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Background: The electrically evoked auditory brainstem response (eABR) during cochlear implantation in common cavity (CC) deformity has not been clinically well studied. Aim/Objective: To investigate the eABR wave configuration during cochlear implantation, the postoperative development of hearing, and educational settings in infants with CC deformity. Materials and Methods: Nine infants who were congenitally deaf and found to have CC deformity and suspected cochlear nerve deficiency by temporal bone CT and MRI were studied. All of them underwent sequential and unilateral cochlear implantation and their eABRs were recorded during the surgery. The postoperative development was followed up. Results: eABRs of all the nine infants with CC deformity showed that the mean peak of the evoked wave V (eV) was the same as that in controls at latencies but was twofold higher than that in controls at thresholds and their postoperative hearing thresholds improved markedly. Conclusion and Significance: The brainstem auditory pathways of the infants were considered intact on the basis of the eV peak latencies in the eABRs. The postoperative development of their speech and hearing abilities and their educational settings varied, probably because of the twofold higher thresholds of their eABRs and limited number of auditory neural units. [ABSTRACT FROM AUTHOR]

Background： The function of common cavity deformity demonstrated by temporal bone CT and MRI has been unknown. Aim/Objective: To investigate the developmental changes of vestibular ocular reflex and acquisition of postural control in infants with common cavity deformity. Material and methods: Eight infants who were congenitally deaf complicated by common cavity deformity were studied. The damped rotational chair test was carried out to evaluate vestibular ocular reflex. Acquisition of head control and independent walking in these infants was compared with that in normal infant's milestones of gross motor development. Results: All of the eight infants with common cavity deformity did not show per-rotatory nystagmus in the damped rotational chair test around the first year of life. However, a normal number of beats and a longer duration of per-rotatory nystagmus for their age were recorded at around three or four years of age. Conclusions and significance: In the eight infants with common cavity deformity, vestibular ocular reflex was not present around the first year of life, but appeared after three or four years probably because of some vestibular sensory cells. Head control and independent walking were delayed but eventually acquired by the central vestibular compensation. [ABSTRACT FROM AUTHOR]

Conclusion: Each of eight patients with bilateral microtia and atresia underwent bilateral reconstruction of the auricles and external auditory canals and were fitted bilateral canal-type hearing aids in the operated ears to replace a bone conduction hearing aid. The ability to discriminate inter-aural intensity difference (IID) and even inter-aural time difference (ITD) was retained in all these patients. Objective: This study studied the post-operative sound lateralization ability of patients with bilateral microtia and atresia after total reconstruction of both auricles and external auditory canals, followed by fitting of bilateral canal-type hearing aids. Methods: Eight patients with bilateral microtia and atresia ranging in age from 13–43 years were recruited in this study. Each of them underwent bilateral reconstruction of the auricles and external auditory canals and were fitted canal-type hearing aids in both the operated ears to replace a bone conduction hearing aid. A sound lateralization test was conducted to determine IID and ITD discrimination ability thresholds. Results: In all the patients, the IID discrimination ability thresholds of the patients were more than 3-fold those of the controls, the ITD discrimination ability threshold was more than 5-fold those of controls, and binaural hearing was retained. [ABSTRACT FROM AUTHOR]

To examine the effect of vestibular ocular reflex on gross motor development in children with semicircular canal aplasia and hypoplasia. Case series. Children with congenital hearing loss underwent temporal bone computed tomography to assess their inner ear morphology. In this study, we examined eight children with bilateral complete aplasia of semicircular canals and seven children with bilateral hypoplasia of semicircular canals. Their vestibular ocular reflex was assessed using a damped rotational chair test. Their gross motor development was assessed by examining their ages of acquisition of head control and independent walking. All eight children with semicircular canal aplasia were diagnosed as having CHARGE syndrome and five children were found to have CHD7 mutations. Cochlear morphological examination showed that cochlear hypoplasia type III was the most common in eight of 16 ears in children with semicircular canal aplasia. In semicircular canal hypoplasia, incomplete partition type II was found in seven of 14 ears. All eight children with semicircular canal aplasia showed no response in the damped rotational chair test. Even the three children followed up were unresponsive in all tests. In the group with semicircular canal hypoplasia, three children showed normal responses, one child showed no response, and three children showed poor responses. The mean age of acquisition of head control was 9.1 ± 6.3 months and that of independent walking was 31 ± 8.1 months in children with semicircular canal aplasia. The mean age of acquisition of head control was 6.0 ± 2.8 months and that of independent walking was 19.9 ± 4.9 months in children with semicircular canal hypoplasia. We found that children with semicircular canal aplasia have severe dysfunction of the vestibular ocular reflex, and vestibular sensory cells derived from the semicircular canal may not be present. Semicircular canal hypoplasia is associated with dysfunction of the vestibular ocular reflex, but vestibular sensory cells may be present, and rotary nystagmus develops with growth similar to that observed in normal children previously reported. Semicircular canal aplasia is associated with CHARGE syndrome, and affected children tended to have a slower gross motor development. It was suggested that the combination of visual impairment and mental retardation may delay the development of central-level integrated functions and may further delay motor development. [ABSTRACT FROM AUTHOR]

Conclusion: In patients with unilateral microtia and atresia after reconstruction of the auricle and external canal and fitting of a canal-type hearing aid for the operated ear, the ability to discriminate the inter-aural intensity difference (IID) was acquired in all of the patients, whereas that to discriminate inter-aural time difference (ITD) was acquired in one-half of the patients. Objective: To study the post-operative sound lateralization ability in patients with unilateral microtia and atresia after reconstruction surgery of the auricle and external canal and fitting of a canal-type hearing aid of the operated ear. Methods: Eighteen patients with unilateral microtia and atresia ranging from 13–24 years of age were recruited in this study. All of them underwent reconstruction of the auricle and external canal and were fitted a canal-type hearing aid for the operated ear. The sound lateralization test was conducted to determine IID and ITD using a self-recording apparatus. The test stimulus was a continuous narrow-band noise at 500 Hz and 50 dBHL presented to the right and left ears through the air conduction receivers. Results: IID could be measured in all of the patients, whereas ITD could be measured in only nine out of the 18 patients. Post-operative binaural hearing could be acquired in all the patients. [ABSTRACT FROM AUTHOR]

In 1996, a new type of bilateral hearing disorder was discerned and published almost simultaneously by Kaga et al. [1] and Starr et al. [2]. Although the pathophysiology of this disorder as reported by each author was essentially identical, Kaga used the term "auditory nerve disease" and Starr used the term "auditory neuropathy". Auditory neuropathy (AN) in adults is an acquired disorder characterized by mild-to-moderate pure-tone hearing loss, poor speech discrimination, and absence of the auditory brainstem response (ABR) all in the presence of normal cochlear outer hair cell function as indicated by normal distortion product otoacoustic emissions (DPOAEs) and evoked summating potentials (SPs) by electrocochleography (ECoG). A variety of processes and etiologies are thought to be involved in its pathophysiology including mutations of the OTOF and/or OPA1 genes. Most of the subsequent reports in the literature discuss the various auditory profiles of patients with AN [3,4] and in this report we present the profiles of an additional 17 cases of adult AN. Cochlear implants are useful for the reacquisition of hearing in adult AN although hearing aids are ineffective. In 2008, the new term of Auditory Neuropathy Spectrum Disorders (ANSD) was proposed by the Colorado Children's Hospital group following a comprehensive study of newborn hearing test results. When ABRs were absent and DPOAEs were present in particular cases during newborn screening they were classified as ANSD. In 2013, our group in the Tokyo Medical Center classified ANSD into three types by following changes in ABRs and DPOAEs over time with development. In Type I, there is normalization of hearing over time, Type II shows a change into profound hearing loss and Type III is true auditory neuropathy (AN). We emphasize that, in adults, ANSD is not the same as AN. [ABSTRACT FROM AUTHOR]

Conclusion: A right-handed 38-year-old man's complete loss of hearing could be diagnosed as cortical deafness caused by cerebral vascular lesions in bilateral auditory cortices. Objective: The aim of this case report was to study the pathophysiology of a particular patient who manifested deafness without residual hearing and lost somatosensory sensation, vestibular sensation, and articulation ability after a right internal carotid-posterior communicating artery (IC-PC) aneurysm and subarachnoidal hemorrhage. Methods: MRI, aphasia and neurological tests, subjective and objective audiometry, and vestibular function tests were performed. Results: The neurological test revealed system loss of somatosensory sensation with normal motor function and articulation ability. Brain imaging revealed extensive infarction in the bilateral primary auditory cortices, postcentral gyruses, and the bilateral partial third frontal gyruses. Pure-tone audiometry of both ears revealed off-the-scale results and speech audiometry demonstrated 0% maximum speech discrimination. However, objective audiometry showed normal distortion product otoacoustic emissions (DPOAE) and normal auditory brainstem response (ABR). The patient showed 0% perception of environmental, speech, and music sounds in both ears. He was unable to feel vestibular sensation despite normal caloric nystagmus. He showed no damage to his larynx or articulation organs. [ABSTRACT FROM AUTHOR]

Introduction: Recent studies have reported poor cognition, such as attention and working memory, in adults with listening difficulties (LiD). However, they do not adequately describe the actual state of poor attention ability in adults with LiD. We examined the state of auditory attention in adults with and without LiD in tasks requiring multiple attention controls. Methods: Twenty-one adults who had normal hearing but complained about LiD encountered during everyday life and 22 healthy controls were included. We presented a target detection task using an odd-ball format for one ear and a sentence repetition task for the other ear. In the target detection task, participants listened to the 1,000-Hz tone served as the standard stimulus, while they had to accept a 2,000-Hz tone presented as the deviant stimulus. In the sentence repetition task, short sentences were presented. The stimuli presented to them were played on a personal computer at the most comfortable level. The participants heard these stimuli through headphones. They were required to press a key for standard stimuli in the target detection task and repeat what they heard immediately in the repetition task. We compared the response accuracy for each ear task between adults with and without LiD. Results: Our results showed that there were significant differences between the participant groups in the auditory dual-task under the dichotic listening situation. When examined individually, four adults with LiD had decreased scores in both the sentence repetition and target detection task, while the other nine participants showed a bias toward either task. Furthermore, the analysis of reaction time for pressing button revealed that the standard deviation of reaction time was extended in participants who scored poorly in either of the ear tasks. On the other hand, all adults without LiD were able to conduct the auditory dual-task exactly and promptly. Conclusion: The results suggest that adults with LiD have difficulties in appropriately allocating various cognitive abilities required for each task. We concluded that auditory attention is an important ability to conduct the auditory dual-task, and this is applicable for adults with LiD. Therefore, we believe that it is necessary to use auditory tests that require complex attentional abilities in listening, such as those required in daily life, to assess adults with LiD. [ABSTRACT FROM AUTHOR]

Conclusions: When vestibular function is reduced in the rotational chair test in children with severe hearing loss, the vestibular function may be acquired later due to maturing vestibular sensory cells and vestibular nerve of the inner ear along with physical growth. Objectives: To examine the relationship between acquisition of motor function and vestibular function in children with bilateral severe hearing loss. Methods: A total of 97 children under 4 years old with hearing loss defined as a hearing threshold of both ears greater than 80 dB were included in this study. For evaluation of vestibular function, a damped-rotational chair test was performed and the horizontal nystagmus was recorded using electronystagmography (ENG). Results: Head control and independent walking were delayed in 28 of 97 children with severe hearing loss. Reduced response to the rotational chair test was observed in 16 of 97 children (16.5%), with 11 of these children having inner ear anomalies and reduced vestibular function. Of the 10 children who were followed up by the rotational chair test, 2 children with idiopathic congenital hearing loss without inner ear anomalies (100%) and 6 of 8 children with bilateral inner ear anomalies (75%) showed more obvious nystagmus during rotation compared with the initial examination. [ABSTRACT FROM AUTHOR]

Abstract: We report VEMP results in a patient with aplasia of bilateral semicircular canals and a small vestibular cavity. The patient was a 27-year-old male. The computed tomograph showed absolutely no formation of his semicircular canals, together with hypoplasia of his vestibular cavity and cochlea in both ears. His oVEMP was recorded near the extraocular muscles on the left side when elicited by BCV in the Fz. The clinical profile of this patient suggested that oVEMP elicited by BCV recorded near the extraocular muscles originated from otolithic end organs, and not from semicircular canal afferents. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Pelizaeus-Merzbacher disease (PMD) is a white matter dystrophy of the brain. Most children with PMD require comprehensive nursing care. Their speech and language abilities are poor or absent. Therefore, evaluating hearing ability is difficult in children with PMD. We have followed up two patients with PMD since early childhood. Patient 1 is an 11-year-old boy, and patient 2 is a 15-year-old adolescent boy in whom horizontal nystagmus was recognized after birth. Magnetic resonance imaging showed diffuse dysmyelination of the cerebral white matter. Auditory brainstem response recordings showed only waves I and II and the absence of all subsequent components. However, conditioned orientation reflex audiometry showed a threshold of 20-30 dB. Both patients can converse orally and have auditory perception and speech abilities better than those of most patients with PMD in the literature. We report on the development of their hearing and speech abilities. [ABSTRACT FROM AUTHOR]

The case of an 8-year-old girl who manifested cortical blindness and whose color drawings of faces and objects were without outlines is reported. Her birth was uneventful. When she was 10 months old, she fell down to the floor from a chair, resulting in a subarachnoidal hemorrhage. A repeat brain MRI revealed localized lesions in the visual cortices in the right and left hemispheres. As she grew older she was found to have visual imperceptions. She was found to have difficulties in learning visually the names of objects with form and letters, and in recognizing faces of her family. However, she was able to discriminate well the colors of faces and objects and learn easily the names of the objects with form by touching. She seemed to utilize subcortical vision for seeing colors of faces and objects. [ABSTRACT FROM AUTHOR]

A 27-year-old female showed auditory agnosia after long-term severe hydrocephalus due to congenital spina bifida. After years of hydrocephalus, she gradually suffered from hearing loss in her right ear at 19 years of age, followed by her left ear. During the time when she retained some ability to hear, she experienced severe difficulty in distinguishing verbal, environmental, and musical instrumental sounds. However, her auditory brainstem response and distortion product otoacoustic emissions were largely intact in the left ear. Her bilateral auditory cortices were preserved, as shown by neuroimaging, whereas her auditory radiations were severely damaged owing to progressive hydrocephalus. Although she had a complete bilateral hearing loss, she felt great pleasure when exposed to music. After years of self-training to read lips, she regained fluent ability to communicate. Clinical manifestations of this patient indicate that auditory agnosia can occur after long-term hydrocephalus due to spina bifida; the secondary auditory pathway may play a role in both auditory perception and hearing rehabilitation. [ABSTRACT FROM AUTHOR]

The influence of aging on hearing and vestibular function in patients with auditory neuropathy has not been investigated. The purpose of this study was to investigate how hearing and vestibular function in this disease change with aging. The subjects were three female patients with auditory neuropathy. We checked their hearing and vestibular function by speech discrimination tests, ABR, ECochG, DPOAE, caloric test, damped-rotational chair test, and VEMPs. In all three patients, speech discrimination ability and vestibular function markedly declined with aging. However, speech language understanding and higher brain function were less affected by aging. [ABSTRACT FROM AUTHOR]

In 1999, three workers received high doses of radiation in a small Japanese plant while they were preparing fuel for an experimental reactor. This criticality accident at melting point was caused by the addition of too much uranium enriched to a relatively high level, causing a ''criticality'' (a limited uncontrolled nuclear chain reaction), which continued intermittently for 20 h. The three workers concerned were hospitalized, two in a critical condition. The first worker died 12 weeks later, and the second worker 7 months later. The third worker is in a healthy condition. We report on the temporal bone histopathological features of the second worker. Our temporal bone study revealed: 1) the large loss of bone marrow tissue with a small number of myelocytes remaining in the mastoid bone and the abundance of fatty tissue in the mastoid bone, 2) inflammation of the mucosal layer of the middle ear and the mastoid air cells, 3) mild degeneration of the spiral ganglions and the sensory hair cells of the cochlea, 4) mild degenerative changes of sensory hair cells of the semicircular canals and otolith organs, and 5) vestibular ganglions and geniculate ganglions were well preserved. [ABSTRACT FROM AUTHOR]

Conclusion: We regard spontaneous otoacoustic emission (SOAE) as a unique phenomenon due to spontaneous outer hair cell hyperactivity during the infantile period in these two infants. Objectives: We report the cases of SOAEs in two infants, which were audible to their parents. We were able to hear continuous sounds from these two infants' ears. We studied their hearing and the emitted sounds objectively. Patients and methods: Patient 1 was a 5-month-old girl and patient 2 was an 11-month-old girl. Their parents heard continuous sounds emanating from their infants' ears. Audiological examinations and frequency analysis were conducted. Results: The distortion-product otoacoustic emissions (DPOAEs) and auditory brainstem responses (ABRs) of the two patients were normal. Analysis of the continuous sounds demonstrated frequencies of 4.2 and 6.5 kHz for patient 1 and 6.7 kHz for patient 2. These audible sounds were diagnosed as SOAEs. The SOAEs in these infants did not disappear with their development in the last 2 years. [ABSTRACT FROM AUTHOR]

Using magnetoencephalography (MEG), we report here the hemispheric dominance of the auditory cortex that is selectively modulated by unexpected errors in the lyrics and melody of songs (lyrics and melody deviants), thereby elucidating under which conditions the lateralization of auditory processing changes. In experiment 1 using familiar songs, we found that the dipole strength of responses to the lyrics deviants was left-dominant at 140 ms (M140), whereas that of responses to the melody deviants was right-dominant at 130 ms (M130). In experiment 2 using familiar songs with a constant syllable or pitch, the dipole strength of frequency mismatch negativity elicited by oddballs was left-dominant. There were significant main effects of experiment (1 and 2) for the peak latencies and for the coordinates of the dipoles, indicating that the M140 and M130 were not the frequency mismatch negativity. In experiment 3 using newly memorized songs, the right-dominant M130 was observed only when the presented note was unexpected one, independent of perceiving unnatural pitch transitions (i.e., perceptual saliency) and of selective attention to the melody of songs. The consistent right-dominance of the M130 between experiments 1 and 3 suggests that the M130 in experiment 1 is due to unexpected notes deviating from well-memorized songs. On the other hand, the left-dominant M140 was elicited by lyrics deviants, suggesting the influence of top-down linguistic information and the memory of the familiar songs. We thus conclude that the left- lateralized M140 and right-lateralized M130 reflect the expectation based on top-down information of language and music, respectively. Hum Brain Mapp, 2009. © 2008 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Congenitally deaf infants and children commonly suffer vestibular failure in both ears, and impairment of postural control, locomotion, and gait. The development of gross motor functions, such as head control, sitting, and walking is likely to be delayed, but fine motor function is usually preserved unless disorders of the central nervous system are present. These children can eventually catch up with their normal peers in terms of development and growth as a result of central vestibular compensation. The visual and somatosensory systems, pyramidal and extrapyramidal motor system (cerebellum, basal ganglia, cerebrum) and intellectual development, compensate for vestibular failure in infants and children with congenitally hypoactive or absent function of the semicircular canals and otolith organs. [ABSTRACT FROM AUTHOR]

Conclusions. The horizontal portion of the petrous carotid artery (HPCA) of mandibulofacial dysostosis (MFD) patients had anterior-inferior displacement or was aplasia at birth. Our findings indicate that most MFD patients have aplasia of the internal carotid artery. This information may be very important for safe reconstruction surgery in atresia. Objective. MFD rarely has malformations of the cardiovascular system such as those seen in Goldenhar syndrome. This study aimed to compare MFD patients and normal subjects with respect to the length and diameter of the HPCA. Subjects and methods. We radiographically studied 22 MFD patients (44 sides) using high-resolution computed tomography (HRCT), measuring the length and diameter of the HPCA and the angle between the right and left HPCA using computer software. Findings were compared with those in 86 ears with normal auricles (control group) using the nonparametric test. Results. The HPCA in MFD patients averaged 23.2 mm in length and 4.8 mm in diameter. The angle between the right and left HPCA averaged 100.2°. In MFD patients, on average, HPCA were 2.0 mm shorter (p=0.001) and 0.4 mm narrower (p=0.016) than in control subjects. Mean angle between right and left HPCA was 5.4° more acute in MFD patients than in control subjects (p=0.026). Moreover, the genu of the vertical and horizontal petrous ICA in the MFD group was on average 3.2 mm more inferior than in controls (p<0.001). [ABSTRACT FROM AUTHOR]

Conclusion. The early diagnosis of deafness and the early fitting of hearing aids in multiply handicapped children are recommended for language development in these children even when their neurological or mental status is poor. Subjects and methods. The subjects consisted of 5 hearing-impaired infants with no other problems and 28 hearing-impaired children with multiple handicaps. Behavioral audiometry and auditory brainstem responses were used for evaluating hearing impairment. The 5 hearing-impaired infants with no other problems underwent hearing aid fitting at approximately 1 year of age and the 28 hearing-impaired children with multiple handicaps underwent hearing aid fitting at various times from 1 to 5 years of age. The effects of their hearing aids were compared on the basis of auditory behavioral changes. The developmental scale of auditory behaviors in infancy that we proposed was introduced to evaluate the development of auditory behaviors. Results. The auditory behaviors of the hearing-impaired children with no other problems showed constant changes with age after hearing aid fitting. However, among the 28 hearing-impaired children with multiple handicaps, 17 showed improvement in auditory behaviors, 5 showed no improvement in auditory behaviors because of the associated severe motor and mental retardation, and epilepsy, and 6 were unable to adapt to wearing hearing aids. [ABSTRACT FROM AUTHOR]

This report shows the changes that occurred in consecutive audiograms of a patient who underwent chemotherapy and radiotherapy for nasopharyngeal cancer and the histopathological examination of the temporal bones. Both conductive and sensorineural hearing loss developed, but followed different modes of progression. In the left ear, an air-bone gap appeared and deepened, while in the right ear, severe conductive hearing loss was present upon admission and improved after treatment. Sensorineural hearing loss was worse in the right ear, but deteriorated gradually in both ears. Histology revealed tumor invasion in the right temporal bone. Both middle ears showed effusion, but no radiation-induced changes that may be responsible for the conductive loss. The main changes in the cochlea were vascular stria degeneration, spiral ligament atrophy, and spiral ganglion cell depletion, while the hair cells were only occasionally missing. Apart from confirming what has been established previously by other authors, some interesting findings were observed: 1) in addition to the high frequency hearing loss typically caused by cis-platinum and by radiation, there was also low frequency hearing loss, and 2) the cochlear damage was most severe in the vascular stria and spiral ganglions, sparing the hair cells. [ABSTRACT FROM AUTHOR]

Conclusions. While infants under the age of 1 year exhibited a high rate of abnormal intensities in the middle ear and mastoid cavities, older infants showed no abnormal intensities in these regions. From the signal intensity on T1- and T2-weighted MRI, the abnormal intensities in the middle ear cavity were considered to represent liquid effusion. Taken together with the findings of temporal bone CT, the abnormal intensities in the mastoid cavity were considered to represent bone marrow. Objective. Histopathological studies of the temporal bone and tympanometry investigations have reported the presence of mesenchyme and liquid effusion in the middle ear cavity of infants. However, very few CT or MRI middle ear cavity findings of newborns and infants have been published, and none have included the mastoid cavity. We therefore performed an MRI study of the middle ear and mastoid cavities of infants under 2 years old (83 cases, 88 imaging series). Subjects and methods. MRI (1.5 T) was originally performed on suspicion of brain disorders in infants aged under 2 years. All MRI slices were studied and classified on the basis of the distribution of abnormal intensities in the middle ear and mastoid cavities. Results. All the abnormal imaging appeared in infants under 1 year old, in particular, 74.24% (n=49) of abnormal imaging appeared in the first 20 weeks after birth. [ABSTRACT FROM AUTHOR]

Summary: Objective: The purpose of this study is to investigate the early myelination patterns of brainstem auditory nuclei and pathway on magnetic resonance imaging compared with past histological research. We aimed to identify the time course difference in myelination of the brainstem auditory nuclei and pathway between magnetic resonance imaging and histological research results. Methods: Subjects were 192 infants ranging in age from −4 to 224 corrected postnatal weeks. Images were obtained using a 1.5T magnetic resonance unit. In four sites (cochlear nucleus, superior olivary nucleus, lateral lemniscus, inferior colliculus) of the brainstem auditory nuclei and pathway on four cross-sections obtained perpendicular to the long axis of the brainstem, signal changes of T1- and T2-weighted magnetic resonance images were analyzed using a region-of-interest methodology according to corrected postnatal age. Results: The cochlear nucleus and superior olivary nucleus showed myelinated intensity change from −3 to 13 corrected postnatal weeks on T2-weighted images. The lateral lemniscus showed myelinated intensity change from −3 to 8 corrected postnatal weeks on T1-weighted images and from −1 to 13 corrected postnatal weeks on T2-weighted images. The inferior colliculus showed myelinated intensity change from −2 to 39 corrected postnatal weeks on T2-weighted images. Conclusions: Magnetic resonance imaging revealed the signal intensity change by myelination 11–18 weeks later than those reported in the histological literature. This time lag suggests that apart from histological research, the necessity for the milestones of auditory pathway maturation using MRI is suggested to evaluate the development of brainstem auditory pathway using MRI. This result suggests that myelination does not take place suddenly but happens gradually, so definite myelination, namely the complete change of myelin sheath ingredients, loss of water, and gain of lipids, is needed to be detected by magnetic resonance imaging. [Copyright &y& Elsevier]

The relationship between meningitis and sensorineural hearing loss (SNHL) has long been studied. Many histopathological studies of animal models and human temporal bones with respect to bacterial meningitis have been carried out. However, the relationship between SNHL and tuberculous meningitis was seldom addressed and the pathophysiology remains unclear. We carried out temporal bone studies on material from a 22-year-old patient who developed a right unilateral SNHL before dying from tuberculous meningitis. The histopathological findings for the right temporal bone were as follows: (1) inflammation mainly appeared in the internal auditory canal, modiolus and Rosenthal's canal and extended to the osseous spiral ligament, whereas the perilymphatic spaces were less involved; (2) the organ of Corti, cochlear nerve fibres and spiral ganglion cells were severely degenerated, particularly in the basal and middle turns; (3) the contralateral side (for which the patient had no complaints) showed an inner space free from inflammation, but some granulomatous formations were observed in the middle ear cavity. We conclude that the modiolus and cochlear aqueduct are the main routes for the spread of infection from the meninges to the inner ear. The progression of hearing loss resembles that of bacterial meningitis and shares attributes of retrocochlear SNHL. [ABSTRACT FROM AUTHOR]

Abstract: Objective: In the perception of sound lateralization a sound source exists in the side that the sound reaches an ear earlier in time or louder in intensity than the other ear. It is an imaginary phenomenon where the direction of sound is lateralized by an interaural time difference (ITD) and an interaural intensity difference (IID) of sound by both ears. It is speculated from pathophysiological findings that ITD and IID are processed by different pathways, but it has been not yet proved which of them is predominant in sound lateralization. The time difference can be traded by the intensity difference (fixed time versus intensity trade), and vice versa (fixed intensity versus time trade). In order to investigate predominance in this trade, we measured possible differences in effects by ITD and IID using two opposite trade phenomena of time versus intensity trade and intensity versus time trade. Methods: The fixed time versus intensity trade test for selected narrow-band noise was investigated in 30 subjects with normal hearing. Using headphones, the subjects were instructed to push the button when the sound bias generated by fixed ITD (4dB, 6dB, 8dB, 10dB, 12dB, 14dB, 16dB, 18dB, 20dB) was traded by gradually increased IID. The plot figure with fixed ITD and required IID to trade was made. It was compared with similar fixed intensity versus time trade test in 12 subjects with normal hearing. The fixed ITD (200–600μs) was traded by gradually increased IID and the plot figure was made. Results: In fixed time versus intensity trade test, each fixed ITD could be traded with an average of 6dB of IID. On the other hand, in fixed intensity versus time trade test, ITD required to trade fixed IID increased, in proportion to fixed IID increased. Conclusion: It is concluded that predominance exists. In fixed time versus intensity trade test, the uniform amount of IID is required to trade the different ITD. However, in the novel fixed intensity versus time trade test, the phenomenon was in completely different manner that ITD in proportion to the given IID is required to trade. [Copyright &y& Elsevier]

The aim of this study was to investigate auditory cortex function in the context of auditory stimuli in a patient with auditory agnosia due to bilateral lesions confined to the auditory radiations. A male patient experienced mild left temporal hemiplegia because of right putaminal hemorrhage at the age of 43 years. Thereafter he recovered completely but hypertension persisted. When he was 53 years old, he suffered left putaminal hemorrhage and went into a coma. After recovering from the coma and right hemiplegia he could hear but could not discriminate speech sounds. Brain CT and MRI demonstrated small bilateral lesions confined to the auditory radiations. Magnetoencephalography demonstrated the disappearance of middle latency responses and auditory-evoked potential studies showed a very small Pa peak. In contrast, a positron emission tomography study demonstrated a marked increase in blood flow in the bilateral auditory cortex in response to both click and monosyllable stimuli. It is speculated that the auditory cortex receives functional projections from the cochlea via non-specific pathways in the cerebral hemispheres. [ABSTRACT FROM AUTHOR]

Summary: Mobius syndrome is characterized by congenital bilateral facial palsy and abducens nerve paralysis, but reports of radiological and electrophysiological findings are scarce. A 4-year-old boy presented with mask-like facies noted at birth after a 34-week pregnancy. Examination revealed bilateral facial and abducens nerve paralysis with no other neurological abnormalities. Computed tomography revealed bilateral absence of facial nerve canal in the middle ear. Brain magnetic resonance imaging indicated a narrow than expected nerve in the internal auditory canal (IAC). Evoked electromyography and blink reflex testing to evaluate facial nerve function yielded no responses bilaterally. Facial palsy thus appears to be caused by facial nerve dysplasia or aplasia. [Copyright &y& Elsevier]

Hypoxia in adults frequently causes damage to the brain, but not the inner ear. However, hypoxia in neonates with inadequate blood–inner ear barrier function causes damage to the inner ear, leading to hearing loss and equilibration disorder. Clinically, asphyxiated neonates sometimes have the complication of sensorineural hearing impairment at high frequencies. Many reports suggest that this problem is caused by hypoxic encephalopathy. However, it is not clear whether inner ear disorders are present. In this report we examined the inner ear pathology of four asphyxiated neonates using serial sections of temporal bone. The subjects ( n =4) were 1–13-day-old neonates with pregnancy periods of 24–36 weeks. Their fetal growth curves were within the normal range. There was one case each of twin pregnancy, placental abruption, placenta previa and meconium aspiration syndrome. For the case of severe neonatal asphyxia, damage to the inner ear included the degeneration and disappearance of outer hair cells of the organ of Corti and edematous changes in the stria vascularis. Degeneration of spiral ganglion and vestibular ganglion cells was observed in two of the other cases. [ABSTRACT FROM AUTHOR]

Three young adult males with Pelizaeus–Merzbacher disease have been followed up since childhood. This disease is thought to be a dysmyelinating disorder of the brain during the prenatal period caused by gene mutations. The patients manifested horizontal nystagmus and severe rigidity of the extremities. Although the patients showed only waves I and II in auditory brainstem responses, they had relatively good hearing ability at ≈30&ThickSpace;dB. They could not speak words at all but could hear well and enjoy listening to conversation and music. One of them had a normal hearing threshold in pure-tone audiometry and a normal speech discrimination rate in speech audiometry. This can be explained by a nerve conduction blockade through dysmyelinated axons or the desynchronization of neurons and nerves responsible for the waves following waves I and II. At present, all three patients are living with their families. We report their present hearing, speech and language abilities. [ABSTRACT FROM AUTHOR]

Summary: The location of lesions causing hearing loss in patients with cerebral palsy due to asphyxia or neonatal hyperbilirubinemia has remained unclear. We performed behavioral audiometry, distortion product otoacoustic emission (DPOAE) and auditory brainstem evoked response (ABR) in six patients with cerebral palsy due to asphyxia or neonatal hyperbilirubinemia in order to determine the lesion location causing their hearing impairment. In all cases, behavioral audiometry revealed a threshold elevation of 50–75dB and ABR were no response. DPOAE were totally absent in five patients and normal in one patient. Our study suggests that lesions causing hearing loss potentially include the organ of Corti especially at the outer hair cells and the cochlear nerve. [Copyright &y& Elsevier]

Hearing loss and equilibrium dysfunction have different etiologies in patients with large vestibular aqueduct syndrome. We suggest that all children with distal renal tubular acidosis (dRTA) should be subjected to an equilibrium study and audiological evaluation, as well as to a CT or MRI scan. dRTA has been described in association with sensorineural hearing loss, but there are no reported cases that have been examined in detail using audiological and equilibrium studies. We report here a case of progressive sensorineural hearing loss with a large vestibular aqueduct and dRTA, and the results of audiological and equilibrium studies. A 31-year-old female presented with hearing loss, tinnitus and vertigo. She had been treated with oral sodium citrate, potassium citrate and potassium chloride supplementation because of dRTA since the age of 1 month. The pure-tone audiogram of the patient was off the scale for the right ear and showed progressive sensorineural hearing loss for the left ear. Ice-water caloric testing showed canal paresis on the left side. Temporal bone CT and inner ear MRI revealed a large vestibular aqueduct and a large endolymphatic sac on both sides. [ABSTRACT FROM AUTHOR]

We report on two sisters with a T8993G point mutation of mitochondrial DNA, and their hearing evaluation. Considering auditory function, hearing in the elder sister remains almost normal. However, in the younger sister, the auditory brainstem response (ABR) threshold has fluctuated remarkably during a 3-year follow-up. The threshold changes of ABR in the younger sister suggest that her hearing problems may well be caused by both cochlear nerves and retrocochlear lesions. Our experience is clinically important because there have been only a few reports on hearing evaluation in patients with a T8993G point mutation of mitochondrial DNA. [Copyright &y& Elsevier]

Objective --To demonstrate the influence of auditory cortex lesions on auditory middle-latency responses (AMLRs) and middle-latency auditory-evoked magnetic fields (MLAEFs) in humans. Material and Methods --A total of 15 normal subjects, 9 patients with left auditory cortex lesions and 1 patient with a right auditory cortex lesion were studied. MLAEFs were recorded from each hemisphere of the brain in a magnetically shielded room using a 37-channel SQUID gradiometer. Simultaneously, AMLRs were recorded from the scalp at the vertex, C3 and C4. Tone bursts were used as auditory stimuli. Results --Pam responses of the MLAEF, which are typically evoked in the latency range of the Pa of the AMLR, and are localized at the auditory cortex as dipoles, were impaired or abolished over the left auditory cortex lesion in the patients with left-hemisphere lesions, but the Pa of the AMLR persisted. Conclusion --The main generator of the Pam in MLAEF was demonstrated to be the auditory cortex. The results also show that the Pa of the AMLR is evoked only partly from the auditory cortex. [ABSTRACT FROM AUTHOR]

Changes in the inner ear due to increased intracranial pressure have not yet been clearly defined. We present a postmortem temporal bone study of child with hydrocephalus. The temporal bone was from a 2-year-old female with IVth ventricle ependymoblastoma. In the basal turn of the cochlea, degeneration of the organ of Corti and the nerve ganglion was observed. In the top and middle turn, structures were intact. The utricle and saccule were well preserved. We propose that changes in the inner ear due to increased intracranial pressure begin in the base of the cochlea, and extend to the apex in decreasing degree. [Copyright &y& Elsevier]

Generally, cortical deafness is not complicated by anarthria and cortical anarthria does not affect auditory perception. We report a case of simultaneous progressive cortical deafness and anarthria. At the age of 70 years, the patient, a woman, noticed hearing problems when using the telephone, which worsened rapidly over the next 2 years. She was then referred to our hospital for further examinations of her hearing problems. Auditory tests revealed threshold elevation in the low and middle frequencies on pure-tone audiometry, a maximum speech discrimination of 25% and normal otoacoustic emissions and auditory brainstem, middle- and long-latency responses. An articulation test revealed abnormal pronunciation. Because of these problems only written and not verbal communication was possible; her ability to read and write was unimpaired. She showed no other neurological problems. Brain MRI demonstrated atrophic changes of the auditory cortex and Wernicke's language center and PET suggested low uptake of (18F) 2-fluoro-2-deoxy-d-glucose around the Sylvian fissures in both hemispheres. Neurologically, the patient was suspected of having progressive aphasia or frontotemporal dementia. Her cortical deafness and anarthria are believed to be early signs of this entity. [ABSTRACT FROM AUTHOR]

Objective: Event-related potentials (ERPs) and response latencies were recorded from aphasic subjects with auditory language processing impairments and age-matched normal controls, while performing a lexical-semantic evaluation task, aiming at clarifying whether ERPs could be a reliable measure for indicating language impairments in aphasic patients. Methods: The stimuli were 50 pairs of spoken words (prime word–target word): 25 pairs, which were semantically and/or associatively related to each other, and 25 pairs which were not. The subjects pressed a switch in response to the presentation of target words semantically related to the prime words. The ERP component analyzed in this study was N400. Results: With the performances, the response latencies were longer in the aphasic subjects than in the normal controls. With the ERPs, onset latencies of N400 were shifted behind in the aphasic patients compared to the normal controls. For the aphasic patients, there were correlations between the size of N400 and performances in auditory comprehension evaluated in the aphasia test. Conclusion: The conclusions drawn from the results are that not only response latencies in the lexical-semantic judgement task, but also N400 effects, may be a reliable clinical measure of the severity of even mild lexical-semantic impairments in aphasic patients. [Copyright &y& Elsevier]

Seven patients with Treacher–Collins syndrome were studied. All of patients were children or teenagers. Helical CT scanner (Toshiba) was used to reconstruct zygomatic arch and temporomandibular joint capsule on lateral aspect of temporal bone in five patients of microtia and atresia of both ears and two patients of narrow ear canals of both ears without microtia.Three-dimensional reconstructions of computed tomography on lateral aspect of temporal bone demonstrated various congenital abnormality including aplasia of zygomatic arch in seven patients and dislocation of temporomandibular joint capsule in seven patients. [Copyright &y& Elsevier]

Four pediatric patients whose bilateral auditory cortices were damaged by herpes encephalitis at an early age were studied. Their brain CT and MRI scans demonstrated common bilateral lesions of the auditory cortices. Their auditory perception was investigated by means of behavioral and objective hearing tests and auditory perception tests. All four patients showed mild or moderate hearing loss in the behavioral hearing test and normal auditory brainstem responses but did not manifest total deafness. Moreover, perception tests involving speech, environmental sounds and music demonstrated that most auditory perception ability had been lost in all patients. On reaching school age, the patients were enrolled in schools for the deaf or special schools for handicapped children. [ABSTRACT FROM AUTHOR]

We herein report a case of a 14-month-old infant who revealed a progressive hearing loss by repeated auditory evoked brainstem responses (ABR) during his 1 year stay in the neonatal intensive care unit (NICU). He was born prematurely with asphyxia, hyperbilirubinemia and respiratory distress. During his 1 year stay in the NICU he was under constant mechanical ventilation. Repeated ABRs over this year initially showed normal waves but subsequently demonstrated progressive hearing impairment (HI) leading finally to no responses. Possible causes of this progressive deafness (PF) include the multiple problems of asphyxia, hyperbilirubinemia and pulmonary disorders. [Copyright &y& Elsevier]

The human vestibule has preserved an ancestral sound sensitivity and it has been suggested that a reflex could originate from this property underlying cervical muscle micro-contractions secondary to strong acoustic stimulation. Previous studies have established that an early component of loud sound-evoked myogenic potentials from the sternocleidomastoid muscle originate in the vestibule. This is based on findings that the response can still be obtained from patients with complete loss of cochlear and vestibular (semi-circular canal) function. Our data confirm, in a more direct way, a saccular origin of this short-latency acoustic response and verifies that a saccular acoustic response persists in the human ear. The contribution of this response to the perception of loud sounds is discussed. It is concluded that vestibular response to sound might be used to assist in the rehabilitation of deafness. [ABSTRACT FROM AUTHOR]

Three infants with an almost complete absence of the cerebral hemispheres as a result of brain anomalies were studied both audiologically and neurologically. The brain anomalies were diagnosed by means of MRI and CT scans. Behavioral audiometry revealed reactions only to loud sound stimulations but auditory brainstem responses showed wave configurations and thresholds compatible with the ages of the infants. There were significant differences in the thresholds obtained by behavioral audiometry and auditory brainstem responses. It can be considered that these auditorily stimulated behavioral responses are evoked by auditory motor reflexes originating in the brainstem, but not by auditory perception. [ABSTRACT FROM AUTHOR]

Examines the necessity of geometric data for vocal cord dimensions to define boundaries to the laryngeal framework. Accessibility to define in various dimensions; Data measurements to be useful for biomechanical modelling; Approximations of the actual vocal cords to be reliable.

Bone-conducted sound lateralization tests to determine interaural time difference (ITD) and interaural intensity difference (IID) were conducted by means of a self-recording apparatus in 20 children and a young adult with bilateral microtia and atresia of the ear. This apparatus changes ITD automatically from 0 to 2,000 μs at 50 μs/s and IID from 1 to 40 dB at 1 dB/s. When ITD exceeds approximately 200 μs/s and IID exceeds 5 dB in normal subjects the sounds are recognized separately. The test stimulus was a continuous narrow-band noise at 500 Hz and 30 dB SL applied to the right and left mastoids through bone vibrators. In the patients with bilateral atresia of the ears, ITD results revealed approximately normal thresholds of discrimination in half the patients and IID results revealed threshold elevation in only 10%. It is noted that bone-conducted sound lateralization abilities of ITD or IID are maintained in many of these patients. [ABSTRACT FROM AUTHOR]

Auditory neuropathy is characterized by mild-to-moderate pure-tone hearing loss, poor speech discrimination out of proportion with this loss, absent or abnormal auditory brainstem responses and normal outer hair cell function as measured by otoacoustic emissions and cochlear microphonics. We followed three patients in our clinic whom we classified as auditory neuropathy patients. These patients also complained of balance disorders and we report our auditory and vestibular system analyses of these patients. The data presented herein include results of audiometric tests (serial pure-tone audiometry and speech discrimination tests), otoacoustic emissions, auditory-evoked brainstem responses and vestibular function tests (clinical tests of balance, electronystagmography, damped rotation tests and vestibular-evoked myogenic potentials). In all patients, pure-tone audiometry revealed mild-to-moderate sensorineural hearing loss, markedly poor speech discrimination scores and absent auditory-evoked brainstem responses, all in the presence of normal otoacoustic emissions. Balance tests (caloric tests and damped rotation test) were abnormal. Saccades, smooth pursuit eye movements and optokinetic nystagmus were normal in all patients. Neurological and motor system evaluations were normal in all patients. These three auditory neuropathy patients manifest a disorder of cochlear nerve function in the presence of normal outer hair cell activity. They additionally manifest a disorder of the vestibular nerve and its end organs. We conclude that, in patients with isolated auditory neuropathy, the vestibular branch of the VIIIth cranial nerve and its innervated structures may also be affected. We suggest the use of the term "cochlear neuropathy" to characterize those patients with involvement of only the auditory branch of the VIIIth cranial nerve and its innervation. [ABSTRACT FROM AUTHOR]

Short- and long-term changes in the middle latency response (MLR) after bilateral ablation of the auditory cortices were studied in awake cats. The amplitude of the negative peak with a latency of about 15 ms (NA) decreased to 60% of the original value 1 week after ablation (short-term change). In the long term, i.e. 11-30 months, NA either decreased further (decreased group) or remained unchanged (non-decreased group). A histological study with light microscopy revealed degeneration of neurons in the ventral nucleus of the medial geniculate body (MGv) in the decreased group, whereas the neurons in this region were preserved in the non-decreased group. This study suggests that long-term changes in NA reflect retrograde degeneration in the MGv after auditory cortical ablation. [ABSTRACT FROM AUTHOR]

Our patient was first diagnosed with auditory agnosia following his second cerebral vascular accident (CVA) in 1975 when he was 37 years old. Comprehensive follow-up examinations of auditory function were periodically conducted until his sudden death 15 years later. His brain was studied postmortem for neuropathology. Initial pure-tone audiometry revealed moderate sensorineural hearing loss in the right ear and mild sensorineural hearing loss in the left ear. However, repeated pure-tone audiometry revealed that thresholds became progressively poorer over time, bilaterally. Speech audiometry of both ears consistently revealed that the patient was unable to discriminate any monosyllabic words (i.e. speech intelligibility scores were 0%, bilaterally). In general, speech and hearing tests demonstrated that he could not comprehend spoken words, but could comprehend written commands and gestures. Postmortem neuropathological study of the left hemisphere revealed total defect and neuronal loss of the superior temporal gyrus, including Heschl's gyrus, and total gliosis of the medial geniculate body. In the right hemisphere, examination revealed subcortical necrosis, gliosis in the centre of the superior temporal gyrus and partial gliosis of the medial geniculate body. The pathological examination supports clinical results in which the patient's imperception of speech sounds, music and environmental sounds could be caused by progressive degeneration of bilateral medial geniculate bodies. [ABSTRACT FROM AUTHOR]

In this study auditory brainstem responses (ABRs) were recorded repeatedly in three awake cats before and after bilateral aspiration of the inferior colliculi (ICs). All surgical procedures were performed under anaesthesia with Nembutal. Postoperative recordings were obtained 1 week, 3 months, 8 months and 13 months after bilateral aspiration of the ICs in order to study the long-term changes in ABRs. The P5 amplitude was markedly reduced only at 1 week after aspiration. P1 and P2 amplitudes were affected slightly at 3 months and 1 year, but those of P3 and P4 decreased significantly. After perfusion of these cats, histological examination of the brainstem revealed complete ablation of both ICs, neuronal loss in the nucleus of the lateral lemniscus and the superior olivary complex and preservation of the cochlear nucleus. Our results suggest that retrograde degeneration of neuronal cells of the brainstem, which project to the IC from the nucleus of the lateral lemniscus and superior olivary complex except the cochlear nucleus, affect the peak amplitudes of the ABR over the long-term. [ABSTRACT FROM AUTHOR]

Conclusion. Our bedside interviews with patients with head neck cancer are unique and valuable educational experiences for undergraduate medical students. Objective. How can we help medical students to understand patients' thoughts and feelings? We believe that students can learn and practice empathy at the patient's bedside. Subjects and methods. Sixty medical students in their final year at the University of Tokyo and 10 patients with head and neck cancer were supervised by a professor and senior head and neck surgeons. Questionnaires were delivered to each student before and after bedside teaching, to investigate their impressions on thoughts and feelings of patients with head and neck cancer. Questions to patients were composed of: 1) backgrounds: birthplace, education, occupation and hobby; 2) cancer: the time of the first visit to clinic and the time of referral to the University of Tokyo Hospital; 3) preoperative feelings; 4) impression of surgical treatment and postoperative care; and 5) messages to medical students from the patient. Medical students also asked additional questions. Results. Before the bedside teaching our medical students believed that it must be important to listen to patients (100%); and that it must be possible to encourage patients (50%). After the bedside teaching they noticed that a medical interview could have a positive influence on the patient (93%), probably because of general conversation (45%), the patient's personality (50%), listening to information about the patient's birthplace, education, occupation and hobby (48%), and the instructor's life experiences (25%). Most patients asked medical students to be good doctors who can understand their thoughts and feelings. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the perception mechanism of environmental sounds in postlingual patients with cochlear implants compared with that in patients with central auditory disorders. Seventeen postlingual patients with cochlear implants were studied; six patients with auditory nerve disease (auditory neuropathy) and ten patients with cortical deafness were selected for the comparison. A taperecorded environmental sound perception test of 24 environmental sounds was carried out. This test is divided into two categories: the category of voice includes human voice, animal and bird sounds, and the category of non-voice includes musical instrument sound, natural sound and artificial sound. The percentage of correct perception of environmental sounds in postlingually deaf patients with cochlear implants was markedly higher than that in patients with cortical deafness, but was similar to that in patients with auditory nerve disease (auditory neuropathy). [ABSTRACT FROM AUTHOR]