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Biomedical subjects

I Honjo

Publications and source records attributed to I Honjo.

At least 253 records · Page 14Linked to original sources
PubMedDate not supplied

Effect of adenoidectomy on otitis media with effusion, tubal function, and sinusitis.

Three clinical studies were performed to investigate the effects of adenoidectomy on otitis media with effusion (OME), especially with regard to eustachian tube (ET) disfunction and sinusitis, which often accompanies OME. In the first study, the audiograms, tympanograms, and ET ventilatory functions of 78 adenoidectomized patients (121 ears) and 54 non-adenoidectomized patients (63 ears) were compared over 6 months. The audiograms and tympanograms of the adenoidectomized group showed significant improvement; however, no difference in passive tubal opening pressure was noted despite an improvement in positive pressure equalizing function observed in the adenoidectomized group at 6 months after the operation. In the second study, tubal passive resistance (PR) and the ratio of passive resistance to active resistance (PR/AR) were compared before and 1 month after adenoidectomy using the forced response test (12 subjects, 12 ears). Neither PR nor PR/AR had significantly improved after the operation. In the third study, sinusitis improvement in 45 adenoidectomized patients 6 months after the operation was evaluated in comparison with 33 non-adenoidectomized patients. This condition was found to have improved significantly in the adenoidectomized group. Overall, adenoidectomy appeared effective in reducing the incidence of OME and sinusitis, and in improving the active ventilatory function of the ET without causing changes in the tubal passage. It is conceivable that tubal active ventilatory function was improved due to a reduction of inflammation and pollution around the nasopharynx by adenoidectomy, and that the effect of adenoid mass on the ET is minimal.

Adenoidectomy↗
PubMedDate not supplied

Refractory otitis media with effusion from viewpoints of eustachian tube dysfunction and nasal sinusitis.

INTRODUCTION: Most children with otitis media with effusion (OME) recover spontaneously before adolescence. However, some children have refractory OME. This study was undertaken to evaluate eustachian tube function and concurrent upper respiratory tract inflammatory conditions in adolescents with refractory OME. METHODS: A group of 83 adolescent patients with refractory OME was identified. Ages range from 10 to 20 years. A control group of 108 children with OME (ages 4 to 9) serve as the basis for comparison. All underwent both passive and active eustachian tube function testing, dye clearance studies, and a sniffing test. Upper respiratory tract inflammation was assessed by roentgenograms of the paranasal sinuses and mucosalivary function. RESULTS: High-pressure tubal opening was demonstrated in 31% of patients with refractory OME. In contrast, 84% of children with routine OME had normal opening. A marked disturbance of dye clearance was noted in refractory OME cases. Active tubal function during swallowing was disturbed in both adolescent and children's OME groups without any significant difference between them. Paranasal sinusitis was identified in 49% of adolescents with refractory OME. In contrast, 78% of children with OME had abnormality of the sinuses. CONCLUSION: Approximately one half of adolescents with refractory OME have demonstrable organic abnormality of the eustachian tube. These data suggest tubal dysfunction may be more important in refractory OME than upper respiratory tract inflammation.

Adolescent↗
PubMedDate not supplied

Pumping and clearance function of the eustachian tube.

The purpose of this study was to clarify the relationship between mucociliary and muscular clearance in the eustachian tube. Displacement of various viscosities and volumes of a colored fluid through the tube was observed endoscopically in cats. To test ciliary clearance, the fluid was placed in either the tympanum or the mastoid bulla. The interval between the instillation and beginning of discharge of the fluid from the pharyngeal orifice of tube was measured. Clearance time was prolonged with fluids having high viscosities, and the clearance time from the tympanum was shorter than that from the mastoid bulla. To test muscular clearance, the tensor veli palatini muscle was stimulated electrically to simulate swallowing, and the number of contractions necessary for massive discharge of the fluid was counted. Massive discharge occurred only with low viscosity fluid placed in the tympanum, whereas small amounts of highly viscous fluid were cleared by linear discharge. The authors concluded that when the volume of middle ear effusion was small, the fluid was cleared by mucociliary clearance. When the volume of fluid was large, the low viscosity fluid was cleared by muscular clearance only, while highly viscous fluid was cleared both by ciliary and muscular clearance.

Animals↗
PubMedDate not supplied

Clearance of the eustachian tube under negative middle ear pressure.

The influence of negative middle ear pressure on clearance function of the eustachian tube was examined in cats. In experiment 1, mucociliary clearance of a colored fluid through the eustachian tube was examined under negative middle ear pressure. The results showed that negative pressure affects mucociliary clearance only at quite high levels. In experiment 2, muscular clearance of fluid under negative middle ear pressure was investigated during electrical stimulation of the tensor veli palatini muscle. It was found that massive discharge of fluid by the muscle activity occurs only when the negative middle ear pressure was low. For massive discharge of effusion, muscular clearance is more effective than ciliary clearance. The findings suggest that it is clinically important to maintain middle ear ventilation.

Animals↗
PubMedDate not supplied

Magnetic resonance imaging around the eustachian tube.

Magnetic resonance imaging (MRI) of the eustachian tube, the nasopharynx, and the middle ear was performed in normal subjects and patients with ear diseases. In normal subjects, the high soft tissue contrast resolution of MRI gave a clearer view of nasopharyngeal structures compared to roentgenologic examinations including computed tomography (CT). Several cases of nasopharyngeal pathology are also presented. Nasopharyngeal carcinoma was excellently depicted, and its margin was clearly visualized. Tumor involvement of the eustachian tube and accompanying otitis media with effusion were clearly visualized. In a patient with submucous cleft palate, abnormal arrangement of levator veli palatini muscles and possible deformity of the eustachian tube cartilage were found. Magnetic resonance imaging is expected to become a valuable tool for the diagnosis of nasopharyngeal and middle ear diseases.

Adolescent↗
PubMedDate not supplied

A new microviscometer for determining the viscosity of middle ear effusion.

A new microviscometer has been developed based on the capillary viscometer method. The device uses a glass sensor tube for aspirating 15-microliter samples. The relative viscosity of the samples was estimated from the negative pressure required for aspiration of the fluid. These pressures ranged widely from 1 centipoise (cp) to 10,000 cp. Measurement of the viscosity of middle ear effusions in 119 samples from 110 otitis media with effusion patients using this device revealed a close relation between their values and their gross appearance (serous less than seromucoid less than mucoid). The microviscometer is useful to determine the relative viscosity of a very small amount of fluid such as middle ear effusion.

Exudates and Transudates↗
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Three-dimensional computer graphics of the eustachian tube.

Images of the eustachian tube from various directions were obtained using computer graphics. Serial cross sections of a human temporal bone specimen including the eustachian tube were digitized for reconstruction. Wire-frame models of the structures such as the eustachian tube lumen, the tubal cartilage, the tensor veli palatini muscle, and the levator veli palatini muscle were drawn. Through observation of the eustachian tube from various directions with the tubal muscles attached or detached, the physiology of the eustachian tube system could be understood more clearly.

Cartilage↗
PubMedDate not supplied

Site of eustachian tube dysfunction in patients with otitis media with effusion.

This study was conducted to identify an exact site of ventilatory dysfunction within the eustachian tube among patients with otitis media with effusion (OME). Using 10 adults with OME, a fine polyethylene tube with a small pore at its tip was inserted into the eustachian tube via its pharyngeal orifice. Negative middle ear pressure was applied through a ventilation tube in the eardrum, and the patients were asked to swallow repeatedly at every 5-mm depth of insertion of the polyethylene tube toward the middle ear. Negative middle ear pressure could be equilibrated by swallowing within 10 mm of tube advancement from the pharyngeal orifice of the eustachian tube in seven of ten patients. It was concluded that the site of tubal ventilatory dysfunction is in the distal part of the cartilaginous portion of the eustachian tube in most adult patients with OME.

Adult↗
PubMedDate not supplied

Compliance of the eustachian tube in patients with otitis media with effusion.

To analyze the compliance of the eustachian tube, we measured the decrease in tubal resistance (pressure/air flow) with increasing air flow rate through the eustachian tubal lumen. When the eustachian tube is compliant, the tubal resistance decreases greatly because of the high distensibility of the tube. The tubal compliance index (TCI), which is the ratio of the tubal resistance between two different air flow rates, was compared among three groups: 36 ears of children with otitis media with effusion (OME), 26 ears of adult OME patients, and 10 otherwise normal ears with traumatic perforations of the eardrum. Compared with normal subjects, OME children had a significantly higher TCI (P less than .005), whereas OME adults had a significantly lower TCI (P less than .05). From these results, we concluded that eustachian tubes are compliant in children with OME but rigid in adults with OME.

Adult↗
PubMedDate not supplied

Mastoid condition and clinical course of cholesteatoma.

This study was carried out to establish which type of cholesteatoma is controllable by conservative treatment from the viewpoint of mastoid ventilation. We examined the area of the air cell system and airspace (aeration) in the mastoid cavity by computed tomography and eustachian tube (ET) function by inflation-deflation test in 20 ears (20 patients) with severe attic retraction for over 12 months (retraction pocket group), 16 ears (16 patients) with cholesteatoma which could be controlled only by conservative treatment for over 12 months (nonsurgical group) and 43 ears (43 patients) which required surgery within a year in spite of similar conservative treatment (surgical group). The size of the mastoid air cell system in the retraction pocket group, nonsurgical group and surgical group was 2.9 +/- 1.3, 1.9 +/- 0.7 and 1.5 +/- 0.9 cm(2) on average, respectively, with no significant difference between both cholesteatoma groups (nonsurgical and surgical group). While aeration was observed in the mastoid in 17 of 20 ears (85.%) in the retraction pocket group and in 12 of 16 ears (75.0%) in the nonsurgical group, aeration was present only in 9 of 43 ears (26.5%) in the surgical group, being significantly less in the surgical group than in the nonsurgical group and the retraction pocket group. In all ears in the retraction pocket and nonsurgical groups, and 19 of 30 ears in the surgical group, ET function was poor, there being no significant difference among the three groups. The present clinical observations suggest that progressiveness of cholesteatoma could be related to the ventilatory conditions in the mastoid rather than ET function, and that conservative treatment may be effective when ears with cholesteatoma have aeration in the mastoid.

Adolescent↗
PubMedDate not supplied

Computed tomographic image analysis of ears with otosclerosis.

To evaluate the usefulness of quantitative analysis of computed tomographic images in diagnosing stapedial otosclerosis, high-resolution temporal bone computed tomography (CT) of 32 ears with otosclerosis and 19 control ears was used. The images on the section containing the oval window were digitized using a scanner, and the ratio of the mean gray scale value of 5 areas in the optic capsule including the area anterior to the oval window to that of the cortical bone was calculated. The mean value of the ratio of the area anterior to the oval window was significantly lower in the otosclerosis group (0.85 +/- 0.10) than in the control group (1.03 +/- 0.03; Student t test: t = 7.94, p < 0.0001). In 30 of 32 (93.7%) otosclerotic ears, the values were lower than the normal range calculated in the control group. This method of quantitative CT image analysis comparing the area anterior to the oval window was considered useful in diagnosing stapedial otosclerosis.

Adolescent↗
PubMedDate not supplied

Cineradiogrphic analysis of eustachian tube function. Experimental study.

In order to determine the effect of muscular contraction upon the opening processes of the eustachian tube, cineradiography of four monkeys' tubes during stimulation of the tensor and levator veli palatini muscles was carried out. Levator stimulation produced no opening of the tube except a dilation of the pharyngeal orifice. On the other hand, tensor stimulation produced a consistent opening of the tube by outward displacement of the tubal wall along its entire cartilaginous part. A marked time lag in the movement of the tube between its proximal (isthmic) and distal (pharyngeal) parts was regarded to be important in the clearance function of the tube.

Animals↗
PubMedDate not supplied

Opening mechanism of the eustachian tube. A clinical and experimental study.

In order to examine the mechanism of tubal opening in detail, the following three experiments were conducted. Experiment 1: The tensor and the levator muscle were selectively stimulated in four monkeys. Tensor stimulation produced constant tubal opening, while levator stimulation had no effect on the opening. This result indicates that the tube opens by the tensor alone. Experiment 2: Cineradiographic studies of the tube during swallowing were conducted in three patients. Motion of the tube, made visible by means of contrast medium, was filmed at a vertical angle. Frame by frame analysis of the film revealed a marked difference between movement of the tube at its pharyngeal orifice and at its cartilaginous part. The result suggested that there are two muscles which dilate two different parts of the tube. Experiment 3: Cineradiography of the tube during selective stimulation of the tensor and the levator muscles was carried out on thre monkeys. Levator stimulation produced dilation of the pharyngeal orifice, but no tubal opening. On the other hand, tensor stimulation produced opening of the tube as a whole, by outward displacement of the lateral wall of the tube. It is concluded that almost the entire cartilaginous part of the eustachian tube opens by contraction of the tensor muscle, while the distal end of the tube increases in diameter by contraction of the levator, but the tube never opens as a whole by its contraction.

Animals↗
PubMedDate not supplied

Experimental study of the Eustachian tube function with regard to its related muscles.

Utilizing electromyography and electrical muscle stimulation, the muscle responsible for opening the Eustachian tube was examined im 12 dogs. Different time values for tubal opening and levator activity indicate little contribution of the levator in the functioning of the tube. By relatively low stimulation of the tensor, the tube opened consistently, while the levator failed to produce any dilation of the tube, regardless of the amount of stimulation, in 6 dogs. Thus, it is concluded that the sole muscle responsible for tubal opening is the tensor, while the levator does not participate in the functioning of the tube.

Animals↗
PubMedDate not supplied

Role of the tensor tympani muscle in eustachian tube function.

In order to determine the role of the tensor tympani muscle in Eustachian tube function, pressure changes in the external and middle ear of 13 cats were measured under four experimental conditions. It was revealed that contraction of the tensor tympani muscle during swallowing did not result in any tympanic pressure rise which might assist in tubal ventilation. Acoustic stimulation was then used to measure consistent contraction of the tensor tympani muscle. Combined contraction of the tensor veli palatini and tensor tympani muscle under the condition of positive tympanic pressure failed to open the tube. It was concluded that the tensor tympani muscle might not play any part in tubal function.

Acoustic Stimulation↗
PubMedDate not supplied

Influence of altered middle ear pressure on cochlear microphonics.

Patients with otitis media with effusion often have impaired hearing loss caused by bone conduction. Among several possible causes for this hearing loss, the influence of middle ear pressure upon hearing was examined. Cochlear microphonics (CM) of guinea pigs were recorded under positive or negative pressure created simultaneously in the middle ear and in the external ear canal. CM was recorded from each turn (basal, second, third and apical). Whereas under negative pressure CM decreased suddenly but soon became stable, under positive pressure CM normalized gradually after the initial drop. Thus, in the stable state, CM amplitude was low under negative pressure but was slightly subnormal under positive pressure. One possible explanation is that perilymphatic efflux appears to cause such recovery of CM under positive pressure. it is postulated that perilymphatic inflow does not seem to occur under negative pressure, since CM and perilymphatic pressure were stable.

Animals↗
PubMedDate not supplied

Localization of motoneurons innervating the Eustachian tube muscles in cat.

The localizations of the motoneurons supplying the tensor tympani muscle (TTM), tensor veli palatini muscle (TVPM) and levator veli palatini muscle (LVPM) were determined by retrograde transport of horseradish peroxidase (HRP) in the cat. TTM motoneurons were found ipsilaterally outside the trigeminal motor nucleus in an area just ventral to it. TVPM motoneurons were distributed mainly in the ventral part of the ipsilateral trigeminal motor nucleus. They were more compactly distributed in the rostral part of the nucleus than in the caudal part. LVPM motoneurons were found in the ipsilateral nucleus ambiguus. There were no HRP-labelled cells in the contralateral nucleus ambiguus.

Animals↗