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Biomedical subjects

S M Quigley

Publications and source records attributed to S M Quigley.

4 recordsLinked to original sources

Accuracy of high-resolution computed tomography in cochlear implantation.

Multichannel cochlear implants are a proven method for the auditory rehabilitation of individuals who have severe-to-profound sensorineural hearing loss. These devices typically require insertion into the scala tympani of the cochlea to provide auditory stimulations. A patent scala provides the best chance for an adequate insertion of the electrode array. Preoperative high-resolution computed tomography imaging has traditionally been used to determine the patency of the scala tympani. Its ability to accurately predict the patency of the cochlea has been questioned in several retrospective studies. A prospective study was undertaken in 28 consecutive individuals undergoing cochlear implant surgery to compare the findings on high-resolution computed tomography with the surgical findings in an attempt to determine high-resolution computed tomography's accuracy. Cochlear obstruction caused by ossification was accurately predicted in six of six individuals but overestimated in the round window region in three individuals. High-resolution computed tomography accurately predicted patent cochleas in 19 individuals. No false-negative results were encountered. In this study sensitivity of high-resolution computed tomography was 100%, and specificity was 86%. High-resolution computed tomography appears to be more helpful than previously reported for determining cochlear patency.

Acoustic Stimulation

Ear candles--efficacy and safety.

Ear candles are a popular and inexpensive alternative health treatment advocated for cerumen removal. A hollow candle is burned with one end in the ear canal with the intent of creating negative pressure and drawing cerumen from the ear. If effective, significant savings could result from the use of ear candles. This study evaluates the efficacy and safety of this alternative method for cerumen management. Tympanometric measurements in an ear canal model demonstrated that ear candles do not produce negative pressure. A limited clinical trial (eight ears) showed no removal of cerumen from the external auditory canal. Candle wax was actually deposited in some. A survey of 122 otolaryngologists identified 21 ear injuries resulting from ear candle use. Ear candles have no benefit in the management of cerumen and may result in serious injury.

Cerumen

Use of botulinum toxin to prevent facial nerve stimulation following cochlear implantation.

Facial nerve stimulation can develop because of the electric fields generated from an activated cochlear implant. This problem can usually be ameliorated by reducing or eliminating the current through the electrodes causing the undesirable stimulation. Occasionally there may be numerous electrodes that have to be deactivated in order to eliminate the facial nerve stimulation, and this may result in a marked reduction of auditory benefit to the cochlear implant user. Botulinum toxin causes transient neuromuscular blockade and has been shown to be effective in reducing or eliminating facial nerve hyperactivity due to a variety of causes. This report details the use of botulinum toxin in a patient with a cochlear implant who developed excessive facial nerve stimulation that necessitated the deactivation of 15 of the implant's 22 electrodes. After treatment with botulinum toxin, twice as many electrodes could be comfortably activated without causing facial nerve stimulation. The dynamic range was increased in 4 of the remaining 6 electrodes that were activated prior to treatment. The patient reported a marked improvement in sound quality and understanding of speech without lipreading as compared to her pretreatment performance. Treatment with botulinum toxin appears to be useful for patients who have excessive facial nerve stimulation after cochlear implantation.

Botulinum Toxins

Cochlear implants in children.

Cochlear implants are no longer considered new or experimental technology. Difficulty in evaluating the degree of hearing loss and response to traditional forms of amplification in young children makes pediatric cochlear implant candidacy a complex issue. Cochlear implantation and, in particular, pediatric cochlear implantation, requires a team commitment with contributions from surgeons, audiologists, speech pathologists, psychologists, and special educators. Elements discussed include assessment and candidacy issues, surgical technique, elements of a cochlear implant team, outcome assessment, and potential complications. The decision to perform pediatric cochlear implantation should not be undertaken without serious consideration to the enormous commitment required in both financial and personnel terms.

Child