Phenotypic variability of patients homozygous for the GJB2 mutation 35delG cannot be explained by the influence of one major modifier gene

Hereditary hearing loss (HL) is a very heterogeneous trait, with 46 gene identifications for non-syndromic HL. Mutations in GJB2 cause up to half of all cases of severe-to-profound congenital autosomal recessive non-syndromic HL, with 35delG being the most frequent mutation in Caucasians. Although a genotype-phenotype correlation has been established for most GJB2 genotypes, the HL of 35delG homozygous patients is mild to profound. We hypothesise that this phenotypic variability is at least partly caused by the influence of modifier genes. By performing a whole-genome association (WGA) study on 35delG homozygotes, we sought to identify modifier genes. The association study was performed by comparing the genotypes of mild/moderate cases and profound cases. The first analysis included a pooling-based WGA study of a first set of 255 samples by using both the Illumina 550K and Affymetrix 500K chips. This analysis resulted in a ranking of all analysed single-nucleotide polymorphisms (SNPs) according to their P-values. The top 250 most significantly associated SNPs were genotyped individually in the same sample set. All 192 SNPs that still had significant P-values were genotyped in a second independent set of 297 samples for replication. The significant P-values were replicated in nine SNPs, with combined P-values between 3 x 10(-3) and 1 x 10(-4). This study suggests that the phenotypic variability in 35delG homozygous patients cannot be explained by the effect of one major modifier gene. Significantly associated SNPs may reflect a small modifying effect on the phenotype. Increasing the power of the study will be of greatest importance to confirm these results.

Common Misconceptions Regarding Pediatric Auditory Processing Disorder

Pediatric hearing evaluation based on pure tone audiometry does not always reflect how a child hears in everyday life. This practice is inappropriate when evaluating the difficulties children experiencing auditory processing disorder (APD) in school or on the playground. Despite the marked increase in research on pediatric APD, there remains limited access to proper evaluation worldwide. This perspective article presents five common misconceptions of APD that contribute to inappropriate or limited management in children experiencing these deficits. The misconceptions discussed are (1) the disorder cannot be diagnosed due to the lack of a gold standard diagnostic test; (2) making generalizations based on profiles of children suspected of APD and not diagnosed with the disorder; (3) it is best to discard an APD diagnosis when another disorder is present; (4) arguing that the known link between auditory perception and higher cognition function precludes the validity of APD as a clinical entity; and (5) APD is not a clinical entity. These five misconceptions are described and rebutted using published data as well as critical thinking on current available knowledge on APD.

Psychometric evaluation of children with auditory processing disorder (APD): comparison with normal-hearing and clinical non-APD groups

PURPOSE

To investigate the clinical utility of the Children's Auditory Processing Performance Scale (CHAPPS; Smoski, Brunt, & Tannahill, 1992) to evaluate listening ability in 12-year-old children referred for auditory processing assessment.

METHOD

This was a prospective case control study of 97 children (age range = 11;4 [years;months] to 12;7). Auditory processing disorder (APD) was diagnosed based on findings of deficits on at least 1 nonverbal test and on at least 2 tests of an auditory processing test battery. Clinically referred children were grouped as APD (n = 38) or non-APD (n = 20).

RESULTS

The study found that (a) the APD group performed lower than the non-APD group on the Quiet, Ideal, Memory (p < .0001), and Attention (p < .05) subscales of the CHAPPS; (b) the non-APD group performed lower than the group with normal hearing on the Noise, Multiple Inputs, and Attention subscales (p < .0001); and (c) there were significant moderate-to-strong correlations (Spearman's ρ > .04) between Dichotic Digits, Duration Pattern tests, and the CHAPPS Attention, Memory, and total scores.

CONCLUSION

The CHAPPS may be a clinically useful tool to evaluate listening ability in 12-year-old children suspected of having APD. Restricting use of the CHAPPS to older children may help address its limitations as reported by other studies.

A personalized, Monte Carlo-based method for internal dosimetric evaluation of radiopharmaceuticals in children

PURPOSE

Herein, we introduce a methodology for estimating the absorbed dose in organs at risk that is based on specified clinically derived radiopharmaceutical biodistributions and personalized anatomical characteristics.

METHODS

To evaluate the proposed methodology, we used realistic Monte Carlo (MC) simulations and computational pediatric models to calculate a parameter called in this work the "specific absorbed dose rate" (SADR). The SADR is a unique quantitative metric in that it is specific to a particular organ. It is defined as the absorbed dose rate in an organ when the biodistribution of radioactivity over the whole body is considered. Initially, we applied a validation procedure that calculated specific absorbed fractions (SAFs) from mono-energetic photon sources in the range of 10 keV-2 MeV and compared them with previously published data. We calculated the SADRs for five different radiopharmaceuticals (99m Tc-MDP, 123 I-mIBG, 131 I-MIBG, 131 I-NaI, and 153 Sm-EDTMP) based on their biodistributions at four or five different times; the biodistributions were derived from the clinical scintigraphic data of pediatric patients. We used six models representing male and female patients aged 5, 8, and 14 yr to investigate the absorbed dose variability due to anatomical variations. The GATE Monte Carlo toolkit was used to calculate absorbed doses per organ. Finally, we compared the SADR methodology to that of OLINDA/EXM 1.1 using rescaled masses according to the studied models. Four target organs were considered for calculating the absorbed doses.

RESULTS

The ratios of SAFs calculated with GATE simulations to those based on previously published data were between 0.9 and 2.2 when the liver was used as a source organ. Subsequently, we used GATE to calculate a dataset of SADRs for the six pediatric models. The SADRs for pediatric models whose total body weights ranged from 20 to 40 kg varied up to approximately 90%, whereas those for models of similar body masses varied less than 15%. Finally, we found absorbed dose discrepancies of approximately 10-150% between the SADR methodology and OLINDA for two different radiopharmaceuticals. Absorbed doses from SADRs and from individualized S-values in the same pediatric model differed approximately 1-50%.

CONCLUSIONS

Because pediatric radiopharmaceutical dosimetric estimates demonstrate large variation due to the patient's anatomical characteristics, personalized data should be considered. Using our SADR method in a larger population of phantoms and for a variety of radiopharmaceuticals could enhance the personalization of dosimetry in pediatric nuclear medicine. The proposed methodology provides the advantage of creating time-dependent organ dose rate curves.

Contribution of psychoacoustics and neuroaudiology in revealing correlation of mental disorders with central auditory processing disorders

BACKGROUND: Psychoacoustics is a fascinating developing field concerned with the evaluation of the hearing sensation as an outcome of a sound or speech stimulus. Neuroaudiology with electrophysiologic testing, records the electrical activity of the auditory pathways, extending from the 8th cranial nerve up to the cortical auditory centers as a result of external auditory stimuli. Central Auditory Processing Disorders may co-exist with mental disorders and complicate diagnosis and outcome. DESIGN: A MEDLINE search was conducted to search for papers concerning the association between Central Auditory Processing Disorders and mental disorders. The research focused on the diagnostic methods providing the inter-connection of various mental disorders and central auditory deficits. MEASUREMENTS AND MAIN RESULTS: The medline research revealed 564 papers when using the keywords 'auditory deficits' and 'mental disorders'. 79 papers were referring specifically to Central Auditory Processing Disorders in connection with mental disorders. 175 papers were related to Schizophrenia, 126 to learning disabilities, 29 to Parkinson's disease, 88 to dyslexia and 39 to Alzheimer's disease. Assessment of the Central Auditory System is carried out through a great variety of tests that fall into two main categories: psychoacoustic and electrophysiologic testing. Different specialties are involved in the diagnosis and management of Central Auditory Processing Disorders as well as the mental disorders that may co-exist with them. As a result it is essential that they are all aware of the possibilities in diagnostic procedures. CONCLUSIONS: Considerable evidence exists that mental disorders may correlate with CAPD and this correlation could be revealed through psychoacoustics and neuroaudiology. Mental disorders that relate to Central Auditory Processing Disorders are: Schizophrenia, attention deficit disorders, Alzheimer's disease, learning disabilities, dyslexia, depression, auditory hallucinations, Parkinson's disease, alcoholism, anorexia and childhood mental retardation. Clinical awareness should be high in order for doctors of the two specialties, psychiatry and otorhinolaryngology-audiology to collaborate.

Audiological profile of the prevalent genetic form of childhood sensorineural hearing loss due to GJB2 mutations in northern Greece

The present study describes the audiological profile of genetic hearing loss resulting from GJB2 mutations in northern Greece, as this represents the most frequent single cause of childhood sensorineural hearing loss. The 35delG mutation in homozygosity was detected in 27 of 107 patients (25.2%). The audiological profile is that of a profound or severe sensorineural hearing loss, with a sloping or flat configuration of the audiogram, mostly symmetrical, non-progressive and affecting more the higher frequencies. This profile underlines the importance of early identification and genetic family counseling leading to the future possibility of prevention of deafness.

Clinical Expertise Is Core to an Evidence-Based Approach to Auditory Processing Disorder: A Reply to Neijenhuis et al. 2019

The opinion article "An Evidence-based Perspective on Misconceptions Regarding Pediatric Auditory Processing Disorder" by Neijenhuis et al. (1) presents a distorted view of the evidence-based approach used in medicine. The authors focus on the amorphous non-diagnostic entity "listening difficulties" not auditory processing disorder (APD) and create confusion that could jeopardize clinical services to individuals with APD. In our perspective article, we rebut Neijenhuis et al. (1), and more importantly, we present a rationale for evidence-based practice founded on the premise that research on APD is only clinically applicable when conducted on clinical populations diagnosed with APD.

Prelingual nonsyndromic hearing loss in Greece. Molecular and clinical findings

Mutations in the gene encoding the gap-junction protein connexin 26 (GJB2) on chromosome 13q11 have been shown as a major contributor to prelingual, sensorineural, nonsyndromic deafness. One specific mutation, 35delG, has accounted for the majority of the mutations detected in the GJB2 gene in Caucasian populations and is one of the most frequent disease mutations identified so far with highest carrier frequency of 3,5% in the Greek population. In a collaboration with the major referral centers for childhood deafness in Greece, patients were examined by an extensive questionnaire to exclude syndromic forms and environmental causes of deafness and by allele-specific PCR for the detection of the 35delG mutation. The 35delG mutation was found in 32.1% of the alleles in 173 unrelated cases of prelingual deafness: 50 homozygotes and 11 heterozygotes. Individuals heterozygous for the 35delG mutation were further analyzed by direct genomic sequencing of the coding region of the GJB2 gene, which revealed R184P and 486insT mutations in single alleles. We conclude that the 35delG GJB2 mutation is responsible for one third of prelingual, sensorineural deafness in Greece, which is higher than the usually quoted 20% for Caucasian populations.

Early Prediction of Planning Adaptation Requirement Indication Due to Volumetric Alterations in Head and Neck Cancer Radiotherapy: A Machine Learning Approach

Background: During RT cycles, the tumor response pattern could affect tumor coverage and may lead to organs at risk of overdose. As such, early prediction of significant volumetric changes could therefore reduce potential radiation-related adverse effects. Nevertheless, effective machine learning approaches based on the radiomic features of the clinically used CBCT images to determine the tumor volume variations due to RT not having been implemented so far. Methods: CBCT images from 40 HN cancer patients were collected weekly during RT treatment. From the obtained images, the Clinical Target Volume (CTV) and Parotid Glands (PG) regions of interest were utilized to calculate 104 delta-radiomics features. These features were fed on a feature selection and classification procedure for the early prediction of significant volumetric alterations. Results: The proposed framework was able to achieve 0.90 classification performance accuracy while detecting a small subset of discriminative characteristics from the 1st week of RT. The selected features were further analyzed regarding their effects on temporal changes in anatomy and tumor response modeling. Conclusion: The use of machine learning algorithms offers promising perspectives for fast and reliable early prediction of large volumetric deviations as a result of RT treatment, exploiting hidden patterns in the overall anatomical characteristics.

Deformable image registration to assist clinical decision for radiotherapy treatment adaptation for head and neck cancer patients

Head and neck (H&N) cancer patients often present anatomical and geometrical changes in tumors and organs at risk (OARs) during radiotherapy treatment. These changes may result in the need to adapt the existing treatment planning, using an expert's subjective opinion, for offline adaptive radiotherapy and a new treatment planning before each treatment, for online adaptive radiotherapy. In the present study, a fast methodology is proposed to assist in planning adaptation clinical decision using tumor and parotid glands percentage volume changes during treatment. The proposed approach was applied to 40 Η&Ν cases, with one planning Computed Tomography (pCT) image and CBCT scans for 6 weeks of treatment per case. Deformable registration was used for each patient's pCT image alignment to its weekly CBCT. The calculated transformations were used to align each patient's anatomical structures to the weekly anatomy. Clinical target volume (CTV) and parotid gland volume percentage changes were calculated in each case. The accuracy of the achieved image alignment was validated qualitatively and quantitatively. Furthermore, statistical analysis was performed to test if there is a statistically significant correlation between CTV and parotid glands volume percentage changes. Average MDA for CTV and parotid glands between corresponding structures defined by an expert in CBCTs and automatically calculated through registration was 1.4 ± 0.1 mm and 1.5 ± 0.1 mm, respectively. The mean registration time of the first CBCT image registration for 40 cases was lower than 3.4 min. Five patients show more than 20% tumor volume change. Six patients show more than 30% parotid glands volume change. Ten out of 40 patients proposed for planning adaptation. All the statistical tests performed showed no correlation between CTV/parotid glands percentage volume changes. The aim to assist in clinical decision making on a fast and automatic way was achieved using the proposed methodology, thereby reducing workload in clinical practice.

Spoken Word Recognition Enhancement Due to Preceding Synchronized Beats Compared to Unsynchronized or Unrhythmic Beats

The relation between rhythm and language has been investigated over the last decades, with evidence that these share overlapping perceptual mechanisms emerging from several different strands of research. The dynamic Attention Theory posits that neural entrainment to musical rhythm results in synchronized oscillations in attention, enhancing perception of other events occurring at the same rate. In this study, this prediction was tested in 10 year-old children by means of a psychoacoustic speech recognition in babble paradigm. It was hypothesized that rhythm effects evoked via a short isochronous sequence of beats would provide optimal word recognition in babble when beats and word are in sync. We compared speech recognition in babble performance in the presence of isochronous and in sync vs. non-isochronous or out of sync sequence of beats. Results showed that (a) word recognition was the best when rhythm and word were in sync, and (b) the effect was not uniform across syllables and gender of subjects. Our results suggest that pure tone beats affect speech recognition at early levels of sensory or phonemic processing.

A systematic review and metanalysis of questionnaires used for auditory processing screening and evaluation

The recognition of Auditory Processing Disorder (APD) as a distinct clinical condition that impacts hearing capacity and mental health has gained attention. Although pure tone audiometry is the gold standard for assessing hearing, it inadequately reflects everyday hearing abilities, especially in challenging acoustic environments. Deficits in speech perception in noise, a key aspect of APD, have been linked to an increased risk of dementia. The World Health Organization emphasizes the need for evaluating central auditory function in cases of mild hearing loss and normal audiometry results. Specific questionnaires play a crucial role in documenting and quantifying the difficulties faced by individuals with APD. Validated questionnaires such as the Children's Auditory Processing Performance Scale, the Fisher's Auditory Problems Checklist, and the Auditory Processing Domains Questionnaire are available for children, while questionnaires for adults include items related to auditory functions associated with APD. This systematic review and meta-analysis identified six questionnaires used for screening and evaluating APD with a total of 783 participants across 12 studies. The questionnaires exhibited differences in domains evaluated, scoring methods, and evaluation of listening in quiet and noise. Meta-analysis results demonstrated that individuals with APD consistently exhibited worse scores compared to healthy controls across all questionnaires. Additionally, comparisons with clinical control groups showed varying results. The study highlights (i) the importance of standardized questionnaires in identifying and assessing APD, aiding in its diagnosis and management, and (ii) the need to use sub-scores as well as overall scores of questionnaires to elaborate on specific hearing and listening situations. There is a need to develop more APD specific questionnaires for the adult population as well as for more focused research on APD diagnosed individuals to further establish the validity and reliability of these questionnaires.

Auditory processing disorder may be present in schizophrenia and it is highly correlated with formal thought disorder

The present study investigates the presence of Auditory Processing Disorder (APD) in schizophrenia and its association with symptomatology, especially Formal Thought Disorder (FTD). 50 patients with schizophrenia and 25 matched healthy controls completed a battery of three auditory processing tests. Positive and Negative Syndrome Scale (PANSS) and Thought, Language and Communication (TLC) scale were used to assess clinical symptoms. The patient group was divided into two subgroups, according to FTD severity. Auditory processing performance of the control group and the patient group was evaluated. Correlations between auditory processing scores and TLC scores, as well as auditory processing scores and PANSS scores were examined. Most of the patients, especially those with FTD, had auditory deficits that can be classified as APD. Patients showed impaired performance compared to controls in all tests. Total severity and specific factors of FTD, as well as other clinical symptoms and symptom categories were correlated with auditory processing performance. We provided evidence that APD may be present in schizophrenia and that FTD, as well as other clinical symptoms are associated with auditory processing deficits. There are important clinical implications for non-pharmacological interventions and early diagnosis of schizophrenia.

Auditory Processing in Musicians, a Cross-Sectional Study, as a Basis for Auditory Training Optimization

Μusicians are reported to have enhanced auditory processing. This study aimed to assess auditory perception in Greek musicians with respect to their musical specialization and to compare their auditory processing with that of non-musicians. Auditory processing elements evaluated were speech recognition in babble, rhythmic advantage in speech recognition, short-term working memory, temporal resolution, and frequency discrimination threshold detection. All groups were of 12 participants. Three distinct experimental groups tested included western classical musicians, Byzantine chanters, and percussionists. The control group consisted of 12 non-musicians. The results revealed: (i) a rhythmic advantage for word recognition in noise for classical musicians (M = 12.42) compared to Byzantine musicians (M = 9.83), as well as for musicians compared to non-musicians (U = 120.50, p = 0.019), (ii) better frequency discrimination threshold of Byzantine musicians (M = 3.17, p = 0.002) compared to the other two musicians' group for the 2000 Hz region, (iii) statistically significant better working memory for musicians (U = 123.00, p = 0.025) compared to non-musicians. Musical training enhances elements of auditory processing and may be used as an additional rehabilitation approach during auditory training, focusing on specific types of music for specific auditory processing deficits.

Auditory processing in patients with temporal lobe epilepsy: A systematic review and meta-analysis

BACKGROUND

Hearing efficiency is known to influence and interact with communication and mental health. Hearing impairment may be hidden when co-occurring with neurological disorders.

PURPOSE

We performed a systematic review and meta-analysis in order to address the following questions: 1) which specific tools of auditory processing show clear deficits, separating Temporal Lobe Epilepsy (TLE) patients from normal controls,2) How well is TLE evaluated in terms of hearing and auditory processing?

METHODS

The study inclusion criteria were: 1) patients diagnosed with temporal lobe epilepsy, 2) presence of a normal control group, 3) auditory processing assessment using auditory stimuli with behavioral tests and/or P300 or Mitch Match Negativity (MMN) latency and/or amplitude, 4) publications written in English, 5) publication date after 2000. 132 articles were retrieved and based on PRISMA & PICO criteria 23 articles were analyzed.

RESULTS

Temporal resolution and processing as measured by the behavioral tests of Gaps-In-Noise (GIN) and Duration Pattern Test (DPT) document deficiencies in TLE patients and separate them from normal controls. Electrophysiology as measured by MMN & P300 shows statistically significant differences in TLE patients compared to controls with patients showing deficient auditory processing. A clear difference between studies with psychoacoustic assessment as opposed to electrophysiology ones may be due to lacking or incomplete evaluation of peripheral hearing by gold standard tools (76.9% in electrophysiology studies).

CONCLUSION

Auditory processing is deficient in patients with TLE. There is a clear need to evaluate hearing efficiency before proceeding to auditory processing evaluation with behavioral or electrophysiological tests.

Temporal resolution and pitch discrimination in music education: novel data in children

BACKGROUND

Rehabilitation of hearing and listening difficulties through neuroplasticity of the auditory nervous system is a promising technique. Evidence of enhanced auditory processing in adult musicians is often not based on clinical auditory processing tests and is lacking in children with musical education.

PURPOSE

The aim of this study is to investigate the temporal resolution and frequency discrimination elements of auditory processing both in adults and children with musical education and to compare them with those without any musical education.

METHODS

Participants consisted of ten children without musical training and ten children with musical training with mean age 11.3 years and range 8-15 years as well as ten adults without musical education and ten adults with musical education with mean age 38.1 years and range 30-45 years. All participants were tested with two temporal resolution tests (GIN:Gaps-In-Noise and RGDT:Random Gap Detection Test), a temporal ordering frequency test (FPT:Frequency Pattern Test), and a frequency discrimination test (DLF: Different Limen for Frequency).

RESULTS

All test results revealed better performance in both children and adults with musical training for both ears.

CONCLUSION

A positive effect of formal music education for specific auditory processing elements in both children and adults is documented. Larger samples, longitudinal studies, as well as groups with impaired hearing and/or auditory processing are needed to further substantiate the effect shown.

Sensitivity Analysis in Economic Evaluations of Immuno-Oncology Drugs: A Systematic Literature Review

OBJECTIVES

This study aimed to review, assess, and report the characteristics and strategies of sensitivity analyses (SAs) that were performed in the context of published economic evaluations of immuno-oncology drugs.

METHODS

The systematic literature search was conducted in Scopus and MEDLINE for articles published from 2005 to 2021. Study selection, based on a predefined set of criteria, was performed by 2 reviewers independently. We included economic evaluations of Food and Drug Administration-approved immuno-oncology drugs that were published in English and assessed the accompanying SAs on a set of items, including the range justification of the baseline parameters within the deterministic SA, the provisions for the correlation/overlay between parameters, and the justification of the chosen parameter distribution for the probabilistic SA, among others.

RESULTS

A total of 98 of 295 publications met the inclusion criteria. A total of 90 studies included a one-way and probabilistic SA and 16 of 98 studies had one-way and scenario analysis, alone or together with probabilistic analysis. Most studies provide explicit references as to the choice of parameters and values; nevertheless, there is a lack of a reference of correlation/overlay between parameters in most of the evaluations. In 26 of 98 studies, the most influential parameter for the incremental cost-effectiveness ratio was the under-evaluation drug cost.

CONCLUSIONS

Most of included articles contained an SA that was implemented according to commonly accepted published guidance. The under-evaluation drug cost, the estimates of progression-free survival, the hazard ratio for overall survival, and the time horizon of the analysis seem to play an important part in the robustness of the outcomes.

Better education required for professionals in healthcare regarding auditory processing disorder

BACKGROUND

Global research has revealed inadequate levels of Auditory Processing Disorder (APD) awareness and knowledge among related professionals leading to neglect of this specific type of hearing impairment that is estimated to present in 50% of children with learning disabilities (dyslexia included) and more than 70% of adults with presbycusis or mild cognitive impairment.

PURPOSE

The aim of the current study was to record APD awareness and knowledge among professionals working in both Healthcare and Education sectors.

METHODS

A 36-question questionnaire was developed and addressed to medical doctors of different specialties (ENTs and non-ENTs), therapists (speech & language therapists, occupational therapists, psychologists), and educators (of both typical and special education). The questionnaire was sent to Professional Societies of interest as well as a University Rectorate where authors are affiliated, requesting the spreading to all members, and was also posted to related private groups in social media. Data concerning APD-training and knowledge were gathered from 522 questionnaires. Level of knowledge was recorded both subjectively (self-rating) and objectively (pre-defined scoring of items).

RESULTS

Analysis showed insufficient knowledge concerning APD among specialties. ENTs and/or therapists scored statistically significantly higher compared to other medical specialties and educators, while still lower than 50%. The current level of awareness on APD might negatively affect the way individuals with APD are addressed, all the way from referral to management. Levels of awareness and knowledge among professions which are related to APD either directly or indirectly can be further improved through formal education targeting bachelor, master and PhD programs of medical doctors, therapists and educators.

CONCLUSION

We are proposing the development of educational programs that target ENT doctors so that children and adults receive more elaborate services both diagnostically and from a rehabilitation point of view. This will improve quality of life and mental health.