PATTERNS OF NEURAL DEGENERATION IN THE HUMAN COCHLEA AND AUDITORY NERVE : IMPLICATIONS FOR COCHLEAR IMPLANTATION

摘要: Although the identity of all variables that may influence speech recognition after cochlear implantation is unknown, degree preservation spiral ganglion cells generally considered to be primary importance. A series experiments in our laboratories, directed at quantification surviving profoundly deaf, evaluation predictive value a variety clinical parameters, and consequences inner ear, summarized. Histologic study ears patients who were deafened during life demonstrated cause deafness accounted for 57% variability cell counts. Spiral counts highest individuals by aminoglycoside toxicity or sudden idiopathic lowest those postnatal viral labyrinthitis, congenital genetic deafness, bacterial meningitis. Study determinants degeneration revealed most severe basal compared with apical turn more when both outer hair are absent. Unlike findings some experimental animal studies, no survival advantage type II could identified. There was strong negative correlation between bony occlusion cochlea normality count. However, even specimens which there occlusion, significant numbers survived. positive diameter cochlear, vestibular, eighth cranial nerves total count ( p < 0.001) found. This would suggest modern imaging techniques used predict residual population implant candidates. Trauma from electrode array studied cadaveric human temporal bone models bones received implants life. characteristic pattern damage lateral wall basilar membrane identified upper turn. New formation perielectrode fibrosis common implantation. Despite this trauma reaction, firm evidence further can predicted as consequence. (Otolaryngol Head Neck Surg 1997;117:220-8.)