB - Hypothesis: Unintentional electrical stimulation of the facial nerve by cochlear implants occurs when advanced otosclerosis invades the endosteum of both the upper basal turn of the cochlea (UBTC) and the facial nerve canal (FNC) and all the bone between these 2 structures. Background: A complication of cochlear implantation is facial nerve stimulation (FNS) known to be more common in otosclerosis. Otosclerotic involvement of the enchondral bone of the otic capsule results in areas of bone resorption, new bone formation, vascular proliferation, and a connective tissue stroma. This may reduce impedance, shunting current to the facial nerve. The cause of FNS has not been fully elucidated, and remarkable differences in FNS rates have been reported using different types of electrode arrays. Methods: Thirteen implanted temporal bones from 11 patients with otosclerosis, 10 with straight, and 3 with perimodiolar electrodes, were histologically processed after death. The data were analyzed using Fisher's exact test. Results: In the straight electrode group (n = 10), only those subjects with temporal bones showing involvement by otosclerosis of the UBTC and of FNC endosteum and the bone between these 2 structures (n = 4; 40%) showed FNS during life (p = 0.005), which was consistent with the location of problematic electrodes during life. None of the cases in the perimodiolar group had FNS even with endosteal involvement by otosclerosis. Conclusion: FNS is a common complication of cochlear implantation in patients with otosclerosis and occurs most commonly with straight electrode implants where the endosteum of both UBTC and FNC and the intervening bone are otosclerotic.
KW - Cochlear implantation
KW - Facial nerve
KW - Otosclerosis
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U2 - 10.1097/MAO.0b013e3182979398
DO - 10.1097/MAO.0b013e3182979398
M3 - Article
C2 - 23928519
AN - SCOPUS:84892787315
SN - 1531-7129
VL - 34
SP - 1603
EP - 1609
JO - Otology and Neurotology
JF - Otology and Neurotology
IS - 9
ER -