Cytomegalovirus-induced pathology in human temporal bones with congenital and acquired infection.

OBJECTIVE: Publications on histopathology of human temporal bones with cytomegalovirus (CMV) infection are limited. We aim to determine histopathology of the inner ears and the middle ears in human temporal bones with congenital and acquired CMV infections. METHODS: Temporal bones from 2 infants with congenital and 2 adults with acquired CMV infection were evaluated by light microscopy. RESULTS: Two infants with congenital CMV infection showed striking pathological changes in the inner ear. There was a hypervascularization of the stria vascularis in the cochlea of the first infant, but no obvious loss of outer and inner hair cells was seen in the organ of Corti. However, cytomegalic cells and a loss of outer hair cells were found in the cochlea of the second infant. The vestibular organs of both infants showed cytomegalic cells, mostly located on dark cells. There was a loss of type I and type II hair cells in the macula of the saccule and utricle. Loss of hair cells and degeneration of nerve fibers was also seen in the semicircular canals. Both infants with congenital infection showed abundant inflammatory cells and fibrous structures in the middle ear cavity. No evidence of cytomegalic cells and hair cell loss was found in the cochlea or vestibular labyrinth in acquired CMV infection. CONCLUSIONS: In two infants with congenital CMV infection, the cochlea, vestibule, and middle ear were highly affected. Temporal bones of adult donors with acquired viral infection showed histological findings similar to donors of the same age without ear disease.

Cochleosaccular (Scheibe) dysplasia in dogs: A temporal bone study.

The objective of this study was to evaluate any otopathologic changes in temporal bone specimens from dogs with deafness related to cochleosaccular (Scheibe) dysplasia (CSD). We used the canine temporal bone collections of the Otopathology Laboratory at the University of Minnesota and of the Massachusetts Eye and Ear Infirmary at Harvard University in Boston. Our morphometric analysis included measuring the areas of the stria vascularis and the spiral ligament and counting the number of spiral ganglion cells. In addition, we noted the presence of the organ of Corti and cochlear hair cells, assessed the location of Reissner's membrane and the saccular membrane, and counted the number of both Type I and Type II vestibular hair cells in the macule of the saccule and vestibular ganglion cells. In the group of specimens from dogs with cochleosaccular dysplasia, we observed generalized degeneration in the cochlea and a significantly decreased number of Type I and Type II vestibular hair cells and vestibular ganglion cells. As hereditary deafness is presently untreatable with known therapeutic methods, dogs with cochleosaccular dysplasia should not be considered for breeding. Future therapeutic approaches, such as stem cell therapies, should be designed to target all the elements of the cochlea in addition to the saccule as it was found that both are affected in dogs with CSD.

L'objectif de la présente étude était d'évaluer tous changements otopathologiques dans des spécimens d'os temporal provenant de chiens avec surdité reliée à de la dysplasie cochléosacculaire (Scheibe) (DCS). Nous avons utilisé la collection d'os temporal canin du Otopathology Laboratory à l'Université du Minnesota et du Massachusetts Eye and Ear Infirmary de l'Université Harvard à Boston. Notre analyse morphométrique incluait de mesurer les régions de la stria vascularis et du ligament spiral et de compter le nombre de cellules du ganglion spiral. De plus, nous avons noté la présence de l'organe de Corti et des cellules ciliées cochléaires, évalué la localisation de la membrane de Reissner et de la membrane sacculaire, et compté le nombre de cellules ciliées vestibulaires de Type I et Type II dans la macule du saccule et les cellules vestibulaires ganglionnaire. Dans le groupe de spécimens provenant de chiens avec dysplasie cochléosacculaire, nous avons observé une dégénérescence généralisée de la cochlée et une diminution significative du nombre de cellules ciliées de Type I et Type II et ces cellules du ganglion vestibulaire. Étant donné que la surdité héréditaire est présentement non-traitable par des méthodes thérapeutiques connues, les chiens avec de la dysplasie cochléosacculaire ne devraient pas être utilisés pour la reproduction. Des approches thérapeutiques futures, telles que les thérapies avec des cellules souches, devraient être planifiées afin de cibler tous les éléments de cochlée en plus du saccule étant donné qu'il a été démontré que les deux sont affectés chez les chiens avec DCS.(Traduit par Docteur Serge Messier).

Quantitative assessment of vestibular otopathology in granulomatosis with polyangitis: A temporal bone study.

OBJECTIVE: To investigate the temporal bone histopathology of vasculitis, especially in the vestibular organs, in granulomatosis with polyangitis (GPA). METHODS: Using light and differential interference contrast microscopy, we examined 12 human temporal bones from six deceased GPA patients and 12 histopathologically normal human temporal bones from six deceased age-matched patients. RESULTS: In the GPA group, three patients had undergone tympanostomy tube placement. Two of them had suffered mixed hearing loss; one, sensorineural hearing loss; and one, conductive hearing loss. Of the 12 specimens in the GPA group, the granulation tissue invaded the round window niche in seven; cochlear hair cells were not preserved in five. Hemosiderin was deposited in the stria vascularis in eight specimens, in the ampulla or semicircular duct in 10, and in the vestibule in three. The spiral ligament showed severe loss of cellularity in two specimens. In the GPA group, type I vestibular hair cell density was significantly decreased; however, type II vestibular hair cell density did not significantly differ between the GPA group and the control group. CONCLUSION: Our histopathologic findings in human temporal bone specimens of GPA patients delineated changes in the tympanic membrane, middle ear cavity, round window membrane, organ of Corti, stria vascularis, spiral ligament, ampulla, semicircular duct, and vestibule. Type I vestibular hair cell density significantly decreased in the GPA group, as compared with the control group. LEVEL OF EVIDENCE: N/A.

Secondary Endolymphatic Hydrops.

HYPOTHESIS: A review of the most recent literature will provide clinicians with an update of secondary endolymphatic hydrops, aiding in diagnosis and treatment of affected patients. BACKGROUND: Secondary endolymphatic hydrops is a pathologic finding of the inner ear resulting in episodic vertigo and intermittent hearing loss. It is a finding for which extensive research is being performed. METHODS: A review of the most recent literature on secondary endolymphatic hydrops was performed using PubMed literature search. RESULTS: Recent investigation of secondary endolymphatic hydrops has brought attention to traumatic and inflammatory insults as causes for secondary endolymphatic hydrops. Such etiologies, including postsurgical effects of cochlear implantation and endolymphatic sac ablation; otosclerosis and its operative intervention(s); acoustic and mechanical trauma; medications; and systemic inflammatory processes, have been determined as causes of secondary lymphatic hydrops. Histopathological slides for many of the etiologies of secondary endolymphatic hydrops are presented. CONCLUSION: Through an understanding of the pathophysiology and etiologies of secondary endolymphatic hydrops, clinicians will gain a better understanding of this complex disease process, which will aid in treatment of patients with this disease process.