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The aim of our study is to examine vestibular-evoked myogenic potentials (VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle (SCM) in healthy subjects for clinical applications of auditory neuropathy or vestibular neuropathy in the future.

Congenital auditory neuropathy (AN) affects hearing and speech development. The degree of hearing difficulty in congenital AN varies as a function of pathology at the inner ear hair cell (IHC) synapses or the auditory nerve. We report a case of a Chinese girl with AN revealed by OTOF (otoferlin) gene mutation analysis who had only a mild hearing loss.

Most adults with auditory processing disorder (APD) often have trouble at work. It is possible that these listening problems in adults with APD influence their mental health. Thus, we have to take the subject's personality and mental status into consideration when supporting subjects with APD. However, studies on APD in adults are comparatively rare. In this study, we aimed to evaluate the relationships between the results of auditory tests, APD symptoms, and psychological status in subjects with APD. This study included 22 adults who complained of listening problems in everyday life, and they underwent auditory processing tests and were questioned regarding their psychological characteristics.

Infants with congenital deafness caused by severe bilateral inner ear malformations frequently suffer from severe hearing loss and poor balance. Unfortunately, the use of hearing aids is usually ineffective in recovering hearing, necessitating cochlear implants. We report a case of a 6-year-old boy with congenital deafness and bilateral inner ear malformations (right side, incomplete partition type I [IP-I]; left side, common cavity deformity). Hearing aids had a remarkable effect in this patient, enabling sufficient and favorable hearing recovery such as to allow the patient to engage in daily conversations. Per-rotatory nystagmus was recorded on an electronystagmogram for both right and left rotations in a damped rotational chair test. It is rare for deaf children with severe bilateral inner ear malformation to demonstrate favorable development in hearing and good equilibrium function. Our findings suggest that auditory–vestibular hair cells in this patient may have been partially preserved despite IP-I in the right ear and common cavity deformity of the left ear.

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Bilateral Cochlear implants (CIs) improved speech intelligibility, speech perception in background noise, and sound localization in quiet and noisy situations. However, it is unclear whether these advantages essentially result in binaural integration of acoustic stimuli from each ear. In this study, we investigated the effectiveness of binaural integration by bilateral CIs placement using binaural hearing tests and subjective auditory perceptual assessment. A 61-year-old bilateral CIs subject underwent the following four tests: the Japanese Hearing in Noise Test (HINT-J), the dichotic listening test (DLT), the Rapidly Alternating Speech Perception (RASP) test, and subjective auditory perceptual assessment. The HINT-J score was significantly higher for bilateral CIs than for a unilateral CI. However, DLT and the RASP test revealed contradictory results. Subjective auditory perceptual assessment revealed active and bright impressions for bilateral hearing, which were also noisy and strong compared with those for unilateral hearing. The results of this study revealed that bilateral CIs improved speech perception in background noise and an improved auditory impression, although the bilateral integration abilities were not improved. This was probably because the patient was required to combine information from the two ears into a single perception in DLT and the RASP test. More longitudinal data should be collected and analyzed in future studies to evaluate the long-term effects of bilateral CIs.

This study compared vestibular and dynamic visual acuity in 19 adult athletes with deafness participating in Deaflympics to those of 25 young adults with normal hearing. Balance capability was evaluated using a one-leg standing test with eyes open and stabilometry. Caloric tests and vestibular evoked myogenic potential tests were conducted to test vestibular function. Visual function was evaluated using a dynamic visual acuity test. No significant difference was found between results of the one-leg standing test with eyes open and stabilometry with eyes open. Athletes with deafness performed better than normal hearing young adults with eyes closed. The caloric test indicated hypofunction of the lateral semicircular canal function in 5 of the 19 athletes with deafness. Balance-function tests showed normal results for both groups. The results for athletes with deafness on visual acuity were better than those of controls. Young Deaflympics athletes with deafness can adjust their balance function as well as or better than normal hearing young adults using dynamic visual acuity.

We understand from experience that musical contexts are formed when chords are combined according to the rules of harmony. In this study, the N1 component of the auditory-evoked potential was measured using comparable three-chord sequences; these sequences were constructed as a consecutive task (cf.C-C-C vs. Cm-Cm-Cm; control) and a cadence task (cf.C-G-C vs. C-G-Cm). In the cadence task, compared with cadences ending with a major chord (anticipated chord), those ending with a minor chord (unanticipated chord) showed a significantly larger amplitude of N1 waves. These components of auditory-evoked potentials reflect the effect of chord progression in musical perception and suggest that the musical context is recognized at least 100 ms after a chord is played.

This study aimed to establish more reliable formulae for predicting the prognosis for patients with Bell's palsy at initial examination.

Background: Nasal airway remodeling exists in allergic rhinitis, but it appears to be far less extensive than in asthma. However, there has been little study about nasal airway remodeling and no study using mice models. It has been reported that airway hyperresponsiveness decreased after prolonged allergen challenge in a chronic murine asthma model together with the progression of remodeling. However, there has been no study of the relation of remodeling and airway responsiveness in nasal allergy. Therefore, we have undertaken this investigation to characterize nasal airway structural changes after prolonged allergen challenge and to examine the relationship between nasal airway hyperresponsivity and remodeling.

Objective:To evaluate the relationship between hearing level and temporal bone abnormalities in patients with microtia.

We aimed to quantitatively determine whether middle ear inflammation associated with unilateral chronic otitis media (COM), cholesteatoma, or otosclerosis affects gustatory function.

Abstract: In our first report, we investigated nasopharyngeal bacterial flora related to penicillin-resistant Streptococcus pneumoniae (PRSP) and β-lactamase-negative ampicillin-resistant Haemophilus influenzae (BLNAR) and their relation to acute upper respiratory tract infection (AURTI). This report analyzes the results of a study of nasopharyngeal bacterial flora before the administration of antimicrobial agents in 172 AURTI patients aged 6 years or younger. In addition to Gram staining, microscopic observation, and culturing, a polymerase chain reaction (PCR) method was used to identify PRSP (gPRSP) and BLNAR (gBLNAR) drug-resistant genes. Of the patients analyzed, 90% had acute otitis media (AOM) and were aged 2 years or younger. The antimicrobial agents administered were amoxicillin (34%), clavulanic acid/amoxicillin (11%), cefditren pivoxil (CDTR-PI) (43%), and others (12%). This was particularly true for patients administered CDTR-PI, among whom there were many who had already suffered one or more episodes of AOM by the age of 1 year or younger, and many in which gPRSP were detected (P < 0.01). There was a significant relation between the degree of nasopharyngeal inflammation indicated by leukocyte infiltration images and the amount of S. pneumoniae and H. influenzae detected, which are the main pathogenic bacteria causing AOM (P < 0.01). In addition to leukocyte infiltration images, there were cases in which shedding of ciliated cells was observed and/or giant monocytic cells. Both nasopharyngeal leukocyte infiltration images and/or shed cell findings observed in infant AURTI cases are important indices for the prompt detection of gPRSP and/or gBLNAR and appropriate doses of antimicrobial agents.

Objectives:Canalplasty is a surgical procedure of the external auditory canal. In this study we examined anatomic risk factors for facial nerve injury in aural atresia surgery, in addition to facial nerve outcomes and the time course of recovery in patients with facial nerve palsy following atresia surgery.Methods:Transient facial palsy was observed immediately after surgery in 6 of 99 ears (6 of 87 patients) after canalplasty and tympanoplasty for the treatment of congenital aural atresia. We assessed the course of recovery and mean scores using Jahrsdoerfer's grading system.Results:The rate of absence of the stapes and the rate of presence of positional anomalies of the facial nerve were significantly higher among cases with facial palsy, and Jahrsdoerfer total scores were significantly lower among cases with facial palsy. The mean recovery time in 5 cases with a minimum electroneurography value of 0% was 16.2 weeks (range, 14 to 18 weeks). No trends during recovery were detected for the nerve excitability test and R1 components of the blink reflex.Conclusions:The anatomic conditions that cause a predisposition to transient facial palsy include absence of the stapes and the presence of positional anomalies of the facial nerve. Although some patients displayed transient facial palsy after surgery, all patients fully recovered. Mechanisms of facial nerve injury are proposed.

Abstract: This report focuses on changes in the nasopharyngeal bacterial flora before and after administration of antimicrobial agents in 172 cases of acute upper respiratory infection in patients aged 6 years or younger. The antimicrobial agents administered were amoxicillin (AMPC) (34%), clavulanic acid/amoxicillin compound (11%), cefditren pivoxil (CDTR-PI) (43%), and others (12%). Changes in nasopharyngeal bacterial flora were investigated with reexaminations conducted after 2–5 days (day 2–5 subgroup), 6–10 days (day 6–10 subgroup), and 11 days and thereafter. There was a significant reduction in the Streptococcus pneumoniae detected in the group administered AMPC (AMPC group) in the day 2–5 subgroup and the day 6–10 subgroup. There was also a significant decrease in H. influenzae in the group administered CDTR-PI (CDTR-PI group) in the day 2–5 subgroup. From this it was inferred that for the most part significant changes in infectious nasopharyngeal bacteria occurred in the day 2–5 subgroups. However, a significant improvement in the degree of inflammation, as indicated by leukocyte infiltration images for the AMPC group, was observed in the day 2–5 subgroup, and for the CDTR-PI group in the day 6–10 subgroup. On the other hand, in both the antimicrobial agent groups, S. pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were newly detected at reexamination. Furthermore, a difference in the incidence of these bacteria was observed between the 2 antimicrobial agent groups. It was suggested that such phenomena related to the survival of resistant strains or a recurrence otitis media.

Magnetic brain responses were recorded to clarify the cortical representation of vowel processing in Japanese. We investigated the peak latencies and equivalent current dipoles of the auditory N1m responses to the Japanese vowels a, i, o, and u. In intraindividual analyses for a single participant, well-replicated results for the dipole parameters supported the existence of phoneme-specific cortical maps for vowels. In the interindividual analyses for the eight participants, a and i elicited significantly earlier N1m responses than u, and the dipole for i was more posteriorly oriented than a in the left hemisphere. The results of the current study suggest left hemispheric predominance in vowel processing and that factors associated with a different language system may modify the cortical map.

With the appearance of penicillin-resistant Streptococcus pneumoniae, there has been increasing debate concerning antimicrobial treatments for acute upper respiratory tract infection (AURTI) and acute otitis media in children. This study compares the nasopharyngeal bacterial flora in patients with AURTI (AURTI group; 710 subjects) and healthy subjects (HS group; 380 subjects). The comparisons were made between subjects aged 6 years or younger (0–6 subgroup: 330 subjects), between 7 and 74 years (7–74 subgroup: 668 subjects), and 75 years and older (92 subjects), because the subjects were subgrouped as described above dependent on the maturity of the protective immunity. In the HS group 7–74 subgroup, viridans group streptococci, Staphylococcus aureus, coagulase-negative staphylococci, and Corynebacteriumsp. with a detection rate of 10% or more were classified as normal nasal flora (NNF), and Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhaliswere classified as drum cavity pathogens (DCP). In the 0–6 subgroup, although the detection rate for DCP bacteria in the AURTI group tended to be high, it did not reach a significant difference, whereas the detection rate for NNF bacteria was significantly lower. This trend was also observed to some degree in the other age subgroup. In the 0–6 subgroup, leukocyte infiltration observed with a microscope indicated the closest relationship between S. pneumoniaedetection rate and detection quantity. These results suggest that in the 0–6 subgroup the tendency for patients with AURTI to have NNF bacteria as well as DCP bacteria should be taken into consideration.

Sound lateralization tests were performed to compare the magnet coil bone-conduction headphone with the giant magnetostrictive bone-conduction headphone using 18 healthy participants. Although, no significant difference between these bone-conduction headphones was obtained for the interaural time difference and interaural intensity difference, a significant difference was obtained for the time–intensity trade. This revealed that the difference between the headphones is apparent in the integration of the heterogeneous sensations of the time and intensity difference at the cognitive level, but no difference is apparent between the homogeneous sensations of the discrimination of interaural time difference or interaural intensity difference at the sensory level. It was concluded that the difference at the cognitive level indicates the better performance of the giant magnetostrictive headphone.

Objectives:Since 1997, we have performed the autologous transplantation of fascia into the vocal fold (ATFV) procedure on cases of sulcus vocalis. In what follows, we report the long‐term results of our new surgical approach and discuss the role of these transplantations. We also review and report some complications that can be caused by ATFV. Finally, we discuss the ATFV technique as a contribution to the phonosurgery of the future.

The contribution of nerve fibers to the maintenance of vestibular sensory cells is a controversial issue in previous studies using animals and has not yet been studied in humans. The authors investigated this issue by observing vestibular end organs in the temporal bone of three patients in whom the internal auditory canal was infiltrated with tumor cells, and Scarpa's ganglion cells showed complete degeneration.

Background:Histamine is one of the most important chemical mediators causing nasal allergic symptoms, and H1receptor antagonist have been used as the treatment first choice in nasal allergy. The presence of H3receptors has also been determined in the human nasal mucosa, but few studies have investigated the involvement of H3receptors in nasal allergy.

Objective:Hearing impairment and the often concurrent loss of vestibular function, which is rarely assessed in infants, can both impair sensory integration critical to the development of normal motor coordination. This study demonstrates, for the first time, that vestibular function in infants can be noninvasively assessed using vestibular‐evoked myogenic potentials (VEMPs). Our intentions were to demonstrate that VEMPs can be reliably recorded from neonates and to compare neonatal VEMPs with those obtained from normal adults.

A mismatch between auditory sensation and expectant imagery of syllables elicited a possible equivalent of mismatch negativity in a previous study. The purpose of this study was to verify whether auditory imagery from musical notation could also mediate such imagery-based mismatch negativity. Neuromagnetic recording was obtained from eight musicians, who were instructed to identify unpredictably occurring pitch mismatches between a random tone sequence and a visually presented musical score. The difference between incongruent and congruent responses showed a magnetic distribution consistent with two frontal-negative current dipoles bilaterally located in the vicinity of Heschl's gyrus, peaking at approximately 150 ms in latency. This imagery-based mismatch negativity may represent an early neural process of deviance detection between the sensory input and expectant imagery.

Blind individuals require to compensate for the lack of visual nformation by other sensory inputs. In particular, auditory inputs are crucial to such individuals. To investigate whether blind individuals localize sound in space better than sighted individuals, we tested the auditory ability of adolescent blind individuals using a sound lateralization method. The interaural time difference discrimination thresholds of blind individuals were statistically significantly shorter than those of blind individuals with residual vision and controls. These findings suggest that blind individuals have better auditory spatial ability than individuals with visual cues; therefore, some perceptual compensation occurred in the former.

We established a new parallel paradigm for mismatch negativity by presenting repetitive trains of three consonant–vowel syllables and those of three sinusoidal tones alternately. Magnetoencephalography was performed to test the new method, and mismatch negativities in six study participants with normal hearing were compared with the results of the conventional oddball paradigm. Peak amplitude and latencies of mismatch negativity showed no significant difference between the methods. The maximum amplitude in short memory probe interval of 1.0 s was significantly larger than in long memory probe interval of 3.0 s, demonstrating decay in auditory echoic memory caused by a prolonged memory probe interval. The new method facilitated simultaneous evaluation of mismatch negativity with various stimuli in a shorter period.

During silent reading, visual information provided by letters is converted to auditory information in the mind. The purpose of this study was to identify the primary locus for auditory verbal imagery in the brain. Neuromagnetic recording was obtained from 10 right-handed study participants, who were instructed to identify infrequently occurring phonological mismatches between a random-ordered sequence of syllable sounds and a visually presented syllabogram sequence. The activity difference in early latency, calculated by subtracting the averaged responses to matched syllables from the averaged responses to mismatched syllables, showed a spatiotemporal profile strikingly similar to that of mismatch negativity. Auditory imagery of forthcoming verbal sounds may establish a memory trace as a template for imagery-based mismatch negativity generation in the auditory cortex.

Magnetic responses to periodic complex sounds with equivalent acoustic parameters except for two different fundamental frequencies (F0) and 12 different spectral envelopes of vocal, instrumental, and linear shapes were recorded to determine the cortical representation of timbre categorization in humans. Responses at approximately 100 ms (N1m) to vocal and instrumental (nonlinear) sounds were localized significantly anterior to linear sound responses. N1m source strength for nonlinear sounds was significantly larger than that for linear sounds, and this difference was more marked in the left hemisphere than in the right. N1m peak latency only for vocal sounds was not affected by F0. Perceptual categorization was reflected in N1m source strength and location (linear or nonlinear), and in N1m latency (vocal or nonvocal).

Many surgical approaches have been developed for the treatment of adduction-type spasmodic dysphonia (SPD). We developed and performed a new type of surgical approach (autologous replacement of the vocal fold).Our new surgical technique increases the advantages and decreases the disadvantages of previous surgical procedures in three ways: (1) It has similar effects to the previous procedures in that it prevents contraction of the thyroarytenoid muscle. (2) It decreases vocal-fold tension, as in framework surgery. (3) It reduces glottal incompetence, as does fibrinogen-glue injection, but it is more suitable because it is autologous. Furthermore, it produces increases in the mass and volume of the vocal-fold body and is also safe because the replacement tissue is autologous.The short-term results appear encouraging in preventing spastic voice while also avoiding vocal-fold atrophy. Long-term follow up will be necessary to determine the actual efficacy. However, this is clearly a possible choice as a surgical approach for treating adduction-type SPD.

Prevailing studies of auditory systems pay most attention to the dynamic temporal changes of sound intensity, but poorly enlighten the encoding of steady-state aspects. Using tone bursts as test stimuli, we epipially map auditory evoked potentials over the rat auditory cortex and investigate how the cortex represents the dynamic and steady states. Our results demonstrate that all of the auditory fields investigated potentially have at least two strategies to represent the two states; a temporal combination of early and late components of the potentials, and a spatial combination of an arbitrary component. In addition, the optimal combination that can distinguish between the two states differs across auditory fields, suggesting robust analyses of sound intensity in the auditory cortex.

Pleomorphic adenoma, the most common type of tumor of the parotid gland, may transform into a malignant tumor. In the current study, we investigated whether the expression of cyclooxygenase-2 (COX-2) is elevated in adenocarcinoma as compared to pleomorphic adenoma. Ten pleomorphic adenomas and 10 adenocarcinomas were examined. The tumor specimens were immunohistochemically stained with antibodies against COX-2 and Ki-67. The labeling indices of COX-2 in pleomorphic adenoma and adenocarcinoma were 6.0% ± 4.1% and 16.1% ± 4.6%, respectively, and those of Ki-67 in pleomorphic adenoma and adenocarcinoma were 0.77% ± 0.62% and 6.9% ± 6.6%, respectively. The labeling indices of both COX-2 and Ki-67 were significantly greater (p < .001) in adenocarcinoma than in pleomorphic adenoma. Together with the biological effects of COX-2, these results suggest that overexpression of COX-2 plays a crucial role in the pathogenesis of malignant transformation of pleomorphic adenoma in the parotid gland.

Objective:The purpose of this study is to verify the hypothesis that ErbB‐2 protein is overexpressed in human middle ear cholesteatomas and to elucidate the relationship between overexpression of ErbB‐2 protein, cell proliferation, and apoptosis.

We epipially mapped tone-burst-evoked potentials over the rat auditory cortex, and investigated the representation of intensity information. The experiments were designed to elucidate how the auditory cortex represents a steady-state plateau sound pressure level (SPL) and dynamic onset temporal structure, i.e., the rate of pressure change (in Pas), and how the representations differ across the auditory fields. The anterior and ventral fields have spatial axes of the rate of pressure change. Characteristic frequency (CF) locations mainly handle the dynamic state, while off-CF locations have the potential to code the steady state. Each field represents the intensity information differently, particularly at the off-CF locations. These results suggest that intensity information is distributed in various aspects in the multiple auditory fields.

We characterized the auditory-evoked offset responses of the rat auditory cortex by multiple-site surface microelectrode recording. Tone bursts served as test stimuli. Offset responses did not appear tonotopically, but at the fringe of tonotopic onset distributions. Offset amplitude was significantly sensitive to sound intensity, fall time at tone termination, and duration. These results suggest that offset responses are associated with inhibitory responses surrounding excitatory onset responses, and offset responses become large when inhibition becomes strong and long or terminates synchronously. Thus, the rebound after the inhibition in the presence of a stimulus is likely to be a major cause of offset responses in the auditory cortex.

We have found that damage from a local anesthetic solution containing phenol permitted -galactosidase (-gal) gene delivery to the guinea pig inner ear via the round window membrane (RWM). RWM damage was evident as degeneration of the outer epithelium. After adenovirus lacZ vector was applied to the damaged RWM, immunohistochemistry showed strong -gal expression in the RWM, mesothelial cells, organ of Corti, spiral limbus, spiral ligament and spiral ganglion. In the vestibular labyrinth, expression was seen in the sensory and supporting cells, transitional cells, and the dark-cell area. Thus, adenovirus can transfect a variety of inner ear cells in the guinea pig through a damaged RWM.

ObjectiveTo study the difference in the facial canal anatomy in terms of the severity of microtia and deformity of the middle ear in patients with microtia using high‐resolution computed tomography (HRCT).

To evaluate the usefulness of cartilage plates as tympanic membranes combined with total middle ear reconstructive surgery for radicalized ears.

To evaluate the efficacy of total middle ear reconstructive surgery (TMRS) for patients with open cavity problems.

The purpose of this study was to establish a hair cell‐specific marker and a convenient explant culture system for developing chick otocysts to facilitate in vivo and in vitro studies focusing on hair cell genesis in the inner ear. To achieve this, a hair cell‐specific monoclonal antibody, 2A7, was generated by immunizing chick inner ear tissues to a mouse. Through the use of immunofluorescence and immunoelectron microscopy, it was shown that 2A7 immunoreactivity (2A7‐IR) was primarily restricted to the apical region of inner ear hair cells, including stereocilia, kinocilia, apical membrane amongst the extending cilia, and superficial layer of the cuticular plate. Although the 2A7 antibody immunolabeled basically all of the hair cells in the posthatch chick inner ear, two different patterns of 2A7‐IR were observed; hair cells located in the striolar region of the utricular macula, which consist of two distinct cell types identifiable on the basis of the type of nerve ending, Type I and II hair cells, showed labeling restricted to the basal end of the hair bundles. On the other hand, hair cells in the extrastriolar region, which are exclusively of Type II, showed labeling extending over virtually the entire length of the bundles. These findings raised the possibility that chick vestibular Type II hair cells, characterized by their bouton‐type afferent nerve endings, can be divided into two subpopulations. Analysis of developing inner ear by using the 2A7 antibody revealed that this antibody also recognizes newly differentiated immature hair cells. Thus, the 2A7 antibody is able to recognize both immature and mature hair cells in vivo. The developmental potential of embryonic otocysts in vitro was then assessed by using explant cultures as a model. In this study, conventional otocyst explant cultures were modified by placing the tissues on floating polycarbonate filters on culture media, thereby allowing the easy manipulation of explants. In these cultures, 2A7‐positive hair cells were differentiated from dividing precursor cells in vitro on the same schedule as in vivo. Furthermore, it was found that hair cells with both types of 2A7‐IR were generated in culture as in vivo, indicating that a maturational process of hair cells also occurred. All these results as presented here suggest that the 2A7 monoclonal antibody as a hair cell‐specific marker together with the culture system could be a potential tool in analysis of mechanisms underlying hair cell development. J. Comp. Neurol. 445:176–198, 2002. © 2002 Wiley‐Liss, Inc.

Four cases (seven ears) of metastatic tumour of the internal auditory canal were studied. The histopathological findings confirmed that the inner ear invasion of the tumour follows a unique course, as reported in the literature. Relationship between duration of deafness and extent of tumour invasion in the inner ear is discussed. It is suggested that the deafness could occur via neural invasion or compression near the ductus spiralis foraminosus.

This study shows distributions of lacZ-positive cells in the vestibular labyrinthine explants of young guinea pigs with mature ears. When adenovirus lacZ vectors were administered to the vestibular labyrinth following removal of the otoconial membrane, lacZ-positive cells were observed in the mesothelial cells in the perilymphatic space, in the sensory and supporting cells in the utricle and ampulla, and in the transitional and dark cells in the ampulla. When the otoconial membrane was preserved, lacZ-positive cells were not distributed in the utricular sensory epithelium. These findings suggest that adenovirus vectors can transform a variety of vestibular epithelial cells, but that it is difficult for adenovirus vectors to pass through the otoconial membrane.

Five patients of various ages with difficulty in speech discrimination were evaluated. All showed evidence of abnormal auditory brainstem responses (ABRs) beginning with the VIIIth cranial nerve. Broad summating potentials were evoked on their electrocochleograms (EcochGs) and they all exhibited almost normal cochlear outer hair cell function by otoacoustic emissions (OAEs) recordings. Behavioural audiometric testing revealed a mild to moderate elevation of pure-tone threshold in all patients. The shape of their pure-tone losses varied, being predominantly low-frequency in four patients (rising slope pattern) and flat across all frequencies in one patient. Speech intelligibility scores of all patients were poor and out of proportion to what would have been expected if threshold elevation of pure-tone was of cochlear origin (i.e. markedly poor scores on the speech audiogram with good scores on the auditory comprehension test). Patients were neurologically normal when the hearing impairment was first manifested. We suggest that this type of hearing impairment is due to an isolated and sporadic disorder of auditory nerve function. It occurs in isolation and does not seem to be part of a generalized neuropathological process.

To better understand the roles of NeuroD, a member of the basic helix-loop-helix transcription factor family, during the differentiation of olfactory receptor neurons, we studied the expression of NeuroD in developing and aging mouse olfactory epithelium (OE). During embryonic period, NeuroD expression is confined in the basal compartment of OE. During neonatal period, NeuroD expression is detected in the middle compartment and in the basal compartment of OE. In the adult, the number of NeuroD expressing cells in the basal compartment significantly decreased, while the NeuroD- positive cells in the middle compartment was maintained throughout lifetime. This dual phase expression pattern of NeuroD suggests multiple roles of NeuroD in the neurogenesis of ORNs.

Olfactory neuroblastoma (ONB) is a highly vascularized and malignant tumor arising in olfactory neuronal precursors from the paranasal sinuses. Previously, we showed that treatment of JFEN cells with transforming growth factor (TGF)-α caused them to differentiate and respond to chemical odorants, whereas basic fibroblast growth factor (bFGF) treated cells differentiated and died. In the present study we show that established ONB tumors treated with bFGF upregulate the bFGF receptor (FGFR1) prior to differentiation. This cellular differentiation was evidenced by bFGF-induced expression of the human runt homologue AML1 (PEBP2αB, CBFA-2) that is highly expressed in developing olfactory neuroepithelium and TrkA, a preferred nerve growth factor receptor. Since TrkA is expressed in supporting cells, but not in mature olfactory neurons, we hypothesize that the expression of AML1 and TrkA in bFGF-treated JFEN cells induced supporting cell differentiation. Collectively, these results have implications for the treatment of patients afflicted with ONB.

We measured human evoked magnetic fields to binaural sounds with an interaural time delay as a cue for auditory localization. By analyzing the topography of auditory-evoked magnetic fields in the middle-latency, we demonstrated that particular cortical regions represent the direction of sound localization by their activity level. Upon presenting a binaural sound, the first representations were found in the middle frontal region as well as the superior temporal region of the right hemisphere approximately 19 ms after the stimulation, but their patterns differed. Other cortical regions including the prefrontal and parietal spatial areas were affected within roughly 60 ms. The results showed that the right hemisphere is dominant even in the preattentive stage of auditory spatial processing of sounds from different directions.

We report a pediatric patient with auditory agnosia as a sequel of herpes encephalitis. His early development was completely normal. He uttered three words at 12 months old. Disease onset was 1 year and 2 months of age. He was discharged from the hospital seemingly with no sequel; however, he could not recover his intelligible words even at age 2 years. He was diagnosed as having auditory agnosia caused by bilateral temporal lobe injury. We began to train him at once, individually and intensively. Adult patients with pure auditory agnosia followed by two episodes of temporal lobe infarction have impairment in central hearing but not inner language. Therefore, they can communicate by reading and writing. Moreover, impairment in hearing is not always severe and is often transient. However, despite long-term (more than 15 years) energetic education and almost normal intellectual ability (Performance IQ of Wechsler Intelligence Scale for Children-Revised was 91), our patient's language ability was extremely poor. Cerebral plasticity could not work fully on our patient, whose bilateral temporal lobe was severely injured in early childhood. The establishment of a systematic training method in such patients is an urgent objective in this field. (J Child Neurol2000;15:626-629).