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Objectives/hypothesis: To investigate possible association of hearing loss and SLC26A4 mutations with the subgroups of enlarged vestibular aqueduct (EVA) morphology in Japanese subjects with hearing loss., Study Design: Retrospective multicenter study., Methods: Forty-seven subjects who had vestibular aqueduct with midpoint diameter >1 mm by computed tomography of the temporal bone were enrolled at multiple sites across Japan, and DNA samples and clinical data were collected. EVA morphology was classified into four subgroups by the pattern of enlargement: aperture, aperture and midpoint, midpoint, and borderline enlargement. Venous blood DNA samples were subjected to polymerase chain reaction-based direct sequencing of all exons and exon-intron boundaries of the SLC26A4., Results: Four novel SLC26A4 mutations were identified in the present study. SLC26A4 mutations were detected in almost all subjects with aperture, aperture and midpoint, and midpoint enlargement. In contrast, 71% of subjects with borderline enlargement had no SLC26A4 mutation. No significant difference was found in the distribution of truncating and nontruncating SLC26A4 mutations between the EVA subgroups. In addition, no significant correlation was observed between the EVA subgroups and hearing levels, incidence of hearing fluctuation, or progression of hearing loss., Conclusions: Subgroups of EVA morphology were significantly correlated with the presence or absence of SLC26A4 mutation. In a subgroup analysis of subjects with SLC26A4 mutations, however, differences in the EVA subgroups were not correlated with SLC26A4 genotypes or characteristics of hearing loss., Level of Evidence: NA., (© 2013 The American Laryngological, Rhinological and Otological Society, Inc.)

In 1999, three workers received high doses of radiation in a small Japanese plant while they were preparing fuel for an experimental reactor. This criticality accident at melting point was caused by the addition of too much uranium enriched to a relatively high level, causing a 'criticality' (a limited uncontrolled nuclear chain reaction), which continued intermittently for 20 h. The three workers concerned were hospitalized, two in a critical condition. The first worker died 12 weeks later, and the second worker 7 months later. The third worker is in a healthy condition. We report on the temporal bone histopathological features of the second worker. Our temporal bone study revealed: 1) the large loss of bone marrow tissue with a small number of myelocytes remaining in the mastoid bone and the abundance of fatty tissue in the mastoid bone, 2) inflammation of the mucosal layer of the middle ear and the mastoid air cells, 3) mild degeneration of the spiral ganglions and the sensory hair cells of the cochlea, 4) mild degenerative changes of sensory hair cells of the semicircular canals and otolith organs, and 5) vestibular ganglions and geniculate ganglions were well preserved.

Conclusion: Among mass lesions inside the temporal bone, benign tumors and cholesteatomas can be differentiated by contrast enhancement in T1-weighted images (T1WI) and by diffusion-weighted images (DWI). Moreover, DWI will also facilitate discrimination between cholesteatomas accompanied by granulation and other non-neoplastic lesions such as mucoceles and cholesterol granulomas., Objectives: To review the imaging characteristics of mass lesions inside the temporal bone and to investigate pertinent imaging modalities for differential diagnosis, which is crucial for appropriate treatment planning., Patients and Methods: This was a retrospective case series study of six patients seen between 2002 and 2005 with mass lesions deep inside the temporal bone., Results: One patient had facial schwannoma, two had glomus jugulare tumor, and three had cholesteatoma. Plain high resolution CT gave few clues to the nature of the mass lesions. MRI study provided us with better clues: contrast enhancement on T1WI was observed only in benign tumors and only cholesteatomas showed high intensity on DWI. With the assistance of neurosurgeons, surgery was successfully performed in all cases.

We report a case in which metastasis occurred from a left-side maxillary carcinoma to bilateral temporal bones through different routes, manifested by rapidly progressing left-side mixed hearing loss, left-side vestibular dysfunction, and serous otitis media. Later the left-side hearing threshold became severely elevated, suggesting profound sensory hearing loss. Histopathology of the temporal bones revealed that the side with the lesion was severely damaged by tumor through direct and hematogenous metastasis. On the contralateral side, it showed four findings: (i) sparse and separate tumor invasion of the petrous bone, the mastoid cavity, and the facial canal (hematogenous spread); (ii) tumor involvement in the lower part of the cochlear aqueduct without invasion of the internal acoustic canal or cochlea, implying early meningeal carcinomatosis; (iii) vascular stria atrophy, spiral ganglion diminution, and well preserved hair cells; and (iv) diffuse effusion in the middle ear and mastoid cavity. Our observations revealed that tumor cells dispersed to the same side through different routes, whereas early metastasis to the contralateral side was mainly through hematogenous and subarachnoid spread.

This report shows the changes that occurred in consecutive audiograms of a patient who underwent chemotherapy and radiotherapy for nasopharyngeal cancer and the histopathological examination of the temporal bones. Both conductive and sensorineural hearing loss developed, but followed different modes of progression. In the left ear, an air-bone gap appeared and deepened, while in the right ear, severe conductive hearing loss was present upon admission and improved after treatment. Sensorineural hearing loss was worse in the right ear, but deteriorated gradually in both ears. Histology revealed tumor invasion in the right temporal bone. Both middle ears showed effusion, but no radiation-induced changes that may be responsible for the conductive loss. The main changes in the cochlea were vascular stria degeneration, spiral ligament atrophy, and spiral ganglion cell depletion, while the hair cells were only occasionally missing. Apart from confirming what has been established previously by other authors, some interesting findings were observed: (1) in addition to the high frequency hearing loss typically caused by cis-platinum and by radiation, there was also low frequency hearing loss, and (2) the cochlear damage was most severe in the vascular stria and spiral ganglions, sparing the hair cells.

The relationship between meningitis and sensorineural hearing loss (SNHL) has long been studied. Many histopathological studies of animal models and human temporal bones with respect to bacterial meningitis have been carried out. However, the relationship between SNHL and tuberculous meningitis was seldom addressed and the pathophysiology remains unclear. We carried out temporal bone studies on material from a 22-year-old patient who developed a right unilateral SNHL before dying from tuberculous meningitis. The histopathological findings for the right temporal bone were as follows: (1) inflammation mainly appeared in the internal auditory canal, modiolus and Rosenthal's canal and extended to the osseous spiral ligament, whereas the perilymphatic spaces were less involved; (2) the organ of Corti, cochlear nerve fibres and spiral ganglion cells were severely degenerated, particularly in the basal and middle turns; (3) the contralateral side (for which the patient had no complaints) showed an inner space free from inflammation, but some granulomatous formations were observed in the middle ear cavity. We conclude that the modiolus and cochlear aqueduct are the main routes for the spread of infection from the meninges to the inner ear. The progression of hearing loss resembles that of bacterial meningitis and shares attributes of retrocochlear SNHL.

Objective: This study examined whether subjective visual horizontal (SVH) could be compensated in patients with complete loss of unilateral vestibular function., Patients: Patients comprised two men and three women who underwent subtotal resection of the unilateral temporal bone due to squamous cell carcinoma of the middle or external ear. Mean patient age was 63.2 years (range, 59-69 yr)., Intervention: Diagnostic., Main Outcome Measures: Patients were tested postoperatively (mean, 4 yr 5 mo after the surgery; range, 2 yr 9 mo to 8 yr 6 mo). The task for patients involved adjusting a laser projection bar four times to SVH in darkness., Results: All patients displayed marked deviation of SVH toward the operated side-down. Mean deviation from four trials for each subject was 4.5, 2.9, 3.7, 3.0, and 3.4 degrees., Conclusion: Deviation of SVH in patients with definite unilateral vestibular deafferentation can be long term, lasting more than 2 years at least.

Objective: To evaluate the relationship between hearing level and temporal bone abnormalities in patients with microtia., Study Design: Retrospective case series study between 1992 and 2004., Setting: Academic, tertiary care referral medical center., Patients: We evaluated 115 ears of 89 patients (68 males, 21 females; mean age, 11 yr; range, 5-44 yr) with microtia., Main Outcome Measures: Hearing level was examined in patients with microtia. Developmental abnormalities of the temporal bone were evaluated by Jahrsdoerfer's computed tomography (CT) scoring system using high-resolution CT (HRCT) scans of the temporal bone. Temporal bone malformation scores were divided into four subgroups: ossicular development, windows connected to the cochlea, aeration of the middle ear cavity, and facial nerve aberration. Patients were divided into the stenosis and atresia groups on the basis of the appearance of the external auditory canal (EAC). We also evaluated the relationships between hearing level and four subtotal scores of the HRCT findings in the stenosis and atresia groups., Results: There was no relationship between hearing level and total points of HRCT scoring system or between hearing level and severity of microtia scored by Marx classification. With regard to subtotal points related to ossicles (4 points), the hearing level in ears with low scores (<2) (64.7 +/- 1.6 dB) was significantly different (P = .03) from that in ears with high scores (> or =2) (54.0 +/- 2.8 dB) in the stenosis group. In the atresia group, the hearing level was 64.3 +/- 2.2 dB in ears with low scores and 62.3 +/- 1.1 in ears with high scores (P > .5). As for subtotal points related to the windows connected to cochlea (2 points), the hearing level was 64.8 +/- 2.6 dB in ears with low scores (0) and 55.9 +/- 2.4 dB in ears with high scores (> = 1) in the stenosis group. In the atresia group, the hearing level was 67.7 +/- 2.3 dB in ears with low scores and 61.5 +/- 1.0 in ears with high scores. There was significant difference between ears with low and high scores in the stenosis group (P = .03) and atresia group (P = .009). There was no significant difference between ears with low and high scores with respect to the subtotal points related to aeration of the middle ear cavity and aberration of the facial nerve., Conclusion: The hearing level in microtic ears correlated with the formation of oval/round windows and ossicular development but not with the degree of middle ear aeration, facial nerve aberration, or severity of microtia. The hearing level can also serve as an indictor, such as the HRCT findings, to determine whether a subject's hearing will likely improve after reconstructive surgery.

Objective: The contribution of nerve fibers to the maintenance of vestibular sensory cells is a controversial issue in previous studies using animals and has not yet been studied in humans. The authors investigated this issue by observing vestibular end organs in the temporal bone of three patients in whom the internal auditory canal was infiltrated with tumor cells, and Scarpa's ganglion cells showed complete degeneration., Study Design: Retrospective case review., Setting: University Hospital, Department of Otolaryngology., Patients: Three patients with malignant metastatic temporal bone tumors., Intervention: We investigated the preservative state of vestibular sensory hair cells with the Scalpa's ganglion was destructed., Main Outcome Measures: Maintenances of vestibular sensory hair cells., Results: We found that sensory cells were intact despite the severe destruction of Scarpa's ganglion cells in two of the patients., Conclusion: The findings suggest that human vestibular sensory cells can be maintained for an indefinite period after denervation.

Hypoxia in adults frequently causes damage to the brain, but not the inner ear. However, hypoxia in neonates with inadequate blood-inner ear barrier function causes damage to the inner ear, leading to hearing loss and equilibration disorder. Clinically, asphyxiated neonates sometimes have the complication of sensorineural hearing impairment at high frequencies. Many reports suggest that this problem is caused by hypoxic encephalopathy. However, it is not clear whether inner ear disorders are present. In this report we examined the inner ear pathology of four asphyxiated neonates using serial sections of temporal bone. The subjects (n=4) were 1-13-day-old neonates with pregnancy periods of 24-36 weeks. Their fetal growth curves were within the normal range. There was one case each of twin pregnancy, placental abruption, placenta previa and meconium aspiration syndrome. For the case of severe neonatal asphyxia, damage to the inner ear included the degeneration and disappearance of outer hair cells of the organ of Corti and edematous changes in the stria vascularis. Degeneration of spiral ganglion and vestibular ganglion cells was observed in two of the other cases.

Objective: To evaluate the relationships between temporal bone abnormalities and the severity of microtia in Japanese patients using objective grading systems., Design: Retrospective case series study conducted between 1992 and 2003., Setting: Academic, tertiary care, referral medical center., Patients: One hundred forty-two ears of 109 Japanese patients (85 male and 24 female patients; mean age, 12.8 years [range, 2-36 years]) with microtia., Main Outcome Measures: The severity of microtia was classified according to Marx classification. Developmental abnormalities of the temporal bone were evaluated by a computed tomographic (CT) scoring system modified after the system used by Jahrsdoerfer and colleagues, using high-resolution CT scans of the temporal bone. Correlations between the scores obtained from these 2 grading systems were evaluated using a nonparametric statistical method., Results: Male preponderance and incidence of bilateral cases of approximately 30% were observed in our Japanese patients with microtia. There was no significant difference in the severity of microtia between unilateral and bilateral cases. The mean +/- SEM total points in the CT scoring system (full marks, 10) was 7.9 +/- 0.4 for grade I microtia, 6.6 +/- 0.6 for grade II, and 6.4 +/- 0.3 for grade III; the total points correlated inversely with the microtia grade. Development of the auricle correlated significantly with aeration in the middle ear spaces but not with ossicular development or formation of the oval/round windows. Proportion of acceptable surgical candidates according to the CT scoring system (>5 points) was 79% for grade I microtia, 52% for grade II microtia, and 65% for grade III microtia., Conclusion: The principle "the better developed the auricle, the better developed middle ear" was confirmed in Japanese patients with microtia; however, even with grade II/III microtia, more than half of the patients were considered suitable for atresia surgery.

Changes in the inner ear due to increased intracranial pressure have not yet been clearly defined. We present a postmortem temporal bone study of child with hydrocephalus. The temporal bone was from a 2-year-old female with IVth ventricle ependymoblastoma. In the basal turn of the cochlea, degeneration of the organ of Corti and the nerve ganglion was observed. In the top and middle turn, structures were intact. The utricle and saccule were well preserved. We propose that changes in the inner ear due to increased intracranial pressure begin in the base of the cochlea, and extend to the apex in decreasing degree.

Purpose: To ascertain the location of the facial nerve in patients with microtia by using thin-section computed tomography (CT)., Materials and Methods: Thin-section CT was performed in 66 ears of patients with microtia (unilateral, n = 12; bilateral, n = 34) and mandibulofacial dysostosis (MFD, n = 20). Findings were compared with those in 22 ears with normal auricles (control group) by using the Dunnett two-sided t test., Results: The facial nerve at the mastoid portion in patients with MFD was 2 mm more lateral and 3 mm more anterior than that in control subjects (P <.01). The same portion in patients with microtia was 3 mm more anterior than that in the control subjects (P <.01). The distance between the facial nerve and the most lateral point of the temporal bone in patients with MFD was 10 mm shorter and that in patients with bilateral microtia was 3 mm shorter than that in the control subjects (P <.01)., Conclusion: The facial nerve in patients with microtia was not more lateral from the Bill bar (vertical crest) than that in control subjects. The facial nerve in patients with MFD was different from that in patients with microtia who had no other head anomalies.

Four cases (seven ears) of metastatic tumour of the internal auditory canal were studied. The histopathological findings confirmed that the inner ear invasion of the tumour follows a unique course, as reported in the literature. Relationship between duration of deafness and extent of tumour invasion in the inner ear is discussed. It is suggested that the deafness could occur via neural invasion or compression near the ductus spiralis foraminosus.

To examine the effect of vestibular ocular reflex on gross motor development in children with semicircular canal aplasia and hypoplasia. Case series. Children with congenital hearing loss underwent temporal bone computed tomography to assess their inner ear morphology. In this study, we examined eight children with bilateral complete aplasia of semicircular canals and seven children with bilateral hypoplasia of semicircular canals. Their vestibular ocular reflex was assessed using a damped rotational chair test. Their gross motor development was assessed by examining their ages of acquisition of head control and independent walking. All eight children with semicircular canal aplasia were diagnosed as having CHARGE syndrome and five children were found to have CHD7 mutations. Cochlear morphological examination showed that cochlear hypoplasia type III was the most common in eight of 16 ears in children with semicircular canal aplasia. In semicircular canal hypoplasia, incomplete partition type II was found in seven of 14 ears. All eight children with semicircular canal aplasia showed no response in the damped rotational chair test. Even the three children followed up were unresponsive in all tests. In the group with semicircular canal hypoplasia, three children showed normal responses, one child showed no response, and three children showed poor responses. The mean age of acquisition of head control was 9.1 ± 6.3 months and that of independent walking was 31 ± 8.1 months in children with semicircular canal aplasia. The mean age of acquisition of head control was 6.0 ± 2.8 months and that of independent walking was 19.9 ± 4.9 months in children with semicircular canal hypoplasia. We found that children with semicircular canal aplasia have severe dysfunction of the vestibular ocular reflex, and vestibular sensory cells derived from the semicircular canal may not be present. Semicircular canal hypoplasia is associated with dysfunction of the vestibular ocular reflex, but vestibular sensory cells may be present, and rotary nystagmus develops with growth similar to that observed in normal children previously reported. Semicircular canal aplasia is associated with CHARGE syndrome, and affected children tended to have a slower gross motor development. It was suggested that the combination of visual impairment and mental retardation may delay the development of central-level integrated functions and may further delay motor development. [ABSTRACT FROM AUTHOR]