Faculty Bibliography

We have investigated developmental alterations in the tonotopic projection of the gerbil lateral superior olive. Single neurons were characterized in the frequency domain and the recording site marked with fast green. Transverse tissue sections from the auditory brainstem of each animal were visualized with a video-equipped microscope, and the image was digitized for subsequent alignment. The three-dimensional display indicated little variation in the rostrocaudal axis, allowing us to collapse the data into a two-dimensional tonotopic map. The tonotopic map was found to change with age such that the characteristic frequency of neurons in a given anatomical location became successively higher during development. These results are consistent with the hypothesis that the place code gradually shifts in the developing cochlea

Among the various diagnostic modalities that have been recommended for preoperative assessment of the patient with laryngeal carcinoma is computed tomography. While good overall correlation between CT findings and operative findings has been noted, a significant number of false positives and false negatives have been found, particularly with regard to cartilage invasion and lymphadenopathy. We compared the findings of direct laryngoscopy, palpation of the neck, and CT with pathologic specimens in 29 patients who underwent surgery for carcinoma of the larynx. We found that CT scanning underestimated the extent of neoplastic involvement in over half the cases. With respect to cartilage invasion we determined a significant number of false-negative findings. Computed tomographic scanning was equivalent to palpation in predicting cervical metastasis. Our findings indicate that the role of CT scanning may be more limited than previously acknowledged, particularly in patients for whom nonconservation surgery is planned

The large vestibular aqueduct as an isolated anomaly of the temporal bone has been previously identified radiologically, and its association with sensory neural hearing loss has been recognized. It has not, however, been defined as a distinct clinical entity in children. We studied 12 children, ages 3 to 9 years, with downward-fluctuating progressive high-frequency neurosensory hearing losses whose symptoms were thought to be related to the isolated enlargement of the vestibular aqueduct identified by high-resolution computed tomographic scanning. Previously it had been assumed that a large vestibular aqueduct is a temporal bone dysplasia that is a variant of the Mondini type of deformity and that the associated hearing loss is congenital in nature. Our clinical observations, however, indicate that the hearing loss in children with an isolated enlargement of the vestibular aqueduct is acquired during childhood. The natural history of this progressive deafness is reviewed, and a pathophysiologic hypothesis is presented

Granulomatous disorders of the larynx can take on many forms and usually represent the end stage of chronic disease. In the past, laryngeal granulomas were much more prevalent primarily because of the frequency of tuberculosis. Seldom is the larynx the site of origin for granulomatous disease, but it is usually a manifestation of a pulmonary entity such as histoplasmosis, blastomycosis, sarcoidosis, or tuberculosis. The actual diagnosis is frequently arrived at while trying to rule out carcinoma. Laryngeal tuberculosis, although rare in the United States, remains the most common granulomatous disease of the larynx. Its increasing incidence has paralleled the diminished incidence of tuberculosis in the general population. Specific clinical characteristics for diagnosis are few and diagnosis is arrived at through a high index of suspicion and biopsy. When biopsy is carried out, adequate tissue should be obtained for both histological sections, cultures, and sensitivities.

Successful management of frontal sinus fractures depends on correct identification of structural pathology, which may lead to inflammatory complications. Obstruction of the frontonasal duct is a significant factor predisposing to such complications and its evaluation is thus critical in the management of these fractures. Specific radiographic CT criteria and an intraoperative dye irrigation test are presented to determine the likelihood of frontonasal duct injury. Eighteen cases of frontal sinus fractures are reviewed, which have been treated based on these principles. A scheme is presented outlining the management of frontal sinus trauma using these methods

Clinical staging of supraglottic carcinoma requires evaluation of the pre-epiglottic space (PES). To explore the role of fine needle aspiration biopsy of the PES in the staging of epiglottic carcinoma, endoscopic transvallecular fine needle aspiration biopsies of the PES were performed in 16 patients with epiglottic carcinoma. The results of aspiration cytology were compared with CT scanning and postoperative histopathologic sections of the PES after total or supraglottic laryngectomy. This preliminary report shows that needle aspiration biopsy of the PES is a safe and sensitive technique, having a high correlation with histopathologic follow-up. Needle biopsy, along with CT scan, is clinically useful in staging the PES, which cannot be examined directly