Hugo Estibeiro

The posterosuperior quadrant of the tympanic membrane.

Objective: To document the anatomic relationship of the posterosuperior segment of the tympanic membrane. Study Design: Point-prevalence study of postmortem material. Subjects and Materials: One hundred seventy temporal bones from adults without history of otologic pathology were studied. The anatomic details of the tympanic membrane were observed, histology was documented on 30 sectioned bones, and, with the use of the scanning electron microscope, lamina propria was studied in 40 bones. Results: We established that the posterosuperior quadrant was the largest, representing 28.7 percent of the total area of the eardrum. This feature implies that this quadrant is more likely than are the other quadrants to exhibit changes prompted by pressure challenges. We also verified that the posterosuperior part of tympanic sulcus, above the chorda tympanic nerve, lost its depth in an unexpected way in 60 percent of the cases. In association, we established that at this level there was a decrease in annulus caliber. In 25 percent of cases, by the absence of the circular fibers of lamina propria, the posterosuperior quadrant had only the radial fiber layer. Conclusions: Anatomic and morphologic details in posterosuperior quadrant were newly described and may explain the greater incidence of retraction pockets and marginal perforations that provide origin for the cholesteatoma.

S221 – The Postero-superior Quadrant of the Tympanic Membrane

Objectives The purpose of this study was to document the anatomic relationship of the postero-superior segment of the tympanic membrane and its clinical implications. Methods 100 temporal bones from adults without history of otologic pathology were studied. The morphological and anatomical details of the tympanic membrane were observed in 70 bones, which implied the use of macroscopic sections of the bones. The histological results were documented in 30 serially sectioned bones, stained previously with hematoxylin-eosin. Results We established that the postero-superior quadrant was the largest in size, with a mean dimension of 21.05 mm2, which represents 28.7% of the total area of the tympanic membrane. This feature implies that this quadrant is more exposed to pressure changes. We also verified that the posterosuperior part of the tympanic sulcus, above the chorda tympanic nerve, lost its depth in an unexpected way (60%) or that it gradually diminished from 0.9 to 0.5 mm until it disappeared near the posterior tympanic spine. In association, we established that at this level there was a decrease in the annulus caliber. Additionally, in 25% of cases, given the absence of the circular fibers of lamina propria, the postero-superior quadrant had only the radial fiber layer. Conclusions Anatomic and morphologic details in the postero-superior quadrant were newly described and may explain the greater incidence of retraction pockets and marginal perforations that provide the origin of cholestheatoma.

P112: Intratemporal Facial Nerve Tumors: Management Controversies

male and 32 female) were recruited from a tinnitus clinic and underwent a detailed neuro-otological examination including otoscopy, stapedius reflexes, middle ear pressure measurements, pure tone audiometry, tinnitus pitch and loudness matches. Tinnitus severity was assessed by the Tinnitus Questionnnaire (TQ) and subjects were genotyped for two biallelic BDNF markers, an intronic A T substitution (refSNP# rs2049046), plus a functional missense variant (Val66Met, rs6265). RESULTS: When genotypes were grouped at both loci assuming dominance of the lesser alleles, no effects were observed for the intronic BDNF variant. However, carriers of the BDNF missense variant differed significantly from other subjects with regard to the prevalence of comorbid hearing impairment (p .01). In addition, tinnitus symptomatology was found to be milder in male subjects carrying the missense variant (p .05). CONCLUSIONS: This is the first study to address the participation of BDNF variants in the genetic susceptibility to chronic tinnitus. Pending replication in larger samples, a genotype-wise association with comorbid hearing impairment and, to a lesser extent, with tinnitus severity, argues in favour of a modifying role in defined tinnitus phenotypes.

P138: Treatment of Imbalance Post-Gentamicin

history, scientific discoveries and chronology of Menière’s disease and the importance of Charles Skinner Hallpike and Hugh Cairns. METHODS: The authors reviewed medical literature and medical history of Prosper Menière’s, Charles Skinner Hallpike, and Hugh Cairns. Special emphasis is given on the investigations of Hallpike on temporal bones of patient with Menière’s disease: clinical history, removal and methods of preparation of the temporal bones, and interpretation of the microscope readings. RESULTS: The observations of Hallpike on the temporal bones of patients with Menière’s disease when compared with others from normal individuals were published on 1938 and tried to explain the disease: obliteration of the endolymphatic duct, failure of re-absortion of endolymph and ionic changes, pressure increase leading to ischemia of macula and producing an attack, explanation of hearing loss and tinnitus by compression of the Corti unit. CONCLUSIONS: Through a review of medical literature the authors point out some aspects of Menière’s disease, with special interest in the thorough works of Charles Skinner Hallpike on temporal bones of patients with Menière’s disease and his explanation of Menière’s disease and attacks.

Tympanic insertion: an explanation for the origin of cholesteatoma

Objectives: This study on the tympanic insertion has several goals. First, we were interested in acquiring a better understanding of the morphology of the membrane. Second, we wished to correlate this to the pathologic changes which affect the membrane when the middle ear is subjected to episodic bouts of inflammatory disease. Hopefully, correlation of the anatomy and pathology will enhance both medical and surgical therapies in this area. Methods: In the morphological study 190 adult human temporal bone necropsy specimens representing both sexes were utilized. The specimens exhibited no pathological changes and were subjected to microscopic observation, histological techniques, and electronic scanning microscopy studies. Results: We divided the tympanic sulcus in three parts according to the relationships established with the cavity’s walls and external auditory canal: the anterior portion and the inferior sulcus; in these two sections the sulcus has a depth of 0.9 mm with its edges equally well defined. The posterior part of the tympanic sulcus subdivides itself in two distinct parts separated by the emerging of the chorda tympani nerve. These alterations are shown in the morphology of the edges that no longer exist or become less evident. Conclusion: In association with these deviations of the sulcus morphology we saw that there was a decrease in the annulus caliber and a smaller resistance in the structure of the lamina propria. The assemblage of all these elements contributes to the understanding of the retraction pocket physiopathology as well as the marginal perforations which are at the origin of the cholesteatoma.