Supporting cells in the vestibular sensory epithelia from the ears of mature guinea pigs and adult humans proliferate in vitro after treatments with aminoglycoside antibiotics that cause sensory hair cells to die. After 4 weeks in culture, the epithelia contained new cells with some characteristics of immature hair cells. These findings are in contrast to expectations based on previous studies, which had suggested that hair cell loss is irreversible in mammals. The loss of hair cells is responsible for hearing and balance deficits that affect millions of people.
Objectives/Hypothesis: Cartilage-perichondrium grafting of the tympanic membrane has been used in an effort to reduce recurrence or progression of middle ear disease. The rigidity of cartilage has obvious benefit in preventing tympanic membrane retraction, but concern has been raised regarding its sound conduction properties. Few studies in the literature address hearing results after cartilage tympanoplasty. The purpose of this study was to investigate the hearing results after primary cartilage tympanoplasty and compare them with results after primary tympanoplasty with temporalis fascia. Study Design: A retrospective review of all ear surgeries using cartilage between 1994 and 1999 was performed. Methods: Only primary cases in which the ossicular chain was intact and no mastoid surgery was performed were included. Indications for surgery included tympanic membrane perforation, retraction, and cholesteatoma. Pre-and postoperative speech reception thresholds and air-bone gaps at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz were compared. Results: Eleven patients comprised the cartilage study group, and there were 11 age-and temporally matched control subjects. The mean improvement in speech reception threshold for both the study group and the control group was 10 dB. The majority of patients in both groups had ABG closure to within 10 dB at all frequencies examined. There were no statistically significant differences in speech reception threshold improvement or air-bone gap closures between the two groups. Conclusions: These results demonstrate that hearing results after cartilage tympanoplasty are comparable to those after temporalis fascia tympanoplasty. Therefore, when indicated, a cartilage-perichondrium graft can be used for prevention of disease recurrence or progression without fear of impairing hearing.
\s=b\This study examines the temporal pattern of hair cell loss in the chick basilar papilla following ten days of gentamicin administration in hatchling chicks. Chicks were subsequently killed at ages 11, 18, 25, and 32 days. The basilar papillae were embedded in plastic and serially sectioned for light microscopic analysis. Hair cell counts were obtained at 100-\g=m\m intervals throughout the length of the papilla. Significant hair cell loss was documented basally in the 11-day-old chicks, and spread apically over time to maximal loss in the 18-day-old animals. Relative to the control chicks, there was a 36% hair cell loss in these animals. Interestingly, there appears to be a progressive partial recovery of the normal hair cell counts in the 25-and 32-day-old animals.It has been well established that therapy with aminoglycosides can cause cochlear damage. Several stud-
Patients with spontaneous cerebrospinal fluid otorrhea are often middle-aged and obese, with females being affected nearly twice as often as males. Empty or partially empty sella was observed in 80% of patients with spontaneous cerebrospinal fluid otorrhea as demonstrated by preoperative magnetic resonance imaging. Patients with spontaneous cerebrospinal fluid otorrhea who display these demographic and radiographic features should be further evaluated for the presence of idiopathic intracranial hypertension.
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