Speech recognition scores in bilateral and unilateral atretic ears.

OBJECTIVE: Congenital aural atresia causes severe conductive hearing loss disturbing auditory development. The differences in speech recognition were investigated between bilateral and unilateral aural atresia. DESIGN: The maximum speech recognition scores (SRSs) were compared between patients with bilateral and unilateral aural atresia. In patients with unilateral aural atresia, the maximum SRSs were compared between the atretic and unaffected ears. Furthermore, the correct response rates for test material monosyllables were compared with those of patients with sensorineural hearing loss (SNHL), which had been previously obtained. STUDY SAMPLE: Twenty-four patients with aural atresia (8 bilateral, and 16 unilateral) participated. RESULTS: The maximum SRS in unilateral atretic ears (median: 72%) was significantly lower than that in unaffected ears (median: 89%) (p < 0.05) and in bilateral atretic ears (median: 91%) (p < 0.05). Patients with aural atresia had relatively high correct response rates for monosyllables with low correct response rates by patients with SNHL. Conversely, incorrect responses were obtained for several words for which high correct-response rates were attained by patients with SNHL. CONCLUSIONS: Poor unilateral atretic-ear development may induce low speech recognition, and the mechanisms underlying speech-recognition reduction differ from those in SNHL.

Effects of noise exposure on neonatal auditory brainstem response thresholds in pregnant guinea pigs at different gestational periods.

AIM: Noise exposure during pregnancy has been reported to cause fetal hearing impairment. However, little is known about the effects of noise exposure during various gestational stages on postnatal hearing. In the present study, we investigated the effects of noise exposure on auditory brainstem response (ABR) at the early, mid-, and late gestational periods in newborn guinea pigs. METHODS: Pregnant guinea pigs were exposed to 4-kHz pure tone at a 120-dB sound pressure level for 4 h. We divided the animals into four groups as follows: the control, early gestational exposure, mid-gestational exposure, and late gestational exposure groups. ABR thresholds and latencies in newborns were recorded using 1-, 2-, and 4-kHz tone burst on postnatal days 1, 7, 14, and 28. Changes in ABR thresholds and latencies were measured between the 4 × 4 and 4 × 3 factorial groups mentioned above (gestational periods × postnatal days, gestational periods × frequencies). RESULTS: The thresholds were low in the order of control group < early gestational exposure group < mid-gestational exposure group and late gestational exposure group. Noise exposure during pregnancy influenced ABR thresholds in neonatal guinea pigs. CONCLUSION: This is the first study to show that noise exposure during the early, mid-, and late gestational periods significantly elevated ABR thresholds in neonatal guinea pigs.

Sarcopenia and decline in appendicular skeletal muscle mass are associated with hypoperfusion in key hubs of central autonomic network on 3DSRT in older adults with progression of normal cognition to Alzheimer's disease.

AIM: Although sarcopenia is common in patients with Alzheimer's disease (AD), the neural substrates involved remain unclear. We investigated the relationship between sarcopenia, as well as its definition components, and regional cerebral blood flow (rCBF) in older adults with progression of normal cognition to AD. METHODS: 99m Tc-ethyl-cysteinate-dimer single-photon emission computed tomography was carried out in 95 older adults with progression of normal cognition to AD (40 men and 55 women, mean ± SD age 80.9 ± 6.8 years). The associations of rCBF determined by 3-D stereotactic region of interest template software, with sarcopenia and its definition components, slower gait speed, weaker grip strength, and decline in appendicular skeletal muscle mass index (ASMI) were analyzed. RESULTS: Logistic regression analysis adjusted by age, sex, mini-mental state examination score and education showed that sarcopenia as well as ASMI less than the cut-off (men 7.0 kg/m2 , women 5.7 kg/m2 ) were associated with significantly reduced rCBF in the key hub of the central autonomic network, including the insula, anterior cingulate cortex, subcallosal area, rectal gyrus, hypothalamus, amygdala and caudate head. Sarcopenia and ASMI decline were associated with hypoperfusion in the aforementioned cortical hubs of the central autonomic network in men, but with hypoperfusion of the hypothalamus in women. Linear regression analysis showed significant correlations of ASMI/cut-off with rCBF in the bilateral medial frontal cortex, as well as rCBF in the aforementioned key hubs. CONCLUSIONS: Hypoperfusion in key hubs of central autonomic network is implicated in the emergence of sarcopenia, probably through ASMI decline in vulnerable older adults. Geriatr Gerontol Int 2023; 23: 16-24.

Late-onset and congenital hearing loss detected using AABR due to congenital cytomegalovirus infection that improved with valganciclovir.

Congenital cytomegalovirus (cCMV) infection is the most common congenital viral infection and is the leading non-genetic cause of sensorineural hearing loss and an important cause of neurodevelopmental disabilities. Auto auditory brainstem response (AABR) is a simple hearing test and used for the purpose of neonatal hearing screening, but can use it for early detection hard of hearing within the study age of the model. We experienced two case of asymptomatic CMV infection in which congenital and late-onset hearing loss were diagnosed early with AABR, and hearing loss improved with valganciclovir.

Evaluation of the Recovery of Idiopathic Sudden Sensorineural Hearing Loss Based on Estimated Hearing Disorders.

Various prognostic factors for idiopathic sudden sensorineural hearing loss (SSNHL) have been reported. Hearing loss directly derived from idiopathic SSNHL is important for understanding underlying pathogenesis and outcomes. We assessed the usefulness of evaluating hearing loss and recovery of idiopathic SSNHL on the basis of estimated hearing loss. The study included 115 patients whose characteristics and outcomes of hearing loss were investigated. The effects of vertigo/dizziness and age on hearing thresholds before/after treatment, nonaffected ear threshold, estimated hearing loss, improvement of hearing loss, and estimated remaining hearing loss were investigated. Vertigo/dizziness was a significant prognostic factor for hearing. In vertigo/dizziness patients, significantly more severe hearing loss and poorer improvement of hearing loss were observed above 500 Hz and below 1000 Hz, respectively. Severe hearing disorder remained at all frequencies. Conversely, post-treatment thresholds were significantly higher in the older population (≥65 years), although no differences in pretreatment thresholds were observed between the younger (≤64 years) and older populations. However, on the basis of nonaffected ear thresholds, previously existing hearing loss could have influenced the outcome. Thus, comparison of hearing outcomes between affected and nonaffected ears is essential for understanding hearing loss and outcomes in idiopathic SSNHL cases with existing hearing disorder.

Four cases of medullary thyroid carcinomas associated with multiple endocrine neoplasia 2B with rearranged during transfection codon M918T mutation in the same family.

Multiple endocrine neoplasia (MEN) with medullary thyroid carcinoma (MTC) is associated with rearranged during transfection (RET) mutations. The authors encountered four cases of MTC-related MEN type 2B (MEN2B) with RET codon M918T mutation in one family. Case 1 included a 19 year-old male diagnosed with MTC with lung metastases. Genetic testing revealed an RET codon M918T mutation, which indicated MEN2B. The patient responded partially to vandetanib and the disease has shown no progression in 25 months. Case 2 involved the mother of the patient in Case 1. She underwent total thyroidectomy (TT) when diagnosed with MTC-related MEN2B at 12 years of age, but was not counseled adequately. Cases 3 and 4 involved the sisters of the Case 1 patient and were assessed after Case 1 was diagnosed. Genetic testing revealed the same mutation. Case 3 was diagnosed with MTC and underwent TT. Case 4 was asymptomatic but underwent prophylactic TT; histopathologic examination revealed MTC tissue. Prophylactic TT prevented MTC from being detected at an advanced state. Genetic counseling is essential in treating MEN2B. The mother was uninformed about the genetic characteristics of MEN2B, delaying the detection of MTC in her children. The present study reaffirms the importance of family history and screening.

Cartilage Conduction Hearing and Its Clinical Application.

Cartilage conduction (CC) is a form of conduction that allows a relatively loud sound to be audible when a transducer is placed on the aural cartilage. The CC transmission mechanism has gradually been elucidated, allowing for the development of CC hearing aids (CC-HAs), which are clinically available in Japan. However, CC is still not fully understood. This review summarizes previous CC reports to facilitate its understanding. Concerning the transmission mechanism, the sound pressure level in the ear canal was found to increase when the transducer was attached to the aural cartilage, compared to an unattached condition. Further, inserting an earplug and injecting water into the ear canal shifted the CC threshold, indicating the considerable influence of cartilage-air conduction on the transmission. In CC, the aural cartilage resembles the movable plate of a vibration speaker. This unique transduction mechanism is responsible for the CC characteristics. In terms of clinical applications, CC-HAs are a good option for patients with aural atresia, despite inferior signal transmission compared to bone conduction in bony atretic ears. The advantages of CC, namely comfort, stable fixation, esthetics, and non-invasiveness, facilitate its clinical use.

Effect of transducer placements on thresholds in ears with an abnormal ear canal and severe conductive hearing loss.

OBJECTIVES: Providing hearing compensation to patients with aural atresia is considerably challenging. Hearing aid transducers vibrating the aural cartilage (cartilage conduction; CC) have been devised, and hearing aids utilizing them (CC hearing aids) have quickly become a beneficial option for aural atresia in clinical applications. However, it remains unclear which placement (on the aural cartilage or mastoid) is beneficial to signal transmission. METHODS: This study included 35 patients (53 ears with an abnormal ear canal and severe conductive hearing loss) who were using CC hearing aids. Thresholds were compared between the transducers on the aural cartilage and on the mastoid. RESULTS: In ears with bony aural atresia, thresholds were significantly improved when the transducer was placed on the aural cartilage compared to when it was placed on the mastoid for frequencies ≤ 500 Hz (P < .05). In aural atresia ears with a fibrotic tissue pathway, the aural cartilage stimulation improved the thresholds by approximately 20 dB for frequencies ≤ 1000 Hz (P < .05). In non-atretic ears, the aural cartilage locations significantly worsened the threshold at 4000 Hz (P < .05). CONCLUSION: Our findings demonstrated that placing the transducer at the aural cartilage improved the mid-to-low frequency thresholds compared to mastoid transduction in aural atretic ears. In contrast, no clear improvement to the signal transmission due to the transducer's placement on the aural cartilage was recognized in non-atretic ears. LEVEL OF EVIDENCE: 2.

Benefits of Cartilage Conduction Hearing Aids for Speech Perception in Unilateral Aural Atresia.

Severe conductive hearing loss due to unilateral aural atresia leads to auditory and developmental disorders, such as difficulty in hearing in challenging situations. Bone conduction devices compensate for the disability but unfortunately have several disadvantages. The aim of this study was to evaluate the benefits of cartilage conduction (CC) hearing aids for speech perception in unilateral aural atresia. Eleven patients with unilateral aural atresia were included. Each participant used a CC hearing aid in the atretic ear. Speech recognition scores in the binaural hearing condition were obtained at low speech levels to evaluate the contribution of aided atretic ears to speech perception. Speech recognition scores were also obtained with and without presentation of noise. These assessments were compared between the unaided and aided atretic ear conditions. Speech recognition scores at low speech levels were significantly improved under the aided atretic ear condition (p < 0.05). A CC hearing aid in the unilateral atretic ear did not significantly improve the speech recognition score in a symmetrical noise presentation condition. The binaural hearing benefits of CC hearing aids in unilateral aural atresia were predominantly considered a diotic summation. Other benefits of binaural hearing remain to be investigated.

Audiological evaluation of infants using mother's voice.

OBJECTIVES: Hearing loss is a serious problem in infants and children because it may interfere with the development of typical speech, verbal language, and auditory and communication skills. By measuring hearing ability (thresholds) as early as possible, even as early as during infancy, effective treatment can be administered. These treatments may significantly reduce the handicap associated with hearing loss. However, at times during behavioral auditory tests, observers cannot determine whether or not an accurate threshold was obtained. To support the use of infant audiometry for accurate diagnosis, audiologic behavioral responses may be obtained by selecting stimuli that interest infants, e.g., their mothers' voices. METHODS: We evaluated 30 infants who were presented to our hospital for behavioral auditory assessment in 2016. The infants' ages ranged from 4 months to 3 years and 6 months. The mean age was 1 year and 10 months ±10 months (±standard deviation). The infants' hearing thresholds for their mothers' voices and warble tones at 250-4000 Hz were measured. Auditory brainstem response (ABR) had already been evaluated in 24 infants. Relationships between mother's voice and warble tone or ABR thresholds as well as responses to the initial stimuli and stimuli at the threshold were investigated. These responses were classified into four grades (no response, uncertain response, possible positive response, and positive response), and the response to mother's voice and warble tone were subsequently compared. RESULTS: Mother's voice thresholds significantly correlated with all warble tone thresholds. In the relationship between the mother's voice threshold and average hearing levels of 500, 1000, and 2000 Hz, two infants were outliers. In these infants, the average hearing levels were relatively higher than the mother's voice thresholds. Judging from their ABR thresholds, the mother's voice thresholds were valid and the average hearing levels were worse than their original assessed hearing ability. The responses to mothers' voices were more distinct than those to warble tones, both for initial stimuli presentation and the determined threshold. CONCLUSIONS: Audiologic behavioral responses to mothers' voices were clearer than those for warble tones. Evaluations that use the mother's voice threshold are useful for estimating hearing levels in infants.

The Role of Estrogen Receptor ß in the Dorsal Raphe Nucleus on the Expression of Female Sexual Behavior in C57BL/6J Mice.

17ß-Estradiol (E2) regulates the expression of female sexual behavior by acting through estrogen receptor (ER) α and ß. Previously, we have shown that ERß knockout female mice maintain high level of lordosis expression on the day after behavioral estrus when wild-type mice show a clear decline of the behavior, suggesting ERß may be involved in inhibitory regulation of lordosis. However, it is not identified yet in which brain region(s) ERß may mediate an inhibitory action of E2. In this study, we have focused on the dorsal raphe nucleus (DRN) that expresses ERß in higher density than ERα. We site specifically knocked down ERß in the DRN in ovariectomized mice with virally mediated RNA interference method. All mice were tested weekly for a total of 3 weeks for their lordosis expression against a stud male in two consecutive days: day 1 with the hormonal condition mimicking the day of behavioral estrus, and day 2 under the hormonal condition mimicking the day after behavioral estrus. We found that the level of lordosis expression in ERß knockdown (ßERKD) mice was not different from that of control mice on day 1. However, ßERKD mice continuously showed elevated levels of lordosis behavior on day 2 tests, whereas control mice showed a clear decline of the behavior on day 2. These results suggest that the expression of ERß in the DRN may be involved in the inhibitory regulation of sexual behavior on the day after behavioral estrus in cycling female mice.

Sound transmission by cartilage conduction in ear with fibrotic aural atresia.

A hearing aid using cartilage conduction (CC) has been proposed as an alternative to bone conduction (BC) hearing aids. The transducer developed for this application is lightweight, requires a much smaller fixation force than a BC hearing aid, and is more convenient to use. CC can be of great benefit to patients with fibrotic aural atresia. Fibrotic tissue connected to the ossicles provides an additional pathway (termed fibrotic tissue pathway) for sound to reach the cochlea by means of CC. To address the function of fibrotic tissue pathway, BC and CC thresholds were measured in six ears with fibrotic aural atresia. The relationship between the CC thresholds and the results of computed tomography was investigated. In the ears with the presence of a fibrotic tissue pathway, the CC thresholds were lower than the BC thresholds at 0.5 and 1.0 kHz. At 2.0 kHz, no significant difference was observed between the BC and CC thresholds. The current findings suggest that sound in the low to middle frequency range is transmitted more efficiently by CC via a fibrotic tissue pathway than BC. The development of hearing devices using CC can contribute to rehabilitation, particularly in patients with fibrotic aural atresia.

Regional difference in sex steroid action on formation of morphological sex differences in the anteroventral periventricular nucleus and principal nucleus of the bed nucleus of the stria terminalis.

Sex steroid action is critical to form sexually dimorphic nuclei, although it is not fully understood. We previously reported that masculinization of the principal nucleus of the bed nucleus of the stria terminalis (BNSTp), which is larger and has more neurons in males than in females, involves aromatized testosterone that acts via estrogen receptor-α (ERα), but not estrogen receptor-ß (ERß). Here, we examined sex steroid action on the formation of the anteroventral periventricular nucleus (AVPV) that is larger and has more neurons in females. Morphometrical analysis of transgenic mice lacking aromatase, ERα, or ERß genes revealed that the volume and neuron number of the male AVPV were significantly increased by deletion of aromatase and ERα genes, but not the ERß gene. We further examined the AVPV and BNSTp of androgen receptor knockout (ARKO) mice. The volume and neuron number of the male BNSTp were smaller in ARKO mice than those in wild-type mice, while no significant effect of ARKO was found on the AVPV and female BNSTp. We also examined aromatase, ERα, and AR mRNA levels in the AVPV and BNSTp of wild-type and ARKO mice on embryonic day (ED) 18 and postnatal day (PD) 4. AR mRNA in the BNSTp and AVPV of wild-type mice was not expressed on ED18 and emerged on PD4. In the AVPV, the aromatase mRNA level was higher on ED18, although the ERα mRNA level was higher on PD4 without any effect of AR gene deletion. Aromatase and ERα mRNA levels in the male BNSTp were significantly increased on PD4 by AR gene deletion. These results suggest that estradiol signaling via ERα during the perinatal period and testosterone signaling via AR during the postnatal period are required for masculinization of the BNSTp, whereas the former is sufficient to defeminize the AVPV.