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We investigated the effect of administering hypertonic glycerol on cochlear and auditory nerve responses to rectangular-pulse clicks and on pure-tone behavioral thresholds. Eleven ears with Ménière's disease, and 20 ears without the disease were studied. Among the ears with Ménière's disease summating potential (SP) amplitudes decreased and 250 to 1,000-Hz thresholds improved after glycerol administration. Action potential amplitudes from the ears with Ménière's disease also decreased after glycerol ingestion, but to a lesser degree. In contrast, among the ears without Ménieère's disease, 250- to 1,000-Hz behavioral thresholds did not change significantly after glycerol nor did any of the electrophysiologic responses. Analogous group differences were found when the ears were regrouped according to the presence of absence of pathologic SP enlargement. These results demonstrate a tendency for three variables-(1) clinical diagnosis of Ménière's disease, (2) enlarged SP, and (3) positive glycerol test result-to cluster together in the same population of ears.

The cross-sectional area of scala tympani is measured in midmodiolar sections of both human and cat temporal bones (20 pairs each). The areal sizes of scala tympani in different turns of human cochlea are more than twice those in the cat. A noticeable area reduction between the lower basal turn and the upper basal turn is found in the cat. The cross-sectional view of scala tympani is ovoid to round and flat on top in the basal turns, but it is more like a flat triangle in the lower middle turn and above. The area measurement of the scala tympani assists the development of the implantable electrode. The information also contributes to the construction of models for physiological experiments.

We retrospectively studied tumors of the parapharyngeal space treated at the Baylor College of Medicine Affiliated Hospital System, Houston, from 1972 to 1985. Of the 42 lesions, 30 (71.4%) were benign and 12 (28.6%) were malignant. Tumors of neurogenic origin were present in 17 (40.5%). Tumors of salivary gland origin were present in 16 (38.1%): ten were benign, six were malignant. Nine (21.4%) of the patients presented with miscellaneous lesions, six of which proved to be malignant. We have found that a preoperative arteriogram is no longer routinely indicated. High-resolution computed tomography is now the best initial diagnostic study because it helps determine the size and extent of the tumor, differentiate tumors of parotid and extraparotid origin, demonstrate degree of tumor vascularity, and separate benign from malignant lesions.

Spontaneous, positional, and paroxysmal positional nystagmus were studied before and after sectioning the superior division of the vestibular nerve and the anterior vestibular artery in squirrel monkeys. Histopathologic study of the temporal bones confirmed the degeneration of the macula utriculi with release of statoconia, but failed to identify the released utricular statoconia within the vestibular endolymphatic space in any animal. Postoperatively the animals consistently demonstrated direction-fixed spontaneous nystagmus until the end of the experiment (five months). Positional tests and Dix-Hallpike maneuver occasionally changed the intensity of the spontaneous nystagmus, but never elicited paroxysmal positional nystagmus. Possible reasons for not demonstrating paroxysmal positional nystagmus in the squirrel monkey are as follows: a resorption of statoconia; slight morphological alteration of the sensory epithelia of the posterior cristae; interference of the posterior crista function due to partial collapse of the membranous ampulla; the existence of interspecies difference; or possibly a faulty hypothesis regarding the etiologic mechanism of benign paroxysmal positional vertigo.

A case of a highly destructive, cytologically nondysplastic squamous epithelial lesion of the middle ear is presented. The cranial nerve involvement and bone destruction are more extensive than has been seen in cholesteatoma. Cultures are negative for Pseudomonas, and the patient does not have the reported diathesis for malignant otitis externa. The gross and microscopic features are those of verrucous carcinoma. To our knowledge, the middle ear has not been previously reported as a site of involvement by verrucous carcinoma.

Computerized tomography scanning has been proven useful in defining complex anatomical areas of the head and neck and in delineating soft-density foreign bodies. This was helpful in a child in whom all other modalities, including surgical exploration, had failed to localize a foreign body.

We report a rare case of bilateral sudden and profound hearing loss caused by bilateral temporal bone metastasis from a primary adenocarcinoma of the tail of the pancreas. The hearing loss was the patient's only reason to seek medical care. Seventh nerve involvement was very minimal, when compared with that of the eighth nerve.

A 19-year-old woman with cryptococcal meningitis died as a result of her disease, in spite of both intravenous and intraventricular administration of amphotericin B. Gross and microscopic examinations revealed multiple cysts containing Cryptococcus neoformans within the central nervous system. Studies of the temporal bones revealed both neural and end organ destruction with the presence of Cryptococcus when stained by Gomori methenamine silver nitrate method. We present the results of audiometric and vestibular examinations. The case history depicts a progressive neurological involvement by Cryptococcus.

A 19-month-old boy had adrenocerebroleukodystrophy and unusually severe cochlear nerve degeneration and demyelination, a condition in advance of that expected from known disease entities. We report the only known temporal bone study in adrenocerebroleukodystrophy.