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Papers - Ogawa, Kaoru

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Evaluation of hearing recovery and a grading system established by the Research Group on Sudden Deafness of the Japanese Ministry of Health and Welfare

Sato M., Matsunaga T., Kanzaki J., Ogawa K., Inoue Y., Houya N.

Journal of Otolaryngology of Japan 104 ( 3 ) 192 - 197 2001.03

ISSN 0030-6622

A grading system for sudden deafness has been established by the Research Group on Sudden Deafness of the Japanese Ministry of Health and Welfare. According to this grading system, sudden deafness cases are classified according to the initial hearing level and the vestibular symptoms. Few clinical analyses of sudden deafness cases have been made using this grading system. In this study, 263 sudden deafness cases were classified into 6 groups based on the grading system. All of the cases presented with an initial hearing level of more than 40 dB and underwent treatment within 1 week of the onset of symptoms. The relationship between the grading system and hearing recovery is discussed. Fixed hearing levels with a good prognosis were grades 2b, 2a, 3b, 3a, 4b and 4a. To quantitatively evaluate hearing recovery, the average hearing recovery rate and the percentage of the complete recovery cases were analyzed for each group. Average hearing recovery was ranked into five levels, regardless of the evaluation method. Grades 2b and 3b were the best, and grade 4a was the worst. After grades 2b and 3b, grade 2a was the second best, grade 3a was the third, and grade 4b was the fourth. The cases included in grades 2 and 3 were more strongly effected by whether the cases had vestibular symptoms or not than by their initial hearing levels. When grade 4 cases were classified by their initial hearing level, a large difference existed among grade 4a cases with regard to whether they presented with an initial hearing level of under or more than 100 dB. The hearing recovery of grade 4a cases with an initial hearing level of less than 100 dB was almost the same as that of grade 3a. However, the hearing recovery of grade 4b cases varied only slightly. Consequently, some ranges of initial hearing level exhibited similar degrees of hearing recovery. In cases without vestibular symptoms, the range of initial hearing levels was 40-89 dB. These cases had a 60% chance of complete recovery, and the hearing recovery rate was 80% on average. In cases with vestibular symptoms, the range of initial hearing levels was 60-99 dB. These cases had a 40% possibility of complete recovery, with an average hearing recovery rate of 60%. After comparing the initial grades and the final grades using the same grading system, the majority of grade 2 and 3 cases attained a grade 1 fixed hearing level. However, most grade 4 cases had a grade 3 fixed hearing level.

耳硬化症における耳閉塞感の発症機序に関する検討

Ogawa Kaoru, Kanzaki Jin, Inoue Yasuhiro, Houya Noriyuki

日本耳鼻咽喉科学会会報 104 ( 3 ) 187-191 2001.03

Research paper (scientific journal), Joint Work

突発性難聴の重症度分類と予後との関係

Sato Minako, Matsunaga Tatsuo, Kanzaki Jin, Ogawa Kaoru, Inoue Yasuhiro, Houya Noriyuki

日本耳鼻咽喉科学会会報 104 ( 3 ) 192-197 2001.03

Research paper (scientific journal), Joint Work

Pathogenesis mechanism in ear fullness in otosclerosis

Ogawa K., Inoue Y., Shinden S., Kumanomidou H., Ide R., Kanzaki J.

Journal of Otolaryngology of Japan 104 ( 3 ) 187 - 191 2001.03

ISSN 0030-6622

To clarify the mechanism underlying ear fullness in otosclerosis, we studied the relationship between clinical features and examinations. Subjects were 116 otosclerosis patients (140 ears). The presence or absence of ear fullness was judged from a questionnaire in initial diagnosis or a chart description. Ear fullness was observed in 44 ears (31%) and absent in 96. The averaged air and bone conduction hearing levels (500 Hz-4 k Hz) in initial diagnosis were significantly lower in the group with ear fullness. The difference in averaged hearing was mainly apparent at 2 k Hz and 4 k Hz. The difference in hearing at lower frequencies (125 Hz, 250 Hz, and 500 Hz) and higher frequencies (2 k Hz, 4 k Hz, and 8 k Hz) was significantly larger in the group of ear fullness. From these results, we postulated that ear fullness in otosclerosis is caused by fixation of the stapes. The psychoacoustic abnormal sensation caused by lower input of lower-frequency sound or incomplete fixation of the stapes may cause ear fullness. Further study is needed to clarify the pathogenesis of ear fullness in different ear pathologies.

外リンパ圧異常と感音難聴

Kanzaki Jin，Inoue Yasuhiro，Ogawa Kaoru

Otology Japan 11 ( 1 ) 33-38 2001.02

Research paper (scientific journal), Joint Work

高度難聴まで進行した急性低音障害型感音難聴の2症例

Ogawa Kaoru，Kanzaki Jin，Inoue Yasuhiro，Shiduki Ken

Audiology Japan 44 ( 1 ) 60-65 2001.02

Research paper (scientific journal), Joint Work

The quality of life in vestibular schwannoma patients after surgery

Inoue Yasuhiro, Kanzaki Jin, Ogawa Kaoru

Acta Otolaryngologica 121 ( 1 ) 59-61 2001.01

Research paper (scientific journal), Joint Work

Perilymph fistula -45 case analysis-

Goto Fumiyuki, Ogawa Kaoru, Kunihiro Takanobu, Kurashima Kazuhiro, Kobayashi Hironari, Kanzaki Jin

Auris Nasus Larynx 28 ( 1 ) 29-33 2001.01

Research paper (scientific journal), Joint Work

Effects of changes in stimulus level on phases of distortion product otoacoustic emissions

Harada Tatsuhiko, Ogawa Kaoru, Inoue Yasuhiro, Kanzaki Jin

Hearing Research 152 ( 1-2 ) 152-158 2001.01

Research paper (scientific journal), Joint Work

Quality of life of vestibular schwannoma patients after surgery

Inoue Y., Ogawa K., Kanzaki J.

Acta Oto-Laryngologica 121 ( 1 ) 59 - 61 2001

ISSN 0001-6489

The quality of life of vestibular schwannoma (VS) patients after surgery was investigated. The subjects consisted of 236 unilateral VS patients who underwent tumor removal between 1990 and 1997. A questionnaire was sent to all patients regarding their hearing, tinnitus, dizziness and the changes in their daily life after surgery; 176 out of 204 patients (86%) who received the questionnaire completed and returned it. The answers were compared with recent data reported in other clinical studies. Ninety percent of the patients with postoperative class A hearing were satisfied with their hearing. However, only 30% of patients with postoperative class B hearing were satisfied. Tinnitus worsened after surgery more often in patients who underwent a labyrinthectomy than in those who did not. Dizziness improved after surgery in the majority of VS patients. However, 30% of patients had difficulty driving a car and 50% of patients could not enjoy activities such as playing sport after surgery.

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The learning curve in post-operative hearing results in vestibular schwannoma surgery

Kanzaki Jin, Inoue Yasuhiro, Ogawa Kaoru

Auris Nasus Larynx 28 ( 3 ) 209 - 213 2001

ISSN 0385-8146

Purpose: We chronologically investigated whether the hearing preservation (HP) rate improved or not in vestibular schwannoma (VS) surgery. Subjects and methods: HP surgery has been attempted in 127 VS patients with pre-operative class A and B hearing from 1976 to 1999. The HP rate was chronologically compared with hearing level and tumor size. Results: The preservation rate of pre-operative class A hearing which was preserved post-operatively as class A has recently been increasing especially in patients with an intracanalicular (IC) tumor. This rate was improved to 67% from 1995, although this was 33% from 1989 to 1994. However, the preservation rate of pre-operative class B in patients with an IC tumor and that of pre-operative class A hearing which was preserved as class A in patients with a larger tumor extending into the posterior fossa, have not improved over the last 10 years. Conclusion: These results indicate that the improvement of the HP rate is mainly due to the increased number of patients with an IC tumor with class A pre-operative hearing. In patients with a tumor of 4-20 mm in size, especially in those showing pre-operative class B hearing, there may be histologically some limitations such as gliosis in the cochlear nerve in the preservation rate of good quality (class A or B) of hearing.

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Effects of neuropeptide Y on cochlear blood flow in guinea pigs

Itou M., Ogawa K., Inoue Y., Sato M., Kanzaki J.

Acta Oto-Laryngologica 121 ( 5 ) 573 - 578 2001

ISSN 0001-6489

The aim of this study was to clarify the effects of neuropeptide Y (NPY) on cochlear blood flow (CBF) in pigmented guinea pigs. NPY was administered with or without noradrenaline (NA) by systemic perfusion or perilymphatic local perfusion, and CBF was measured using a laser Doppler flowmeter. The systemic and perilymphatic administrations of NPY with NA induced greater prolongation of the increase in and recovery of CBF than the administration of NA or NPY alone. Continuous reduction in CBF induced by NPY may play an important role in the pathogenesis of stress-induced sensorineural hearing losses, such as sudden deafness.

Effects of changes in stimulus level on phases of distortion product otoacoustic emissions

Harada Tatsuhiko, Ogawa Kaoru, Inoue Yasuhiro, Kanzaki Jin

Hearing Research 152 ( 1-2 ) 152 - 158 2001

ISSN 0378-5955

Effect of changes in stimulus levels of both lower (f₁) and higher (f₂) stimulus tones on phases of 2f₁-f₂ component of the distortion product otoacoustic emission (DPOAE) was examined in five normal hearing adults. The f₂ was fixed at 4004 Hz in all of the measurements, and the stimulus frequency ratio (f₂/f₁) was varied from 1.15 to 1.3. Change of the level of lower stimulus tone (L₁) and the level of higher stimulus tone (L₂) showed different effects on the DPOAE phases. The phase lags increased with increasing L₁, when f₂/f₁ was above 1.22, whereas the phase gains increased with increasing L₁, when f₂/f₁ was below 1.22. On the other hand, the difference in L₂ minimally affected DPOAE phase at most f₁s. The previous studies about basilar membrane vibration revealed that phase lags increase with increasing stimulus level, when the stimulus frequency is below the best frequency, while phase gains increase with increasing stimulus level, when the stimulus frequency is above the best frequency, and the effect of phase change in stimulus level diminished, when the stimulus frequency was far above the best frequency. Based on the comparison between the results of the present study and the previous findings of others concerning basilar membrane vibration, the DPOAE generation site is assumed to be located at apical of the peak of the f₂ traveling wave.

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Heterogeneity of phospholipase C in the cochlea of the guinea pig

Oba Toshihiko, Ogawa Kaoru, Inoue Yasuhiro, Kanzaki Jin

ORL 63 ( 5 ) 272 - 279 2001

ISSN 0301-1569

In the present study, we investigated the presence of phosphatidylinositol-specific phospholipase C (PLC) isoforms in the cochlea of the guinea pig using Western blot analysis and immunocytochemistry. By Western blotting, PLCβ1 and δ1 were expressed in the cochlear sensory epithelia (CSE) and PLCβ1, γ1 and δ1 were expressed in the cochlear lateral wall. By immunocytochemistry of the CSE, PLCβ1-like immunoreactivity was mainly expressed in the outer hair cells (OHCs), but not in the inner hair cells (IHCs). PLCγ1 and δ1 were expressed neither in the OHCs nor in the IHCs. In the cochlear lateral wall, PLCβ1, δ1 and γ1 were expressed in the stria vascularis and the spiral ligament. In addition, PLCβ1, δ1 and γ1 were also present in type I spiral ganglion cells. Based on these results, we discussed the function of these PLC isoforms in the cochlea.

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Perilymph fistula - 45 Case analysis

Goto Fumiyuki, Ogawa Kaoru, Kunihiro Takanobu, Kurashima Kazuhiro, Kobayashi Hironari, Kanzaki Jin

Auris Nasus Larynx 28 ( 1 ) 29 - 33 2001

ISSN 0385-8146

Purpose of the study: Though perilymph fistula (PLF) is not a rare disease, preoperative diagnosis still remains to be established. Some new diagnostic methods are challenging, but there is still no established diagnostic method except exploratory tympanotomy that verifies the occurrence of leakage. Early diagnosis of PLF is fully depending on history taking and some clinical examinations. To know the clinical features of PLF is one of the greatest helps to make both earlier and accurate diagnosis. In spite of some innovations in clinical examinations classic diagnostic procedure is thought to be still reliable. Procedures: We investigated the clinical symptoms, basic tests results and therapeutic results in patients with PLF. Results: From 1983 to 1998 PLF was identified in 44 patients (45 ears) with exploratory tympanotomies in our hospital. With respect to clinical history the predisposing factors such as blowing the nose, lifting heavy goods, and landing in an airplane were found in almost half of the patients, while the rest of them had no clear inducing factors. Their major symptoms included hearing loss (93%), vertigo and dizziness (91%), tinnitus (76%), and aural fullness (31%). The patients who have a clear predisposing factor tended to make diagnosis easily; on the other hand the rest of the patients who do not have clear etiology had some diagnostic difficulty. Subjective positive fistula signs were observed in 71% of patients. Vestibular symptoms improved in 80% of patients after closure of PLF. Conclusions: These results suggest that the variety of clinical manifestation make diagnosis more difficult. At the moment meticulous clinical history taking and close follow-up applying repeating fistula tests are the most important for not only earlier but also accurate diagnosis.

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難聴，耳鳴，耳閉塞感の診断と治療

Ogawa Kaoru

日本医事新報 ( 3998 ) 19-36 2000.12

Research paper (scientific journal), Single Work

術前鑑別診断が困難であった小脳橋角部腫瘍の経験

Inoue Yasuhiro，Ogawa Kaoru，Kumanomidou Hiroshi，Shinden Seiichi，Ide Rika，Kanzaki Jin

Otology Japan 10 ( 5 ) 593-597 2000.12

Research paper (scientific journal), Joint Work

Hypoglossal neurinoma: Resport of two cases

Hoshi M, Yoshida K, Ogawa Kaoru, Kawase Takeshi

Neurol Med Chir 40 ( 9 ) 489-493 2000.09

Research paper (scientific journal), Joint Work

Hypoglossal neurinoma- Two case reports-

Hoshi M, Yoshida K, Ogawa K, Kawase T

Neurologia medico-Chirurugica 40 ( 9 ) 489-493 2000.09

Research paper (scientific journal), Joint Work

低音障害型感音難聴の診断基準に関する検討

Shizuki Ken, Ogawa Kaoru, Inoue Yasuhiro, Kanzaki Jin

Audiology Japan 43 ( 4 ) 242-249 2000.08

Research paper (scientific journal), Joint Work

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