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症例は28歳,女性.労作時息切れを主訴に近医受診し,胸写上肺動脈拡張を指摘され当科入院.膠原病を疑わせる検査所見あるも診断基準を満たさず,心臓カテーテル検査などの結果より原発性肺高血圧症と診断し退院.退院後1ヵ月頃より蝶形紅斑および抗二本鎖DNA抗体が出現したことより全身性エリテマトーデス(SLE)の診断が確定したため,ステロイド投与および血漿交換を行ったところ, 4ヵ月後の心臓カテーテル検査にて肺動脈圧および肺血管抵抗の低下を認めた. SLEに肺高血圧症を伴う例のあることは知られているが,肺高血圧症がSLEの診断に先行することは極めてまれである.また原発性肺高血圧症の20～30%にレイノー現象,関節炎,免疫反応の異常など全身性疾患を示す所見を有するものが認められ,これらに対するステロイドなどの免疫抑制療法の可能性を考えるうえで参考になる1例と思われた.

The influence of external auditory canal pressure on the activity of the vestibular nerve was studied in normal guinea pigs and in those with experimental endolymphatic hydrops. Vestibular nerve action potentials were continuously monitored when a pressure of 300mmH2O above or below atmospheric pressure was applied to the external auditory canal. Activity changed significantly during positive pressure application in 19% of the normal group and in 73% of the hydrops group, whereas 35% of the normal and 20% of the hydrops group responded to negative pressure. Responses of normal guinea pigs were reversed according to the polarity of the pressure, and their sensitivities to the pressure correlated to their coefficients of variation. In the hydrops group, polarity of the pressure did not reverse the responses and the correlation between the sensitivity and the coefficient of variation was not apparent.

Activation of cortical areas related to visual motion processing and control of eye movement, and deactivation of parieto-insular vestibular cortices (PIVC) were revealed by functional magnetic resonance imaging (fMRI) with small-field optokinetic stimulation (OKS). The results agreed well with those of previous studies, which indicates that the current protocol is reliable enough to be used as a clinical examination.To propose an fMRI set-up with OKS that is reliable and simple enough to be performed as a clinical test.Ten right-handed healthy volunteers participated in this study. fMRI was used to measure blood oxygen level-dependent (BOLD) signal increases (contrast: OKS - rest) and decreases (contrast: rest - OKS) during small-field OKS. Functional images were acquired using a standard clinical scanner operating at a magnetic field strength of 1.5 T. The data were analyzed by statistical parametric mapping (SPM2), and the significance level was set at p0.001, uncorrected.BOLD signal increases were observed in the visual association area of both hemispheres (BA19) (MT/V5), primary visual cortex (BA17) of the right hemisphere, bilateral superior parietal lobules (BA7), and bilateral frontal eye fields (BA6). Decreases of BOLD signals were observed in the PIVC bilaterally.

Red cells of the clam Barbatia reeveana express two hemoglobins, one composed of 16- to 17-kDa chains and the other of 35-kDa chains. The nucleotide sequence of the cDNA encoding the 35-kDa chain shows that the polypeptide has two very similar heme-binding domains, which are joined without use of an additional bridging sequence. Two novel introns occur in the gene for the two-domain globin: one, the "precoding" intron, is located two bases 5' from the start codon, and the other, a "bridge" intron, separates the DNA sequences encoding the two domains. Close correspondence exists between the 3' end of the precoding intron and the 3' end of the bridge intron and between parts of the 3' noncoding region of the cDNA for the two-domain globin and the 5' end of the bridge intron. These observations indicate that the bridge intron arose by unequal crossing-over between two identical or very similar genes for a single-domain globin. This conclusion, together with the proposal that exons were initially independent "minigenes" [Gilbert, W. (1987) Cold Spring Harbor Symp. Quant. Biol. 52, 901-905], suggests that many introns may have evolved from the 5' noncoding region of one gene and/or the 3' noncoding region of a second gene. This hypothesis implies that splice junctions would be associated with the original NH2 and COOH termini of proteins and provides an explanation for the observation that splice junctions usually map to protein surfaces. They do so because most NH2- and COOH-terminal residues are usually located on or near the surfaces of proteins.

A 41-year-old female visited our clinic complaining of right facial palsy. CT and MRI findings suggested a cholesteatoma in the petrous apex. It was extracted by a translabyrinthine approach. The facial nerve and the vestibulocochlear nerve were thought to have been injured at the level of the internal acoustic meatus. Preoperative diagnosis with CT and MRI were very useful for the operation. The macula utriculi from the involved ear was studied by electron microscopy. We found hair cell loss and degeneration.

The use of fluorodeoxyglucose positron emission tomography (FDG-PET) with a visual language task provided objective information on the development and plasticity of cortical language networks. This approach could help individuals involved in the habilitation and education of prelingually deafened children to decide upon the appropriate mode of communication.To investigate the cortical processing of the visual component of language and the effect of deafness upon this activity.Six prelingually deafened children participated in this study. The subjects were numbered 1-6 in the order of their spoken communication skills. In the time period between an intravenous injection of 370 MBq 18F-FDG and PET scanning of the brain, each subject was instructed to watch a video of the face of a speaking person. The cortical radioactivity of each deaf child was compared with that of a group of normal- hearing adults using a t test in a basic SPM2 model.The widest bilaterally activated cortical area was detected in subject 1, who was the worst user of spoken language. By contrast, there was no significant difference between subject 6, who was the best user of spoken language with a hearing aid, and the normal hearing group.

The bottom oxide was found to play an important role on the integrity of interpolysilicon ultrathin oxide/nitride/oxide (ONO) films. Natural oxides grown on phosphorus‐doped polysilicon by diffusion from source contain defects and weak spots, which degrade the integrity of ONO films grown on these. On in situ phosphorus‐doped LPCVD polysilicon, defect‐free oxides can be obtained and introduce much better yield in ONO films. Dielectric strength measurement by voltage ramping method cannot separate this difference of integrity. We were able to discriminate this difference only by time dependent dielectric breakdown measurement in which negative voltage was applied to the upper polysilicon. The intrinsic wearout phenomena of ONO films, which have been observed on single‐crystal silicon surfaces, and depend only on the thicknesses of bottom oxide, nitride, and top oxide, were observed also on polysilicon if the bottom oxide has grown on in situ phosphorus‐doped LPCVD polysilicon.

Physiological reactions of the otolith neurons were investigated in the lateral vestibular nucleus (LVN) in the cat. The physiological differences between the ventral and dorsal part of the LVN were examined by tilting and rotating stimulation. 1) In the ventral part of the LVN, many neurons reacted to lateral tilting, and a close relation of this region to the utricles was suspected. 2) In the dorsal part of the LVN, neurons reacting to tilting and those reacting to rotating were found, and some reacted to both. This region was suspected to have indirect connections with otoliths and semicircular canals. 3) In the neurons of the LVN which reacted to lateral tilting, 67% (16/24) were excited by ipsilateral tilting.

We have reported that middle ear pressure changes influenced vestibular nerve activity. In the present study the influence of middle ear pressure on the lateral vestibular nucleus neurons was investigated in anesthetized cats. The activities of the lateral vestibular nucleus neurons, especially the lateral vestibulo-spinal tract neurons, were recorded extracellularly. Positive or negative pressure was applied to the middle ear cavity bilaterally through perforation of the tympanic membrane.In most lateral vestibular nucleus neurons firings were increased with negative pressure and decreased with positive pressure. These effects were more prominent when pressure changes were applied to the contralateral middle ear cavity. These influences of middle ear pressure on the lateral vestibular nucleus neurons were opposite to those on the vestibular nerve, and the existence of inhibitory interneurons was considered.

リンパ節腫大を伴う高ガンマグロブリン血症がみられて5年後に全身性エリテマトーデス(SLE)の確定診断が得られた症例を報告する.症例は33歳の女性. 28歳時,血液検査で偶然に高ガンマグロブリン血症を指摘され入院.自覚症状はなく,理学的には左側頚部に数個の小豆大のリンパ節腫大を認めるのみであった. LE細胞現象は陰性で,抗核抗体,抗DNA抗体は弱陽性であった.リンパ管造影で両そけい部から腹部大動脈周囲にかけてリンパ節の腫大を認め,リンパ節生検にて形質細胞の増生がみられた. SLEが疑われたが, ARA診断基準(1971年)を満たさず,特発性高ガンマグロブリン血症またはlatent SLEの診断の下で経過観察をしていた. 5年後に全身倦怠感,起床時の手指のこわばり,発熱,脱毛が出現, SLEの確定診断が得られた.本症例はSLEの確定診断以前の病態を把握しており, SLEの進展ならびに自然経過を考えるうえで興味ある症例と思われた.

Of 27 patients with unilateral paranasal sinus disease detected by CT scans, 15 had tumors and 12 had inflammatory disease or cysts. Most of those with malignant tumors had CT evidence of bone destruction. Maxillary sinus wall thickening was usually found in patients with inflammatory disease or cysts. However, two patients with malignant tumors showed only bone thickening. Therefore, pathological examination by biopsy or exploratory opening of the sinus should be performed when unilateral paranasal sinus disease is found.

Cortical processing of sound in patients with mild to moderate sensorineural hearing loss, which is common and experienced by most people with age, has rarely been reported. In this article, our three previous studies are reviewed to investigate how disorders in the peripheral auditory organ influence the brain activation pattern, which may provide further information about the strategy used by the brain to process and recognize incomplete sensory signals delivered to it.

Conclusion. Diuretics significantly improved hearing in patients with contralateral-type DEH, whereas they did not inpatients with ipsilateral-type DEH. Objective. We report a review of 26 cases of DEH treated in recent 6 years. Patients and methods. The study group comprised 22 contralateral and 4 ipsilateral types of DEH. The efficacy of diuretics on the improvement in hearing was examined quantitatively. The efficacy of hyperbaric oxygenation therapy (HBO) on hearing was examined in six patients. Results. The general properties of these cases were similar to those reported previously, except for the high proportion of patients with contralateral-type DEH. Diuretics significantly improved the hearing of patients with contralateral-type DEH. In contrast, no significant improvement by diuretics was noted in ipsilateral-type DEH.

We report a rare case of cerebellopontine angle (CPA) meningioma whose sole symptom was severe vertigo. A 39-year-old woman with right CPA meningioma was referred for surgery. She experienced severe vertigo for 2 years without any other symptoms. Caloric test indicated right canal paresis of 90%. Her audiogram was normal. After surgery, vertigo symptoms disappeared dramatically. The mechanisms of restoration from vertigo are discussed.

Objectives To examine the correlation between the middle-ear pressure-regulation functions including active eustachian tube (ET) functions and transmucosal gas exchange function, and outcome of tympanoplasty. Patients and methods Seventy five patients (78 ears) with non-cholesteatomatous chronic otitis media with eardrum perforation but without ossicular damage or middle-ear anomaly participated in this study. Before surgery, patency of the ET was examined by applying positive pressure to the middle ear through the eardrum perforation, and then the ET pressure-regulation functions were examined using the inflation–deflation test. Also their transmucosal gas exchange function was evaluated by examining the presence or absence of aeration in the mastoid on the CT before surgery or through the microscope during the surgery. All of them underwent type-I tympanoplasty, and their postoperative conditions including the hearing were followed for more than 6 months. The outcome of the surgery was judged as poor outcome when they had any of the following conditions; more than 20 dB of mean air-bone gap, spontaneous perforation within 6 months, or persistent wet condition including recurrent otorrhea. Results First, the outcome of all the four ears of which ETs were considered mechanically obstructed was poor. Next, among the remaining 74 ears, none of the three individual parameters, including positive and negative middle-ear pressure-equalizing functions and mastoid aeration, showed significantly positive correlation with the outcome of the surgery, but significantly higher incidence of poor outcome was seen only when all the three parameters were poor. Conclusions These results indicated that impairment of all the middle-ear pressure-regulation functions was likely to cause poor outcome of tympanoplasty, and also allowed us reconfirm that ears with mechanically obstructed ETs were contraindicated for tympanoplasty. Therefore, assessment of mastoid condition is important as well as the ET function before tympanoplasty.

Objective We previously reported enhanced activation of auditory cortex in patients with bilateral chronic inner-ear hearing loss. To determine whether this enhancement can exhibit a short-term alteration, we measured auditory evoked magnetic fields (AEFs) in patients with idiopathic sudden sensorineural hearing loss (ISSHL) in the acute phase (AP) and recovery phases (RPs). Methods We recorded AEFs in two unilateral ISSHL patients at three time points (AP, RP1, and RP2) using a whole-head neuromagnetometer. Tone bursts of 1 kHz were presented monaurally to the affected and healthy ear at four different intensities (40–70 dB HL). Results Both patients showed the enhancement of N100 m moment at AP and not at RPs in response to the affected ear stimulation, and stronger N100 m moment in ipsilateral than contralateral hemisphere in response to the healthy ear stimulation at AP. Conclusions Enhancement of N100 m amplitude occurs in ISSHL patients and disappears on the scale of days. Enhancement of activity in the auditory cortex derived from inner-ear hearing loss can thus exhibit short-term change. Significance The results of this study provide first evidence for a recovery from enhancement of activation in the auditory cortex following injury of peripheral hearing organ.

Two different types of steep loudness growth have been reported in detail in psychoacoustical studies but have rarely been evaluated by objective methods in humans. One occurs in inner-ear hearing-impaired patients and is known as loudness recruitment. Another similar phenomenon is observed in healthy subjects with concurrent presence of background noise. Concerning the first type, our previous study using magnetoencephalography (MEG) showed that enhancement of the dipole moment of N100m with increase in stimulus intensity was greater in patients than in normal individuals. However, it is unclear whether the enhancement of activity in auditory cortex will also be detected with background noise in healthy subjects. To elucidate the effects of continuous background noise on tone-evoked cortical activity, we measured auditory-evoked magnetic fields (AEFs) from 7 normal-hearing subjects in two different conditions, with and without 55 dB SPL continuous masking white noise (noise/quiet conditions). The stimuli were 200 ms 1-kHz tones delivered monaurally and randomly at 4 different intensities (40-70 dB SPL) with constant 1-s interstimulus intervals. The N100m increased in amplitude and decreased in latency as a function of stimulus intensity in both noise and quiet conditions. The dipole moment of N100m was significantly smaller in the noise than in the quiet condition, showing that continuous background noise suppresses the strength of tone-evoked cortical responses. The mechanisms underlying these two psychoacoustically similar phenomena of rapid loudness growth thus differ.

Objectives: Recent experimental studies have demonstrated the efficacy of various agents including neurotrophins for the treatment of inner ear diseases. However, clinical application of these findings has rarely been realized. One possible reason for this is that the strategy for application of these agents has not been established. In this study, we examined the efficacy of the biodegradable gel for application of brain-derived neurothrophic factor (BDNF) into the inner ear. Methods: The concentration of BDNF in the perilymph harvested from guinea pig cochleae after application using a biodegradable gel was compared with that after a single injection of BDNF into the cochlea. The efficacy of application of BDNF by a biodegradable gel was evaluated by histological and functional analysis for protection of spiral ganglion neurons (SGNs) affected by deletion of cochlear hair cells. Results: The concentrations of BDNF in the perilymph collected from animals treated with a biodegradable gel were over 40 holds higher than those collected from animals received a single injection. An application of BDNF by a biodegradable gel significantly increased the number of surviving SGNs following deletion of hair cells by ototoxic treatment. Functional assessment by electrically evoked auditory brainstem responses demonstrated that an application of BDNF by a biodegradable gel significantly decreased elevation of thresholds. Conclusion: These findings indicate that the biodegradable gel is useful for application of BDNF into the inner ear.

The aim of this study was to investigate validity and limitation of the novel infrared system to record and analyze horizontal visual-vestibular interaction using whole-body rotation rapidly and conveniently in the routine vestibular clinic. We examined 11 patients with cerebellar dysequilibrium and 25 patients with peripheral dysequilibrium for vestibulo-ocular reflex in darkness (DVOR), visually-enhanced vestibulo-ocular reflex (VEVOR), and fixation suppression of vestibulo-ocular reflex (FSVOR), and compared the results with those of examination for head-fixed smooth pursuit and fixation suppression during caloric stimulation. The manual rotation stimuli were 0.5-0.75 Hz in frequency and 60-90 degrees /s in maximal angular velocity. Gain of vestibulo-ocular reflex in darkness was not significantly correlated with maximal slow phase velocity (MSPV) of caloric-induced nystagmus at that stimulus condition either in patients with peripheral dysequilibrium or in those with cerebellar dysequilibrium. An index for fixation suppression of vestibulo-ocular reflex during rotation stimulus was significantly lower in patients with cerebellar dysequilibrium than in normal control subjects and those with peripheral dysequilibrium. On the other hand, there was no significant difference among the two disease groups and the normal control group in gain of visually-enhanced vestibulo-ocular reflex. In about a half of patients with cerebellar dysequilibrium, measured smooth pursuit gain was lower than estimated smooth pursuit gain calculated based on a simple superposition theory of vestibulo-ocular reflex and smooth pursuit. Testing fixation suppression using the present system is an unusually convenient tool for detection of cerebellar dysequilibrium.

This study aimed to evaluate the potential of bone marrow stromal cells for treatment of inner ear diseases. Autologous marrow cells labeled with Dil were implanted into the inner ear of five gentamicin-treated chinchillas. Histological analysis 3 weeks later revealed robust survival of grafted marrow cells in multiple regions within the cochlea. Marrow cells implanted in the basal turn of the cochlea migrated as far as the apical end or into the spiral ligament of the cochlea. Some grafted cells expressed a neuronal or glial cell marker, indicating their ability to differentiate into neuronal or glial cells. Survival, migrational mobility and differentiation of autologous marrow cells in damaged cochlea suggest their potential as transplants for treatment of various degenerative inner ear diseases.

This study aimed to examine the possibility of restoration of spiral ganglion neurons, which transmit sound stimulation to the brain, by transplantation of fetal neural stem cells (NSCs) into the modiolus of cochleae. Fetal mouse NSCs expressing green fluorescence were injected into the modiolus of cisplatin-treated cochleae of mice. The temporal bones were collected 14 days after transplantation, and provided histological examination. The cell fate of transplants was determined by immunohistochemistry for a neural or glial cell-marker. Histological analysis 2 weeks after transplantation revealed robust survival of transplant-derived cells in the modiolus of the cochlea. NSCs injected in the basal portion of cochleae migrated as far as the apical end of the modiolus Grafted NSCs expressing a neural cell marker were identified, but the majority of grafted NSCs differentiated into glial cells. These findings suggest the possible use of NSCs in cell therapy for restoration of spiral ganglion neurons. However, further treatments are required to increase the number of NSC-derived neurons in the modiolus to realize functional recovery.

This study aimed to evaluate the relationship between the diameters of the auditory and eighth cranial nerves and improvements in post-implant performance. Twenty prelingually deafened children (aged from 2.0 to 6.0 years) who received the Nucleus 24 cochlear implant participated in this study. All subjects had used their implant for at least 1 year after device connection. The diameters of cochlear and eighth cranial nerves were retrospectively measured on preoperative T2-weighted axial magnetic resonance image (MRI). In 17 of 20 subjects, the cochlear and eighth cranial nerves could be identified on MRI. The mean diameter of the cochlear and eighth cranial nerves were 0.9 +/- 0.2 mm and 1.2 +/- 0.3 mm, respectively. In the remaining three subjects, the cochlear and eighth cranial nerves could not be identified on MRI. These three subjects had significantly lower scores in the Infant-Toddler-Meaningful Auditory Integration Scale (IT-MAIS) than the other 17 subjects at 12 months post-implant. There was no significant correlation among the maximal diameters of the nerves and age, ECAP thresholds and IT-MAIS scores. A sufficient outcome from cochlear implantation can be expected when cochlear and eighth cranial nerves are depicted on MRI, regardless of the nerve diameters.

Previous studies on regeneration of mammalian vestibular hair cells have indicated the potential for self-repair of damaged hair cells. The rescue of damaged hair cells from cell death may therefore increase regenerated hair cells in affected vestibular epithelia. The role of apoptosis in the degradation of vestibular hair cells following aminoglycoside treatment has been elucidated. To seek a method of protecting vestibular hair cells from aminoglycoside toxicity, we examined the apoptosis signaling pathway of vestibular hair cells due to aminoglycoside toxicity. Induction of apoptosis in hair cells of mouse ampullar cristae damaged by local application of neomycin was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) method and transmission electron microscopy (TEM). Immunohistochemistry for apoptosis-related proteins was employed to determine the signaling pathway of apoptosis of hair cells. The occurrence of apoptosis in hair cells was demonstrated by TUNEL staining and TEM. In apoptotic hair cells, activation of caspase-3 and -9, and redistribution of cytochrome c was identified, while there was no expression of activated caspase-8 or apoptosis-inducing factor. In conclusion, these findings indicate that the mitochondria-mediated pathway of apoptosis may play a role in inducing the apoptosis of vestibular hair cells due to aminoglycoside toxicity. Stabilization of the mitochondrial membrane may therefore rescue vestibular hair cells from apoptosis, leading to an increase in self-repaired hair cells in affected vestibular epithelia.

Loss of sensory hair cells in the inner ear is a major cause of permanent hearing loss, since regeneration of hair cells rarely occurs in mammals. The aim of this study was to examine the potential of neural stem cell transplantation to restore inner ear hair cells in mice. Fetal neural stem cells were transplanted into the mouse inner ear after drug-induced injury. Histological analysis demonstrates that the majority of grafted cells differentiated into glial or neural cells in the inner ear. Strikingly, however, we show that grafted cells integrate in vestibular sensory epithelia and express specific markers for hair cells. This finding suggests that transplanted neural stem cells have the potential to differentiate and restore inner ear hair cells.

Objectives/Hypothesis The survival of the spiral ganglion (SG) is a critical issue in preservation of hearing. Research on topics related to this issue requires a mouse experimental model because such a model has advantages including use of genetic information and knockout or “knockin” mice. Thus, the aim of the study was to establish a mouse model for induction of apoptosis of SG neurons with a definite time course. Study Design Laboratory study using experimental animals. Methods C57BL/6 mice were used as experimental animals and were subjected to direct application of cisplatin into the inner ear. Terminal deoxynucleotidyl transferase–mediated dUTP nick-end labeling (TUNEL) assay and immunostaining for Neurofilament 200-kD (NF) and peripherin were used for analysis of SG degeneration. In addition, generation of peroxynitrite in affected spiral ganglions was examined by immunostaining for nitrotyrosine. Cellular location of activated caspase-9 and cytochrome-c in dying SG neurons were examined for analysis of cell death pathway. Results The TUNEL assay and immunohistochemical analysis for NF and peripherin indicated that type I neurons in spiral ganglions were deleted through the apoptotic pathway over time. Spiral ganglion neurons treated with cisplatin exhibited expression of nitrotyrosine, indicating induction of peroxynitrite by cisplatin. In dying SG neurons, expression of activated caspase-9 and translocation of cytochrome-c from mitochondria to cytoplasm were observed, indicating the mitochondrial pathway of apoptosis. Conclusion The predictable fashion of induction of apoptosis in SG neurons over a well-defined time course in the model in the study will aid studies of the molecular mechanism of cell death and elucidation of a strategy for prevention of SG degeneration.

With significant development of mouse genomics and the availability of transgenic and knockout mice, the mouse will be the preferred animal model for inner ear research. However, few studies have used mice as experimental animals for examination of hair cell degeneration, because of their relative resistance to ototoxic agents and difficulties in surgical treatment. This study presents a model for induction of apoptotic cell death in sensory epithelia of the mouse inner ear using injection of neomycin into the posterior semicircular canal. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay revealed that local application of neomycin produced sufficient induction of apoptotic cell death in both auditory and vestibular epithelia over a definite time course. Supplementation of the general caspase-inhibitor significantly reduced induction of TUNEL-positive cells, indicating caspase-dependency of apoptotic cell death observed in the present model. In addition, the approach to the posterior semicircular canal was an easy technique, and sham-operation induced no significant induction of TUNEL-positive cells. This model, hence, enables the use of various genetic tools in studies for mechanisms of hair cell apoptosis.

The aim of this study was to examine if adhesion molecules had relation with degeneration and regeneration processes of mammalian vestibular epithelia. The distribution of E-cadherin and beta-catenin was immunohistochemically examined in normal and aminoglycoside-treated utricles of mice. E-cadherin and beta-catenin linearly expressed between epithelial cells in normal specimens. Aminoglycoside injury resulted in temporal alteration in distribution of these molecules with induction of apoptosis in hair cells. Degradation of both molecules was widely observed in vestibular epithelia, while some supporting cells exhibited accumulation of beta-catenin. After completion of induction of apoptosis, expression of these adhesion molecules was normal in distribution. These findings suggest that the E-cadherin-beta-catenin complex plays roles in degeneration and subsequent repair processes in vestibular epithelia affected by aminoglycosides.

The etiology of spasmodic dysphonia (SD) is still unknown. In the present study, cortical function of a 59-year-old male patient with adductor type SD was examined during phonation with positron emission tomography (PET). Magnetic resonance imaging showed no organic abnormality in the brain. However, PET showed remarkable activities during phonation in the left motor cortex, Broca's area, the cerebellum, and the auditory cortices, whereas the supplementary motor area (SMA) was not activated. The SMA is known to function for motor planning and programming and is usually activated in normal phonation. Several previous reports have shown that the damage of the SMA caused a severe disturbance of voluntary vocalization. In the present case, it was suggested that the functional deficit of the SMA might be related to SD.

We surveyed on cochlear implant (CI) users using a questionnaire to determine how they use their CIs in daily life and to what degree they are satisfied with them. We also studied the relationship between the degree of satisfaction and speech perception score, age at operation, and deafness duration. Subjects were 37, postlingually-deafened adult CI users were subjected to this study. Average CI use per day was 13.6 hours. Some 60% of subjects understood person-to-person conversation without lipreading, but most could not communicate on the telephone, in meetings, or in noisy places, for example. Most--about 80%--were satisfied with CI, but 20% were not. Those not satisfied tended to be unable to understand person-to-person conversation even with CI and lipreading, indicating that understanding person-to-person conversation is one of the most important reasons for satisfaction in CI users. Speech recognition scores improved in all cases after implantation. Most patients with high speech recognition score-->40% in consonant recognition--were satisfied with CI, but those with recognition scores < 40% in consonant recognition, the degree of satisfaction varied. These results indicate that the degree of satisfaction in CI users does not always correspond to the degree of improvement in speech recognition score. Two patients not satisfied with CI had undergone surgery after the age of 65 years and deafness duration exceeding 20 years. Advanced age and a long deafness duration may thus reduce satisfaction with CIs.

To investigate the cortical activities while listening to noise and speech in cochlear implant (CI) users, we compared cerebral blood flow in postlingually deafened CI users with that in normal hearing subjects using positron emission tomography. While noise activation in CI users did not significantly differ from that in normal subjects, hearing speech activated more cortical areas in CI users than in normal subjects. A comparison of speech activation in these two groups revealed higher activation in CI users not only in the temporal cortices but also in Broca’s area and its right hemisphere homologue, the supplementary motor area and the anterior cingulate gyrus. In postlingually deafened subjects, the hearing of speech coded by CI may be accompanied by increased activation of both the temporal and frontal cortices.

A new vestibulo-ocular reflex (VOR) recording system was developed, which consists of an infrared eye camera, a small velocity sensor and a frequency modulator. Using this system, the head velocity signal was frequency modulated and simultaneously recorded as a sound signal on the audio track of a Hi8 video recorder with eye images. This device enabled recording of the VOR response in routine vestibular clinical practice. The reliability and effectiveness of this system were estimated by recording and analysing the VOR response against manually controlled rotation in normal subjects (n = 22) and in patients with unilateral severe vestibular hypofunction (n = 11). VOR gain on clockwise rotation viewed from the top was defined as R gain, and counterclockwise rotation as L gain. Directional preponderance (DP%) was also calculated. VOR gain towards the diseased side was significantly lower than that towards the intact side, and also significantly lower than that of normal subjects. DP% of unilateral vestibular hypofunction cases was significantly larger than that of normal subjects. These findings indicate that this VOR recording system reliably detects severe unilateral vestibular hypofunction.

Although cochlear implants (CIs) have provided the opportunity for bilaterally deaf individuals to recover their hearing abilities, the speech perception performances of the CI users varies considerably. To elucidate the cortical mechanisms of processing speech signals coded by CIs, we evaluated the correlation between the brain activity during speech activation and speech perception in CI users by PET.Fourteen postlingually deaf CI users were examined. CI used in the patients was a 22-channel system and its speech-coding strategy was the Nucleus spectral peak (SPEAK) strategy. To evaluate the speech perception performances, we examined vowel perception, consonant perception and speech tracking performances in the Japanese language. Regional cerebral blood flow (rCBF) was measured during no sound stimulation and speech sound stimulation. PET data of the silent condition was subtracted from that of speech stimulation to determine changes in rCBF. In the search for changes in rCBF in the areas for auditory processing, three regions of interest (ROI) were selected; primary auditory area, auditory association area and Broca's area. The correlation between the rCBF changes in the ROIs and the speech perception performances was analyzed using Pearson's correlation coefficient.The patient's speech perception performances ranged widely. Although there were no significant correlations between the speech perception and the rCBF increases in the primary auditory area and Broca's area, there were positive correlations in the auditory association area. In the left auditory association area, the correlation coefficient of the vowel perception performance was 0.546 (P0.05) and that of the speech-tracking test was 0.657 (P0.05). Regarding the consonant perception performance, the correlation coefficient was 0.743 (P0.01). There was a positive correlation only between the consonant perception performance and the rCBF increase (R = 0.576, P0.05) in the right auditory association area. These correlations are stronger in the left hemisphere than in the right hemisphere.It is suggested that the improvement of the auditory processing of speech in CI users with SPEAK strategy is accompanied by the recruitment of more neurons in the auditory association areas. The adult auditory cortices may still have plasticity or