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従来よりABRは幼小児の難聴の早期発見に多大な貢献を果たしてきた。 しかしABRは検査音としてclick音を用いているため聴覚の低音部の評価は困難である。 我々はABRで評価しにくい低音部0.5kHz-1kHzの幼小児の内耳機能の評価を主目的に外耳道誘導蝸電図を施行したのでその実態を報告する。 対象は10ヵ月-2歳6ヵ月の幼小児7名。 症例3は0.5kHzおよび1kHzにおいて70dBまでCMの反応が認められた。 他にもABRでたとえ反応が悪くても, 低音部のCMは残存していることが認められた。 小児にも侵襲の少ない外耳道誘導蝸電図を利用することで幼小児の内耳機能を他覚的に評価することが可能であると推測された。 幼小児難聴の限られた残存聴力を活用, そして保護するためにも, このCMからの情報は補聴器のフィッティングに有効であると考えられた。

With the increasing long-term use of interferon (IFN), several new adverse effects have been recognized. Very little attention, however, has been paid to auditory acuity. We encountered 3 cases of sudden hearing loss associated with IFN. We then conducted a prospective study to assess the auditory function of 73 patients receiving IFN. Auditory disability (tinnitus and/or hearing loss) occurred in 32 patients (43.8%) during IFN therapy, among which audiometry documented sensorineural hearing loss in 27 cases (36.9%); 17 (48.6%) of the 35 patients receiving IFN-beta had auditory disability, including hearing loss in 13 cases (37.1%), and 15 (39.5%) of 38 patients receiving IFN-alpha suffered from auditory disability. There was not much difference between the influences of IFN-alpha and -beta. Auditory disability frequently developed in the later stages of treatment, and most patients recovered 7-14 days after the discontinuation of IFN. The results demonstrate that sudden hearing loss can occur as a side effect of treatment with IFN. This may reveal the association between autoimmunity and sudden hearing loss.

We studied the distribution of T-lmphocyte subpopulations and activated EG2 positive cells in nasal polyps. CD4 positive cells and CD8 positive cells were seen in the epithelium and lamina propria. The CD4/CD8 ratio in nasal polyps was 2.13 on the average. EG2 positive cells were present in nasal polyps, and in the superficial lamina propria extracellular ECP release was seen.Treatment with Roxithromycin lowered the CD4/CD8 ratio in nasal polyps from 2.13 to 0.91, but the distributions of EG2 positive cells did not change.

It is well known that there is a sex difference in the incidence of many disease. In some disease, the reason for this difference has been elucidated by recent progress in the studies on hormone receptors. Moreover, it is believed that autoimmune disease occur more frequently in women than in men, because the immune response is influenced by the period of hyperactivity or hypoactivity of estrogen. In this paper, Some otorhinolaryngological diseases are discussed from the point of view of sex hormones.

Laryngomalacia is usually a benign condition which occurs soon after birth, and is resolved by 2 years of age. A 12-year-old female, with a history of nasal allergy, had complained of inspiratory stridor and cough. Laryngoscopy revealed a flaccidity of all the supraglottic structures. The arytenoids and aryepiglottic folds were fluttering during inspiration. The stridor was improved after resecting the excess tissue with a CO2 laser. A barking cough appeared about 10 days after the operation and placebos were effected to it. We suggest that she had a tendency to inspiratory laryngeal collapse and that her symptoms might have been triggered by allergic and/or psychological factors.

過去10年間に長崎大学耳鼻咽喉科を受診し, 蝸電図あるいは聴性脳幹反応Auditory Brainstem Response (ABR) を施行して詐聴と診断し得た82名について検討を行った。 昭和54-58年の前期5年間と昭和59-63年の後期5年間を比較すると, 症例数は約2倍, 当科にて蝸電図またはABRを行った全症例に対する比も約1.5倍と増加しており, 70歳以上の高齢者症例も増加していた。

最初メニエール病と診断されたが, その後の臨床経過から椎骨脳底動脈循環不全 (VBI) によるメニエール病様症状と判明した2症例を報告した。 症例1は47歳の女性で, 椎骨動脈造影 (VAG) では異常は指摘できなかったが, 患側の三叉神経障害を認めた。 また, 純音聴力検査及び蝸牛マイクロフォン電位 (CM) 検出域値の著明な改善が見られ, VBIによる内耳血管条のanoxiaが原因と考えた。 症例2は53歳の男性で, 患側半身の知覚鈍麻, VAGにて健側の椎骨動脈の高度狭窄を認めた。 また, 蝸電図検査では, 純音聴力域値よりも良好なCM検出域値, 幅の広いAPの所見から, VBIによる蝸牛神経障害と考えた。

A study was devised to determine whether or not any immune defense mechanism is present when a virus invades the human endolymphatic sac (ES). The ES was removed from 14 fresh autopsy cases having no known pre-mortem diseases in the middle and inner ears. Specimens were then examined for viral antigens including herpes simplex (HSV) type 1 and 2, mumps and cytomegalovirus using immunohistochemical methods. DNA examination by in situ hybridization was also performed for HSV. HSV antigen and DNA were observed in 9 of the 14 cases studied. These findings suggest that the virus invades the ES but is impeded by an immune defense mechanism under normal conditions. Since disease may alter host defenses, further studies are warranted to study the relationship between HSV and patients with Meniere's disease.

Changes in vascular permeability to sodium fluorescein following experimentally induced nerve le- sions were examined in the rabbit facial nerve. Sodium flu- orescein was injected intravenously as a permeability tracer and then localized by fluorescence microscopy. In control nerves, endoneurium showed only slight fluorescence while intense fluorescence was observed in the epineurium and perineurium. In nerves demonstrating edema and Waller- ian degeneration, endoneurium was found to have an in- creased accumulation of tracer. This increased endoneur- ial vascular permeability in facial nerve lesions may ex- plain nerve enhancement seen in gadolinium-enhan ced magnetic resonance imaging in patients with facial nerve paralysis.

Recently, it has been reported that the facial nerve shows enhancement on gadolinium-enhanced magnetic resonance imaging (Gd-MRI) in patients with such conditions as Bell’s palsy or traumatic facial nerve paralysis. The site of involvement in Bell’s palsy remains unknown, and accurate lesion-site information is useful for surgical planning in cases of facial nerve paralysis. The importance of this technique in detecting the lesion site has been discussed, but the mechanism of facial nerve enhancement is unknown. In the present study, in order to elucidate the correlation between facial nerve enhancement and lesion site, Gd-MRI study was performed in the rabbit.

Vascular permeability in cranial nerve roots was examined after intravenous injection of sodium fluorescein in the adult rabbit. Fluorescence was observed in the distal nerves through the following portions: intracavernous portion of the oculomotor nerve, distal internal auditory camal segment of the facial nerve, and ganglionic portions of the trigeminal, glossopharyngeal and vagus nerves. In the acoustic nerve, the vestibular ganglion showed fluorescence. No fluorescence was observed in the olfactory or optic nerves. During in vivo gadolinium-enhanced magnetic resonance imaging (Gd-MRI) of two separate animals, trigeminal nerve enhancement was observed in the region showing fluorescence. Histologically, intense fluorescence was observed in ganglia and external nerve sheaths of the cranial nerves showing macroscopic fluorescence. A slight fluorescence was also seen in endoneurial connective tissue but not observed within the nerve fibers. The results of this study suggest that the physiological enhancement of human cranial nerves seen on Gd-MRI may correlate with vascular permeability.

The distribution of Langerhans cells in human oral mucosa, nasal mucosa and nasal polyps was studied by means of immunohistochemistry. Our study involved 35 participants. The specimens were frozen to -70 degrees C and sliced at 4 microns with a cryostat. Monoclonal antibodies CD1 (OKT6) and the peroxidase-antiperoxidase staining method were used to detect Langerhans cells. In the oral mucosa and the nasal vestibule lined with stratified squamous epithelium, CD1 positive cells were observed and these cells were dendric in form. The cells were found mainly from the intermediate layer to the deep layer of the epithelium. In the inferior turbinate lined with ciliated epithelium, we could not find any CD1 positive cells at all. The nasal polyps in some cases had a normal ciliated columnar epithelium while others had metaplastic stratified squamous epithelium. Both types of epithelium in the same polyp were noted on some occasions. In nasal polyps, CD1 positive cells which showed dendric form were found in the metaplastic squamous epithelium only, and could not be observed in the ciliated columnar epithelium at all. Based on the above results, the presence of Langerhans cells is confirmed not by the anatomical location but by the type of epithelium. Langerhans cells could be detected only in the squamous epithelium. Keratinocytes, which constitute the squamous epithelium, are known to release cytokines. IL-1 (interleukin-1) and GM-CSF (granulocyte-macrophage colony stimulating factor) released from keratinocytes are thought to influence the viability and function of Langerhans cells. The migration of Langerhans cells into squamous epithelium may be regulated by cytokines released from keratinocytes.

The alteration of motor neurons in the brainstem after recovery from experimental facial nerve paralysis was examined by the retrograde horseradish peroxidase (HRP) technique in the rabbit. Six months after nerve crush injury at the center of the vertical portion, HRP was injected into the zygomatic muscle on the recovered side. The distribution of labelled neurons in the brainstem was compared with that in the normal rabbit. In control animals, motor neurons in the facial nucleus were somatotopically organized, and there were no labelled neurons in other nuclei in the brainstem. In recovered animals, on the contrary, the somatotopic organization of the facial nucleus was obscure and multipolar neurons of varying size were labelled bilaterally in the reticular formation from the pons to the medulla.

Experimental positional nystagmus (EPN) similar to benign paroxysmal positional nystagmus (BPPN) was induced in 8 of 20 rabbits by argon laser irradiation to the footplate. The power of the argon beam used was 2.0 watts and irradiation time was 1 or 2 sec. EPN and BPPN showed the following similarities maintained (1) When the head was maintained in the affected ear down position and the head positioned from the sitting to the supine position nystagmus directed to the affected ear or vertical nystagmus corresponding to rotatory nystagmus in man were provoked. (2) Delayed onset for provocation of nystagmus. (3) Limited duration. (4) Fatigability. (5) The direction of nystagmus was reversed when the head returned to the initial position (in two rabbits). Histological examination of the temporal bones showed separation of otoconia from the otolithic membrane of the saccule and bleeding in the saccule in both conditions. No lesions in the utricle and semicircular canals were evident. It was assumed that ablation of otoconia of the saccule causes this experimental positional nystagmus.

• Auditory nerve action potential (AP), cochlear microphonics (CM), and summating potential (SP) were recorded from 32 patients with Meniere's disease. Patients were classified into three groups according to the degree of their hearing impairment. The group of patients that had a mild to moderate hearing loss and whose hearing was reversible showed notably satisfactory responses for AP, CM, and negative SP (-SP), and also showed a high incidence of positive SP (+SP). Low responses for AP and CM with an increase of detection thresholds and a high -SP/ AP ratio were obtained from patients with moderate hearing impairment, whose hearing fluctuated slightly. These electrocochleographic findings were suggestive of the pathophysiologic differences at the various stages of Meniere's disease. ( Arch Otolaryngol 1982;108:284-288)

Experimental vestibular disorders of the peripheral type were induced using transtympanic infusion of several drugs. Drugs with high specific gravity such as saturated sodium chroride and pottasium chroride, heavy water, ethylene glycol, glycerine, isosorbid and urea induced direction-changing, positional nystagmus. The nystagmus was directed upward when the head was held with the right or left side down, to the injected side with the nose-up, to the non-injected side with the nose-down position, respectively. Ethyl-alcohol and aceton which have low specific gravities also induced direction-changing, positional nystagmus, although the direction was opposite to that of those drugs with high gravities.Most of these positional nystagmus developed to paralytic nystagmus which directing toward the non-injected side in all head positions or disappeared in three hours. Some animals had a second phase of positional nystagmus before it disappeared. Only pottasium chroride produced irritative nystagmus which directing towared the injected side in all positions and changed to paralytic nystagmus.

We surveyed elderly patients over 65 years of age who were treated for vertigo or dizziness in our Clinic between 1984 and 1993. There was a significant increase from 17.2% in the earlier 5-year period to 21.7% in the later period. This increase exceeded the growth in the elderly population in Nagasaki. Female patients showed a greater increase than male patients, especially among patients in their 70's. There were various causes in these aged patients, but BPPV and Cerebro-vascular disorders were common. From these results, vertigo or dizziness in aged patients might be prevented by suitable treatment of factors causing Cerebro-vascular disorders, such as hypertension.

The effect of the changes of interstimulus interval (ISI) was compared among the four groups consiting of normal hearing subjects sensorineural deafness due to hair cells damage, due to endolymphatic hydrops and cerebello-pontine angle lesion.The click sound stimulation was used for measurement of the auditory whole nerve action potential (AP), using the transtympanic technique in electrocochleography.A moderate decrease in similar manner was shown in two groups of normal hearing subjects and sensorineural hearing loss with hair cells damage. On the other hand, a remarkable decrease was shown in order two groups of sensorineural hearing loss with endolymphatic hydrops and with cerebello-pontine angle lesion.It is suggested that a remarkable decrease in amplitude of AP with shortening of ISI is due to abnormal function in synaptic junction between the cochlear hair cell and the first auditory neuron and/or abnormal function in the post synaps.

Five patients with episodic vertigo, tinnitus and hearing loss were found to have compression of the eighth cranial nerve by small aneurysm or arterial loops.The characteristic symptoms in these patients were :1) Short term and sudden-onset vertigo occurring frequently and not responding to medical treatment.2) Patients became asymptomatic immediately when the attacks ended.3) Hearing loss fluctuated widely but briefly at low or wide frequency ranges.4) In some cases there were associated ipsilateral facial spasms and/or trigeminal neuralgia.5) Nausea and vomiting during the vertigo attacks were less prominent than with Meniere's syndrome.6) Severe and frequent attacks were observed even, in patients with severe semicircular canal palsy.7) Vertebral angiography showed elongation and enlargement and sharp angulation of the fourth segment of the vertebral artery on the affected side.

Cerebral Spinal Fluid (CSF) of 22 patients with Meniere's disease was examined regarding pressure, number of cells, protein, glucose, and IgA, G, M and E. Almost of all values were within normal limits.There were no differences of each mean value and SD between the irritative and paralytic stage and also between Meniere's diseases and labyrinth related syphilis. Regarding the osmolarity of CSF, 5 of 22 patients showed normal values.Other peripheral vestibular lesions (vestibular neuritis, inner ear vertigo due to unknown causes, Ramsey-Hunt's syndrome and Vogt-Koyanagi-Harada's disease) were considered to be due to viral infections and immunological disorders.Thus causes of Meniere's disease may not be revealed in the CSF, and the inner ear fluid should be examined.

Ultrastructural findings in the peripheral nerves in idiopathic hemifacial spasm and trigeminal neuralgia were similar. At an early stage, microneuroma of the nerve fibers was characteristic, and the thickening of the myelin sheath was slight. The myelin sheath markedly thickened after repeated attacks. Segmental demyelination or thinning of the myelin sheath seemed to be related to paroxysm. It is postulated that this is because of the formation of a short circuit between the afferent and efferent fibers.

Chronological changes of the whole nerve action potential (AP), cochlear microphonics (CM) and summating potential (SP) in experimental endolymphatic hydrops in guinea pigs were studied during a perio

A 45-year-old house wife with hemifacial spasm developed a profound sensorineural deafness after neuro-vascular decompression operation of the facial nerve at cerebellopontine angle.Electrocochleography was performed using the transtympanic electrode technique.The results obtained were as follows:The wave form of action potential (AP) showed a broad pattern and a low amplitude, but AP threshold was remarkably lower than that of pure tone audiogram.The cochlear microphonics showed the well-developed responses.The above findings seem to indicate that the organ of Corti was found to be functioning because of the preservation of blood supply, but the first neuron region or spiral ganglion cell region was impaired partially and retrogradely, by the surgical procedure on the eighth cranial nerve.

A patient with Tullio's phenomenon of the right ear was tested with infrasound through the auditory canal which was generated at 100115dB SPL of 1545Hz by an ear drum massager. Nystagmus towards the right was recorded on ENG when the infrasound was produced in the right ear and it shifted to the left when the infrasound was interrupted, but no nystagmus occurred when the left ear was exposed to infrasound. In stabilometry tests the area of the stabilogram was increased significantly when infrasound was produced in the right ear, but it was normal when the left ear was exposed to infrasound. These findings were believed to be elicited by the transmission of pressure from the ossicles to the membranous labyrinth which was speculated to be distended by endolymphatic hydrops. Probe tympanotomy was performed, and no abnormality of the middle ear was noted, but the symptoms of Tullio's phenomenon disappeared postoperatively.

AP and SP responses were investigated by the single electrode technique.The recording sites were the round window, mid-portion of the bony wall of cochlea, the apical portion of the cochlea and bony wall of the hypotympanum.One cycle of sound stimuli at 8kHz, 4kHz, 1kHz and 0.5kHz was used and the sounds were given from 50cm lateral to the tested ear.The tone bursts with duration of 30msec were used as measurement of SP.The results obtained were as follows:The highest value of AP out-put potential was obtained by the round window recording. The highest value of AP out-put potential was obtained by the stimulation of one cycle of 4kHz and 8kHz.The positive SP as seen in the round window recording changed to a decreased positive SP or negative SP at the recording sites except the round window.The SP induced by a tone burst from the round window showed the positive SP at high frequency and the negative SP at low frequency.These results will contribute to the research on the single electrode recording of AP and SP responses in these animals.

The purpose of the present study was to determine the degree of nerve degeneration in patients with facial palsy from the number of spikes in M-wave which were induced from the facial muscle by means of a bipolar concentric needle electrode when the facial nerve was stimulated. Ten normal cases between 14 and 72 years of age and 46 cases with facial palsy between 12 and 73 years of age were examined. Histopathological findings of ten denervated nerves were studied to determine to what extent this method may reflect the state of nerve degeneration.

The cases with low tone sensorineural deafness were studied using the transtympanic-electrode technique of electrocochleography.The results obtained were as follows:1) Low tone sensorineural deafness of sudden onset without vertigo:All the cases showed high AP and -SP amplitude and satisfactory CM response. These findings resembled the electrocochleographic findings of type I of Meniere's disease suggesting of the relationship with endolymphatic hydrops. The hearing returned to normal range in a half of the cases but remained hardly changed in the other half. The difference between these two groups could not be clarified electrocochleographically.2) Familial progressive deafness showed low tone sensorineural deafness:This case showed a high threshold and a low amplitude of CM at low frequency, and showed cochlear hair cell damage at low frequency range.3) Low tone sensorineural deafness due to retrolabyrinthine lesion:This case showed a normal CM but a low AP amplitude, and lacked a rapid increase of AP amplitude with increasing click intensity in the intensity region of AP input-output functions.

Auditory nerve action potentials (AP N1) and summating potentials (SP) which were evoked by sound stimuli were investigated at the first attendance on twenty patients of sudden deafness. A recording was performed by use of the transtympanic needle electrode technique, that is, needle electrode was placed on the promontry through the tympanic membrane and average responses were recorded by a computer. Sound stimulus used was the sine wave of one cycle (duration 0.25msec).This type of stimulus was similar to the click in analysis using sound spectrogram. The patterns of the wave forms of AP and SP response obtained in these cases were divided into the following types. 1. The Dominant -SP: The -SP appears as negative deflection which develops immediately after the start of sound stimuli. The dominant SP having an amplitude almost equal to that of the AP or, having a much higher voltage than that of the normal hearing subject in the segment of High-Response Curve termed by Yoshie (1967) 2. The AP High Response: The wave forms of AP response having a higher amplitude or one almost equal to that of the normal hearing subject in the segment of High-Response Curve. 3. The Decreased AP High Response: The wave forms of AP response having a reduced AP amplitude in the High-Response Curve Segment and loss of the Low-Response Curve Segment.No increment of the N1 amplitude is encountered with increasing intensity. 4. The AP Low Response: The wave forms of AP N1 having a markedly low voltage and delayed latency (>2.5msec) at sound intensity of 90-100dB HL. 5. The +SP: The wave forms of response having a positive deflection that develops immediately after the start of sound stimulus at the intensity of 100dB HL. Neither is the response of AP obtained. 6. The AP and SP No Response: The wave forms of AP and SP responses can not be obtained even at the maximum sound intensity of 100dB HL. A total of twenty patients with sudden deafness was examined by electrocochleography. Therewas a significant difference of the wave forms recorded between the cases of complete recovery or remarkable improvement and cases of slight improvement or no change. In four of the seven cases in which complete recovery or remarkable improvement were shown the Dominant -SP was obtained and in the remaining three the AP High Response was obtained. In cases in which slight improvement or no change was shown Decreased AP High Respnse, AP Low Response, +SP and AP, SP No Response were obtained. It was concluded that the electrocochleography could be very helpful in estimating the prognosis of sudden deafness during the early stage of the onset

Cochlear microphonics (CM) and action potential (AP) were measured in animals in which labyrinths were damaged by injection of the various kinds of solution into the facial nerve through the stylomastoid foramen.The results obtained were as follows:1) After the injection of tetracycline and hydrochloride, the CM and AP waves were not recorded, even applying the maximal sound stimulus.2) After the first injection of antigen into the sensitized rabbits, CM amplitude was markedly increased at 4KHz, while increased slightly at 0.5KHz.After the repeated injections, caloric response was reduced and the CM and AP amplitude decreased or did not show response to the sound stimuli of the 20dB above VDL in both frequencies.The CM and AP amplitude, however, recovered to the same threshold as before the first injection limits 24 hours after the first procedure.Histopathological findings of the organ of Corti after the injection of tetracycline and hydrochloride revealed degeneration, but no remarkable change was seen in immunologically treated cases.It is thought that these electrophysioiogical phenomena induced by the injection of antigen into sensitized animals were resulted from the antigen-antibody reactions in the autonomic nerve and microcirculations in the cochlea.

Two hundred and eight cases of benign paroxysmal positional vertigo (BPPV) were studied.The number of patients with BPPV has increased recently, especially those over 60 years of age.Head injury, hypertension, prolong bed rest and administration of streptomycin were significant causative factors.A neurotic tendency was more evident in BPPV patients than in normal subjects, but less than in those with Meniere's disease.The change in direction of positioning nystagmus between the sitting and the hanging position, which is supposed to indicate the pathology of the side, coincided with the side of semicircular canal palsy, critical position, hearing disturbance, etc. in 57%-74%.Vertigo disappeared in 40% of the case within the first week and in 40% more within the first month, but BPPV recurred in 30%.Physical exercise was very effective in the treatment of BPPV.

Electrocochleography by the tympanic electrode technique was performed on 37 ears of positive recruitment phenomenon and 10 ears of negative recuitment, totalling 47 ears, and the following results were obtained. The positive recruitment phenomenon was understood to be observed in cases wherein the auditory nerve action potential (AP) shows a steep increment, and where the AP output potnetial at intensive sound stimulation is equal to or higher than normal level. The recruitment phenomenon was positive in cases of dominant negative summating potential (dominant — SP) even if the AP output potential was low. The negative recruitment phenomenon was observed mostly in cases wherein the AP output potential was much lower than normal level even at stimulation of intensive sound pressure, and where the —SP was lower than normal level. Even though clinical EcoG is recorded from the promontory, the —SP seems to play an important role in increasing the AP output potential, in other words, causing recruitment phenomena.

Decompression operation was performed on patients with Bell's palsy and facial nerve palsy due to temporal bone fracture or otitis media, and a study was made on the relation between the fluorescence findings of the nerve and prognosis. The fluorescence of nerve was visible in 4 cases of Bell's palsy but none of the patients was completely cured, though the degree of cure tended to be proportional to the intensity of fluorescence. On the other hand, cure was seen even in cases of facial nerve palsy due to temporal bone fracture or otitis media that showed no fluorescence or any response in the maximal stimulation test (MST). It is suggested that Bell's palsy and facial nerve palsy due to trauma or otitis media do not share the same pathophysiology.

By performing electrocochleography (AP, SP and CM) on 34 patients with sudden deafness, it was thought that the pathophysiology of this disease could be deduced. The various waveform patterns of AP and SP responses obtained in cases of sudden deafness were classified into the following types: 1) AP high response; 2) decreased AP high response; 3) AP low response; 4) dominant — SP; 5) — SP or + SP; and 6) AP, SP no response. The cases showing the type of dominant — SP and AP high response had satisfactory prognoses. In these cases the sensory epithelium and the cochlear nerve seemed to indicate a reversible condition being affected by the temporary functional block. Furthermore, it seemed to indicate that the neural regions related to the source of AP(N1) response were impaired in cases in which CM were recorded at normal response threshold in spite of the absence of AP(N1) response. In the unsatisfactory prognosis cases with decreased AP high response, AP low response and AP, SP no response in which only the extremely low or depressed CM responses could be recorded, it seemed that the sensory epithelium and the cochlear nerve were affected permanently, although the degree of impairment varied.

Electrocochleography was performed on six patients with posterior cranial Fossa tumors which consist of three cases of acoustic neurinoma of grade II-III, a case of glioblastoma multiforme originating from cerebello-superior pons, a case of astrocytoma of grade III originating from medulla oblongata-inferior pons, and a case of meningioma originating from Meckel's cavity. Recording was made with the use of the transtympanic needle technique. AP input-output functions with acoustic neurinoma were very similar to those obtained in patients with sensorineural hearing loss showing the phenomenon of recruitment. In AP responses recorded from the patients with cerebello-superior pontine tumor and Meckel's cavity tumor, a loss of the positive portion of the potentials (P1) was characteristic. This phenomenon may be due to the compression on the auditory nerve by the growing tumor. The polarity of SP in all cases showed negative deflection without abnormal increment. CM responeses recorded from the patients were the same as in a normal subject. In the cases presented, although the abnormal changes in input-output functions as well as the changes in the wave form patterns of AP responses revealed a lesion of the portions corresponding to the sensory and/or to the neural structure, the presence of a well-developed CM may be explained by the fact that the hair cells remain unaffected. Therefore, it is thought that simultaneous recording of CM and AP gives great promise as a means of differential diagnosis between neural and cochlear pathology.

The purpose of this investigation is to study the site of lesions in mumps deafness by Electrocochleography.Sixteen affected ears of fifteen patients ranging in age from four to fourty-two with the average being 15.5 were investigated. Recording was made in an electrically shielded sound proof room with the use of the transtympanic needle electrode technique. Clicks for measurement of auditory nerve action potential (AP) and short tone-bursts for cochlear microphonics (CM) were used as sound stimuli.Although the audiometric examination in all cases confirmed no response, the following three categories of cochlear pathophysiological features in mumps deafness can be classified according to CM responses.1) No AP response and the well-developed CM response: It seemed to indicate that the neural regions related to the source of AP response were impaired, but the organ of Corti was found to be functioning because the recorded CM responses were the same as in a normal hearing subject.2) Neither AP nor CM response: It seemed to indicate that both the neural and the organ of Corti were impaired severely.3) No AP response and the decreased CM responses: It seemed to indicate that the neural regions were impaired severely, but the organ of Corti were impaired only partially.

In the study on regional difference in susceptibility to damage of vestibulosemicircular canals upon causing labyrinthine lesion by four different procedures, namely, by intracranial approach, through the middle ear, through the facial nerve and by means of experimental endolymphatic hydrops, the following results were obtained. 1. The crista of posterior semicircular canal among the semicircular canals and the macula of the saccule within the vestibule were most susceptible to impairment. In other words, the most susceptible region was the so-called pars inferior. In regard to the impairment of the cupulas, the posterior semicircular canal was the most susceptible region. 2. 2. Recovery from markedly reduced caloric nystagmus within a short period so as to see provocation of caloric nystagmus may result from the reconstruction of the cupulas and the normalization of vacuole-like findings of the sensory epithelium.

Sixteen cases of Ramsay Hunt syndrome were investigated concerning the prognosis of facial nerve palsy, hearing impairment, and vestibular disorder. The satisfactory prognosis of facial nerve palsy was achieved in those cases which a good response was evoked by the maximal stimulation test as well as in cases of Bell's palsy. And also, the satisfactory prognosis of hearing impairment was achieved in those cases which showed a well-developed auditory whole nerve action potential and a well-developed cochlear microphonics the electrocochleography as well as in cases of sudden deafness. On the contrary, both facial nerve palsy and hearing impairment showed unsatisfactory prognosis in those cases which there was a low amplitude or even no response. Thus, satisfactory prognosis was achieved in those cases which showed well-developed responses induced by an intensive stimulation. This phenomenon is suggestive of the pathophysiology of reversible impairment of sensorineural elements. However, no correlation among the prognosis of facial nerve palsy, hearing impairment, or vestibular disorder was observed.

Many etiologies of sudden deafness have been reported and three of them are especially noticed, which are viral, vascular and labyrinthine window rupture. In addition, immunological factor may also be important. Three cases of sudden deafness with vertige were reported and the etiology discussed in each case. Case 1: A 37-year-old male who had been suffering from common cold for two weeks, complained of right severe hearing loss and Vertigo following sneezing. He was examined and found with high pressure of cerebrospinal fluid (270mm H2O). As there was no improvement in hearing by any treatment, probe tympanotomy was performed and fluid leak at the round window niche was observed (round window rupture). Cerebrospinal fluid was examined virologically and herpes type virus was detected. Case 2: A 71-year-old female complained vertigo and left severe hearing loss after symptoms of common cold. Examination revealed disturbance of the left inner ear function, normal pressure of cerebrospinal fluid (120mm H2O), and round window rupture. Herpes type virus was detected in her cerebrospinal fluid. There was no improvement in hearing by any treatment. Case 3: A 17-year-old high school girl suffered from the sudden onset of severe hearing loss in the right ear vertigo. No episodes like common cold or sneezing were found. Examination revealed only disturbance of the right inner ear function, and her hearing and vertigo were improved by treatment with anticoagulant (heparin). We could not detect virus in her cerebrospinal fluid.On the basis of these findings, it was suggest that Case 1 and Case 2 are of the viral etiology with round window ruptures due to increased pressure of cerebrospinal fluid or of the middle ear cavity associatdd with anatomical factor as patent cochlear aqueduct, and the prognosis of these cases may be poor. Case 3 is suggested to be of the vascular etiology because of good response to anticoagulant, but, as the symptoms of this case resemble those of Meniere's disease, immunological factor may play an important role

Pathophysiology and prognosis of hearing acuity in 16 ears of 10 cases with inner ear syphilis were studied by the transtympanic electrode technique of electrocochleography.The results were obtained as follows:The improvement of hearing acuity after steroid therapy was obtained at low frequency range on audiogram. These cases showed a well defined AP, a dominant-SP and remarkable CM response at 0.5kHz. It was speculated that there may be endolymphatic hydrops and the reversible change of hair cells at low frequency area of the cochlea.On the other hand, in the cases showing slight improvement of hearing acuity, both AP and CM responses shwed a low out-put potential which suggests a reversible change or organic damage of the hair cells or cochlear nevre.

Cerebrospinal fluid was examined in 20 patients experiencing sudden deafness. Pressure, protein, glucose and cell counts were measured, virus culture was done, and IgG, IgA, IgM in concentrated cerebrospinal fluid were measured by means of the single radial immunodiffusion method and IgE also by means of the radio-immunosorbent test. Pressures ranged from 110 mm H2O to 330 mm H2O and the mean being 178 mm H2O. Protein and glucose were almost normal, IgG and IgE were normal. In five cases, IgM were demonstrated. IgA ranged from 0.08 mg/dl to 1.7 mg/dl. In two cases, the viruses were cultured and were determined to be Herpes according to morphological features. In the group showing complete recovery and/or improvement, the initial pressure and glucose value were rather low; in the group showing no change, the value of IgA was low. In the two cases where virus was isolated, there was no alteration of pure tone audiometry nor was there any improvement of hearing acuity. The virus isolated from the two cases presented was of low virulence since the number of cells in the CSF was small and the virus grew poorly even after serial cultivation. Accordingly, virus such as these may act one of the causative agents in sudden deafness.

The purpose of this paper is to demonstrate the variation of the direction of nystagmus which is elicited from the peripheral labyrinth. The direction of nystagmus depends, among other things, on the nature of the stimulus. Depending on the degree of pathophysiological conditions in the labyrinth, atypical nystagmus which does not comply with the rule is occasionally elicited even though the same stimulus is given. Hyperfunctional stimulation to the labyrinth, such as allergy, causes nystagmus which beats to the affected side and also shows hyperactivity of the whole nerve action potential and cochlear microphonics.