Anticipating real-ear insertion response using an external auditory canal model.

OBJECTIVES: This study aimed to determine the acoustic characteristics of the external auditory canal (EAC) and predict the real-ear aided response (REAR) using an EAC model that includes the standing wave effect. METHODS: The EAC transfer function equations were derived by summing the incoming and outgoing waves. First, we investigated the real-ear unaided gain (REUG). Second, seven patients (eight ears) wearing hearing aids (HAs) were enrolled as subjects to examine the REAR. We conducted wideband tympanometry (WBT) to measure the absorbance, the frequency response at 65 dB (65dB-FR) of the HAs, and the measured REAR for an international speech test signal (ISTS) at 65 dB. RESULTS: The EAC model that includes the standing-wave effect is considered to be valid from examination of the REUG. A significant correlation was found between the measured and calculated REARs at 900 Hz, 1000 Hz, 2000 Hz, and 3000 Hz in an uncorrelated test. A two-way analysis of variance (ANOVA) found significant differences in the 65dB-FR and the measured REARs at 800, 900, 1000, and 2000 Hz, but this difference disappeared after correction of the calculated acoustic characteristics of the EAC. CONCLUSIONS: By measuring the WBT characteristics and correcting them with an EAC model, the in-situ REAR can be determined from the HA characteristics in the mid-frequency range. There is a risk of insufficient HA amplification in the mid-frequency range when no real-ear measurements are performed.

Clinical practice guidelines for the diagnosis and management of acute otitis media in children-2018 update.

OBJECTIVE: "Clinical Practice Guidelines for the Diagnosis and Management of Acute Otitis Media in Children-2018 update (2018 Guidelines)" aim to provide appropriate recommendations about the diagnosis and management of children with acute otitis media (AOM), including recurrent acute otitis media (recurrent AOM), in children under 15 years of age. These evidence-based recommendations were created with the consensus of the subcommittee members, taking into consideration unique characteristics of bacteriology and antimicrobial susceptibilities of AOM pathogens in Japan, as well as global advances in vaccines. METHODS: The subcommittee re-evaluated key clinical issues based on SCOPE (a master plan of the guidelines) and created clinical questions (CQ) about the diagnosis and management of AOM patients. A literature search of the publications from 2013 to 2016 were added to the Guidelines 2013, not only to assess the evidence on the effectiveness of vaccines, but also to provide up to date information of the bacteriology and antimicrobial susceptibilities of AOM causative pathogens in Japan. RESULTS: We have proposed guidelines for disease severity-based management of AOM patients, after classifying AOM severity into mild, moderate, and severe, based on age, clinical manifestations, and otoscopic findings. CONCLUSIONS: Precise otoscopic findings are essential for judging AOM severity, which can lead to appropriate management of AOM patients.

[Detection of the Presence of Middle-ear Effusion with Wideband Absorbance Tympanometry].

This study evaluated the ability of wideband absorbance (AB) to predict the presence of middle-ear effusion (MEE) in ears with a flat (type B) 226 Hz tympanogram (TG). AB measures were obtained in a no MEE group of 8 ears with a flat TG and a MEE group of 19 ears also with a flat TG. AB was significantly small at frequencies 2 and 4 kHz in the MEE group than in the no MEE group. Based on our results, it appeared that AB could detect MEE with higher specificity than conventional tympanometry. The presence or absence of MEE could be distinguished based on the average AB using 1, 2, and 4 kHz, with 40% as the cutoff point.

Clinical practice guidelines for the diagnosis and management of acute otitis media (AOM) in children in Japan - 2013 update.

OBJECTIVE: To (1) indicate methods of diagnosis and testing for childhood (<15 years) acute otitis media (AOM) and (2) recommend methods of treatment in accordance with the evidence-based consensus reached by the Subcommittee of Clinical Practice Guideline for Diagnosis and Management of AOM in Children (Subcommittee of Clinical Practice Guideline), in light of the causative bacteria and their drug sensitivity of AOM in Japan. METHODS: We investigated the most recently detected bacteria causing childhood AOM in Japan as well as antibacterial sensitivity and the worldwide distinct progress of vaccination, produced Clinical Questions concerning the diagnosis, testing methods, and treatment of AOM, searched literature published during 2000-2004, and issued the 2006 Guidelines. In the 2009 and 2013 Guidelines, we performed the same investigation with the addition of literature, which were not included in the 2006 Guidelines and published during 2005-2008 and during 2009-2012, respectively. RESULTS: We categorized AOM as mild, moderate, or severe on the basis of tympanic membrane findings and clinical symptoms, and presented recommended treatment for each degree of severity. CONCLUSION: Accurate assessment of tympanic membrane findings is important for judging the degree of severity and selecting a method of treatment. Some of new antimicrobial agents and pneumococcal vaccination are recommended as new treatment options.

Subgroups of enlarged vestibular aqueduct in relation to SLC26A4 mutations and hearing loss.

OBJECTIVES/HYPOTHESIS: To investigate possible association of hearing loss and SLC26A4 mutations with the subgroups of enlarged vestibular aqueduct (EVA) morphology in Japanese subjects with hearing loss. STUDY DESIGN: Retrospective multicenter study. METHODS: Forty-seven subjects who had vestibular aqueduct with midpoint diameter >1 mm by computed tomography of the temporal bone were enrolled at multiple sites across Japan, and DNA samples and clinical data were collected. EVA morphology was classified into four subgroups by the pattern of enlargement: aperture, aperture and midpoint, midpoint, and borderline enlargement. Venous blood DNA samples were subjected to polymerase chain reaction-based direct sequencing of all exons and exon-intron boundaries of the SLC26A4. RESULTS: Four novel SLC26A4 mutations were identified in the present study. SLC26A4 mutations were detected in almost all subjects with aperture, aperture and midpoint, and midpoint enlargement. In contrast, 71% of subjects with borderline enlargement had no SLC26A4 mutation. No significant difference was found in the distribution of truncating and nontruncating SLC26A4 mutations between the EVA subgroups. In addition, no significant correlation was observed between the EVA subgroups and hearing levels, incidence of hearing fluctuation, or progression of hearing loss. CONCLUSIONS: Subgroups of EVA morphology were significantly correlated with the presence or absence of SLC26A4 mutation. In a subgroup analysis of subjects with SLC26A4 mutations, however, differences in the EVA subgroups were not correlated with SLC26A4 genotypes or characteristics of hearing loss. LEVEL OF EVIDENCE: NA.

GJB2-associated hearing loss undetected by hearing screening of newborns.

The hearing loss caused by GJB2 mutations is usually congenital in onset, moderate to profound in degree, and non-progressive. The objective of this study was to study genotype/phenotype correlations and to document 14 children with biallelic GJB2 mutations who passed newborn hearing screening (NHS). Genetic testing for GJB2 mutations by direct sequencing was performed on 924 individuals (810 families) with hearing loss, and 204 patients (175 families) were found to carry biallelic GJB2 mutations. NHS results were obtained through medical records. A total of 18 pathological mutations were identified, which were subclassified as eight inactivating and 10 non-inactivating mutations. p.I128M and p.H73Y were identified as novel missense GJB2 mutations. Of the 14 children with biallelic GJB2 mutations who passed NHS, eight were compound heterozygotes and 3 were homozygous for the c.235delC mutation in GJB2, and the other three combinations of non-c.235delC mutations identified were p.Y136X-p.G45E/p.V37I heterozygous, c.512ins4/p.R143W heterozygous, and p.V37I/p.R143W heterozygous. These 14 cases demonstrate that the current NHS does not identify all infants with biallelic GJB2 mutations. They suggest that the frequency of non-penetrance at birth is approximately 6.9% or higher in DFNB1 patients and provide further evidence that GJB2 hearing loss may not always be congenital in onset.

[Two cases of pediatric psychogenic gait disturbance].

We report herein on 2 cases of pediatric psychogenic gait disturbance. Both patients (boys) were aged 10 years. Patient 1 had psychogenic fever and psychogenic visual disturbance. His symptoms improved after 4 months. Patient 2 had headache and general fatigue and was subfebrile. His symptoms disappeared after 5 months. Pediatric psychogenic gait disturbance is rare, and it is important to understand the clinical characteristics of the affected patients. In most cases, treatment can be time-consuming. To treat these patients, it is important to rule out organic disorders. A diagnosis of psychogenic gait disturbance should be made on the basis of the clinical characteristics of the disorder, such as (1) momentary fluctuations of stance and gait, often in response to suggestions; (2) excessive slowness or hesitation of locomotion incompatible with neurological disease; and (3) uneconomic postures with wastage of muscle energy. These symptoms typically improve in 4-5 months.

Treating pediatric psychogenic dizziness with a Japanese herbal medicine.

OBJECTIVE: No conventional pharmacotherapy is available for the treatment of psychogenic dizziness in pediatric patients. Adults with psychogenic dizziness are treated with psychiatric medicines as the standard treatment. In children, this treatment is not widely accepted because of the potential for adverse reactions. Instead, Kampo, an alternative medicine, is probably the best choice of treatment. DESIGN: We report herein three of four cases of pediatric psychogenic dizziness successfully treated with Yoku-kan-san-ka-chimpi-hange (YKCH), a traditional Japanese Kampo medicine known to ameliorate psychiatric symptoms. SUBJECTS: YKCH was prescribed to four patients (two boys and two girls) with psychiatric dizziness whose ages ranged from 11 to 15 years. Four weeks after the initiation of treatment, clinical improvement was assessed by the Clinical Global impression-Improvement scale. RESULTS: In three of the four patients, the drug showed some significant effects. The remaining patient could not continue the medication. It is reasonable to assume that YKCH was effective because of its serotonergic mechanism and the improvement of sleep in our patients. CONCLUSIONS: This report is the first to describe the beneficial effects of YKCH in the treatment of pediatric psychogenic dizziness. We conclude that administration of YKCH may be a suitable complementary therapy for pediatric psychogenic dizziness.

[Clinical features associated with sudden hearing loss in children].

Sudden sensorineural hearing loss is usually unilateral, and the cause is not identified in most adult cases. However, a specific cause has frequently been found in the case of children, in whom idiopathic sudden sensorineural hearing loss (ISHL) is comparatively rare. We investigated 20 cases of acute unilateral sensorineural hearing loss in children associated with a certain disease, but which was first diagnosed as ISHL. Thirteen patients aged 6 to 16 years old were diagnosed as having psychogenic (functional) hearing loss. Discrepancies in behavioral and objective tests are most valuable when functional hearing loss is suspected. Elevated pure-tone thresholds associated with normal distortion product otoacoustic emissions (DPOAEs) enable prompt further investigation. There are several conditions that may mimic functional hearing loss, so auditory brainstem response (ABR) testing is necessary to verify the actual cause. The unilateral profound hearing loss in 2 patients aged 7 and 11 years old was due to asymptomatic mumps proven by detecting the mumps IgM antibody. Total hearing recovery in the 125-1000 Hz frequencies occurred in one case. In 5 patients aged 6 to 12 years old with acute hearing loss and vertigo, high resolution CT imaging showed an abnormally enlarged vestibular aqueduct on the affected side. Large vestibular aqueduct syndrome should be considered in acute high-frequency sloping hearing loss with an A-B gap at low frequencies.

Unilateral cochlear nerve hypoplasia in children with mild to moderate hearing loss.

CONCLUSION: Even if hearing loss is mild to moderate, the presence of cochlear nerve (CN) hypoplasia associated with retrocochlear disorders should be considered. OBJECTIVES: CN hypoplasia is a term that refers to an absent cochlear nerve on high-resolution magnetic resonance imaging (MRI). Most cases of CN hypoplasia are associated with profound hearing loss. The present study reports six pediatric cases of unilateral CN hypoplasia with mild to moderate hearing loss. METHODS: Between May 2008 and April 2011, pure-tone hearing tests were performed in 17 patients who were diagnosed with CN hypoplasia on high resolution for evaluation of unilateral sensorineural hearing loss at the National Center for Child Health and Development. Of these, six patients had average hearing levels in the affected ears of < 60 dB and were therefore included in this study. RESULTS: All six ears with CN hypoplasia were associated with CN canal stenosis. DPOAEs were present in one (17%) of the six affected ears. The ABR thresholds of the ears with CN hypoplasia were significantly elevated compared with 1-4 kHz pure-tone hearing levels in one of three cases. In two of five cases, the maximum word recognition scores of the affected ears were poor compared with pure-tone hearing levels.

Langerhans cell histiocytosis with disequilibrium.

Langerhans cell histiocytosis (LCH) is a very rare disease in which granulation tissue forms in various organs and the central nervous system (CNS) due to monoclonal proliferation of Langerhans cells. Some patients develop ataxia, tremor, or neurodegenerative abnormalities (such as personality changes and mental deterioration) several years after the onset as the late effects of LCH. We report a case of a 4-year-old boy with LCH, showing speech disorder, truncal ataxia and a wide-based gait with abnormal findings of central nervous system in CT and MRI image. The results of auditory brain stem response revealed a conduction block in the auditory conduction pathway, suggesting an axonopathy of the brain stem. Disequilibrium may be due to brainstem dysfunction associated with paraneoplastic syndrome because an anti-GluRε2 antibody was seen. Paraneoplastic syndrome is a neuropathy induced through an autoimmune mechanism caused by an antibody directed against the nervous system. Neuro-otological examination is helpful for the assessment of CNS neurodegeneration associated with LCH.

Systematic analysis of mitochondrial genes associated with hearing loss in the Japanese population: dHPLC reveals a new candidate mutation.

BACKGROUND: Variants of mitochondrial DNA (mtDNA) have been evaluated for their association with hearing loss. Although ethnic background affects the spectrum of mtDNA variants, systematic mutational analysis of mtDNA in Japanese patients with hearing loss has not been reported. METHODS: Using denaturing high-performance liquid chromatography combined with direct sequencing and cloning-sequencing, Japanese patients with prelingual (N = 54) or postlingual (N = 80) sensorineural hearing loss not having pathogenic mutations of m.1555A > G and m.3243A > G nor GJB2 were subjected to mutational analysis of mtDNA genes (12S rRNA, tRNALeu(UUR), tRNASer(UCN), tRNALys, tRNAHis, tRNASer(AGY), and tRNAGlu). RESULTS: We discovered 15 variants in 12S rRNA and one homoplasmic m.7501A > G variant in tRNASer(UCN); no variants were detected in the other genes. Two criteria, namely the low frequency in the controls and the high conservation among animals, selected the m.904C > T and the m.1105T > C variants in 12S rRNA as candidate pathogenic mutations. Alterations in the secondary structures of the two variant transcripts as well as that of m.7501A > G in tRNASer(UCN) were predicted. CONCLUSIONS: The m.904C > T variant was found to be a new candidate mutation associated with hearing loss. The m.1105T > C variant is unlikely to be pathogenic. The pathogenicity of the homoplasmic m.7501T > A variant awaits further study.

[Clinical characteristics of benign paroxysmal vertigo of childhood (BPVC)].

Pediatric subjects with vertigo or dizziness are rare in Japan, although considerable statistical data accumulated, mostly indicating that orthostatic hypotension is the most frequent clinical symptoms in Japan, as opposed to Benign paroxysmal vertigo of childhood (BPVC), reported to be most frequent abroad. We studied BPVC incidence and clinical features. Subjects were 5 boys and 7 girls aged 4 to 15 years old (average +/- sd 9.5 +/- 3.1 years). The predominant diagnosis was BPVC in 8, orthostatic hypotension in 6, labyrinthitis in 2, and delayed endolymphatic hydrops, and conversion disorder in 1 case each. BPVC was most common. All subjects with BPVC had a history or a family history of migraine. Based on BPVC diagnostic criteria, subjects had neither organic nor functional abnormalities. Information is thus required on attack, injury, and personal or family migraine history to determine a final diagnosis. Note that subjects with BPVC have high orthostatic hypotension. These statistics indicate the importance of diagnostic BPVC criteria in pediatric subjects with dizziness or vertigo.

Risk factors for elevation of ABR threshold in NICU-treated infants.

OBJECTIVE: Several risk factors for hearing impairment among infants treated in the neonatal intensive care unit (NICU) have been reported, but there have been few studies that show the correlation strength between the risk factors in NICU-treated infants and hearing impairment in childhood. The aim of this study was to clarify the relationship between risk factors in NICU-treated infants and a deteriolation of auditory brainstem response (ABR) threshold in their childhood. METHODS: One hundred one NICU-treated infants with ABR threshold of 50 dBnHL or more underwent 2nd ABR test at 20 months after delivery. Multiple regression analysis was performed with ABR threshold change as an objective variable and risk factors as explanatory variables. RESULTS: Two ABR tests of the 101 infants resulted in that 7 showed an elevation of ABR threshold by 20 dB, 70 showed a drop of ABR threshold by 20 dB, and 24 showed no significant change. Multiple regression analysis revealed that the factors contributing to the elevation of ABR threshold were congenital diaphragmatic hernia, severe respiratory disease, and a high C-reactive protein (CRP) level. CONCLUSIONS: In the infants treated in NICU, an incidence of ABR threshold of 50 dBnHL or more was 9.0%, and 6.9% of the infants with the ABR threshold abnormality showed a significant elevation of ABR threshold in their childhood. Factors significantly related to an elevation of ABR threshold were a history of congenital diaphragmatic hernia, severe respiratory disease, and elevation of CRP. In infants with such factors, periodical examination of hearing is required.

CT and MR imaging for pediatric cochlear implantation: emphasis on the relationship between the cochlear nerve canal and the cochlear nerve.

BACKGROUND: Cochlear implantation has become an accepted treatment for deafness. As the frequency of cochlear implantation has increased, requests for images have also increased in the work-up for candidates. An absent cochlear nerve (CN) is a contraindication to cochlear implantation. Therefore, MRI is performed to evaluate the CN in patients with sensorineural hearing loss. Recently, some authors have reported the relationship between cochlear nerve canal (CNC) stenosis and CN hypoplasia. OBJECTIVE: To review the relationship between CNC and CN. MATERIALS AND METHODS: During a period of 78 months, 21 children (42 ears) with unilateral or bilateral sensorineural hearing loss underwent both HRCT and MRI of the cochlear nerve. We retrospectively reviewed two factors: the evaluation of inner ear malformations and the relationship between CNC stenosis and CN hypoplasia. RESULTS: Inner ear malformations were recognized in ten ears. The mean CNC diameter was approximately 2 mm (ranging from 0.6 to 2.7 mm). CN hypoplasia was seen in eight of the 42 ears; all eight were associated with CNC stenosis (1.5 mm in diameter and the remaining two ears, with incomplete partition type I, had CNC stenosis. CONCLUSION: Children with CNC stenosis had a high incidence of CN hypoplasia. CNC stenosis (1.5 mm. Therefore, we conclude that children with CNC stenosis or malformations on HRCT should receive MR imaging of the CN.

Hearing loss in Turner syndrome.

OBJECTIVE: To address the characteristics of hearing loss in patients with Turner syndrome (TS), we evaluated hearing levels of patients with TS and analyzed causative factors. STUDY DESIGN: Thirty-three patients with TS (8 to 40 years of age) were studied through the use of audiological measurements, and causative factors were explored. RESULTS: Twenty cases (35 of 66 ears tested) showed high-frequency (8 kHz) sensory neural hearing loss (HFQ-SNHL). Fifteen cases (26 ears) and 15 cases (24 ears) of the impaired 20 cases were unresponsive to distortion-product otoacoustic emissions and transient-evoked otoacoustic emissions, respectively. HFQ-SNHL showed little relation to the history of middle ear infection and puberty, although middle ear infections were seen in 11 of the 20 cases. The hearing thresholds at high frequencies were correlated with age and body height (P < .001). The age-dependent increase in hearing thresholds in the high frequencies was more apparent in patients with TS with monosomic 45, X than in those with the mosaic type (P < .05). CONCLUSIONS: More than 60% of patients with TS had HFQ-SNHL. Because the increase in hearing threshold at high frequencies was shown to depend on karyotype and aging, regular otological examination is important for the determination of proper treatment.

[Congenital laryngeal stridor].

We reviewed the diagnosis, complications and treatment of congenital laryngeal stridor (CLS), in 97 patients who consulted our clinic between 1991 and 2001. The 97 patients were diagnosed with laryngeal malacia (32%), vocal cord paralysis and laryngeal stenosis (22%), a neoplastic disease like hemagioma and papilloma (11%), or cystic disease (7%). The cases with vocal cord paralysis, laryngeal stenosis or laryngeal cysts were usually diagnosed within 2 months of birth based on severe dyspnea. Two of the 31 cases of laryngeal malacia and 2 of the 22 cases of vocal cord paralysis were associated with neuromuscular disorders. Three patients suffered from vocal cord paralysis complicated by laryngeal stenosis. Thirty-three of the 97 cases required a tracheostomy; these 33 cases included the one case of laryngeal papilloma (100%), 9 of the 10 cases of hemangioma (90%), and 18 of the 24 cases of laryngeal stenosis (75%). Since any disorders of the upper airway can potentially induce stridor, establishing an accurate diagnosis is sometimes difficult when stridor is the only presenting symptom. Hence, information on associated symptoms and the past history of the subject is particularly important for an accurate diagnosis. In addition, decisions regarding the course of treatment course require adequate consideration of possible complications.