Hirotsugu Kinoshita

Ear involvement in patients with rheumatoid arthritis.

Objective: This study evaluates the degree of hearing impairment in patients with rheumatoid arthritis (RA) and examines the correlation between hearing impairment and the clinical data or chemical mediators. Background: Both sensorineural hearing loss (SNHL) and conductive hearing loss (CHL) have been reported in patients with RA, but the results of most studies are not in agreement, and the pathophysiology of hearing impairment in RA is not well known. Methods: Hearing in patients with RA and controls was examined using pure-tone audiometry and tympanometry. Also, the amounts of pro-inflammatory cytokines and matrix metalloproteinases in addition to antibodies against type II collagen in plasma of the patients with RA were determined using enzyme-linked immunosorbent assay. Results: The frequency of SNHL in the patients with RA was higher than in normal controls (36.1% versus 13.9%), and bone conduction at 2,000 Hz differed significantly between the patients with RA and the controls (p < 0.01). Moreover, the presence of SNHL was related to ESR (p < 0.05), plasma interleukin-6 (p < 0.05), and plasma matrix metalloproteinase-3 (p < 0.001). On the other hand, CHL was not observed, whereas As-type tympanograms increased in the patients with RA (p < 0.01). Abnormal tympanograms were not related to any clinical findings or any chemical mediators tested. Conclusion: We demonstrated that there is increased SNHL in patients with RA, which may result from systemic inflammation and tissue injury, and increased latent-type CHL caused by stiffness of the middle ear system whose mechanisms are not yet clear.

Acoustic tensor tympani response and vestibular-evoked myogenic potential.

Objective To investigate the acoustic response properties and the vestibular‐evoked myogenic potential (VEMP) in various lesions.

Zinc deficiency and tinnitus

OBJECTIVE To determine if there is a correlation between serum zinc levels and audiometric performance in tinnitus patients. METHODS Seventy-three patients participated in this study. Patients age was restricted to 20-59 years. All patients were examined at the otolaryngology outpatient clinic of the St. Marianna University Toyoko Hospital. The control group consisted of 38 age- and sex-matched healthy volunteers. A blood sample was taken to measure serum zinc levels. Hypozincemia was set at a level of the mean minus one S.D. in the control group. An average hearing sensitivity was calculated as the mean value of hearing thresholds at five frequencies: 250, 500, 1000, 2000, and 4000 Hz. Normal hearing was indicated when the hearing threshold at each of these frequencies was within 20 dB of normal thresholds. RESULTS There was no significant difference in serum zinc levels between patients with tinnitus and controls. However, patients with tinnitus who had normal hearing had significantly lower serum zinc levels compared to controls. In contrast, no significant difference in serum zinc levels was found between patients with tinnitus who had hearing loss, and controls. A significant correlation between average hearing sensitivity and serum zinc level was observed. CONCLUSIONS These findings suggest that zinc is involved in the generation of tinnitus, especially in patients whose hearing is relatively normal.

Cochlear Function of Guinea Pigs with Experimental Chronic Renal Failure

This study aimed to evaluate electrophysiologically the cochlear function of guinea pigs that underwent a five-sixths nephrectomy and, additionally, to explore the synergistic action between chronic renal failure (CRF) and noise. Cochlear potentials were recorded at 1, 2, and 3 months postoperatively. Slight changes in compound action potential and cochlear microphonics were seen at 1 month postoperative, while moderate and profound changes were seen at 2 and 3 months. Endocochlear potential showed no significant reduction. The results indicate that CRF may be an etiologic factor for cochlear dysfunction and that the hair cells seem likely to be a main site of the lesion. One-month-postoperative animals were exposed to a broadband noise. In contrast to control animals, the test animals demonstrated no recovery from the decrease in compound action potential and cochlear microphonics that occurred immediately after noise exposure. This suggests a synergistic interaction between CRF and noise.

A case of carcinoid tumor of the middle ear.

We report here a case of a carcinoid tumor observed in the middle ear (ME), which was initially diagnosed as ME adenoma. The patient was a 64-year-old woman who was first seen in our hospital in March 2001 for a 7-month hearing loss. On otoscopic examination, a whitish mass could be observed through the intact tympanic membrane. High-resolution computed tomography demonstrated a tumor-like lesion in the ME with no evidence of bone destruction. A myringotomy and biopsy were performed and an initial diagnosis of ME adenoma was made. Light microscopy showed fragments of cellular tissue in which both glandular (adenomatous) and trabecular (carcinoid) growth patterns could be identified, but neuroendocrine differentiation was not detected by immunohistochemistry (negative staining for chromogranin A and synaptophysin). On the basis of this diagnosis, the patient underwent a tympanomastoidectomy in June 2001, in which the presumed ME adenoma was completely excised and the diagnosis was modified to ME carcinoid tumor. Immunohistochemical examinations at that time showed positive staining of the tumor cells for chromogranin A and synaptophysin. This case suggests the difficulties in distinguishing ME carcinoid tumors from ME adenomas. The patient is without recurrence of her disease to date.

Electrocochleogram after transection of vestibulo-cochlear nerve in a patient with a large acoustic neurinoma

This study reports pre- and post-operative compound action potentials (CAPs) that were recorded from a 27-year-old woman with an acoustic neurinoma. During surgery it was necessary to totally sever her vestibulo-cochlear nerve to excise a large tumor. A pure tone audiogram changed to the scale-out pattern immediately after operation. However, CAP, the waveform of which was broadened, has been recorded 3 years post-operatively with a threshold elevation of 10 dB over the pre-operative threshold. This phenomenon suggests that CAP may originate from the extreme periphery of the auditory nerve within the cochlea. The broadening of the CAP was assumed to result from enhancement of the negative summating potential included in the CAP. We studied the effect of preceding stimulus on CAP using paired click stimuli pre- and post-operatively. A reduction of CAP amplitude in response to the second click of paired clicks was markedly suppressed in the inter-click interval between 3 and 80 ms post-operatively. We speculate that depletion of adaptation induced the abnormal CAP recovery described above and that the lateral efferent nerve system was involved in abnormal CAP adaptation with transection of the vestibulo-cochlear nerve in this case.

Effects of nimodipine on salicylate ototoxicity

The purpose of this study was to examine the effects of nimodipine on salicylate ototoxicity in guinea pigs. The compound action potential (CAP) was recorded at the round window, and the cochlear blood flow (CBF) was measured simultaneously from the lateral wall of the basal turn of the cochlea by laser Doppler flowmetry. After administration of salicylate (100 mg/kg), the CAP thresholds were significantly elevated, by 5 to 20 dB (p < .05), and the CBF was significantly decreased (p < .05). After administration of nimodipine (2 mg/kg), the CAP thresholds were unchanged, but the CBF had increased significantly (p < .05), while systemic blood pressure had decreased significantly (p < .05). Simultaneous administration of both salicylate (100 mg/kg) and nimodipine (2 mg/kg) resulted in significant elevation of the CAP thresholds (p < .05), while the CBF did not decrease. These results suggest that nimodipine prevents the decrease in CBF induced by salicylate, but that nimodipine does not prevent the deterioration in the CAP.

Effect of fexofenadine hydrochloride on cedar pollinosis

OBJECTIVE To investigate the therapeutic efficacy of fexofenadine hydrochloride (Allegra(R) tablets), an antihistaminic launched in 2001, in patients with cedar pollinosis by dividing them into two groups for comparison, i.e. the early-treatment group in which treatment was started before the initial day of the pollen scattering, and the therapeutic-treatment group in which treatment was started after the initial day of the pollen scattering. METHODS Early-treatment group: patients who visited the hospital before the initial day of cedar pollen scattering were orally given one tablet of the drug twice daily. Therapeutic-treatment group: patients who visited the hospital after the initial day of cedar pollen scattering were orally given one tablet of the drug twice daily. The total number of cases in which the efficacy evaluation was possible was 37 cases (19 cases of the early-treatment group and 18 cases of the therapeutic-treatment group) after application of exclusion criteria. RESULTS The useful rate of moderately effective or better against sneeze was 90% in the early-treatment group, and 78% in the therapeutic-treatment group, and there was a significant difference between both groups. The degree of satisfaction in the early-treatment group was 3.8 points, and 4.2 points in the therapeutic-treatment group, and the therapeutic-treatment group showed a higher score, but there was no significant difference between both groups. As adverse reaction, there was only one case of mild dizziness (2.7%), and no other adverse reactions such as sleepiness were observed. CONCLUSIONS It was suggested that fexofenadine hydrochloride administered in patients with cedar pollinosis from before substantial pollen scattering might control their symptoms to mild ones, and might control worsening of their symptoms after the substantial pollen scattering, and, therefore, the drug was considered to be useful in early therapy.

Neurotological findings in a patient with narrow internal auditory canal: a case report

We report neurotological findings in a patient with unilateral narrow internal auditory canal, as confirmed by computed tomography. The patient presented no auditory brainstem response on the affected side. Vestibular tests including vestibular-evoked myogenic potentials (VEMP) and caloric test revealed normal function of both inferior and superior vestibular neural pathways.

Effects of nimodipine on quinine ototoxicity.

The compound action potential (CAP) in response to a click train stimulus was recorded at the round window of guinea pigs. Administration of quinine hydrochloride (200 mg/kg) significantly elevated the CAP thresholds by 5 to 25 dB (p < .05), and the CAP waveform elicited by the click train stimulus was abnormal. The amplitude of the CAP elicited by the second click was bigger than that elicited by the first click. These changes may be caused by an abnormally broadened N1 response to the first click in the click train. In contrast, CAP waveforms elicited by the second and subsequent clicks appeared normal. After administration of nimodipine (2 mg/kg), the CAP thresholds and waveforms elicited by the click train stimulus were unchanged. Simultaneous administration of both quinine (200 mg/kg) and nimodipine (2 mg/kg) resulted in the same electrophysiological changes as those induced by quinine alone. These results suggest that nimodipine prevents neither the deterioration in the CAP nor the abnormal properties in the response to a click train stimulus.