Auditory event-related potentials and function of the medial olivocochlear efferent system in children with auditory processing disorders.

OBJECTIVE: The objectives were to investigate the function of central auditory pathways and of the medial efferent olivocochlear system (MOCS). DESIGN: Event-related potentials (ERP) were recorded following the delivery of the stimulus /da/ in quiet and in ipsilateral, contralateral, and binaural noise conditions and correlated to the results of the auditory processing disorders (APD) diagnostic test battery. MOCS function was investigated by adding ipsilateral, contralateral, and binaural noise to transient evoked otoacoustic emission recordings. Auditory brainstem responses and pure tone audiogram were also evaluated. STUDY SAMPLE: Nineteen children (7 to 12 years old) with APD were compared with 24 age-matched controls. RESULTS: Otoacoustic emissions and ABR characteristics did not differ between groups, whereas ERP latencies were significantly longer and of higher amplitudes in APD children than in controls, in both quiet and noise conditions. The MOCS suppression was higher in APD children. CONCLUSIONS: Findings indicate that children with APD present with neural deficiencies in both challenging and nonchallenging environments with an increase in the timing of several central auditory processes correlated to their behavioural performances. Meanwhile, their modulation of the auditory periphery under noisy conditions differs from control children with higher suppression.

Tablet-Based Hearing Test Among Child Clinical Populations: Performance and Preference.

Background and Introduction: Tablet-based automated audiometry applications are a recent alternative method to perform pure-tone hearing testing. Children, in particular, might benefit from such apps because of the game-like interface. However, how children perceive this alternative approach has not been well studied. This study examined children's preference of hearing test and a relationship between their test preference and hearing test results. Materials and Methods: Forty children 6-12 years of age completed a pure-tone hearing test in both the tablet-based automated (tablet) method and the conventional method. Hearing thresholds were measured at 0.5, 1, 2, 4, 6, and 8 kHz in each ear. An exit interview was conducted to obtain each child's test preference. Results: We found that 59% of the children preferred the tablet method when compared to the conventional method. Preference to the tablet method was stronger in the younger children (6 years) than older children (7-12 years). The linear regression analyses suggest that test preference does not affect the hearing test results in the conventional method, but does negatively affect the results in the tablet method. In addition, poor performance was found among children with a clinical diagnosis, in particular, in the tablet method. Discussion: These results suggest that hearing thresholds may be overestimated in children, especially those with clinical diagnosis such as attention or behavioral issues in the tablet method. Future work is needed to determine which clinical populations have potential benefit from a tablet method. Conclusions: Children's test preference is not a good index of hearing test accuracy.

Neurophysiology of hearing in patients with mucopolysaccharidosis type IV.

BACKGROUND: Hearing impairment is a common problem in patients with mucopolysaccharidosis IV (MPS IV) throughout their life. Many of the adult patients with MPS IV exhibit permanent or severe hearing loss. However, there has been no systematic review of detailed audiological test results in MPS IV. MATERIALS AND METHODS: Fourteen individuals with MPS IV (13 MPS IVA and 1 MPS IVB; aged between 12 and 38 years old) participated in the current study. We obtained auditory neurophysiological responses (auditory brainstem responses and otoacoustic emissions test) in addition to pure-tone audiometry and middle ear function tests (tympanometry and acoustic reflexes). RESULTS: The results indicated various levels and types of hearing loss with abnormal neurophysiological responses even in those patients with MPS IVA with normal pure tone thresholds. We also found a strong relationship between height (short stature is an indicator of skeletal severity) and hearing sensitivity as well as a strong relationship between height and outer hair cell function in the inner ear (measured by otoacoustic emissions) among MPS IVA patients. CONCLUSION: The strong correlation between reduced height and hearing loss indicates that patients with severe skeletal dysplasia may be at higher risk of developing more severe hearing loss. More importantly, the spectrum of hearing disorders indicates that MPS IV patients should have annual neurophysiological hearing tests in addition to audiometric testing from an early age regardless of their skeletal severity to more carefully monitor disease progression.

Molecular genetics and metabolism, special edition: Diagnosis, diagnosis and prognosis of Mucopolysaccharidosis IVA.

Mucopolysaccharidosis IVA (MPS IVA, Morquio A syndrome) is an autosomal recessive disorder caused by the deficiency of N-acetylgalactosamine-6-sulfate sulfatase. Deficiency of this enzyme leads to the accumulation of specific glycosaminoglycans (GAGs), chondroitin-6-sulfate (C6S) and keratan sulfate (KS), which are mainly synthesized in the cartilage. Therefore, the substrates are stored primarily in the cartilage and its extracellular matrix (ECM), leading to a direct impact on bone development and successive systemic skeletal spondylepiphyseal dysplasia. The skeletal-related symptoms for MPS IVA include short stature with short neck and trunk, odontoid hypoplasia, spinal cord compression, tracheal obstruction, obstructive airway, pectus carinatum, restrictive lung, kyphoscoliosis, platyspondyly, coxa valga, genu valgum, waddling gait, and laxity of joints. The degree of imbalance of growth in bone and other organs and tissues largely contributes to unique skeletal dysplasia and clinical severity. Diagnosis of MPS IVA needs clinical, radiographic, and laboratory testing to make a complete conclusion. To diagnose MPS IVA, total urinary GAG analysis which has been used is problematic since the values overlap with those in age-matched controls. Currently, urinary and blood KS and C6S, the enzyme activity of GALNS, and GALNS molecular analysis are used for diagnosis and prognosis of clinical phenotype in MPS IVA. MPS IVA can be diagnosed with unique characters although this disorder relates closely to other disorders in some characteristics. In this review article, we comprehensively describe clinical, radiographic, biochemical, and molecular diagnosis and clinical assessment tests for MPS IVA. We also compare MPS IVA to other closely related disorders to differentiate MPS IVA. Overall, imbalance of growth in MPS IVA patients underlies unique skeletal manifestations leading to a critical indicator for diagnosis.

Activity of daily living for Morquio A syndrome.

The aim of this study was to evaluate the activity of daily living (ADL) and surgical interventions in patients with mucopolysaccharidosis IVA (MPS IVA). The factor(s) that affect ADL are age, clinical phenotypes, surgical interventions, therapeutic effect, and body mass index. The ADL questionnaire comprises three domains: "Movement," "Movement with cognition," and "Cognition." Each domain has four subcategories rated on a 5-point scale based on the level of assistance. The questionnaire was collected from 145 healthy controls and 82 patients with MPS IVA. The patient cohort consisted of 63 severe and 17 attenuated phenotypes (2 were undefined); 4 patients treated with hematopoietic stem cell transplantation (HSCT), 33 patients treated with enzyme replacement therapy (ERT) for more than a year, and 45 untreated patients. MPS IVA patients show a decline in ADL scores after 10years of age. Patients with a severe phenotype have a lower ADL score than healthy control subjects, and lower scores than patients with an attenuated phenotype in domains of "Movement" and "Movement with cognition." Patients, who underwent HSCT and were followed up for over 10years, had higher ADL scores and fewer surgical interventions than untreated patients. ADL scores for ERT patients (2.5years follow-up on average) were similar with the-age-matched controls below 10years of age, but declined in older patients. Surgical frequency was higher for severe phenotypic patients than attenuated ones. Surgical frequency for patients treated with ERT was not decreased compared to untreated patients. In conclusion, we have shown the utility of the proposed ADL questionnaire and frequency of surgical interventions in patients with MPS IVA to evaluate the clinical severity and therapeutic efficacy compared with age-matched controls.

Comparison of Fidgeting in Adolescents with Attention-Deficit/Hyperactivity Disorder Between Before and After Stimulant Medication Intake.

Objective: Fidgeting is a common symptom in patients with attention-deficit hyperactivity disorder (ADHD). The current study investigated ADHD stimulant medication effects on fidgeting in adolescents with ADHD during a short research study session using wrist-worn accelerometers. Method: Adolescents with ADHD who had been taking stimulant medications (ADHD group) and adolescents without ADHD (control group) participated in the study. Accelerometer data were obtained from both wrists of each participant to track their hand movements during two hearing testing sessions. All subjects in the ADHD group abstained from their stimulant medications for at least 24 hours before their first session (off-med session). The second session (on-med session) was conducted about 60-90 minutes after medication intake. The control group participated in two sessions in a similar time frame. Results: The current study focuses on relationships between hand movements and stimulant medication in adolescents with ADHD. Both conditions were compared to evaluate the relationship of hand movements and stimulant medication. We hypothesized the ADHD group will exhibit less hand movements during the on-medication session in comparison to off-medication session. Conclusion: Wrist-worn accelerometer measures obtained during nonphysical tasks in a short duration may not provide hand movement differences between on-med and off-med conditions in adolescents with ADHD. ClinicalTrials.gov Identifier: NCT04577417.

Hearing Loss in Mucopolysaccharidoses: Current Knowledge and Future Directions.

Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders caused by a deficiency of one of the enzymes involved in the degradation of glycosaminoglycans. Hearing loss is a common clinical presentation in MPS. This paper reviews the literature on hearing loss for each of the seven recognized subtypes of MPS. Hearing loss was found to be common in MPS I, II, III, IVA, VI, and VII, and absent from MPS IVB and MPS IX. MPS VI presents primarily with conductive hearing loss, while the other subtypes (MPS I, MPS II, MPS III, MPS IVA, and MPS VII) can present with any type of hearing loss (conductive, sensorineural, or mixed hearing loss). The sensorineural component develops as the disease progresses, but there is no consensus on the etiology of the sensorineural component. Enzyme replacement therapy (ERT) is the most common therapy utilized for MPS, but the effects of ERT on hearing function have been inconclusive. This review highlights a need for more comprehensive and multidisciplinary research on hearing function that includes behavioral testing, objective testing, and temporal bone imaging. This information would allow for better understanding of the progression and etiology of hearing loss. Owing to the prevalence of hearing loss in MPS, early diagnosis of hearing loss and annual comprehensive audiological evaluations are recommended.

Cochlear implantation in a patient with mucopolysaccharidosis IVA.

Mucopolysaccharidosis IVA (OMIM 253000; also known as Morquio A syndrome) is associated with skeletal, airway, and hearing abnormalities. Cochlear implantation is an effective intervention for patients with severe-to-profound hearing loss. Patients can gain substantial improvement in auditory performance, speech perception, and their quality of life from cochlear implantation. Although severe progressive sensorineural hearing loss is a common feature of mucopolysaccharidosis IVA, no detailed description of cochlear implantation for mucopolysaccharidosis IVA has been reported. To review the effectiveness and special considerations associated with cochlear implantation in patients with mucopolysaccharidosis IVA, we here report the case of cochlear implantation in mucopolysaccharidosis IVA by a multidisciplinary team. A retrospective chart review was conducted on a 34-year-old female with mucopolysaccharidosis IVA, who received a cochlear implant. Audiometric thresholds, speech perception scores, and cochlear implant processor mapping information were reviewed during the first 12 months following cochlear implantation. The results of audiological tests indicate improved hearing thresholds as well as remarkable enhancement of speech perception skills over 12 months of cochlear implant use. Cochlear implantation improved auditory performance in a mucopolysaccharidosis IVA patient with postlingually severe-to-profound sensorineural hearing loss. The benefits of cochlear implantation could be meaningful for other Morquio patients with progressive hearing loss, although the risks of surgery and anesthesia should be carefully considered by a multidisciplinary team of experts during the cochlear implant candidacy process.

Is there a clinical application for tablet-based automated audiometry in children?

INTRODUCTION: Recent research supports the clinical use of automated audiometry for pediatric hearing screenings. However, very few studies have tested whether tablet-based automated audiometry can offer a valid alternative to traditional manual audiometry for estimation of hearing thresholds in children. This study examined the validity and efficiency of automated audiometry in school-aged children. METHODS: Hearing thresholds for 0.5, 1, 2, 4, 6, and 8 kHz were collected in 32 children ages 6-12 years using standard audiometry and tablet-based automated audiometry in a soundproof booth. Test administration time, test preference, and medical history were also collected. RESULTS: Results exhibited that the majority (67%) of threshold differences between automated and standard were within the clinically acceptable range (10 dB). The threshold difference between the two tests showed that automated audiometry thresholds were higher by 12 dB in 6-year-olds, 7 dB in 7- to 9-year-olds, and 3 dB in 10- to 12-year-olds. In addition, test administration times were similar, such that standard audiometry took an average of 12.3 min and automated audiometry took 11.9 min. CONCLUSIONS: These results support the use of tablet-based automated audiometry in children from ages 7-12 years. However, the results suggest that the clinical use of at least some types of tablet-based automated audiometry may not be feasible in children 6 years of age.

Auditory function in Pelizaeus-Merzbacher disease.

Pelizaeus-Merzbacher disease (PMD; MIM 312080), an inherited defect of central nervous system myelin formation, affects individuals in many ways, including their hearing and language abilities. The aim of this study was to assess the auditory abilities in 18 patients with PMD by examining the functional processes along the central auditory pathways using auditory brainstem responses (ABR) and cortical auditory evoked potentials (CAEP) in response to speech sounds. The significant ABR anomalies confirm the existence of dyssynchrony previously described at the level of the brainstem in patients with PMD. Despite the significant auditory dyssynchrony observed at the level of the brainstem, CAEPs were present in most patients, albeit somehow abnormal in terms of morphology and latency, resembling a type of auditory neuropathy spectrum disorder.

A case of lupus erythematosus/lichen planus overlap syndrome.

A case of lupus erythematosus/lichen planus overlap syndrome (LE/LP overlap syndrome) was reported. A 53-year-old woman developed violaceous erythema around the nostrils and the upper lips and atrophic scaly erythema on the cheeks and neck. Histopathological studies revealed that the patient had distinct discoid lupus erythematosus (DLE), LP, and a lesion with combined features of DLE and LP. Direct immunofluorescent (DIF) studies of the mixed lesion revealed both prominent immunoglobulin (Ig)G deposits in a granular pattern at the basement membrane zone (BMZ) and IgM deposits in the clusters of cytoid bodies; the former are more typical of LE and the latter more of LP. DIF features in combination were unique for LE/LP overlap syndrome. The patient was satisfactorily treated with topical tacrolimus. While reports support the effectiveness of tacrolimus in either LE or LP, this is the first case of LE/LP overlap syndrome treated with topical tacrolimus.

Prevalence of Auditory Processing Disorder in School-Aged Children in the Mid-Atlantic Region.

BACKGROUND: Although auditory processing disorder (APD) is a widely recognized impairment, its prevalence and demographic characteristics are not precisely known in the pediatric population. PURPOSE: To examine the demographic characteristics of children diagnosed with APD at a tertiary health-care facility and the prevalence of pediatric APD. RESEARCH DESIGN: A cross-sectional study. STUDY SAMPLE: A total of 243 children (149 boys and 94 girls) who were referred to the Nemours Audiology Clinics in the Delaware Valley for an APD evaluation. The mean ages were 9.8 yr for boys and 9.7 yr for girls. Out of 243 children referred for an APD evaluation, 94 children exhibited one or more auditory processing deficits in the areas of auditory closure, auditory figure ground, binaural integration, binaural separation, and temporal processing. DATA COLLECTION AND ANALYSIS: Demographic and audiological data, clinical history (parental reports on prenatal and postnatal information, birth weight and height, medical and developmental history, otologic/audiological history, education information, behavioral characteristics), and results of the APD test battery were retrospectively obtained from the electronic medical records of each participant. The prevalence of APD was estimated using the total number of students enrolled in the same school attended by each participant in the 2011 academic year as cohort. RESULTS: The prevalence of APD was 1.94 per 1,000 children in this study. We found that prevalence of APD among the children who attended private schools was more than two times higher than the children who attended public schools. The results also revealed that the majority of children referred to the clinics were Caucasian (85.6%), whereas minority groups were underrepresented for this geographical area with only 3.7% of Hispanic or Latino children and 5.8% of Black or African American children. CONCLUSIONS: The estimated prevalence of APD in the current study was lower than the previously published estimates. The difference might be due to the diagnosis criteria of APD among studies as well as the use of school enrollment number as the referenced population to estimate prevalence in our study. We also found a significant difference in APD prevalence depending on the school types. The findings of higher prevalence rates among the children attending private schools and higher proportion of Caucasians children referred for APD evaluation suggest that more children among those in public schools and in the Hispanic and African American groups should have been referred for an APD evaluation. Hence, the current estimate is likely an underestimate of the actual APD prevalence. The low percentage of Hispanic or African American children referred to the clinic for APD evaluations may be related to the socioeconomic status and linguistic differences among the concerned families. The results of this study raise the importance of adapting the APD test battery for children with a different linguistic background as well as increasing awareness of available clinical resources to all families in our area.

The perception of syllable affiliation of singleton stops in repetitive speech.

Stetson (1951) noted that repeating singleton coda consonants at fast speech rates makes them be perceived as onset consonants affiliated with a following vowel. The current study documents the perception of rate-induced resyllabification, as well as what temporal properties give rise to the perception of syllable affiliation. Stimuli were extracted from a previous study of repeated stop + vowel and vowel + stop syllables (de Jong, 2001a, 2001b). Forced-choice identification tasks show that slow repetitions are clearly distinguished. As speakers increase rate, they reach a point after which listeners disagree as to the affiliation of the stop. This pattern is found for voiced and voiceless consonants using different stimulus extraction techniques. Acoustic models of the identifications indicate that the sudden shift in syllabification occurs with the loss of an acoustic hiatus between successive syllables. Acoustic models of the fast rate identifications indicate various other qualities, such as consonant voicing, affect the probability that the consonants will be perceived as onsets. These results indicate a model of syllabic affiliation where specific juncture-marking aspects of the signal dominate parsing, and in their absence other differences provide additional, weaker cues to syllabic affiliation.

Ear effect and gender difference of spontaneous otoacoustic emissions in children with auditory processing disorder.

Spontaneous otoacoustic emissions (SOAEs) are found in most healthy ears, and can be used to measure the health of the cochlear structures and feedback mechanism. According to existing literature, right ears tend to exhibit greater numbers of SOAEs than left ears (Bilger et al., 1990) and females tend to show higher incidence of SOAEs than males (Moulin et al., 1993). The SOAE prevalence has not been extensively studied in children with Auditory Processing Disorder (APD), a disorder with unknown etiology that reduces one's ability to process auditory information. This study examined the prevalence and ear advantage of SOAEs between genders in children diagnosed with APD. SOAEs were investigated in 19 children (7 girls and 12 boys) with APD and 2 4 typically developing children (14 girls and 10 boys) aged 7-12. Right ear advantage was more prevalent in control (71%) than APD subjects (42 %). However, over 30% more females exhibited a right ear advantage than males in each group. Although the results are not significant, our findings indicate that the lack of right ear advantage for SOAE is more prevalent in children with APD, particularly in males, suggesting that cochlear mechanisms or their control might be somehow affected in APD.

Perceptual rate normalization in naturally produced rate-varied speech.

The perception of voicing categories is affected by speaking rate, so that listeners' category boundaries on a VOT continuum shift to a lower value when syllable duration decreases [Miller and Volaitis, Percept. Psychophys. 46, 505-512 (1989); Volaitis and Miller, J. Acoust. Soc. Am. 92, 723-735 (1992)]. Previous rate normalization effects have been found using artificially varied stimuli. This study examines the effect of speech rate on voicing categorization in naturally produced rate-varied speech. The stimuli contained natural decreases in VOT with faster speech rates so that VOT values for /b/ and /p/ overlapped at the fastest rates. Consonant identification results showed that the rate effects on the perceptual boundary between /p/ and /b/ very closely matched the effects of rate on the productions, though there was a small mismatch with fast rate productions whereby voiced stops were systematically miscategorized as voiceless. Another group of listeners judged the goodness of the consonant, indicating that best exemplars were rate-varied and shifted away from the /p/-/b/ boundary. These results are discussed in light of exemplar-based and abstractionist models of speech perception.