Shun-ichi Imamura

Clinical Observations on Acute Low-Tone Sensorineural Hearing Loss: Survey and Analysis of 137 Patients

We retrospectively analyzed the clinical records of 137 patients who were treated at our clinic for acute low-tone sensorineural hearing loss of unknown cause over a period of 8 years. The analyses of the clinical records indicated the following clinical characteristics: female preponderance; peak incidence during the fourth decade of life; frequent accompanying tinnitus, sensation of ear fullness, and/or autophony; suspicion of bilateral involvement; and association with autonomic imbalance. The hearing in most of the patients completely recovered, but some selected patients experienced fluctuating hearing loss or progression to Menieres disease. Our results suggest that a subgroup of patients with severe initial hearing loss should be carefully followed up, although it is difficult to predict the outcome of this disorder.

Clinicopathologic study of leptomeningeal carcinomatosis involving the temporal bone.

The temporal bone pathology of a 71-year-old man with bilateral sensorineural hearing loss and facial paralysis caused by diffuse metastatic leptomeningeal carcinomatosis is described. The origin of this malignant disease was an extremely rare entity, a transitional cell carcinoma of the renal pelvis. Histopathologic study of the temporal bone demonstrated that tumor cells filled the internal auditory meatus, infiltrated into the Rosenthals canals, and reached the scala tympani of the basal turn of the bilateral cochleas. The vestibulocochlear nerve and facial nerve trunks in the internal auditory meatus had been destroyed by the bilateral tumor invasion. Case reports of temporal bone metastases of leptomeningeal carcinomatosis published since 1965 were reviewed. In leptomeningeal carcinomatosis, it is suggested that tumor cells infiltrate the internal auditory meatus of both ears simultaneously from the cerebrospinal fluid, involving the seventh and eighth nerve trunks, and then cause bilateral sensorineural hearing loss and facial paralysis.

Clinical Study of Acute Low-Tone Sensorineural Hearing Loss: Survey and Analysis of Glycerol Test and Orthostatic Test

Fifty patients (14 men and 36 women ranging in age from 16 to 66 years) with acute low-tone sensorineural hearing loss (ALHL) were retrospectively analyzed in this study. The glycerol test and the orthostatic test were performed. On the glycerol test, 43.8% of 16 ears of the 14 men and 33.3% of 39 ears of the 36 women with ALHL had a positive result. On the orthostatic test, 42.9% of the 14 men and 52.7% of the 36 women with ALHL had a positive result. In addition, 28.6% of the 14 men and 33.3% of the 36 women had hypotension with a systolic blood pressure of 100 mm Hg or less. Our results suggest that endolymphatic hydrops as shown by the glycerol test and an underlying autonomic imbalance and/or insufficient blood circulation as shown by the orthostatic test may be important factors in the causation of ALHL.

Head and neck metastases from occult abdominal primary site: A case report and literature review

Objectives A very rare case of cervical lymph node metastasis from the liver is reported. The clinical findings and the diagnosis of a metastasis to the head and neck from the isolated silent abdominal cancer are discussed. Material and Methods The clinical and histopathological findings of a 56-year-old woman with a metastatic cervical lymph node of unknown origin are presented, together with a literature review of metastases from an occult abdominal primary. Results The primary site was identified as an undifferentiated cholangiolocellular carcinoma using immunostaining for anti-cytokeratin subclasses after autopsy. Fifty-two cases of head and neck metastases from an abdominal primary cancer were found and separately summarized according to the metastatic routes. Conclusions When a metastatic neck cancer of unknown origin is diagnosed, it is very important to consider the possibility of a metastasis from an abdominal organ. Recognition of metastatic routes and their characteristics is helpful in the search for the occult abdominal primary site. Immunohistochemistry of the metastatic cancer may provide important information for identifying the primary site in cases of metastasis of an undifferentiated carcinoma.

Malignant peripheral nerve sheath tumor of the parotid gland

Malignant peripheral nerve sheath tumor (MPNST) has been defined as any malignant tumor arising from or differentiating toward cells of the peripheral nerve sheath. We treated a case of MPNST arising from the right parotid gland that showed a highly aggressive course. We reviewed the English-language literature published since 1990 and found 142 cases of head and neck MPNST reported within the past 13 years. The results of the review suggested that MPNSTs may arise from any organs of the head and neck. Immunohistochemical analysis of various neural markers plays a significant role in the evaluation of the histologic diagnosis. Curative treatment based on radical resection of MPNSTs of head and neck origin is more difficult than treatment of MPNSTs of other origins.

Carbon Dioxide Laser Vaporization of the Inferior Turbinate for Allergic Rhinitis: Short-Term Results

Carbon dioxide laser vaporization of the turbinate has recently become accepted as a common treatment for allergic rhinitis. Usually, only a single procedure is applied to minimize trauma. However, repeated procedures on separate days are often required to achieve an adequate effect. Therefore, we attempted a new method of vaporization and evaluated the outcome, and also tried to determine which patients have good indications for laser treatment. To widely and deeply vaporize the inferior turbinate, we repeated the procedure 3 times in 1 session after removing the carbon coating from the previous vaporization under nasal endoscopic observation. After the procedure, most patients experienced complete nasal obstruction for 2 or 3 days, but there was no intraoperative or postoperative bleeding or severe pain. All patients obtained improvement of their chief complaints and were satisfied 2 months after the operation. In particular, 60% of the patients were completely relieved of refractory nasal obstruction. Most patients were more satisfied with the effects than are those treated by the usual methods. Completely successful cases (improvement in all symptoms and complete satisfaction obtained) were selected and were compared with other cases. Favorable prognostic factors are more severe complaints, longer symptomatic periods, stronger allergic reactions, and worse nasal resistance and its greater improvement with administration of decongestant nasal drops. This method may be especially accepted by patients with severe complaints, in particular nasal obstruction, who do not experience enough relief with conservative therapies or have enough time to make frequent visits to an outpatient clinic over a period of several weeks.

The relationship between orthostatic dizziness and hypotension in male medical students.

We carried out a questionnaire survey regarding symptoms of orthostatic dysregulation (OD) and administered the Schellong test (orthostatic test) to 123 normal male medical students aged 21-29 years to investigate the relationship between orthostatic dizziness and hypotension. OD was identified in 15 (12.2%) of the subjects based on the questionnaire results. Orthostatic dizziness was noted in 40.7% of the subjects (50/123). The occurrence of orthostatic dizziness was most significantly related to systolic pressure decrease during the procedure for the Schellong test. These results suggest that the testing procedure introduced by Schellong can be useful, and clinically applicable to the assessment of orthostatic dizziness, since it presents the advantage of being simple enough to carry out in clinical practice.

Age‐related Alterations in the Auditory Brainstem Responses and the Compound Action Potentials in Guinea Pigs

The auditory brainstem response (ABR) and the eighth nerve compound action potential (CAP) were measured using click stimuli to investigate the agerelated alteration in the auditory function in 66 guinea pigs consisting of four age groups. With advancing age, a gradual elevation of the thresholds in both the ABR and CAP was clearly seen, together with the prolonged latencies for waves I, II, III, and IV to clicks at 95 dBpeSPL in the ABR. There were some individual differences in either threshold elevation or latency prolongation of both the ABR and CAP in aged guinea pigs. These findings suggest that the effect of individual differences on degenerative aging processes of the auditory system should be considered in selected aged animals, although a significant elevation of the neural auditory threshold is clearly found with advancing age as a whole.

Study on Orthostatic Dysregulation and the Schellong Test in Healthy Young Females

We carried out a questionnaire survey regarding the symptoms of orthostatic dysregulation (OD) and administered the Schellong test to 301 healthy young females ranging in age from 18 to 21 years. OD was identified in 62 (20.6%) of the subjects based on the questionnaire. Although orthostatic dizziness was relatively common in the entire group of young females (171/301, 56.8%), this symptom was much more prevalent in the subjects with OD (58/62, 93.5%). There was also a highly significant difference between the systolic pressure decrease during the Schellong test procedure in 22 subjects with OD with frequent orthostatic dizziness and that in the 239 subjects without OD. Although the clinical value of the Schellong test in the assessment of OD and other related conditions has been brought into question because of its relatively poor specificity, we conclude that this test procedure may be useful in screening for OD or autonomic nerve dysfunction, since it presents the advantage of easy application in clinical practice.

Pathogenesis of experimental aural cholesteatoma in the chinchilla.

Histopathological observation of celloidin serial sections of the chinchilla middle ear after treatment with propylene glycol disclosed the development of severe inflammation of the middle ear mucosa and tympanic membrane, papillary proliferation of the epidermis of the tympanic membrane and external auditory meatus, and retraction and adhesion of the tympanic membrane. The findings for the tympanic membrane, impedance testing and histopathological examination suggested that there were two types of acquired cholesteatoma formation, probably with a difference in the pathogenesis. In one type, the proliferated epidermal layer of the tympanic membrane penetrated into the middle ear cavity making tympanic perforations. In the other type, there was progressive retraction of the tympanic membrane forming a retraction pocket. We discuss the two different patterns of cholesteatoma development.