Masking Effects Caused by Contralateral Distractors in Participants With Versus Without Listening Difficulties.

OBJECTIVES: To examine the effects of distractor sounds presented to the contralateral ear on speech intelligibility in patients with listening difficulties without apparent peripheral pathology and in control participants. DESIGN: This study examined and analyzed 15 control participants (age range, 22 to 30 years) without any complaints of listening difficulties and 15 patients (age range, 15 to 33 years) diagnosed as having listening difficulties without apparent peripheral pathology in the outpatient clinic of the Department of Otolaryngology-Head and Neck Surgery, Tohoku University Hospital. Speech intelligibility for 50 Japanese monosyllables presented to the right ear was examined under the following three different conditions: "without contralateral sound," "with continuous white noise in the contralateral ear," and "with music stimuli in the contralateral ear." RESULTS: The results indicated the following: (1) speech intelligibility was significantly worse in the patient group with contralateral music stimuli and noise stimuli; (2) speech intelligibility was significantly worse with contralateral music stimuli than with contralateral noise stimuli in the patient group; (3) there was no significant difference in speech intelligibility among three contralateral masking conditions (without contra-stimuli, with contra-noise, and with contra-music) in the control group, although average and median values of speech intelligibility tended to be worse with contralateral music stimuli than without contralateral stimuli. CONCLUSIONS: Significantly larger masking effects due to a contralateral distractor sound observed in patients with listening difficulties without apparent peripheral pathology may suggest the possible involvement of masking mechanisms other than the energetic masking mechanism occurring in the periphery in these patients. In addition, it was also shown that the masking effect is more pronounced with real environmental sounds, that is, music with lyrics, than with continuous steady noise, which is often used as a masker for speech-in-noise testing in clinical trials. In other words, it should be noted that a speech-in-noise test using such steady noise may underestimate the degree of listening problems of patients with listening difficulties in their daily lives, and a speech-in-noise test using a masker such as music and/or speech sounds could make listening problems more obvious in patients with listening difficulties.

Familial Paget's disease of bone with ocular manifestations and a novel TNFRSF11A duplication variant (72dup27).

INTRODUCTION: Paget's disease of bone (PDB) is a skeletal disorder characterized by disorganized bone remodeling due to abnormal osteoclasts. Tumor necrosis factor receptor superfamily member 11A (TNFRSF11A) gene encodes the receptor activator of nuclear factor kappa B (RANK), which has a critical role in osteoclast function. There are five types of rare PDB and related osteolytic disorders due to TNFRSF11A tandem duplication variants so far, including familial expansile osteolysis (84dup18), expansile skeletal hyperphosphatasia (84dup15), early-onset familial PDB (77dup27), juvenile PDB (87dup15), and panostotic expansile bone disease (90dup12). MATERIALS AND METHODS: We reviewed a Japanese family with PDB, and performed whole-genome sequencing to identify a causative variant. RESULTS: This family had bone symptoms, hyperphosphatasia, hearing loss, tooth loss, and ocular manifestations such as angioid streaks or early-onset glaucoma. We identified a novel duplication variant of TNFRSF11A (72dup27). Angioid streaks were recognized in Juvenile Paget's disease due to loss-of-function variants in the gene TNFRSF11B, and thought to be specific for this disease. However, the novel recognition of angioid streaks in our family raised the possibility of occurrence even in bone disorders due to TNFRSF11A duplication variants and the association of RANKL-RANK signal pathway as the pathogenesis. Glaucoma has conversely not been reported in any case of Paget's disease. It is not certain whether glaucoma is coincidental or specific for PDB with 72dup27. CONCLUSION: Our new findings might suggest a broad spectrum of phenotypes in bone disorders with TNFRSF11A duplication variants.

Auditory Attention Ability under Dichotic Dual-Task Situation in Adults with Listening Difficulties.

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.

Effects of Ndufs4 Deletion on Hearing after Various Acoustic Exposures.

Mitochondrial dysfunction can cause cochlear dysfunction and accelerate noise-induced hearing loss (NIHL). NADH dehydrogenase (ubiquinone) Fe-S protein 4 (Ndufs4) is one of the subunits of mitochondrial complex I and has a role in the assembly and stabilization of complex I. However, the involvement of Ndufs4 in the pathogenesis of NIHL has not been reported. The aim of this study was to evaluate whether Ndufs4 deletion causes vulnerability to noise exposures. The wild-type (WT) and Ndufs4 knockout (KO) mice with C57BL/6J genetic background were used. Cochlear histology and hearing thresholds were assessed after noise exposure at 100 or 86 dB sound pressure level (SPL). Immunostaining showed the widespread expression of Ndufs4 in the cochlea. After noise exposure at 100 dB SPL, auditory brainstem response (ABR) threshold shifts at 4 kHz in Ndufs4 KO mice were significantly higher than that in WT mice. After noise exposure at 86 dB SPL, ABR threshold shifts, wave 1 amplitudes, and the number of synapses in the inner hair cells were not significantly different. RNA sequencing revealed the decreased expression of energy generation-related genes inNdufs4 KO mice. Ndufs4 deficiency accelerates permanent low-frequency threshold shifts after moderate noise exposure.

Temporal and Directional Cue Effects on the Cocktail Party Problem for Patients With Listening Difficulties Without Clinical Hearing Loss.

OBJECTIVES: To evaluate the listening difficulty in a cocktail party environment in the sound field in order to better demonstrate patients' difficulties listening in noise, and to examine temporal and directional cue effects on the speech intelligibility in patients with listening difficulties in noise in comparison with control subjects. DESIGN: This study examined and analyzed 16 control subjects without any complaints of listening difficulties and 16 patients who had visited the outpatient clinic of the Department of Otolaryngology-Head and Neck Surgery, Tohoku University Hospital, with complaints of listening difficulties, especially in background crowded conditions, despite having relatively good hearing on routine audiograms and speech audiometry. Using five loudspeakers located in front of the subject and at 30° and 60° to the left and right from the front, word intelligibility for the target voice (female talker) presented from one of the loudspeakers in random order with four distractor voices (male talker) was assessed under the following cue conditions: (1) "no additional temporal/directional cue (only talker sex as a cue)"; (2) "fixed temporal cue without directional cue" (white noise bursts [cue sounds] were presented from the five loudspeakers just before word presentation at 500-ms intervals); (3) "directional + variable temporal cues" [cue sounds were presented from the loudspeaker where the next target word would be presented with a variable inter-stimulus interval [ISI] of 500, 1000, 1500, or 2000 ms between the cue sound and word presentation); and (4) "directional + fixed temporal cues" (cue sounds were presented from the loudspeaker where the next target word would be presented with a fixed ISI of 500 ms). RESULTS: The results indicated the following: (1) word intelligibility under distractors was significantly deteriorated in patients with listening difficulties compared with control subjects, although the clinical speech in noise test using the headphone system did not show any significant differences between the two groups; (2) word intelligibility under distractors for patients with listening difficulties was significantly improved with directional cues presented in advance; and (3) under most cue conditions, individual differences in word intelligibility among patients with listening difficulties were significantly correlated with their dichotic listening ability, which is one of the indicators used to assess auditory selective attention ability. CONCLUSIONS: The results of this study indicate the usefulness of the presentation of directional cues for speech comprehension in the cocktail party situation in patients with listening difficulties, as well as the importance of evaluating the degree of listening difficulties spatially in the cocktail party situation.

Loudness functions for patients with functional hearing loss.

OBJECTIVES: To compare the loudness functions (loudness ratings as a function of sound level) obtained from patients diagnosed as having functional hearing loss (FHL) with those for patients with sensorineural hearing loss (SNHL) and healthy volunteers. DESIGN: Loudness functions for a 1000 Hz tone for patients with FHL and SNHL were assessed based on the categorical loudness scaling method. The data were compared with control data obtained in our facilities. STUDY SAMPLE: 18 patients (33 ears) with FHL and 10 patients (19 ears) with SNHL. RESULTS: For patients with SNHL and healthy volunteers, loudness increased progressively with increasing sound level above the audiometric threshold, with no exceptions. However, for about 70% of the patients with FHL, a different type of loudness function was obtained; the thresholds determined from the loudness function, which were defined as the minimum sound levels at which loudness could be judged, were 10 dB or more lower than the audiometric threshold (>10 dB), and/or the loudness ratings were elevated for a sound at the audiometric threshold. CONCLUSIONS: The results support the hypothesis that patients with FHL often make threshold judgments based on a certain loudness.

A computational fluid dynamics simulation of liquid swallowing by impaired pharyngeal motion: bolus pathway and pharyngeal residue.

Common practices to improve the ability to swallow include modifying physical properties of foods and changing the posture of patients. Here, we quantified the effects of the viscosity of a liquid bolus and patient posture on the bolus pathway and pharyngeal residue using a computational fluid dynamics simulation. We developed a computational model of an impaired pharyngeal motion with a low pharyngeal pressure and no pharyngeal adaptation. We varied viscosities from 0.002 to 1 Pa·s and postures from -15° to 30° (from nearly vertical to forward leaning). In the absence of pharyngeal adaptation, a honey-like liquid bolus caused pharyngeal residue, particularly in the case of forward-leaning postures. Although the bolus speed was different among viscosities, the final pathway was only slightly different. The shape, location, and tilting of the epiglottis effectively invited a bolus to two lateral pathways, suggesting a high robustness of the swallowing process.NEW & NOTEWORTHY Thickening agents are often used for patients with dysphagia. An increase in bolus viscosity not only reduces the risk of aspiration but also can cause a residual volume in the pharynx. Because information obtained from videofluoroscopic swallowing studies is only two-dimensional, measurement of pharyngeal residue is experimentally difficult. We successfully quantified the three-dimensional bolus pathway and the pharyngeal residual volume using computational modeling and simulation.

Computed tomography findings of the bony portion of the Eustachian tube with or without patulous Eustachian tube patients.

To investigate the bony segment of the Eustachian tube (ET) using sitting 3D-computed tomography (CT) scans in Patulous Eustachian tube (PET) patients. A retrospective survey of medical records in Sen-En Hospital identified 43 patients and 43 ears with PET and 30 patients and 30 ears with sensorineural hearing loss or vertigo patients as the control. Diagnosis of PET was based on the Proposal on PET Diagnosis Criteria announced by the Otological Society of Japan in 2012. Patients were examined by cone beam CT (Accuitomo; Morita, Kyoto, Japan) in the sitting position. The heights and widths at the tympanic orifice, the middle portion, and isthmus were measured. The lumen of the bony portion was divided into three shapes: peritubal cells (PTC) poor type, PTC good with prominence type, and PTC good without prominence type. In PET patients and the control group, the PTC poor type was identified in nine (21%) and seven ears (23%), PTC good with prominence type was identified in 14 (33%) and seven ears (23%), and PTC good without prominence type was identified in 19 (45%) and 16 ears (53%), respectively. There was no significant difference between the two groups. At the tympanic orifice portion, the average height of the ET lumen was 5.99 ± 1.29 and 6.04 ± 1.41 mm, and the average width of the ET lumen was 2.81 ± 0.82 and 2.78 ± 0.57 mm in the PET and control groups, respectively. The PTC good with prominence type had a significantly smaller width in the tympanic orifice portion than the other types in each group (p < 0.05). The width of the ET lumen in the tympanic orifice averaged 2.87 ± 0.38 and 3.10 ± 0.45 mm in the PTC poor type, 2.23 ± 0.70 and 2.22 ± 0.48 mm in the PTC good with prominence type, and 3.21 ± 0.87 and 2.90 ± 0.50 mm in the PTC good without prominence type in the PET and control groups, respectively. The shape of the bony portion of the ET in PET patients is almost identical to that of controls. Thus, the bony portion has no influence on the pathology of patulous Eustachian tube syndrome. The PTC good with prominence type has a significantly smaller tympanic orifice portion width than the other types. Preoperative evaluation of the bony portion of the ET could provide useful information for ET surgeons.

Osteoid osteoma of the temporal bone manifesting as first bite syndrome and a meta-analysis combined with osteoblastoma.

The objectives of this study were to describe a case of osteoid osteoma arising from the temporal bone manifesting only as first bite syndrome as the sole clinical symptom, to perform a meta-analysis of previously reported cases, and to differentiate the clinical characteristics of osteoid osteoma from those of osteoblastoma arising from the temporal bone. In addition to our case, articles addressing osteoid osteoma or osteoblastoma arising from the temporal bone were selected using PubMed, Embase, and the Japan Medical Abstracts Society database (1954 through 2014), with no language preference. The database was searched using the keywords ["osteoid osteoma" OR "osteoblastoma" AND "temporal bone"]. After critical review of 88 studies, 10 cases of osteoid osteoma and 29 cases of osteoblastoma were selected; therefore, including the present case, a total of 40 cases were eligible for qualitative analyses. The mean size of osteoid osteoma was 1.2 cm, which was significantly smaller than that of osteoblastoma (5.1 cm). Radiologically, osteoid osteoma was associated with a lower prevalence of extension into more than two anatomically categorized spaces in comparison with osteoblastoma (P < 0.01). Again, a lower prevalence of erosion of the outer and/or inner tables of the skull in the osteoid osteoma cases was noted (P < 0.05). Conversely, there were no significant differences in the prevalence of representative clinical symptoms, including pain and swelling. According to the present systematic review, osteoid osteoma and osteoblastoma are clinically uniform other than their size or extension.

Effect of intratympanic application of efinaconazole 10 % solution in the guinea pig.

Efinaconazole 10 % solution is a new triazole antifungal agent developed for the topical treatment of fungal infections of the nails. The current study examined the effect of intratympanic application of efinaconazole 10 % solution in the guinea pig ear. Sixteen male Hartley guinea pigs (weight 501-620 g) were divided into 3 groups to be treated with efinaconazole 10 % solution, gentamicin (50 mg/mL), or saline solution. Topical solutions of 0.2 mL were applied through a small hole made at the tympanic bulla once daily for 7 consecutive days. Post-intervention auditory brainstem responses were obtained 7 days after the last treatment. The extent of middle ear damage and hair cell loss was investigated. The efinaconazole- and gentamicin-treated groups showed severe deterioration in auditory brainstem response threshold. Middle ear examination revealed extensive changes in the efinaconazole-treated group and medium changes in the gentamicin-treated group. Hair cells were preserved in the efinaconazole- and saline-treated groups, but severe damage was seen in the gentamicin group. In conclusion, efinaconazole 10 % solution applied intratympanically to the guinea pig middle ear caused significant middle ear inflammation and hearing impairment.

Osteoma of the internal auditory canal mimicking vestibular schwannoma: case report and review of 17 recent cases.

Osteoma of the internal auditory canal (IAC) is an uncommon benign bone tumor. Its imaging features may be similar to other IAC lesions, such as vestibular schwannomas that are benign and usually slow-growing but sometimes life-threatening tumors. Thus, detecting IAC lesions and differentiating osteoma from other IAC lesions are both important clinically. We report a case of misdiagnosis of an IAC osteoma as an IAC schwannoma based on magnetic resonance (MR) imaging using the three-dimensional constructive interference in steady state (CISS) sequence instead of T1-weighted MR imaging with gadolinium. We also review 17 cases of IAC osteomas reported in the past 22 years. A 61-year-old female was admitted to our department with IAC lesion incidentally discovered by the CISS sequence. The lesion was diagnosed as an IAC schwannoma, and was followed up annually under "wait and scan" management. Follow-up T1-weighted MR imaging with gadolinium showed no enhancement of the tumor, and additional computed tomography (CT) of the temporal bone showed a solitary pedunculated bony lesion, resulting in the diagnosis of IAC osteoma. The CISS sequence is useful for detecting small IAC lesions, such as vestibular schwannomas. However, the CISS sequence has limitations for qualitative diagnosis and can misdiagnose osteomas as schwannomas. Use of the CISS sequence without T1-weighted MR imaging with gadolinium for the screening of a lesion of the IAC and cerebellopontine angle should consider the possibility of IAC osteomas, and temporal bone CT or T1-weighted MR imaging with gadolinium should be performed when an IAC lesion is detected.

[External auditory canal cholesteatoma with chronic renal failure or hemodialysis].

BACKGROUND: External auditory canal cholesteatoma (EACC) is a rare otologic disease, characterized by focal osteonecrosis, sequestration and overlying epithelial loss of the bony external auditory canal (EAC). The etiology and pathogenesis of EACC remain controversial. There are only 2 reports on the association between EACC and chronic renal failure (CRF)/hemodialysis (HD). METHOD & RESULT: (1) This study reviewed seven EACC cases with CRF. The mean age was 68.4 years (range: 56 -81 years), and the male-female ratio was 5:2. There were 12 ears with EACC (5 cases were bilateral and 2 cases were unilateral). The EACCs were found in the inferior or posterior inferior part of the EAC in 11 ears. The number of the ears in stage III or IV was 6. Five cases were on HD. (2) Seventy-six cases with CRF on HD were examined for EACC, and 2 out of those 70 cases were diagnosed as having EACC. (3) A comparative study of the 7 EACC cases on HD and 68 non-EACC cases on HD revealed no significant differences in the sex, age, period on CRF/HD, complications (diabetes mellitus or skin disease), smoking, ear cleaning and the use of an earphone or a hearing aid. CONCLUSION & DISCUSSION: Six out of all 9 EACC cases with CRF developed bilaterally, and in the inferior or posterior inferior part of the EAC, which implies a common pathological condition that contributes to the development of EACC. The mean age of 9 patients with EACC was relatively older (66.7 years), therefore age-related changes in the EAC are suspected in the cases with CRF on HD. The patients with CRF on HD have a high incidence of EACC. This strongly suggests the association between EACC and CRF/HD, but the mechanism of this pathogenesis has not been revealed.

Characteristic findings in the human fetus vestibule: A human temporal bone study.

OBJECTIVE: The "collapse," a highly flexed, dented, or caved membrane between the endo- and peri-lymph of the saccule and utricle in adults, is considered as a morphological aspect of Ménière's syndrome. Likewise, when mesh-like tissues in the perilymphatic space are damaged or lost, the endothelium loses mechanical support and causes nerve irritation. However, these morphologies were not examined in fetuses. METHODS: By using histological sections from 25 human fetuses (crown-rump length[CRL] 82-372 mm; approximately 12-40 weeks), morphologies of the perilymphatic-endolymphatic border membrane and the mesh-like tissue around the endothelium were examined. RESULTS: The highly flexed or caved membrane between the endo- and peri-lymphatic spaces was usually seen in the growing saccule and utricle of fetuses, especially at junctions between the utricle and ampulla at midterm. Likewise, the perilymphatic space around the saccule, utricle and semicircular ducts often lost the mesh-like tissues. The residual mesh-like tissue supported the veins, especially in the semicircular canal. CONCLUSION: Within a cartilaginous or bony room showing a limited growth in size but containing increased perilymph, the growing endothelium appeared to become wavy. Owing to a difference in growth rates between the utricle and semicircular duct, the dentation tended to be more frequently seen at junctions than at free margins of the utricle. The difference in site and gestational age suggested that the deformity was not "pathological" but occurred due to unbalanced growth of the border membrane. Nevertheless, the possibility that the deformed membrane in fetuses was an artifact caused by delayed fixation is not deniable.

Traits of Developmental Disorders in Adults With Listening Difficulties Without Diagnosis of Autism Spectrum Disorder And/or Attention-Deficit/Hyperactivity Disorder.

Background: Some individuals have a normal audiogram but have listening difficulties (LiD). As many studies have investigated the relationship between listening and developmental disorders, the traits of developmental disorders might explain the symptoms of LiD. In this study, we examined the traits of developmental disorders of adults with LiD to help clarify the cause of LiD symptoms. Methods: In total, 60 adults with LiD and 57 adults without LiD were included. Participants completed a questionnaire for the autism spectrum quotient (AQ) test, the Adult Attention-Deficit Hyperactivity Disorder Self-Rating Scale (A-ADHD), the Adolescent/Adult Sensory Profile (SP), and the severity of subjective LiD in daily life. Results: Before analysis, we excluded participants with LiD who were already diagnosed or met the criteria for autism spectrum disorder (ASD) or ADHD, and the results of the remaining 30 participants (50.0%) with LiD were analyzed. Adults with LiD showed higher scores than those without LiD in the AQ. Attention switching in the AQ and attention ability in the A-ADHD scale were correlated with the severity of LiD symptoms in everyday life. The AQ scores were also significantly correlated with subscales of the SP. Conclusions: Adults with LiD showed greater autistic traits than those without LiD; therefore, LiD symptoms are possibly related to autistic symptoms. Furthermore, adults with LiD might have attention disorder traits of both ASD and ADHD and sensory processing problems. These findings suggest that the attention problems in adults with LiD noted in previous studies might be related to these traits of developmental disorders.

Electrophysiological mapping of the cochlear nucleus with multi-channel bipolar surface microelectrodes.

Auditory potentials in response to electrical stimulation of the cochlear nucleus were recorded in guinea pigs using two types of multi-channel surface microelectrodes with inter-electrode distance of 100 and 200 µm. Unequivocal waves of electrically evoked auditory brainstem responses (EABRs), which increased in amplitude with increasing stimulation current, were consistently observed. Electrophysiological mapping with these multichannel electrodes could clearly distinguish stimulation points showing positive EABRs from points showing undetectable EABRs, indicating that multi-channel surface microelectrodes have great potential in clinical use to determine the optimal location for the positioning of auditory brainstem implants, and may allow more precise discrimination of pitch. Further study to clarify the optimal inter-electrode distance for humans is necessary before application to physiological mapping in the human cochlear nucleus.

Transsphenoidal meningocele: an anatomical study using human fetuses including report of a case.

An asymptomatic transsphenoidal meningoencephalocele was discovered incidentally by fiber laryngoscopic examination in a 62-year-old man suffering from hoarseness due to dysplasia of the vocal cord epithelium. To provide a better understanding of the pathogenesis of this anomaly, we performed histologic observations of paraffin-embedded specimens of 42 human fetal heads at 12-16 weeks of gestation. At these stages, ossification had started in the clivus but the sphenoid sinus was not developed. In contrast to the very low incidence of the intra- or trans-sphenoidal remnant of Rathke's pouch after birth, we found (1) the typical mid-line cleft of the sphenoid body in two specimens (2/42 or 4.8 %) and (2) a duct-like, sellar inferior protrusion ending in the sphenoid body in 12 specimens (12/42 or 28.6 %). The cyst-like structure in the protrusion (two specimens) seemed to be composed of obstructed veins. The intra- and trans-sphenoidal anomalies were observed more frequently in specimens without ossification of the sphenoid body than in those with ossification. However, irrespective of ossification, a cyst-like remnant of the most upper part of Rathke's pouch was always seen between the anterior and posterior lobes of the developing pituitary gland. In addition, the bursa pharyngea was seen in four specimens and we confirmed that the notochord was attached to the bursa in each case. The consistent remnant of the intrasellar Rathke's pouch appeared to explain the high incidence of Rathke's cleft cyst in adults. The relatively high incidence of intrasphenoidal anomalies in fetuses (14/42) suggested that the intra- or trans-sphenoidal remnant of Rathke's pouch was physiologically closed by ossification of the sphenoid body.

Suprahyoid neck fascial configuration, especially in the posterior compartment of the parapharyngeal space: a histological study using late-stage human fetuses.

The fascial configuration in the suprahyoid parapharyngeal space was evaluated using semiserial sagittal sections of 15 late-stage human fetal heads. The prevertebral fascia covered the longus colli, longus capitis, and rectus capitis lateralis muscles, but was most evident along the longus colli muscle. The carotid sheath and its extension were located around the internal and external carotid arteries and the lower cranial nerves. The superior cervical ganglion was also inside the sheath. Even near full term, the fetal suprahyoid neck was short, with the jugular foramen and hypoglossal canal located at the posterolateral side of the oropharynx. Thus, the glossopharyngeal and accessory nerves ran across the upper part of the carotid sheath. Fasciae of the stylopharyngeus, styloglossus, and stylohyoideus muscles were attached to and joined the anterosuperior aspect of the carotid sheath. All these neurovascular and muscle sheaths are communicated with the visceral fascia covering the pharynx at multiple sites, and, together, they formed a mesentery-like bundle. This communication bundle was made narrow by the anteriorly protruding longus capitis muscle. The mesentery-like bundle was covered by the posterior marginal fascia of the prestyloid compartment of the parapharyngeal space. The external carotid artery ran on the lateral and posterior sides of the posterior marginal fascia. Consequently, the typical carotid sheath configuration was modified by muscle sheaths from the styloid process, communicated with the visceral fascia and, anteriorly, constituted the posterior margin of the prestyloid space.

Long-term tumor growth and hearing after conservative management of vestibular schwannomas.

BACKGROUND: There has been no report of a detailed long-term study of hearing at defined frequencies. AIMS/OBJECTIVES: This study aimed to evaluate long-term vestibular shwannoma (VS) growth and long-term changes in hearing thresholds at defined frequencies. METHODS: We retrospectively retrieved the medical records of 67 VS patients. Cases that were followed up for more than 5 years were analyzed. RESULTS: Tumor growth was observed in 15 cases (22.4%) and 6 cases underwent gamma knife treatment (9.0%). The longest case of tumor growth and gamma knife treatment was observed 11 years after the initial diagnosis. Hearing thresholds at 500-2000 Hz was significantly different between the no growth and growth group (p < .05). Particularly at 1000 Hz, there was a significant difference between the two groups from an early time-point. CONCLUSIONS AND SIGNIFICANCE: Even a 10-year or longer follow-up of VS may show an increase in tumor growth. Moreover, hearing thresholds, particularly at 1000 kHz, may predict tumor growth when following-up VS patients.

Possibility of additive effects by the presentation of visual information related to distractor sounds on the contra-sound effects of the N100m responses.

Auditory-evoked responses can be affected by different types of contralateral sounds or by attention modulation. The present study examined the additive effects of presenting visual information about contralateral sounds as distractions during dichotic listening tasks on the contralateral effects of N100m responses in the auditory-evoked cortex in 16 subjects (12 males and 4 females). In magnetoencephalography, a tone-burst of 500 ms duration at a frequency of 1000 Hz was played to the left ear at a level of 70 dB as a stimulus to elicit the N100m response, and a movie clip was used as a distractor stimulus under audio-only, visual-only, and audio-visual conditions. Subjects were instructed to pay attention to the left ear and press the response button each time they heard a tone-burst stimulus in their left ear. The results suggest that the presentation of visual information related to the contralateral sound, which worked as a distractor, significantly suppressed the amplitude of the N100m response compared with only the contralateral sound condition. In contrast, the presentation of visual information related to contralateral sound did not affect the latency of the N100m response. These results suggest that the integration of contralateral sounds and related movies may have resulted in a more perceptually loaded stimulus and reduced the intensity of attention to tone-bursts. Our findings suggest that selective attention and saliency mechanisms may have cross-modal effects on other modes of perception.