This study investigated whether decreased endocochlear potential (EP) influences susceptibility to acoustic trauma. Guinea pigs with decreased EP following i. v. administra- tion of furosemide (FUR) and control animals with normal EP were exposed to 2 kHz pure tone ranging from 115 to 130 dB SPL for 5 min. The input-output curves of the compound action potential (CAP) before acoustic overstimulation were compared with those 2 hours after the exposure. With 125 and 130 dB SPL exposure, there was no significant difference in the threshold shift between the FUR and the control groups. With 115 and 120 dB SPL exposures, however, the threshold shift of the FUR group was significantly smaller than that of the control group. These results indicated that the threshold shift of CAP is mainly due to excessive vibration of the basilar membrane in the greater stimulus groups (125∼130 dB SPL), but energy exhaustion of the hair cells participates in the threshold shift to a certain extent when the stimulus is milder (115∼120 dB SPL). It was concluded that susceptibility to acoustic trauma from a milder intensity (115∼120 dB SPL) was reduced, when the energy consumption rate of the organ of Corti was decreased by EP suppression.

View full abstract

Five hundred and forty five temporal bones from 273 individuals were studied histopathologically, to clarify the activity, gender ratio, predilection site and incide nce of otosclerosis among Japanese. The relation between otosclerosis and fissula ante fenestram or constituents in the area anterior to the oval window was also studied. Individua ls ranged in age from 6 to 89 y ears.
1) Histological evidence of otosclerotic foci was found in 12 ears,10 individuals; 6 of 172males (7 of 344 ears) and 4 of 101 females (5 o f 201 ears) aged 48 to 84 years; all cases sho wed histologic otosclerosis without clinical otologic symptoms. The prevalence of histologic otosclerosis was calcul ated as 3.66% by individuals and 2.20%by ears. Females were not significantly predominant statistically. Unilaterality wa s 80%(8 of 10 individuals).
2) The most frequent site of otosclerotic foci from data in this study conbined with that from reports published in Japan was the area anterior to the oval window in 52% of the cases. The percentage was about half that in Caucasians.
3) The volume of the otosclerotic foci in the area anterior to the oval window was measured in 6 ears by three-dimensional computer graphic reconstruction. Volume rang ed from 0.079 to 4.023 mm³. In five ears, volume was less than 1 mm³.
4) Otosclerotic foci involved in the area anterior to the oval window were separated from the fissula ante fenestram, but involved the tympanic side of the fissula ante fenestram. It was considered that otosclerosis might arise not from the fissula ante fenestram, but from the area on the tympanic side of the fissula ante fenestram.
5) In the area anterior to the oval window, there were some constituents such as cartilage, new bone, adipose tissue and connective tissue. However, in the ear involving oto sclerosis in the area anterior to the oval window, these constituents were not observed. O tosclerosis may have no relation to these constituents.
6) The lower incidence of clinical otosclerosis among Japanese compared to that among Caucasians was considered due to:
1. the low prevalence of otosclerosis
2. low activity
3. the low rate of involvement of the area anterior to the oval window that causes earlier impaired hearing.

View full abstract

Human temporal bones from 131 ears of 92 subjects were sectioned horizontally to measure the area of the tensor tympani muscles and related fat tissues.
Under one year of age, the amount of fat tissue of the tensor tympani muscle was slight in ears. After one year of age, however, the ratio of the area of fat tissue to the area of tensor tympani muscle continued to increase with age.
Ears of patients under 10 years of age were examined in detail. There was even a very scant amount of fat tissue in a fetus at 36 weeks gestation and after 2 years of age the quantity of fat tissue increased rapidly. The major areas where fat tissue initially appeared were between the tensor tympani muscle and the bony semicanal.
The quantity of fat tissue of the tensor tympani muscle was not related to the obesity of the particular individual.
From these findings, the fat tissue of the tensor tympani muscle was considered to be fatty degeneration with advancing age, as well as the development of yielding tissue in young persons to facilitate contraction of the muscle within the bony semicanal.

View full abstract

We investigated the relationship between kanamycin ototoxicity and its serum and perilymph levels when administered to rabbits by rapid i. v. or continuous i. v. infusion.
The peak serum level after rapid i. v. was 110-fold higher than that after 24-h infusion, while the peak perilymph level after rapid i. v. was 2.5-fold higher than that after 24-h infusion. Trough serum and perilymph levels 24-h after the start of administration were significantly higher after the 24-h infusion than those after the other administration methods. There was no significant difference in the area under the curve (AUC) of serum level between rapid i. v. and 1-h infusion, while the AUCs of 12-h infusion and 24-h infusion were significantly smaller compared to those of the former two. Also, the slower the administration speed, the smaller the AUC of the perilymph level was. In the 30-day consecutive dosing, rapid i. v. tended to show some slight ototoxicity compared to 12-h infusion. There was a relationship between the peak renal level and the serum concentration, while the trough level became significantly higher as the rate of infusion decreased. Changes indicating renal toxicity were not seen after 30-day consecutive dosing at any rate of administration, expcept for slight changes in BUN and creatinine, and a significant in- crease in kidney weight for the 12-h infusion. No histopathological abnormality was detected in any of the animals. The results of the present study demonstrated that the increased trough serum level due to maintenance of the serum level over a prolonged period in continuous infusion or divided intermittent dosing causes ototoxicity. It was, therefore, suggested that kanamycin administered once a day or by rapid i. v. is less toxic than when given by divided intermittent dosing or continuous infusion.

View full abstract

The distribution of histochemical carbonic anhydrase (CA) activity was investigated in the trachea of a guinea pig. Activity was localized in the tracheal glands, and some epithelial cells and goblet cells in the mucosal epithelium. These cells were not observed in the upper trachea, but appeared in the middle or lower trachea as well as at the carina. The mucosal epithelial cells containing CA could be classified into four types according to their morphology; 1) cells showing long, slender cylindrical morphology (Type I ),2) cells showing bulging at the site corresponding to the nucleus and long, slender process pointing towards the epithelial surface (Type II ),3) cells which resembled Type II but had loop-like processes pointed towards the epithelial surface (Type M), and 4) cells with two types of processes (Type IV).

View full abstract

A new technique which allows immunohistochemical detection of proteins in routinely processed, colloidin-embedded human temporal bone sections was recently developed by Shi, et al. This technique enabled us to immunohistochemically study numerous temporal bone sections preserved for a long period. We examined the reliability and usefulness of this technique using three monoclonal antibodies to cytokeratin, vimentin and neuron specific enolase (NSE). These antibodies showed definite positive staining at the inner ear as previously described by many reaerchers. This technique may prove very useful in the immunohistochemical study of the temporal bone in Heidenhain-SuSa-fixed, acid- decalcified, celloidin-embedded sections.

View full abstract

Inflammatory findings of the external auditory canal in 167 human temporal bones which had otitis media were studied. Histopathological change was observed at four sites in the external auditory canal. Of 167 temporal bones from otitis media cases,93 (55.7%)had external otitis. Differences in the frequency of histopathological change in the external auditory canal existed at each site. Inflammatory findings of the external auditory canal were almost consistent with those of closed lesions in the tympanic cavity. Therefore, it was assumed that otitis media often spread to the external auditory canal and inflammation of the tympanic cavity was reflected in the external auditory canal.

View full abstract

Mastoid cavity problems were studied in 113 ears that had the posterior canal wall removed during surgery (open tympanoplasty, radical mastoidectomy, modified radical mastoidectomy) for middle ear cholesteatoma. Posterior canal wall reconstruction with mastoid obliteration was performed in 19 ears, mastoid obliteration only in 10 ears, and no treatment for the open mastoid cavity in 84 ears.
The total incidence of mastoid cavity problems was 30.1%. Aural discharge was most frequently observed (24.8%). Other problems included postoperative development of mastoid air cells, cholesteatoma or cyst formation, the absorption of the reconstructed canal wall, and mycosis. Cavity problems were more frequently observed in the groups with reconstruction or obliteration because of the absorption of those materials. Patients under 9 years old frequently had cavity problems, and additional surgery was performed in 44.1%.
Preservation of the canal wall is most important in preventing the cavity problems, and firm obliteration of the open mastoid cavity with bone tissue or ceramics is necessary in patients that have the canal wall removed.

View full abstract

Auditory brainstem response (ABR) and caloric test are very useful in diagnosing cerebello-pontine angle tumors (CPAT) because of their high sensitivity. As improvements of CT and MRI make the detection of smaller tumors possible, we encountered a few CPAT cases that have normal ABR and no canal paresis (CP). Three cases of CPAT with normal ABR and no CP are reported. In our series,4 of 44 tumors tested had normal ABR and 4of 42 tumors had no CP. The false-negative rates were 9% and 10%, respectively. Since both tests indicated a high positive rate, they are still used as a screening test for diagnosis of CPAT.

View full abstract

This study examined 54 patients with acute unilateral sudden deafness who visited our department within 1 month after crisis during the past 6 years. Statistic analyses revealed important prognostic factors and interrelation of factors. Patients with vertigo had unfavorable prognosis compared to those without vertigo. However, dizziness had no relation to prognosis. Patients with advanced age tended to have high frequency hearing loss, dizziness and unfavorable prognosis compared to others. Patients with low frequency hearing loss tended to be free from vertigo and have favorable prognosis compared to others. The recovery group and semirecovery group showed a similar pattern of improvement.

View full abstract

This study examined 54 patients with acute unilateral sudden deafness who visited our department within 1 month after crisis during the past 6 years. Average hearing loss was calculated in the low frequency band, middle frequency band and high frequency band, respectively. Patients were divided into 3 groups:
1. Temporarily worsening hearing loss group: Patients with a hearing loss that worsened more than 10 dB in any band after medical treatment.
2. Fluctuating hearing loss group: Patients with an increased hearing loss greater than 10 dB after a recovery of hearing loss greater than 10 dB in any band.
3. Controls: Others.
The fluctuating hearing loss group and temporarily worsening hearing loss group tended to have vertigo, sensorineural hearing loss of the contralateral side and unfavorable prognosis. Fluctuations in hearing were found in the low frequency band or in the low and middle frequency band. Temporarily worsening hearing was found in the low frequency band or high frequency band.

View full abstract

The histopathological findings in the temporal bone of a 51-year-old female with breast cancer are reported. She died of systemic bone metastasis 4 years and 8 months after mastectomy. There was no history of tinnitus, hearing loss, or dizziness in her medical records.
Temporal bone metastasis was found in the petrous apex and tumor cells infiltrated along the posterosuperior and posteromedial tracts into the mastoid air cells. Although the vestibular aqueduct was destroyed, tumor cells were not found around the endolymphatic sac.
It was thought that the connective tissue originating in the dura mater and continuing along the vestibular aqueduct functioned as a barrier and prevented infiltration of tumor cells into the endolymphatic sac.

View full abstract

On autopsy, traumatic neuroma of the facial nerve was found at the temporal bone of a man who died of oropharynx carcinoma with multiple metastases. The neuroma developed. on the horizontal portion of the facial nerve at the Fallopian canal dehiscence and the temporal bone demonstrated chronic otitis media.
It has been occasionally suggested that long-term exposure of the facial nerve to chronic inflammation results in proliferation of neurofibrils leading to neuroma formation. Three dimensional reconstruction clearly showed an anatomical correlation between the Fallopian canal dehiscence and the neuroma.

View full abstract

Sensorineural hearing loss, tinnitis, vertigo or dizziness sometimes occur following subarachnoid hemorrahge (SAH), although clinical case reports are extremely rare due to severe consciousness loss or other brain symptoms following SAH.
A 51-year-old man complained of poor bilateral hearing after losing consciousness for 5 minutes after a head trauma. Clinical examinations revealed bilateral sensorineural hearing loss without temporal bone fracture or brain stem injury but with SAH in the bilateral Silvius fissure. From neuro-otological findings it was thought that sensorineural hearing loss was caused by damage to the inner ear or the brain stem area due to hemorrhage or force.

View full abstract

A case of otogenic extradural abscess due to cholesteatoma is reported. A 9-year-old boy was diagnosed with chronic otitis media and underwent medical treatment.
He complained of left otalgia, ear discharge and headache. CT scan provided the most reliable information for diagnosis, and revealed the presence of an extradural abscess. He was treated by mastoidectomy and craniotomy. He was subsequently treated by staged tympanoplasty and good auditory acuity was secured.

View full abstract

A rare case of leiomyosarcoma located in the preauricular region is presented along with a review of the medical literature. A 17-year-old female developed pain and swelling in the right preauricular region. She was admitted to our hospital, and a tumor was surgically removed. Histological examination of the resected tumor revealed leiomyosarcoma immunohistochemically. She has had no recurrence for a year and 10 months following surgery.

View full abstract

A case of adenoid cystic carcinoma of the nasal septum is reported. The patient was a 53-year-old male who developed a nasal obstruction due to nasal tumor mass. Pathological findings showed adenoid cystic carcinoma.
Carcinoma of the nasal septum is very rare and in Japan, only 71 cases have been reported to date. Including this case, only 9 cases of adenoid cystic carcinoma have been reported. Clinical features and treatment are briefly reviewed.

View full abstract

Malignant fibrous hystiocytoma (MFH) is a common malignant soft-tissue tumor, but it rarely occurs in the nasal cavity. A 42-year-old female with MFH in the right nasal cavity is reported. She had bilateral chronic sinusitis with nasal polyp. Gadolinium-enhanced magnetic resonance imaging was very useful in identifying the tumor mass from inflammatory tissue. The tumor was surgically removed and she has had no recurrence for seventeen months following surgery.

View full abstract

A case of triple cancer, including adenocarcinoma of the nasal cavity is reported. The patient was a 75-year-old man complaining of nasal obstruction and was diagnosed with adenocarcinoma of the left nasal cavity. A general examination later revealed that he also had gastric cancer. Both lesions were surgically treated (extirpation of the tumor of the left nasal cavity and subtotal gastrectomy). Histopathological analyses of the surgical specimens revealed early stage well differentiated tubular adenocarcinoma in the gastric lesion as well as the nasal cavity tumor. We considered, however, that each cancer was distinct, because early gastric cancer rarely metastasizes to other organs and there was no evidence of metastasis to the lung, liver, lymph node and so on. About a year later, he was diagnosed with laryngeal carcinoma (squamous cell carcinoma, T1 aN0M0). He was treated with radiotherapy. The patient is disease free at present.
Primary adenocarcinoma of the nasal cavity is rare. Triple cancer, including adenocarcinoma of the nasal cavity, has not previously been reported in Japan.

View full abstract

A case of Werner's syndrome associated with malignant tumor in the nasal cavity is reported with some consideration of the literature. The patient, a 32-year-old female, complained of left nasal obstruction and hemorrhagic nasal discharge. A tumor was found in the left nasal cavity. Histopathological study showed squamous cell carcinoma. Clinical manifestations included senile face, bilateral cataracts, sclerodermia-like signs, short stature and low body weight, osteoporosis and diabetes mellitus. She was diagnosed with Werner's syndrome and treated with radiotherapy and surgery.
It is well known that this syndrome is characterized by a high frequency of malignant tumors. This is the 5th report describing Werner's syndrome associated with malignant tumor of the nasal cavity in Japan.

View full abstract

A rare case of malignant lymphoma of the parotid gland associated with Sjögren's syndrome is reported along with a review of the medical literature. A 67-year-old female complained of a mass in her left parotid region and was admitted to our hospital. We failed to precisely diagnose the tumor despite various preoperative examinations. The tumor was removed surgically and histological examination of the resected tumor showed non-Hodgkin's lymphoma. She was treated with chemotherapy and has had no recurrence for eighteen months after treatment.

View full abstract

A case of carcinoma in pleomorphic adenoma at the base of the tongue in a 47-year-old male is reported. The histopathological diagnosis of the biopsy specimen was pleomorphic adenoma, and the surgery was performed through the oral cavity. Pathological examination of the excised tissues revealed carcinoma in pleomorphic adenoma. After the initial surgery, an additional excision was performed via cheek flap. Pathological examination of the additionally excised tissues revealed no evidence of carcinoma cells. Seven months later the patient is alive and well without any signs of local recurrence or distant metastasis.

View full abstract

Twenty patients with T2N0M0 glottic cancer were seen during the period from 1978 to 1988 at the Department of Otolaryngology, Fukushima Medical College. Eleven cases were treated surgically. Nine cases were treated with radiation therapy and of these, three cases developed local recurrent and persistent disease. Of these three cases, one was treated. by partial laryngectomy and the others were treated by total laryngectomy. The local control rate with radiation therapy was 63% at both three years and five years. The cumulative five-year survival rate was 89% for cases treated with surgery and 89% for cases treated with radiation therapy. There was no significant difference in results achieved by surgery and those achieved by radiation therapy. Finally, preservation of larynx was achieved in 40% of the cases.
These results suggest that we should improve the rate of preserving the larynx without reducing the survival rate.

View full abstract

Ossifying fibroma, which is a fibro-osseous lesion, is very difficult to differentiate histopathologically from fibrous dysplasia. This is a case report of ossifying fibroma of the maxillary sinus diagnosed in a 36-year-old male with a painless and slowly enlarging mass in the left buccal region. Paranasal sinus X-rays, CT-scan and MRI revealed an expansive and well circumscribed mass which filled the left maxillary sinus. The tumor was easily detached at surgery and completely resected. Histopathological examination of the resected tumor did not show typical features of ossifying fibroma. In this case, X-rays, CT- scan, MRI and surgical findings helped differentiate ossifying fibroma from fibrous dysplasia.

View full abstract

A case of median cervical cyst causing sleep apnea syndrome is reported. A 64-yearold man complained of apneic episodes. A 45×45×60 mm cyst presented between the hyoid bone and the thyroid cartilage, and caused upper-airway obstruction. The cyst was removed surgically and clinical symptoms improved markedly.

View full abstract