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Kentaro Ochi

Publications and source records attributed to Kentaro Ochi.

At least 19 recordsLinked to original sources
PubMed2005

Recovery of human compound action potential using a paired-click stimulation paradigm.

The recovery process from adaptation of the compound action potential (CAP) was studied using an equilevel paired click stimulation paradigm in humans with normal hearing. The CAP amplitude to the second click of paired clicks was normalized to the amplitude to the first click. The second-click CAP amplitude recovered as a function of interclick interval (ICI) between the first and the second click of a pair. A regression line fitted to the recovered amplitude data demonstrated the logarithmic function of the ICI. Full recovery times changed from 118 to 278 ms with increasing click intensity. The regression lines for higher click intensities exhibited two different slopes in two ICI ranges: from 3 to 100 and 120 to 300 ms. We suppose that the CAP recovery for ICI <100 ms is attributable to both the relative refractoriness of auditory nerve and the short-term adaptation mechanisms, while, for ICI >100 ms chiefly to the short-term adaptation mechanisms. The recovery process of the second-click CAP slowed with increasing intensity, which is a similar result to that obtained in the animal experiments by Parham et al. The input-output (I-O) curve of the second-click CAP amplitudes exhibited a different slopes above and below 60 dB normal hearing level (nHL). We assume that the mechanisms underlying this characteristic curve pattern differ from those for the I-O curve of the CAP in response to single-click stimuli. We expect that investigating the CAP recovery in pathological ears will provide clinically useful information on cochlear synaptic function.

Acoustic Stimulation↗
PubMed2004

[Clinical effect of bipolar radiofrequency thermotherapy on allergic rhinitis].

The clinical effect of bipolar radiofrequency thermotherapy on allergic rhinitis was evaluated. A bipolar radiofrequency system (CelonLab ENT) was used to treat 16 patients suffering from allergic rhinitis between February 2003 and August 2003. The thermotherapy was performed under local anesthesia at the otolaryngology outpatient clinic of St. Marianna University Toyoko Hospital. Data were collected by questionnaire and rhinomanometry preoperatively and 2 months postoperatively. The mean visual analogue scale (VAS) score for intraoperative pain was 31 mm (range, 0-100), and nearly all the patients felt no or a subtle pain during the thermotherapy. Postoperative pain was also well tolerated, with nearly all the patients not requiring analgesic drugs. Postoperative bleeding was minor, and none of the patients required additional treatment for bleeding. Nearly all the patients reported an improvement in their nasal patency, rhinorrhea, headaches, and sleeping. Statistically significant improvements were observed for all the measured VAS scores: nasal patency, rhinorrhea, headache, and olfactory function. Nasal resistance, as measured by anterior rhinomanometry, significantly improved after treatment. The effect of decongestion was also measured using anterior rhinomanometry. The ratio of nasal resistance before and after decongestion was significantly higher after thermotherapy, suggesting that nasal decongestion had a smaller effect on nasal patency after treatment. The current results suggest that the CelonLab ENT device is an effective and safe treatment for allergic rhinitis.

Adolescent↗
PubMed2003

Age-related changes in the vestibular-evoked myogenic potentials.

OBJECTIVE: We sought to investigate the effects of gender and age on the vestibular-evoked myogenic potential (VEMP). STUDY DESIGN AND SETTINGS: Sixty healthy adult volunteers (28 male and 32 female) were investigated in this study. The subject age was distributed between 20 and 77 years old. RESULTS: No gender-related differences were detected in the VEMP. There was a significant correlation between age and both the evoking threshold and the pInII amplitude of the VEMP, whereas no significant correlation was observed between age and left-right differences of the VEMP. CONCLUSIONS: The correlation between age and the parameters of the VEMP is presumably secondary to age-related functional changes in the sensory and neural elements of the VEMP. It is safe to evaluate the VEMP using the value of the non-affected side when assessing unilateral lesions. However, it may be necessary to take age into account in evaluating the VEMP when bilateral lesions are suspected.

Adult↗
PubMed2003

Changes in CAP adaptation in experimentally induced endolymphatic hydrops.

OBJECTIVE: To determine the effect of experimentally induced endolymphatic hydrops (ELHs) on compound action potential (CAP) adaptation. METHODS: The CAP was recorded 1 month after surgical treatment to produce ELH. The CAP threshold in response to click stimuli showed no significant differences between the hydropic and control groups. The CAP was elicited from the retroauricular-exposed round window using a silver ball electrode. Click trains consisting of 10 clicks with an interclick interval (Deltat) of either 4 or 8 ms were delivered through a loudspeaker placed in front of the animals' ears. The patterns of adaptation to these click trains were evaluated as functions of Deltat and intensity level. RESULTS: An abnormal pattern of CAP adaptation was observed in hydropic ears. CONCLUSIONS: These findings suggest that early ELH influences CAP adaptation.

Acoustic Stimulation↗
PubMed2003

A rare case of olfactory neuroblastoma with intracranial extension.

Olfactory neuroblastoma (ONB) is a rare form of head and neck tumor, and further ONB presenting an intracranial extension is extremely rare. Therefore, at the present time there is no established therapeutic standard supported by oncological studies. Our report documents a patient who underwent a craniotomy in combination with transnasal approach for tumor excision, followed by postoperative irradiation. We conclude that the patient shows no evidence of recurrence during the 11-year follow-up involving sinus CT scans and endoscopic examinations.

Adult↗
PubMed2003

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.

Adolescent↗
PubMed2003

Two cases of Aspergillus sinusitis with bone destruction.

We experienced the clinical courses of two cases of destructive Aspergillus in paranasal sinuses in which an Aspergillus fungus ball was formed, and which caused bony destruction are described. The case in which a nidus could not be completely surgically removed and with intervening diabetes had an unfavorable prognosis. It is recommend to perform an early expanded operation as well as to administer a sufficient amount of antifungal drugs for the treatment of destructive Aspergillus in paranasal sinuses.

Aged↗
PubMed2003

Video-assisted submandibular sialadenectomy using an ultrasonic scalpel.

OBJECTIVE: To evaluate the benefits in video-assisted submandibular sialadenectomy by using an ultrasonically activated scalpel (HS: Harmonic Scalpel(R), Ethicon, Somerville, NJ) and a special handmade lifting device. METHODS: The study cohort consisted of four male patients. We considered that the intraglandular part sialolithiasis of the submandibular glands was the main indicator for this technique. Under general anesthesia, a 15-20 mm skin incision was performed just above the inferior margin of the submandibular gland lying parallel to the mandible. We used a 4 mm diameter endoscope that we normally use for paranasal sinus surgery. Appropriate working space was created using a special handmade lifting device that was constructed from a wooden tongue depressor. By using HS, we dissected between the capsule and the circumferential tissue in order to minimize the possibility of damage to the facial nerve and lingual nerve. The submandibular gland was pulled out through the surgical wound, and Wharton's duct was then suture-ligated and resected. RESULTS: Endoscopic operation without recourse to conventional open surgery was achieved in all patients. No patients suffered any complications, such as functional disorder of the marginal mandibular, hypoglossal and lingual nerves, or wound hematoma formation. Excellent cosmesis was obtained in all patients. The amount of intraoperative bleeding ranged from 10 to 60 ml (mean: 38.0 ml). The operating time ranged from 175 to 250 min (mean: 232.5 min). CONCLUSIONS: We applied two useful devices to achieve the endoscopic submandibular surgery: an HS and a special handmade lifting device. Excellent cosmesis was obtained in all patients without complications. The disadvantage of this method is that the surgery is more time-consuming than conventional open methods.

Adult↗
PubMed2003

Powered endoscopic marsupialization for recurrent sphenoid sinus mucocele: a case report.

We report a case of recurrent sphenoid mucocele successfully treated by using a powered instrument under endoscopic control. A 59-year-old male came to our clinic complaining of severe headache, right-side facial numbness (in the areas of the first and second branches of the trigeminal nerve), diplopia, and right blepharoptosis. Computed tomography (CT) imaging revealed opacification and expansion of the sphenoid sinus lesion. The lesion was diagnosed as right-side sphenoid mucocele affecting the functions of the trigeminal (first and second branches), oculomotor, and abducent nerves. Endoscopic drainage of the right-side sphenoid mucocele leads to gradual improvement of these symptoms. Approximately 1 year after the drainage procedure, the size of the enlarged sphenoid sinus ostium had decreased. The patient underwent endoscopic right-side total marsupialization of the sphenoid sinus using a powered instrument. Subsequently, the patient has presented no evidence of recurrent disease after 1 year of follow-up.

Cranial Nerve Diseases↗
PubMed2003

Vestibular-evoked myogenic potentials in two patients with Ramsay Hunt syndrome.

We report on the function of the inferior vestibular nerve, as monitored by the vestibular-evoked myogenic potentials (VEMP), in two patients suffering from Ramsay Hunt syndrome. Both the patients presented canal paresis (CP) and hearing loss, but in one patient normal VEMP was recorded while the other presented vagus nerve paralysis plus no VEMP response at the highest stimulus intensity used in our institute (i.e., 105 dB nHL).

Acoustic Stimulation↗
PubMed2003

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. Patient's 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.

Adult↗
PubMed2003

Patency of inferior meatal antrostomy.

OBJECTIVE: To evaluate the patency and effectiveness of inferior meatal antrostomy for the treatment of maxillary lesions. METHODS: Patients suffering from moderate-to-severe chronic sinusitis who underwent inferior meatal antrostomies at St. Marianna University Toyoko Hospital and followed up for at least 1 year after surgery were selected. Thirty sides of 27 patients were analyzed. Postoperative mucociliary function was examined in seven sides of seven patients. RESULTS: No closure was observed in all 30 procedures. Out of 30 antra, 26 (86.7%) had normal antral mucosa. Recurrent mucosal lesions inside the maxillary sinus were successfully treated through the inferior meatal window. No cases showed circular flow on the india ink test. All sinuses exhibited a discharge from the middle meatal window and three out of seven sinuses exhibited a discharge from the inferior meatal window. CONCLUSIONS: Although long-term follow-up is required to determine the patency of inferior meatal antrostomy, initial results are encouraging. The inferior meatal window provides both intra- and postoperative benefits.

Adolescent↗
PubMed2003

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.

Acoustic Stimulation↗
PubMed2003

Hearing impairment and tinnitus pitch in patients with unilateral tinnitus: comparison of sudden hearing loss and chronic tinnitus.

OBJECTIVES: The objectives were to analyze the results of pitch-matching and loudness-balance testing in patients with unilateral tinnitus and to evaluate the relationship between audiological findings based on the tinnitus-affected and tinnitus-unaffected threshold differences and tinnitus pitch by using linear interpolation methods. In addition, the effects of the duration of the tinnitus on this relationship were investigated. Sudden sensorineural hearing loss with tinnitus was selected for the "acute tinnitus" group, and unilateral tinnitus with unknown disease and a duration of more than 3 months was selected for the "chronic tinnitus" group. STUDY DESIGN: Retrospective study of the clinical records of patients. METHODS: One hundred thirty-two patients with unilateral tinnitus (comprising 68 female [51.5%] and 64 male [48.5%] patients) were investigated as subjects. Their mean age was 50.4 years (SD = 15.8 y). All patients underwent otoneurological testing, including the pure-tone audiogram and pitch-matching and loudness-balance tests. RESULTS: The mean difference in the hearing threshold between the tinnitus-affected ear and the tinnitus-unaffected ear was largest near the tinnitus pitch in both the acute and the chronic tinnitus groups. However, the relationship between hearing impairments and tinnitus pitch was somewhat different in the two groups: It exhibited a single smooth peak in the acute tinnitus group but a bimodal peak in the chronic tinnitus group. CONCLUSION: The results suggest that tinnitus is related to hearing impairment in the same frequency region in patients with sudden sensorineural hearing loss with tinnitus or in patients with chronic tinnitus, whereas some instances of chronic tinnitus are caused by reorganization in cortical cells.

Acute Disease↗
PubMed2003

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.

Action Potentials↗