Faculty Bibliography

Lesions involving the petrous apex are rarely encountered in clinical practice. This directly affects the ability of the otolaryngologist to diagnose and effectively treat these lesions. Greater physician awareness and increased technologic capability are leading to more effective management of pathologic conditions involving this area of the temporal bone

In our series of patients operated on for acoustic neuromas at New York University Medical Center between 1974 and 1983, 13% (17 of 133) had sudden hearing loss. Of these, approximately 23% (four of 17) had recovered auditory function before acoustic neuroma extirpation. Three patients spontaneously recovered, while one improved with steroid therapy. Contrast computerized tomography demonstrated a widened internal auditory canal and evidence of cerebellopontine angle tumor, respectively, in 88% and 59% of patients with sudden hearing loss and acoustic neuroma. Clinical characteristics suggesting acoustic neuroma as the cause of sudden hearing loss with or without auditory recovery could not be identified in our series. Our data support the rationale that patients with unilateral sudden hearing loss, even with recovery, must be evaluated for a possible cerebellopontine lesion

Verrucous carcinoma, a familiar lesion of the oral cavity and larynx, is distinctly rare in the ear. We report five cases of verrucous carcinoma of the temporal bone, each of which fulfills Ackerman's histologic and biologic criteria. Only three cases of verrucous carcinoma of the ear have been previously reported. Most cases of verrucous cancers of the head and neck demonstrate a lack of nodal involvement, relatively slow growth potential, local invasiveness, and responsiveness to surgical treatment. In our five cases of verrucous carcinoma of the temporal bone, three had a biologic behavior similar to other verrucous tumors, while two cases were unusually aggressive. Three patients were treated surgically and had favorable outcomes, while the remaining two were treated with combination therapy. These cases highlight the difficulty in diagnosis and treatment as well as the lack of understanding of the biologic behavior of this rare otologic entity

Cochlear implant patients implanted with a programmable, 21-channel stimulator receive information about the dominant spectral peak in the midfrequency range (800-4000 Hz) encoded as electrode position. Three frequency-to-electrode position maps were tried, including one map where frequency-band boundaries were those frequencies that are midfrequency spectral peak boundaries between vowels, in an effort to increase vowel discrimination. Identification tests were not conclusive with respect to one map being better than the others for the three patients, but the two maps which had more electrodes representing lower frequencies were significantly better than the other map, when measured by discrimination tests

A major concern regarding multichannel (multi-electrode) cochlear prosthesis usage has been the possibility of long-term deleterious physiological effects such as the degeneration of spiral ganglion cells, neuronal degeneration, and new bone formation. These effects, if present, would become evident in the deterioration of hearing sensation and performance of the cochlear implant recipient on a battery of audiologic tests. To date, five patients using the Australian multi-electrode multichannel cochlear implant have undergone a 1-year evaluation of the device. The assessment includes a check of electrical threshold and comfort levels for each electrode, sound field pure tone and speech thresholds, the MAC battery, vowel and consonant recognition tests, and speech tracking tasks. All results were compared to those obtained postoperatively following stimulation and a 3-month training period. Results to date have shown no deterioration in implant functioning in all patients tested. Periodic extensive monitoring of all implant recipients is advocated in order to evaluate the possibility of long-term effects

A multichannel cochlear prosthesis was evaluated using the method of Connected Discourse Tracking. Data were obtained from five subjects over a 10-week period. Significant learning effects were obtained both with and without the prosthesis. The method of orthogonal polynomials was used to obtain a statistically precise fit for each learning curve. The curves differed both in terms of shape and average rate of learning. The two best subjects showed substantial improvements, reaching tracking rates in excess of 90 words-per-minute. A method for representing prosthesis-based improvements, which takes learning effects into account, is developed and discussed