Izuru Nozawa

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.

Interaction between Oral Alpha-Streptococci and Group a Streptococci in Patients with Tonsillitis

The incidence of oral α-streptococci with inhibitory activity against group A streptococci, as a defense mechanism against bacterial infection in the oral cavity, was investigated in 141 patients with streptococcal tonsillitis. The study population included both children (n = 79) and adults (n = 62). Infection by group A streptococci appeared to be more common in children than in adults, as the detection rates of inhibitory α-streptococci in healthy children (29.7%), as well as pediatric patients with tonsillitis (14.9%), were lower than those in adults (63.0%; p < .01). It is possible to consider oral α-streptococci with inhibitory activity to be among the indications for tonsillectomy in patients with streptococcal tonsillitis, since the detection rate of inhibitory α-streptococci in surgical cases (10.9%) was significantly lower than that in nonsurgical cases (31.1 %; p < .01). The high detection rate of these strains during the postoperative state supported the observation that the incidence of group A streptococcal infection was decreased postoperatively. Accordingly, it is useful to investigate bacterial interference between oral α-streptococci and group A streptococci in patients scheduled for tonsillectomy.

Efficacy of Long-Term Administration of Isosorbide for Ménière’s Disease

The long-term therapeutic efficacy of isosorbide, an oral hyperosmotic diuretic, was clinically evaluated in 30 patients (14 males and 16 females) who were followed up in our clinic for more than 2 years. The patients ranged in age from 14 to 73 years, with a mean age of 49.2 years. Isosorbide was given orally, continuously or intermittently, for 27-297 weeks, depending on each patients condition. The efficacy of the drug was determined according to the evaluation criteria of the American Academy of Ophthalmology and Otolaryngology (AAOO) and the American Academy of Otolaryngology, Head and Neck Surgery (AAO-HNS) for Ménières disease. Definitive episodes were successfully controlled in 15 of the 20 patients (75%) who received isosorbide continuously according to both the AAOO and the AAO-HNS criteria. Of the 10 patients who were given the drug intermittently, definitive episodes were successfully controlled in 6 patients (60%) according to the AAOO and in 7 patients (70%) according to the AAO-HNS criteria. During the treatment periods, hearing improved in 6 patients (20%), and tinnitus subjectively lessened in 15 patients (50%). Although some patients complained of abdominal discomfort, the side effects of this drug were minimal. Among the patients who responded well to the treatment, the doses of isosorbide could be tapered to a daily dose of 30 ml, less than one half of the usual daily of this drug. The results suggest that most patients should be asked to continue this medical treatment for at least several months before a decision can be made regarding whether the medical response is good or poor.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychosomatic aspects of patients complaining of dizziness or vertigo with orthostatic dysregulation

Eighty-five patients (26 males and 59 females) with orthostatic dysregulation who visited our clinic complaining of dizziness or vertigo between December, 1990 and August, 1996 were analyzed using the Japanese Edition Cornell Medical Index-Health Questionnaire and the Yatabe-Guilford Personality Test. The condition of OD was most commonly noted in 29 patients (34.1%) with dizziness or vertigo of indeterminate etiology, followed by in 14 (16.5%) with Menieres disease, in ten (11.8%) with hypotension and CNS disorder each, and in 22 (25.9%) with other disorders. The percentage classed as Type III (possible neurotic) or Type IV (probable neurotic), was 46.1% in males and 47.4% in females. The percentage classed as Type B or Type E, suggestive of emotional or psychological disturbance, was 38.5% in males and 37.3% in females. There was good correlation between the Japanese Edition Cornell Medical Index-Health Questionnaire and the Yatabe-Guilford Personality Test results as to psychosomatic aspects. We conclude that, in the treatment of patients with orthostatic dysregulation, it is necessary to consider both physical and psychological aspects of the condition.

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.

Analysis of defense mechanisms against bacterial infection by oral streptococcus in normal flora

The incidence of oral alpha-streptococci with inhibitory activity against pathogens as a defense mechanism in the oral cavity was investigated in healthy individuals. Inhibitory strains were isolated from tonsil, tongue, cheek, saliva and dental plaque, and the detection rate of these strains isolated from tonsil was the highest. These results suggested that tonsillar flora is most important as a defense mechanism of the oral cavity. With respect to the effects of antibiotics against inhibitory alpha-streptococci, minimal inhibitory concentration of 90% of cells (MIC90) of PCG, ABPC, CCL, CFIX and EM against inhibitory alpha-streptococci, and relative detection rates of inhibitory alpha-streptococci before and after antimicrobial therapy were investigated. MIC90s of all antibiotics against these strains were low and sensitive to antibiotics tested. However, in vivo, detection rates of these strains before and after therapy did not differ significantly. Therefore, inhibitory strains were not affected by antibiotics as their MIC90 were low during short term medication.