Influences of the duration of stimulus sounds on stimulated oto-acoustic emission (OAE) were studied in 9 normal hearing ears. Tone bursts with two kinds of duration (3ms and 6ms) at 5 frequencies between 1.0kHz and 4.0kHz were used as the stimulus sound. It was found that the pseudothreshold, the latency and the maximum stimulus level differentiating OAE from damped oscillation of stimulus sound were all influenced by the duration of tone burst especially at higt stimulus frequencies.

抄録全体を表示

The oto-acoustic emission evoked by bone conduction stimulation (BC-OAE) was investigated in 12 normal hearing ears and was compared with that evoked by air conduction stimulation (AC-OAE). The stimulus sounds were tone bursts at five frequencies between 1.0 kHz and 4.0 kHz. The BC-OAE was obtained at all five frequencies in all 12 ears. The pseudothreshold of BC-OAE was lower than that of AC-OAE at all five frequencies. The intersubject variance of pseudothreshold of BC-OAE was smaller than that of AC-OAE. The interaural difference of pseudothreshold of BC-OAE was within 5 dB in 80% of the recordings.

抄録全体を表示

Multiple echoes in stimulated oto-acoustic emissions were investigated in 11 normal hearing ears. The stimulus sounds were tone bursts at five frequencies between 1.0kHz and 4.0kHz. Acoustic responses were averaged 500 times with the analysis time of 30ms. The incidence of multiple echoes was highest at 1.5kHz. The number of echoes was also largest at 1.5kHz. The mean pseudothreshold of the first echo was lowest at 2.0kHz and was highest at 4.0kHz. The mean latency of the first echo at the pseudothreshold level was almost the same at five stimulus frequencies, but that of the second echo shortened as the stimulus frequency increased.

抄録全体を表示

The FFT analysis of stimulus sounds and evoked otoacoustic emissions (eOAEs) were studied in 239 recordings. When the stimulus frequency differed from the best recording frequency (BRF), the power spectrum of the responses showed the peaks not only in the stimulus frequency but also in the BRF. This result suggested that the eOAE was not only the frequency following response, but also appeared in the BRF.

抄録全体を表示

Spontaneous and evoked oto-acoustic emissions (SOAE and EOAE) in 4 cases with SOAE were measured before and after administration of Venopirin. Venopirin (475mg of aspirin) was injected intravenously in a few minutes. Sound pressure level of SOAE decresed just after injection and then recovered gradually to the original level in one hour. Frequency of SOAE shifted less than 8-10Hz from the original frequency and recovered, while the pattern of shift and recovery were various. Amplitude of EOAE diminished similarly to the change of SOAE and recovered in two hours. This change of EOAE was observed especially when short tone burst wist 1.0KHz was used as stimulating tone. Usually this dose of aspirin does not effect on cochlear function clinically, but obvious effect on OAEs was observed. We concluded OAEs were very sensitive examination to investigate cochlear mechanism.

抄録全体を表示

Click-evoked otoacoustic emissions (EOE) were recorded in 24 normals and 2 patients with sensorineural hearing loss. Frequency analysis of EOE was performed at every 100Hz bandwidth between 1 and 2KHz with the use of a dual channel variable filter. In normal subjects, low frequencies tended to have longer group latencies than high frequencies. In a case of sudden deafness, EOE became clearly detectable from lower frequencies with hearing improvement. In a case of Meniere's disease with low tone loss, EOE were detectable only at higher frequencies than 1.5KHz.

抄録全体を表示

Slow components of stimulated oto-acoustic emissions were examined. Mean latency of fast component and slow component was 9.4ms and 13.6ms, respectively. OAE of ears with slow component was low in threshold. The threshold of slow component was lower than that of fast component in the same ear. The incidence of slow component decreased according to grade of hearing loss in sudden deafness. It was discussed that the slow component rather than the fast component may be produced by the active tuning mechanism in the cochlea.

抄録全体を表示

In measuring stimulated otoacoustic emissions, other stimulus-dependent acoustic phenomena can be recorded between the stimulus tone and the emissions. The stimulus-dependent phenomena which responded to stimulus tone with 3 ms duration existed at 6 ms or thereabout after onset of stimulus. This stimulus-dependent responses revealed a linear input-output relationship. Similar stimulus-dependent responses were observed in guinea pigs. Anoxia induced a decrease of the response but applications of muscle relaxant did not. The stimulus-dependent response may be not related as the intracochlear micromechanics linked with active mechanical process.

抄録全体を表示

The morphology of horizontal eye movement-related brainstem neurons (Second-order Type I neuron, Abducens motoneuron, Abducens internuclear neuron, Reticular burst neuron, Omnipause neuron) was investigated by intracellular staining with horseradish peroxidase (HRP). Axons and cell bodies of these neurons penetrated in and around the abducens nucleus were identified by their characteristic firing patterns. After injection of HRP each neuron was reconstructed in three dimension using a microscope equipped with a camera lucida drawing attachment. The morphological findings of this study almost correspond with previous electrophysiological studies.

抄録全体を表示

When paralytic nystagmus was experimentally induced, the difference of excitibility between the bilateral vestivular nuclei was investigated by the autoradiographic study using [¹⁴C] 2-deoxy-D-glucose. By introducing potassium ion into the right labyrinth of 3 normal guinea pigs, paralytic nystagmus appeared after disapperance of irritative nystagmus. In this stage, the dosis of glucose uptake in the contralateral vestibular nucleus increased singnificantly as compared with that of the ipsilateral vestibular nucleus.

抄録全体を表示

Blood vessel distribution of the brain stem in guinea pig were observed using microfil rubber. In the brain stem, most of small arteries were terminal arteries. There were poorer blood vascular system in the middle brain stem than that other portion. Mainly basilar artery and it's branches which were anterior side of the brain stem, supplied for the brain stem. The conclusion was that vestibular system dysfunction of probably vascular origin is expected to be influenced on by speciality of brain stem vascularity.

抄録全体を表示

Three cases whose ABRs were abnormal were studied auditory pathology in brain. Case 1 who showed wave I, II in the right and wave I-III in the left was demonstrated to have glioma in the right pons. Case 2 who showed wave I-III in the right and I, II in the left was demonstrated to have hemorrhagic infarction in the left pons and midbrain. Case 3 who showed wave I-IV in the right and wave I, II in the left was demonstrated to have glioma mainly in the left pons. These findings suggest that wave I, II can be elicited if unilateral cochlear nucleus is preserved for the stimulus side and wave I, II, III can be elicited if unilateral cochlear nucleus and superior olivary complex are preserved for the stimulus side.

抄録全体を表示

The present study was designed to examine the effect of intense sound exposure and the ototoxic effect of KM and CDDP, using normal golden hamsters and ones with an inner ear anomaly. When exposed to intense sound (4kHz pure tone at 120dBSPL for 3 hours), all the outer hair cells (OHC) of the normal hamsters and most of those of the hamsters with an inner ear anomaly were destroyed at each response area, but abnormal first row outer hair cells (OHC1), of the hamsters with the anomaly remained intact. When exposed to CDDP (i. p. 10mg/kg) and KM (intratympanic 20mg), the sensory hairs of both hamsters were damaged in the same way. This study showed that the abnormal OHC1 of this inner ear anomaly have some as yet unclear function, but have no receptors for sound.

抄録全体を表示

The investigation was performed on the strain of the mutant C3H/He mice. The animals were used at ages of 10 days-18 months. At 10 days after birth, the organ of Corti is fully developed and both inner and outer hair cells have a normal appearance. At 21 days of age, outer hair cells show signs of degeneration, such as the formation of the lipofuscin granules below the cuticular plate and the shrunken cytoplasm. At the age of 90 days, almost all outer hair cells are not recognizable except for few degenerated cells in the apical turn. No abnormalities have been detectd in the stria vascularis until the age of one year.

抄録全体を表示

Malformations of the external auditory meatus and auricle of mouse fetuses caused by maternal hypervitaminosis A were examined histologically, The fetuses were taken from the mothers on day 12, 13, 14 or 18 of pregnancy, following injections of vitamin A on day 8, 10 or 14 of pregnancy. We observed abnormal separation or enlargement of the primitive external auditory meatus due to disturbance of its extension along the tubotympanic recess. The mice injected on day 8 of pregnancy showed marked or moderate malformations; mice injected with vitamin A on day 14 of pregnancy generally showed a lower grade abnormality. The incidence of malformations was greater in mice injected on on day 8.

抄録全体を表示

We determined the amounts of prostaglandin (PG) D₂, PGE₂, PGF₂α, 6ketoPGF₁α and thromboxane (TX) B₂ formed from endogenous arachidonic acid (AA) or exogenous PGH₂ in the cochlear homogenates of 1-, 2-, 3-, 4- and 8-week-old Mongolian gerbil. After incubation at 37°C for 5 min, in 1-week-old animals 6ketoPGF₁α was determined by radioimmunoasssy to be the major PG formed from endogenous AA followed by PGE₂, PGF₂α and PGD₂. However, the formation of PGE₂ increased 4-fold in the course of maturation of animals to 8 weeks after birth. When we determined the amounts of PGs produced in the cochlear homogenate in the presence of AA exogenously added, there was no acceleration of each PG formation, while the activities of PGE₂-, PGF₂α- and PGD₂-synthetases increased about 7-fold from 1 to 8 weeks after birth.

抄録全体を表示

Organ of Corti and vestibular ampulla were embedded in Lowicryl K4M. Wheat-germ agglutinin (WGA) or Ricinus communis agglutinin (RCA) -gold was applied to thin sections for the localization of N-acetylglucosamine and galactose, respectively. Limax flavus agglutinin (LFA) and feutin-gold were applied for the localization of sialic acid. In the organ of Corti, WGA-gold was localized mainly on the tectorial and basilar membranes. In addition, LFA-gold was localized on reticular membrane. In the ampulla WGA-and RCA-gold were localized mainly on the cupula and the secretory granules in the supporting cells. Functional significance of these findings was briefly discussed.

抄録全体を表示

The postnatal development of substance P immunoreactivity in the acoustic nerve nucleus (ANN) of ddY mice were investigated. Up to day 13 after birth, no substance P immunoreactivity could be observed, but it appeared on day 16 in the cell bodies of the ANN of all specimens examined up to day 50. The significance of this finding was discussed.

抄録全体を表示

The immunocytochemical distribution of substance P in the guinea pig veatibular endorgans and the vestibular ganglion was investigated. Substance P like immunoreactivity was found in both ctistae of the semicircular canal and maculae in all specimen studied. By using electron microscopy, we confirm substance P like immunoreactivity is restricted within the primary afferent neuron. However, the immunoreactivity was not uniformly distributed throughout vestibular endorgans. More numerous reactive fibers were found in the slope of the cristae and in the peripheral region of the maculae.

抄録全体を表示

The study of cell kinetics of the component cells in stria vascularis was preformed by ³H-thymidine autoradiography³H-thymidine was injected in adult mice at intrevals of 2 hours for 10 hours after injection of ethacrinic acid which damage the stria vascularis and microautoradiography was carried out after embedding the cochlea in glycol methacrilate in this study, the labelling rate of the intermediate cells was decreased but a few grain-accumulated cells were observed in the marginae cells and basal cells The marginal and basal cells damaged by ethacrinic acid seemed to be replaced with these labelled cells which were probably generated in the intermediate cells.

抄録全体を表示

Distribution of (Na⁺, K⁺) ATPase, α-subunit in the rat stria vascularis was studied using immunoelectron microscopy. Many enzymes localize on the basolateral membrane of the marginal cell and of the cell membrane of the intermediate cell facing to the marginal cell. The density of (Na⁺, K⁺) ATPase on the both cells is almost equal to that on that on the basolateral membrane of the renal tubule cell. This finding suggests that marginal cell plays an important role to produce the endocochlrar potential and to maintein the endocochlear ionic composition. Intermediate cell also may participate in the ion transport of the stria vascularis.

抄録全体を表示

The effects of fypoxia on the sensory cells of the cochlea were investigated in the chinchilla and guinea pig. Systemic hypoxia was employed by increasing the dead space of the respiratory tidal volum. The main findings observed in the cochlea from hypoxic animal are the disarrangement of sensory hairs and the cytoplasmic protrusions at the level of inner hair cells. These degenerative changes extended toward the outer hair cells in line with the increase in the degree of cochlear hypoxia. From these results, it will be hypothesized that the inner hair cells rather than the outer hair cells are more vulnerable to hypoxia.

抄録全体を表示

The cochlear effects of sudden atomospheric pressure changes on guinea pigs placed in a chamber were studied after varying post loading intervals. Morphological changes in the inner ear with emphasis on the organ of Corti were observed under TEM. The immediate features noted were fracture of stereocilia with minimal intracellular changes and reversible dendritic swelling of the inner hair cells; 24 hours later, there was degeneration of outer hair cells and their replacement by supporting cells one week after. Inner hair cells showed slight degeneration without any further change over passage of time.

抄録全体を表示

The normal ultrastructure and the phagocytotic activity of the endolymphatic sac in guinea pigs were studied. The epithelial cells of the endolymphatic sac were classified into two types, (1) One is characterized by numerous mitochondria, many small vesicles and well-developed microvilli at the apical surface. (2) The other is characteristic for poorly developed cytoorganelles and a few microvilli and numerous intracellular filaments. In addition the intermediate type between the two were also seen. India ink particles injected into the endolymphatic space, were taken up not only by the free floating cells but also by the epithelial cells.

抄録全体を表示

There are many hypotheses regarding macrophage functions. The purpose of this study was to elucidate macrophage functions in the endolymphatic sac with endolymphatic hydrops. Thirty-one Hartley guinea pigs were immunized with rabbit stria vascularis in Freund's complete adjuvant, and 13 guinea pigs were inoculated with anaphylatoxin via the carotid artery. We observed and counted macrophages in the whole endolymphatic sac. Some of the immunized animals showed endolymphatic hydrops, and these endolymphatic sac did not contain more macrophages than in the control animals. The immune functions of macrophages in the endolymphatic sac may play an important role but we surmised these macrophages were directly unrelated to the endolymphatic hydrops.

抄録全体を表示

We made experimental hydrops in guinea pigs after cauterizing the sac with silver nitrate and observed inner ear vessels by scanning electron microscope using the casting method. Results indicated abnormal morphological changes in microvascular system of the cochlear lateral wall and the saccular macula on hydrops side. The existence of circular disturbance in the inner ear was suggested.

抄録全体を表示

We tried to make active endolymphatic hydrops in guinea pigs by four kinds of stress-stimulations. And with intravenous injection of the enzyme, horseradish peroxidase (HRP), it was revealed that the stria vascularis vessels in experimental guinea pigs were more permeable than those in sham operative ones. On the increased permeability of HRP in stria vascularis vessels in our experiment, the mechanisms were proved to be due to both its leakage through loosed tight junctions and an increased amount of its transportation by pinocytotic vesicles.

抄録全体を表示

Isosorbide was administered to guinea pigs with experimentally induced endolymphatic hydrops. Following this, the area of endolymphatic space cross sections and the length of Reissner's membrane were measured using a microscope, video camera, and computer arrangement. The results were then compared with those for guinea pigs which had not received isosorbide. Decrease in endolymphatic hydrops were most pronounced in the saccule and the basal turn of the cochlea, where reduction rates of 25-30% occurred. Decrease became progressively smaller in the cochlea as it progressed toward the apex. The utricular space was virtually unaffected. Reissner's membrane, elongated by expansion of the endolymphatic space, showed no contraction following isosorbide administration, though significant folding was observed.

抄録全体を表示

The fine structure of the crista ampullaris was observed by transmission electron microscopy two or three months after obliteration of the endolymphatic sac and duct in ten pigmented rabbits. Vacuolization, swelling of mitochondria with loss of cristae, and leakage of organelles into the endolymphatic space were observed in the hair cells. There was no difference in the degeneration pattern between the two groups. Caloric test revealed hypoactive responses in the oprated ear.

抄録全体を表示

Semicircular canal ampulla of the guinea pig was immunohistologically studied on the distribution of immunoglobulins, IgG, IgM and IgA. Only the positive reaction of IgG was recognized under the basement membrane of the cells and the cell itself consisting in the semilunar plane. As the reason of these positive reactions, the characteristic electromicroscopic findings, such as the existence of plenty of finger-like projections in the cytoplasmic space of the cells and the thick fibrous connective tissue locating just beneath the basement membrane of the cells, were suspected.

抄録全体を表示

Human vestibular melanocytes had round or spindle-shaped cell bodies with several processes. They were located below the basement membrane but the melanocyte processes were found in the dark cell epithelial layer closely adjacent to the dark cells without any separation by the basement membrane. Submicroscopic observations revealed melanin pigment in various stages of accumulation on the tyrosinase filaments in melanosomes. In view of the close spacial arrangement and contact of the melanocytes with the dark cells, it seems plausible that the melanocytes play some role in vestibular metabolism via the dark cells.

抄録全体を表示

The ultrastructure of glycocalyx and ciliary interconnections of the guinea pig vestibular sensory cells were investigated by the use of tannic acid and ruthenium red staining technique. Glycocalyx was found over the entire length of the cilia, in the form of a fuzzy filamentous layer emerged from the outer layer. Ciliary interconnections emerged from the plasma membrane and tightly connected neighbouring cilia. The tip links stretched from the tips of the sterecilia to their taller neighbours, which arranged in a same direction towards the kinocilium. These findings indicate that the ciliary interconnections may keep the cilia arranged in a bundle and the tip links may be involved in sensory cell mechanical transduction system.

抄録全体を表示

Fine structure of the guinea pig utricular kinocilium was examined with transmission electron microscopy in the use of tannic acid staining. Inner dynein arms and central pair of microtubules were selectively lacking, meanwhile outer dynein arms were typically observed. These findings seem to support the concept that the vestibular kinocilium is nonmotile or weakly motile.

抄録全体を表示

The Computer-aided three dimentional reconstruction (CTDR) of cochlea was named by Prof. I. Sando in 1987. CTDR has been used for the structural observation of the detailed relationship between the target cells of cochlea and adjacent cells, using histological specimens of temporal bone and specimens of TEM.
In this study, the authors have attempted to show the cochlear picture of CTDR on the normal guinea pig, by the method which has been described in other previous papers, using our histological specimens. However, the magnification of specimens were very low, as only ×4 of both cochleae and ×10 of left cochlea. As a result, the authors only could obtain the bird views of both cochleae, the running figures of basal turn of the cochlea, and the reletionship between ear drums and chochlea.

抄録全体を表示

We have continued to undertake computer-aided three-dimensional reconstructions of a temporal bone from routinely processed histologic sections. This time, using the upgraded computer system, reconstruction of the membranous labyrinth and the inner ear sensory organs was performed. Owing to the system's “semitransparent display” function, the reconstructed sensory organs could be observed through the simultaneously reconstructed membranous labyrinth. The results were satisfactory for understanding the spatial relationships of these structures. Computer-aided measurements were also attempted, and the length of the organ of Corti and the angle between the saccular and utricular maculae were calculated.

抄録全体を表示

A new technique was developed to process macrosections of the celloidin embedded inner ear specimens for SEM study. After removing celloidin in ether-alcohol, the sections were transferred into ethanol and then t-butyl alcohol. The sections in the alcohol were then frozen in the freezer at 25.5°C or lower. The frozen sections were dried in a vacuum evaporator. The dried sections were adhered on an electroconductive tape and put on a metal stage for SEM observation.
Overall structure of the cochlea and vestibule was fairly well preserved (Fig). This freeze-drying technique to process the conventional celloidin embedded specimens would provide a powerful tool to study three-dimensionally by SEM the inner structure of the organ of Corti.

抄録全体を表示

The measurement of variation of the course of the internal carotid artery was taken and dehiscence of the carotid canal was observed. One hundred and seventy five human temporal bones (110 individuals) sectioned horizontally were used for this study. The results: aberrant course of carotid artery was not observed; dehiscence of carotid canal was found in 56 out of 175 ears (32%) ; dehiscence of more than 0.4mm in diameter was found in 24 ears (13.7%) ; frequency of dehiscence increased with aging; in cases having dehiscence of more than 0.3mm in diameter, many (66%) had a history of hypertension. The relationship between dehiscence and pulsating pressure to bone is discussed.

抄録全体を表示

The morphological changes of the fissula ante fenestram and anterior portion of vestibular fenestra in 359 temporal bones of 181 individuals were studied. Fissula was observed in 280 bones (78.0%) and opened not only at the site of the vestibular perilymphatic cistern, but also at the site of tympanic cavity. 215 of 280 bones opened only at the site of the former, and 63 bones opened at both sides. According to our observation of anterior portion of the vestibular fenestra, bone tissue is found frequently in aging people. Otosclerotic change was observed in 3 bones (0.8%). This confirms the fact that otosclerotic change occurs less frequently in Japanese than in European.

抄録全体を表示

A few pathoses of the otolithic membrane have so far been morphologically con-firmed. We recognized a supposed abnormal otoconial membranous structure in a specimen of the right temporal bone of a 77-year-old woman who died of mucoepidermoid carcinoma of the parotid gland. A report is made here of this case. The abnormal membranous structure was observed in the sacculus, a partial wall of which has formed a membrane in such a manner as makes up a fold from rear to front. The structure is 25 μm thick and a quasi-transparent layer is covered on its both sides with a flat layer of cells. A particle of about 10 μm in long diameter was seen in the quasi-transparent layer. We presumed the particle to be otoconia. Its functional rela-tionship is not obvious in the absence of the patient's complaint of disequilibrum. Neither period nor mechanism of its pathogenesis is known.

抄録全体を表示

The histopathological changes in the temporal bones from a 12-day-old girl with E trisomy are reported. A review of the literature revealed thirteen previous histopathological reports on the temporal bones in E trisomy. Findings varied widely from normal cases to those with severe malformations of the auditory structures. In the present case, a great difference was observed between the right and left ears. The right ear showed only minor anomalies, such as a wide angle of first genu of the facial nerve, wide dehiscence of the Fallopian canal, large marrow cavities of the incus and malleus, and residual mesenchyme in the round window niche. However, the left ear showed additional severe anomalies, such as a bulky and deformed stapes, a small oval window, flattened crista of the superior semicircular canal, and absence of the bony portion of the posterior semicircular canal which was involved by outpouching of the large vestibule among other anomalies.

抄録全体を表示

The findings in the temporal bones of two fatus with arthroglyposis congenita were reported. Case 1 had a doll-like face, low-set and malformed ears. There were no inner ear anomalies other than lymphatic hydrops limited to the both apical turns. (Fig. 1) In case 2, both of the cochlears were flattened and the modioluses were not well developed. (Fig. 2) On the left, the lateral canal was broad and short, and the facial nerve was underdeveloped. The left cochlear measured 25.4mm in length and had 21/2 turns.

抄録全体を表示

In 1987, we have reported the temporal bone histopathology from a patient with CHARGE association (a 5-month-old girl) showing unusual but characteristic inner ear anomalies as in the other two reported cases. Aplasia of the pars superior (absence of the entire semicircular canals and utricle) and hypoplasia of the pars inferior was observed in both temporal bones. In addition to the two cases of CHARGE association, a review of the ilterature revealed six previous reports of the unusual form of aplasia of the pars superior. Two of the 6 cases were observed to have similar clinical features to the CHARGE association. According to Schuknecht's classification (1967), this anomaly should be classified with Mondini dysplasia, although it is close to the Michel from of aplasia. As proposed by Guyot et al (1987), this specific form of anomaly (aplasia of the pars superior) may become new category in the classification of inner ear anomalies.

抄録全体を表示

Histopathologic findings in the temporal bones of a 71-year-old male with bilateral deafness and facial paralysis due to DMLC originated from transitional cell carcinoma of the renal pelvis are presented. The patient first noticed progressive bilateral hearing loss on July 17, 1986 and became totally deaf bilaterally 4 weeks later. Then, he experienced facial weakness on the left side, which progressed to complete paralysis bilaterally. These symptoms were followed by other cranial nerve paralyses and various meningeal symptoms. He died on Octorber 8, 1986 about 2 months after the onset of otologic symptoms. The temporal bones were removed 3 hours postmortem for study. There are almost identical histopathologic findings in the both temporal bones. The internal auditory meatus is filled with the neoplastic tissue, by which the vestibulocochlear nerve bundles are completely replaced. The neoplastic cells diffusely infiltrate the modioli and the Rosenthal canals of the cochlea through the cribrose areas and reach the scala tympani of the basal turns bilaterally. The facial nerve is completely destroyed from the internal auditory meatus to the geniculate portion bilaterally by neoplastic cell invasion. External and middle ears are free of tumor.

抄録全体を表示

The histopathological findings in the temporal bone of a 75-year-old woman, who was diagnosed with carcinomatous meningitis of an unknown origin, were reported. The histopathological diagnosis of her tumor was papillary adenocarcinoma. She complained of hearing loss in the left ear, but there was no history of tinnitus or dizziness in her medical records. Regrettably, audiometric and vestibular function tests were not carried out. There was infiltration of tumor cells in the surrounding area of the cochlear, vestibular and facial nerves. However, there were only a few tumor cells infilirated into the cochlea and vestibule. It was thought that the tractus spiralis foraminosus and macula cribrosa functioned as a barrier by preventing tumor cells in the cerebrospinal fluid from penetrating into the cochlea and vestibule.

抄録全体を表示

Histopathological findings of the temporal bone in a case of pontine astrocytoma with facial nerve palsy are reported, and the relation to clinical symptoms is discussed. The patient, a 79-year-old female, complained of right facial palsy and right abducens nerve palsy. Audiometric tests showed almost normal hearing. At autopsy, tumor mass was found in the pons, midbrain, cerebllar peduncle and medulla oblongata, and V, VI, VII, IX, XII cranial nerves were enbedded in the tumor mass. Histopathological diagnosis was astrocytoma grade II. The right temporal bone showed complete degeneration of the motor fibers of the facial nerve through out its course. The cochlear and vestibular nerves appeared normal. We believe that there are a few cases in which CP angle tumor does not cause hearing loss until tumor mass is very large.

抄録全体を表示

Only 16 cases of temporal bones with malignant lymphoma have been reported previously. We have added four cases, and studied these 20 cases histopathologically about the relation between the type of malignant lymphoma and temporal bone findings. Lymphosarcoma and small cell type non-Hodgkin's lymphoma had a tendency to infiltrate the temporal bone more than Hodgkin's disease and large cell type non-Hodgkin's lymphoma.

抄録全体を表示

Temporal bone was examined in 44-year-old woman with intracranial infiltration of squamous cell carcinoma of the right maxillary sinus. She experienced a left hypoglossal paralysis about 19 months after the partial maxillectomy. She then complained of dizziness and left tinnitus. The pure tone audiometry showed moderate combined deafness on the left ear. The caloric test was severe canal paresis in the left ear. Left temporal bone findings: There was tumor invasion in the pyramid. The bony labyrinthine capsule and VIIIth nerve were not infiltrated with tumor cells. Blood was seen both in the endolymphatic and perilymphatic spaces of the cochlea, vestibule and semicircular canals. Tissue bleeding was observed in spiral ligament and modiolus. Reissner's membrane was distended.

抄録全体を表示

Inner ear pathology in three cases of cochlear nerve degeneration is reported. Case 1 was a 70-year-old female who died of metastatic tumor of the temporal bone. Case 2 was a 37-year-old male who died of fourth ventricle ependymoma. Case 3 was a 37-year-old male who died of glioblastoma. Inner ear pathology was as follows: there was severe degeneration of spiral ganglion cells in case 1 and case 3, but in case 2 spiral ganglion cells were well preserved; hair cells of the organ of Corti were well preserved in cases 1 and 2, but in case 3 there was severe postmortem change.

抄録全体を表示

Twenty-three temporal bones from 14 patients who had undergone stapedectomy more than 15 years preceding death were studied mictoscopically. A foreign body reaction, which was found in the ears with a PE prosthesis, was hardly seen in the ears with other prostheses. The resorption of the incus was not severe and graft membranes were adequate barrier between the middle ear and the inner ear. Therefore, it was suggested that prostheses and graft membranes were stable for long term after stapedectomy.

抄録全体を表示

We studied temporal bone histopathology in cases diagnosed as subarchnoidhemorrhage clinically or histopathologically. And we examined the quantity of blood in the internal auditory canal, the route of blood into cochlea, the width of cochlea aquaduct and the condition of inner ear. The cases in which blood entered from cochlea aquaduct to scala tympani were more than all the cases in which blood entered from internal auditory canal to modiolus. Therefore, it seemed that the blood in subarchnoid space tended to enter from cochlea aquaduct rather than internal auditory canal whenever blood in the internal auditory canal is a lot or not.

抄録全体を表示