Two cases of myxoma of the external auditory canal.

Myxomas were found in the outer ear canal of a 66-year-old female and a 51-year-old male. Both tumors were soft and sessile and located at the antero-superior part of the external auditory canal near the eardrum. Profuse, clear mucus was seen when the tumor ruptured or was incised. Histology showed spindle-shaped and stellate cells in myxoid extracellular matrix. CT images revealed a small bone defect adjacent to the tumor in the meatal bone. This bony defect was confirmed during surgery. The bony defects seen in both cases may have something to do with the genesis of the tumor. We found only 5 sporadic cases, including ours, reported in the English literature. As myxoma of the outer ear canal is also reported in 18 patients as a symptom of Carney's complex, we must check for accompanying symptoms of the complex such as spotty skin pigmentation, endocrine tumors, or schwannoma. Total removal of the tumor is necessary to prevent recurrence.

Otomycosis: subdermal growth in calcified mass.

Reports on clear identification of fungi in subdermal tissue in chronic fungal external otitis are rare in recent years. Our patient was an immunocompetent adult male with an 8 year history of chronic otitis externa who presented with pustules on the external auditory canal (EAC) and necrosis and perforation of the tympanic membrane. Type I tympanoplasty was performed, but wound healing was delayed and swelling of the EAC occurred. Incision biopsy and staining (Gomori-Grocott and PAS) revealed fungal hyphae within small, calcified, subepidermal masses. A 3 month course of oral itraconazole was effective in healing the lesion. Calcification, a rarely reported finding in otomycosis, may represent a protective reaction against topical use of antifungal drugs.

Displacement of the reticular lamina with and without the tectorial membrane in the guinea pig cochlea.

OBJECTIVE: In an attempt to establish the mechanical relationships between the reticular lamina and tectorial membrane, we studied the morphological changes of the reticular lamina on a micrometer scale when an in vitro preparation of guinea pig cochlea with and without tectorial membrane was exposed to a potassium-rich medium. MATERIAL AND METHODS: Using video-enhanced differential interference contrast microscopy, the radial displacement of the inner hair cells (IHCs) and outer hair cells (OHCs) in the reticular lamina was measured in real time after exposure to the potassium-rich medium for 3 min. RESULTS: The amplitude of the displacement of the OHCs in preparations with an intact tectorial membrane was half of that observed in those in which the tectorial membrane had been removed. A similar displacement response was also observed for the IHCs, although it was smaller than that for the OHCs. There was no significant difference in the amplitude of the displacement among the three rows of OHCs. CONCLUSIONS: These results suggest that the structure linking the OHCs to the pillar cells is very elastic and that the movement of the OHCs in situ is weakly mechanically coupled to the IHCs. The tectorial membrane provides increased compliance in the motion of the IHCs and OHCs.

A model of two-stage newborn hearing screening with automated auditory brainstem response.

Our purpose was to evaluate a two-stage newborn hearing screening program using automated auditory brainstem response (AABR) before discharge and to describe our follow-up program. This study used 4085 infants born in the Seirei-Hamamatsu and Mikatahara General Hospitals during a 2-year period. The initial screening test was performed 2 or 3 days after birth at an intensity of 35 dBnHL. For the infants who were referred from this test, the re-screening test was performed 5 or 6 days after birth. Diagnostic work-up with auditory brainstem response (ABR), otoacoustic emissions (OAE), and a conditioned orientation reflex audiometry (COR) test were performed by the age of 3-6 months. The referral rate was 1.20% (49/4085 infants) in the first test and 0.71% (29/4085 infants) in the two-stage screening. The two-stage screening procedure was able to reduce the false-positive rate from 0.83 to 0.34%. The incidence of bilateral and unilateral congenital hearing loss diagnosed by ABR was 8/4085 (0.20%) infants and 7/4085 (0.17%) infants, respectively. One infant with congenital cytomegalovirus infection, who passed the two-stage AABR tests, was diagnosed with hearing loss 1 month after birth, using ABR. The two-stage measurement of AABR is effective and time efficient due to significant decreases in the referral rate and the false-positive rate.

Effect of single-drug treatment on idiopathic sudden sensorineural hearing loss.

OBJECTIVES: In order to evaluate the effect of a medical administration for the sudden deafness patients, single-drug treatment for idiopathic sudden sensorineural hearing loss (ISSHL) was assessed at multi-centers participating in the Acute Severe Hearing Loss Study Group sponsored by the Ministry of Health, Labor and Welfare of Japan. METHODS: The subjects consisted of ISSHL patients who were (1) 20 years of age or older, (2) diagnosed within 2 weeks after the onset of hearing loss, (3) showing a mean hearing level of 40-90 dB at five frequencies from 250 to 4000 Hz, (4) previously untreated, and (5) with normal for age in hearing of the opposite ear. The drugs used in this study were ATP, alprostadil, hydrocortisone and amidotrizoate, which were administered intravenously, and beraprost sodium and betamethasone, which were given orally. Two drugs were assigned to each center, one of which was selected according to the code hidden in envelopes and administered for 1 week. The treatment after the single-drug administration was conducted at the discretion of each center. The hearing gain and recovery rate at 1 week after the initiation of single-drug treatment and at 1 month or over when the hearing level was fixed, were evaluated based on the criteria for hearing recovery prepared by the Acute Severe Hearing Loss Study Group. RESULTS: There was no statistically significant difference in the recovery rate among drugs either at 1 week after the initiation of single-drug treatment or at the time of fixed hearing level. At the time when the hearing level was fixed, a statistically significant difference in the complete recovery rate was detected only between amidotrizoate and beraprost sodium. CONCLUSION: From these results, we could not find any specific drugs recommended for ISSNHL. In evaluating the effect of the drugs, however, several problems in the clinical trial for ISSHL should be considered.

Photochemically induced double lateral wall lesions in the guinea pig cochlea.

OBJECTIVE: Multiple patches of atrophy have been reported in the stria vascularis (SV) in elderly persons with presbycusis The aim of this study was to investigate the correlation between sensorineural hearing loss and this strial condition. MATERIALS AND METHODS: We established a new animal model comprising two small lesions in the SV in the second turn of the cochlea by means of photochemical reaction. Using this model, we investigated morphological and physiological changes in the cochlea at 3, 7 and 14 days after SV damage. RESULTS: Scanning electron microscopy studies revealed that the strial cells between the two damaged areas of the SV remained intact, although the outer hair cells (OHCs) facing the intact SV area were damaged. Furthermore, damage to the first and second rows of OHCs gradually progressed throughout the 14-day observation period. The endocochlear potential (EP) measured at a point midway between the 2 lesions at 3 and 7 days was found to be significantly lower compared with control values, but had returned to a normal level at 14 days CONCLUSION: The reversible EP change and localized OHC loss seen in the present investigation may help to understand acute idiopathic or progressive sensorineural hearing loss.

Dialysis-related amyloidosis of the external auditory canals.

We present a patient with dialysis-related amyloidosis of the external auditory canals. This diagnosis was supported by histological and immunohistochemical studies. This is to the best of our knowledge the first reported case of amyloidosis of the external auditory canals that relate to the chronic hemodialysis.

Contribution of speech rate to speech perception in multichannel cochlear implant users.

This study describes the effect of speech rate (fast, 11 syllables per second; medium, 9 syllables per second; slow, 6 syllables per second) on speech perception in 10 cochlear implant users. The speech perception performance was evaluated on the basis of the percentage score of syllables that were correctly recalled in sentences composed of 4 to 6 words. The percentage scores at the fast, medium, and slow speech rates were 15.7%, 39.0%, and 56.0%, respectively. The effect of speech rate slowing was significant (p < .0001). Variations in the effect of speech rate slowing were observed in the cochlear implant users. The improvement of speech perception by speech rate slowing was significantly (p < .005) related to the word test score and the score at the fast speech rate. The results reveal that the rate of speech is an important factor in improving the speech perception of cochlear implant users.

Association of clinical features with mutation of TECTA in a family with autosomal dominant hearing loss.

BACKGROUND: The TECTA gene, which encodes alpha-tectorin, has recently been cloned. alpha-Tectorin is a major component of the noncollagenous matrix of the tectorial membrane. Nonsyndromic hearing impairment caused by TECTA mutations has been reported in Austrian, Belgian, Swedish, French, and Lebanese families. The phenotypes and genotypes were different among these families. MATERIALS AND METHODS: Our study family displayed autosomal dominant hearing impairment through 3 generations. We sequenced the coding exons of the TECTA gene in 4 affected individuals, and we report the clinical features in a Japanese family with nonsyndromic hearing impairment and a mutation in the TECTA gene. RESULTS: The 5-frequency average of 250, 500, 1000, 2000, and 4000 Hz in 4 affected individuals was 42.2 +/- 3.7 (mean +/- SD) dB in the right ear and 42.3 +/- 4.5 dB in the left ear. The mean age at onset of hearing impairment was 5 years. The progression of hearing impairment was not confirmed for a 15-year period, from the age of 6 to 21 years, in 1 affected member. The 4 patients had a G-->A missense mutation at nucleotide 6063 in exon 20. This mutation replaces arginine at residue 2021 with histidine (R2021H). CONCLUSIONS: All 4 affected members showed symmetrical and stable bilateral mild to moderate hearing impairment in the midfrequencies. The mean threshold level of 2000 Hz was the worst among the 5 frequencies. All the affected members had normal vestibular function. The mutation in the TECTA gene, localized in the zona pellucida domain, was detected in all 4 affected individuals. The localization of the mutation in the different modules of the protein may have caused the different clinical features.

Degeneration of the stria vascularis during development in melanocyte-deficient mutant rats (Ws/Ws rats).

Developmental changes in the stria vascularis of white spotting (Ws) rats were examined by scanning and transmission electron microscopes and by diaminobenzidine-staining techniques. The stria of Ws/Ws homozygote rats was found to have both pigmented and non-pigmented portions. While the pigmented portions possessed intermediate cells in the same manner as the stria of wild +/+ rats, the non-pigmented portions lacked the cells. Examination at 1, 2, 3, 4, 6, 8 and 14 weeks after birth revealed a progressive degeneration in the marginal cells and strial capillaries in the non-pigmented portions. At 1 week, no significant differences were seen in the marginal cells of any of the rats examined. At 2 weeks, the basolateral infoldings of the marginal cells were seen to be well developed and adult-like in the pigmented portions of Ws/Ws rats and in +/+ rats. In the non-pigmented portions, the basolateral infoldings of the marginal cells appeared well developed; however, vacant spaces were seen around the basolateral infoldings. At 3 weeks, the basolateral infoldings of the marginal cells in the non-pigmented portions had become more atrophic, and the empty spaces around the basolateral infoldings had enlarged. Also, the marginal cells themselves had become flatter or thinner. These findings became more prominent at 4 weeks and 6 weeks. At 8 weeks and 14 weeks after birth, the marginal cells appeared markedly flat, and no basolateral infoldings were seen in the non-pigmented portions. Pigmented portions of the stria in Ws/Ws rats, on the other hand, showed normal development throughout this period. A DAB-staining examination of the stria capillary net in Ws/Ws rats showed it to be well developed at 3 weeks in both pigmented and non-pigmented portions. At 8 weeks, a thickening of the capillary basement membrane was apparent. The above findings lead the authors to believe that intermediate cells play an important role in the development and maintenance of marginal cells and the strial capillary system.