Using high-resolution isotropic volume data obtained by 0.5mm, 4-row multislice CT, cross-sectional observation of the auditory ossicles is possible from any desired direction without difficulty in high-resolution multiplanar reconstruction (HR-MPR) images, also distortion-free three-dimensional images of the ossicles are generated in three-dimensional CT (3D-CT) images. We measured angles of fifty normal ossicles relative to the reference plane, which has been defined as a plane through the bilateral infraorbital margins to the middle portion of the external auditory canal. Based on the results of angle measurement, four optimal sections of the ossicles for efficient viewing to the ossicular chain were identified. To understand the position of the angle measurement and the four sections, the ossicles and the reference plane were reconstructed in the 3D-CT images. As the result of observation of the ossicles and the reference plane, the malleus was parallel to the incudal long process and perpendicular to the reference plane. As the results of angle measurement, the mean angle of the tympanic portion of the facial nerve relative to the reference plane in the sagittal plane was found to be 17°, and the mean angle of the stapedial crura relative to the reference plane in the sagittal plane was found to be 6°. The mean angle of the stapes relative to the reference plane in the coronal plane was 44°, and the mean angle of the incudal long process relative to the stapes in the coronal plane was 89°. In 80% of ears, the stapes extended straight from the incudal long process. Image reconstruction technique for viewing four sections of the ossicles was investigated. Firstly, the image of the malleal head and the incudal short process was identified in the axial plane. Secondly, an image of the malleus along the malleal manubrium was reconstructed in the coronal plane. Thirdly, the image of the incudal long process was seen immediately behind the malleus image. Finally, an image of the stapes was reconstructed in the image of the incudal long process. During sequential reconstruction of the four planes, it was possible to observe the entire auditory ossicular chain from the malleal manubrium attached to the tympanic membrane to the stapedial foot plate embedded in the oval window. This technique is considered to be a useful new imaging technique for observing the ossicles due to its reproducibility.
Objective: To examine measurements of the vestibular aqueduct on axial CT figures and to examine the cases with borderline EVA. Design: The width of the vestibular aqueduct was measured in two places, the midpoint of the duct and the external aperture in the posterior cranial fossa. Criteria was as follow: Enlargement ;≥1.5mm at the midpoint, ≥2mm at the aperture, Borderline; 1-1. 4mm at the midpoint, 1.5-1.9mm at the aperture. Participants: 345 cases with CT scans of the temporal bones taken during July 2003 to June 2004 in the secondary ENT referral center. Those Patients include sensorinearal, mixed or conductive deafness, vertigo, ear infections and other ear diseases. Result: Enlarged vestibular aqueduct was found in 10 ears with sensorinearal deafness (SD) and 2 ears without SD. Borderline measurements were found in 19 ears with SD and 33 ears without SD. The enlarged midpoint measurement was not seen in the cases without SD. Conclusions: More than 1. 5mm of the definition for the enlargement at the midpoint of the vestibular aqueduct seemed to be appropriate in the clinical situation. The measurement at the midpoint of the duct is more reliable than at the external aperture. The conductive component in EVA Syndrome with mixed hearing loss is present only at the lower frequencies (250, 500Hz), not at the middle and higer frequencies. Long-term follow-up of hearing should be done in the borderline cases with check-up of PDS gene anomaly if necessary.
We investigated 49 infants who had been referred to the University of Tokyo Hospital for advanced hearing examination after newborn hearing screening from 2000 to 2004. The examination revealed that 19 babies had severe hearing loss, 11 had moderate hearing loss and 7 had mild hearing loss or normal hearing. The average age of wearing the first hearing aids was 7.5 months old, and the average age enrolling to deaf schools or rehabilitation centers was 6.8 months old. These results demonstrate that newborn hearing screening is very effective for early evaluation of hearing problems and early educational management for babies with hearing problems in Japan.
It is a very important key to maintain a stable reconstructed posterior canal wall with bone plate and cartilage in the posterior canal wall renconstructed tympanoplasty. The authors reconstructed the posterior canal wall with the temporal fascial flap (TFF) and the temporal periosteal falp (TPF) to have a stable posterior canal wall and a tympanic membrane graft. Well-vascularized TFF and TPF enable us to acquire the secure reconstructed posterior canal wall because of the abundant blood supplies to the flaps. In order to investigate the blood supplies of TFF and TPF, we employed Laser Doppler blood flowmeters and measured that in 12 cases of chronic otitis media and 8 cases of cholesteatoma. Both blood supplies were comparatively well, and TFF's blood supplies were statistically better than those of TPF. These findings suggested that the TFF and TPF were reliable source of local well-vascularized to be extremely pliable and facilitate to create the stable posterior canal wall. Furthermore it seemed that it was linked to prompt postoperative healing, avoidance of postoperative infection, satisfactory postoperative hearing improvement, shorter hospitalization stay and early discharge from the hospital.
External auditory canal cholesteatoma (EACC) is a rare lesion, and some types of EACC with recurrent otorrhea despite of conservative care or with extension to the mastoid and/or tympanic cavity often required surgical treatment. Between April/1987 and March/2004, we operated 33 cases of EACC. There were 18 males and 13 females, 2 of them had bilateral lesions, with ages ranging from 5 to 76 years. The follow-up period after surgery ranged from 11 months to 13 years and 1 month, the average 5 years and 5 months. The etiologies were idiopathic in 25 cases, congenital in 4 cases, trauma in 2 cases, and postoperative in 2 cases. CT imaging showed the bone destruction limited to the external canal wall in 19 cases. On the other hand, bone destruction extended into the middle ear in 14 cases: 8 mastoid involvement, 5 tympanic cavity involvement, mastoid and tympanic cavity involvement in one case. Canalplasty was performed in 18 cases with limited lesions to the EAC wall. Canal wall down tympanomasotoidectomy with canal reconstruction was performed in 15 cases. Postoperatively, debridement in outpatient clinic once a month was needed in 6 cases. Recurrence of the cholesteatoma was found in 3 cases, which had advanced lesions that developed to the middle ear preoperatively. In the surgical treatment of EACC, CT is useful to define the extent of the lesion and plan the reconstruction of canal wall defect, and long-term follow up is needed to identify and possible recurrence, in patients, especially who had extensive lesions.
Tinnitus Retraining Therapy (TRT) is a well-defined method for treatment of individuals who suffer from tinnitus. TRT is based on the neurophysiological model that was originally described by Jastreboff and Hazel. TRT involves Directive Counseling and Sound Therapy to habituate tinnitus. For about 80% tinnitus sufferer, TRT is effective therapy, but not effective for the others. We thought that the effectiveness of TRT would be increased by early consultation of clinical psychologist, and we named it as Reinforced TRT (TRT+early consultation of clinical psychologist). We evaluated the effectiveness of early consultation of clinical psychologist. Since 2002, the Reinforced TRT has been performed in Kasugai Municipal Hospital on 58 patients. The success rates were 87.5% with the Tinnitus Handicap Inventory (THI) and Visual Analogue Scale (VAS), respectively. This results suggest that TRT reinforced with early consultation of clinical psychologist improve the effectiveness of the treatment.
We compared the availability of the ossicular reconstruction using the autograft cartilage and ossicle. Postoperative hearing results of 72 ears (cartilage: 49 ears, ossicle: 23 ears) which underwent type III (columella) tympanoplasty for otitis media with cholesteatoma were analyzed. Postoperative air-bone gap of five frequencies was used for the assessment of hearing results. The rate of ears with a postoperative airbone gap of less than 10dB to all operated ears was examined. In the ears with the cartilage columella, the rates at 250Hz, 500Hz, 1kHz, 2kHz and 4kHz were 38%, 55%, 63%, 81%, 43%, respectively. In the ears with the ossicle columella, the rates at 250Hz, 500Hz, 1kHz, 2kHz and 4kHz were 38%, 54%, 67%, 71%, 33%, respectively. There was no significant difference at each frequency between the cartilage and ossicle although the ears with the cartilage columella showed a tendency to have a better postoperative hearing at 2kHz. The study showed no significant difference in the postoperative hearing at 250Hz to 4kHz between the ossicular reconstruction using the autograft cartil age and ossicle.
To elucidate the significance of mastoid air cells and facial recess for thermo-conductance between the external auditory canal and lateral semicircular canal during caloric examination, we examined changes in caloric responses before and after facial nerve decompression surgery. Facial nerve decompression surgery includes surgical processes both of mastoidectomy and posterior tympanotomy and never affects peripheral vestibular function. We performed facial nerve decompression surgery in 19 cases with intractable facial nerve palsy and examined caloric stimulation tests just before and 6 months after surgery. The caloricinduced nystagmus was recorded by using ENG to calculate the maximum slow phase eye velocity (SPEV). There were significant decreases between preoperative SPEV (17. 98±6.57°/sec) and postoperative SPEV (16. 42±7.33°C/sec) with 30 °stimulation (t-test: P<0.05).There were no significant differences between preoperative SPEV (16. 47±7. 98°/sec) and postoperative SPEV (15. 82±8.67°/sec) with 44°Cstimulation. These findings suggest that posterior tympanotomy during facial nerve decompression surgery affected the thermal transmission, resulting in reduction of caloric responses especially in cold stimulation. Actually after temporal bone surgery with posterior tympanotomy, we should consider the effect of structural change in temporal bone on the thermal transmission during caloric stimulation and be careful to evaluate vestibular peripheral function especially by means of cold caloric stimulation.
The rare case of an 18-year-old man with a kind of convergence-evoked nystagmus was presented. His first symptom was vertigo, which was not accompanied by tinnitus or hearing loss. Two months later, he began to suffer from spells of dizziness lasting about 10 minutes which occurred when he walked or moved his head. His hearing was normal but his closed eye stabilometry indicated that he had disturbance in his equilibrium. He had pendular nystagmus which was evoked during convergence and when eyes were open in the dark. He had no gaze or head positional nystagmus. He had normal caloric response when eyes were closed. He also had smooth eye movement in eye tracking test and normal in OKN. His head CT and MRI results were normal. He had no other physiological, neurological or ophthalmological disease. His abnormal eye movement was thought to be the convergence-evoked pendular nystagmus, of which eight cases have been reported in the world. NIH image was very useful software to analyze to nystagmus. It may occur the results of disease in the central nerves. Therefore, follow-ups over 5 to 10 year periods are important.
We presented a case of tuberculosis of the middle ear difficult to treatment due to complicating severe liver dysfunction. This case demonstrated genetic polymorphism of N-acetyltransferase 2 (NAT2*4*7: intermediate acetylator), which contributes to metabolism of isoniazid. One cause of the liver dysfunction was enhancement of the metabolic pathway of the hepatotoxic substance hydrazine due to reduction of acetylation capacity. Concomitant use of rifampicin was also thought to hold potential for a further increase in hydrazine production. We believe that a genetic polymorphism assay of drug metabolism enzymes prior to treatment is useful for obviating adverse effects.