Behavioral characterization of the cochlear amplifier lesion due to loss of function of stereocilin (STRC) in human subjects

Loss of function of stereocilin (STRC) is the second most common cause of inherited hearing loss. The loss of the stereocilin protein, encoded by the STRC gene, induces the loss of connection between outer hair cells and tectorial membrane. This only affects the outer hair cells (OHCs) function, involving deficits of active cochlear frequency selectivity and amplifier functions despite preservation of normal inner hair cells. Better understanding of cochlear features associated with mutation of STRC will improve our knowledge of normal cochlear function, the pathophysiology of hearing impairment, and potentially enhance hearing aid and cochlear implant signal processing. Nine subjects with homozygous or compound heterozygous loss of function mutations in STRC were included, age 7-24 years. Temporal and spectral modulation perception were measured, characterized by spectral and temporal modulation transfer functions. Speech-in-noise perception was studied with spondee identification in adaptive steady-state noise and AzBio sentences with 0 and -5 dB SNR multitalker babble. Results were compared with normal hearing (NH) and cochlear implant (CI) listeners to place STRC-/- listeners' hearing capacity in context. Spectral ripple discrimination thresholds in the STRC-/- subjects were poorer than in NH listeners (p < 0.0001) but remained better than for CI listeners (p < 0.0001). Frequency resolution appeared impaired in the STRC-/- group compared to NH listeners but did not reach statistical significance (p = 0.06). Compared to NH listeners, amplitude modulation detection thresholds in the STRC-/- group did not reach significance (p=  0.06) but were better than in CI subjects (p < 0.0001). Temporal resolution in STRC-/- subjects was similar to NH (p = 0.98) but better than in CI listeners (p = 0.04). The spondee reception threshold in the STRC-/- group was worse than NH listeners (p = 0.0008) but better than CI listeners (p = 0.0001). For AzBio sentences, performance at 0 dB SNR was similar between the STRC-/- group and the NH group, 88 % and 97 % respectively. For -5 dB SNR, the STRC-/- performance was significantly poorer than NH, 40 % and 85 % respectively, yet much better than with CI who performed at 54 % at +5 dB SNR in children and 53 % at + 10 dB SNR in adults. To our knowledge, this is the first study of the psychoacoustic performance of human subjects lacking cochlear amplification but with normal inner hair cell function. Our data demonstrate preservation of temporal resolution and a trend to impaired frequency resolution in this group without reaching statistical significance. Speech-in-noise perception compared to NH listeners was impaired as well. All measures were better than those in CI listeners. It remains to be seen if hearing aid modifications, customized for the spectral deficits in STRC-/- listeners can improve speech understanding in noise. Since cochlear implants are also limited by deficient spectral selectivity, STRC-/- hearing may provide an upper bound on what could be obtained with better temporal coding in electrical stimulation.

Association of Genetic Diagnoses for Childhood-Onset Hearing Loss With Cochlear Implant Outcomes

Importance

In the US, most childhood-onset bilateral sensorineural hearing loss is genetic, with more than 120 genes and thousands of different alleles known. Primary treatments are hearing aids and cochlear implants. Genetic diagnosis can inform progression of hearing loss, indicate potential syndromic features, and suggest best timing for individualized treatment.

Objective

To identify the genetic causes of childhood-onset hearing loss and characterize severity, progression, and cochlear implant success associated with genotype in a single large clinical cohort.

Design, Setting, and Participants

This cross-sectional analysis (genomics) and retrospective cohort analysis (audiological measures) were conducted from 2019 to 2022 at the otolaryngology and audiology clinics of Seattle Children's Hospital and the University of Washington and included 449 children from 406 families with bilateral sensorineural hearing loss with an onset younger than 18 years. Data were analyzed between January and June 2022.

Main Outcomes and Measures

Genetic diagnoses based on genomic sequencing and structural variant analysis of the DNA of participants; severity and progression of hearing loss as measured by audiologic testing; and cochlear implant success as measured by pediatric and adult speech perception tests. Hearing thresholds and speech perception scores were evaluated with respect to age at implant, months since implant, and genotype using a multivariate analysis of variance and covariance.

Results

Of 406 participants, 208 (51%) were female, 17 (4%) were African/African American, 32 (8%) were East Asian, 219 (54%) were European, 53 (13%) were Latino/Admixed American, and 16 (4%) were South Asian. Genomic analysis yielded genetic diagnoses for 210 of 406 families (52%), including 55 of 82 multiplex families (67%) and 155 of 324 singleton families (48%). Rates of genetic diagnosis were similar for children of all ancestries. Causal variants occurred in 43 different genes, with each child (with 1 exception) having causative variant(s) in only 1 gene. Hearing loss severity, affected frequencies, and progression varied by gene and, for some genes, by genotype within gene. For children with causative mutations in MYO6, OTOA, SLC26A4, TMPRSS3, or severe loss-of-function variants in GJB2, hearing loss was progressive, with losses of more than 10 dB per decade. For all children with cochlear implants, outcomes of adult speech perception tests were greater than preimplanted levels. Yet the degree of success varied substantially by genotype. Adjusting for age at implant and interval since implant, speech perception was highest for children with hearing loss due to MITF or TMPRSS3.

Conclusions and Relevance

The results of this cross-sectional study suggest that genetic diagnosis is now sufficiently advanced to enable its integration into precision medical care for childhood-onset hearing loss.

Genetic Heterogeneity and Core Clinical Features of NOG-Related-Symphalangism Spectrum Disorder

OBJECTIVES

To better distinguish NOG-related-symphalangism spectrum disorder (NOG-SSD) from chromosomal 17q22 microdeletion syndromes and to inform surgical considerations in stapes surgery for patients with NOG-SSD.

BACKGROUND

Mutations in NOG cause a variety of skeletal syndromes that often include conductive hearing loss. Several microdeletions of chromosome 17q22 lead to severe syndromes with clinical characteristics that overlap NOG-SSD. Isolated deletion of NOG has not been described, and therefore the contribution of NOG deletion in these syndromes is unknown.

METHODS

Two families with autosomal dominant NOG-SSD exhibited stapes ankylosis, facial dysmorphisms, and skeletal and joint anomalies. In each family, NOG was evaluated by genomic sequencing and candidate mutations confirmed as damaging by in vitro assays. Temporal bone histology of a patient with NOG-SSD was compared with temporal bones of 40 patients diagnosed with otosclerosis.

RESULTS

Family 1 harbors a 555 kb chromosomal deletion encompassing only NOG and ANKFN1. Family 2 harbors a missense mutation in NOG leading to absence of noggin protein. The incus-footplate distance of the temporal bone was significantly longer in a patient with NOG-SSD than in patients with otosclerosis.

CONCLUSION

The chromosomal microdeletion of family 1 led to a phenotype comparable to that due to a NOG point mutation and much milder than the phenotypes due to other chromosome 17q22 microdeletions. Severe clinical findings in other microdeletion cases are likely due to deletion of genes other than NOG. Based on temporal bone findings, we recommend that surgeons obtain longer stapes prostheses before stapes surgery in individuals with NOG-SSD stapes ankylosis.

Elevated basal serum tryptase identifies a multisystem disorder associated with increased TPSAB1 copy number

Elevated basal serum tryptase levels are present in 4-6% of the general population, but the cause and relevance of such increases are unknown. Previously, we described subjects with dominantly inherited elevated basal serum tryptase levels associated with multisystem complaints including cutaneous flushing and pruritus, dysautonomia, functional gastrointestinal symptoms, chronic pain, and connective tissue abnormalities, including joint hypermobility. Here we report the identification of germline duplications and triplications in the TPSAB1 gene encoding α-tryptase that segregate with inherited increases in basal serum tryptase levels in 35 families presenting with associated multisystem complaints. Individuals harboring alleles encoding three copies of α-tryptase had higher basal serum levels of tryptase and were more symptomatic than those with alleles encoding two copies, suggesting a gene-dose effect. Further, we found in two additional cohorts (172 individuals) that elevated basal serum tryptase levels were exclusively associated with duplication of α-tryptase-encoding sequence in TPSAB1, and affected individuals reported symptom complexes seen in our initial familial cohort. Thus, our findings link duplications in TPSAB1 with irritable bowel syndrome, cutaneous complaints, connective tissue abnormalities, and dysautonomia.

The disruptive nature of personalized medicine technologies: implications for the health care system

Genomics technologies, notwithstanding rising complexity and low productivity to date, once translated to clinical care, promise significantly improved outcomes through cost-effective interventions and prevention. But, along the way, every business model and every stakeholder group will be challenged to adapt to the disruptions that will arise as our health care system seeks to embrace those technologies. This paper identifies many of the key issues and stakeholders to be directly effected, including payers, providers, and suppliers. An even greater challenge faces public policy makers if these technologies are to be optimized. Many of these issues are raised as well. Finally, the point is made that the greatest barriers are not necessarily raised by stakeholders but rather arise from the deepening complexity of the science itself, requiring a long-term, large, and consistent research commitment from both the public and private sectors - a commitment made harder by the indisputable need to reform the current health care system.

Integrating molecular medicine into the US health-care system: opportunities, barriers, and policy challenges

Scientific support about the concept of using molecular data for risk stratification and tailoring health-care interventions to the individual--a strategy broadly defined as molecular medicine (MM)--is accumulating. Molecular-based health-care technologies are beginning to enter clinical practice, but their use has revealed many scientific, economic, and organizational barriers to the effective delivery of targeted health care. We conducted a qualitative interview study to describe the MM landscape, with an emphasis on eliciting policy recommendations for the field from a broad range of stakeholders in MM and health care. Molecular medicine has widespread support but will require changes in how molecular-based technologies are evaluated, how health care is financed and delivered, and how clinicians and consumers are trained and prepared for its use. In particular, researchers and developers need to become active participants in a variety of clinical integration strategies to realize the promise of MM.

Evaluation of pulmonary vein stenosis by transesophageal echocardiography

Pulmonary vein stenosis was diagnosed by transesophageal echocardiography in five patients who underwent the study for different clinical indications. Stenosis was encountered in the right upper pulmonary vein in two patients, the right lower pulmonary vein in two patients, and at the confluence of the left pulmonary veins in one patient. In only one patient was the diagnosis suspected on transthoracic echocardiography. Contralateral normal veins from the same patient served as the control. Vessel diameter and peak flow velocity were measured and compared. The diameter of the stenosed veins ranged from 0.3 to 0.8 cm (mean 0.4 +/- 0.09 cm [SEM]), whereas for normal veins the diameter was 0.9 to 1.2 cm (mean 1.0 +/- 0.05 cm [SEM]; p < 0.001). Peak flow velocity in the stenosed veins ranged from 1.1 to 1.6 m/sec (mean 1.4 +/- 0.1 m/sec [SEM]), whereas in normal veins peak flow velocity ranged from 0.4 to 0.7 m/sec (mean 0.6 +/- 0.04 m/sec [SEM]; p < 0.001). There was a strong negative correlation between vessel diameter and peak flow velocity (R = 0.89; p < 0.001). Peak flow velocity of 0.8 m/sec appears to provide the best separation between normal and stenosed pulmonary veins. We conclude that pulmonary vein stenosis is associated with increased flow velocity and turbulence and deformity of the flow signal. Transesophageal echocardiography is a powerful tool in the study of pulmonary vein stenosis.

Swine models for cardiovascular research: a low stress transport and restraint system for large swine

A restraint and transport system was developed for handling large swine during cardiovascular research studies. The major design criteria provided for comfortable, low stress restraint of the swine, safety for laboratory personnel and ability to perform a wide variety of hemodynamic and echocardiographic measurements in the standing, supported standing and sedated, or in Panepinto sling positions. A head gate is provided for venipuncture procedures, and an auxiliary feeding and watering front panel can replace the head gate for use of the system as a post-operative "recovery room". Using this system animals weighing 22 to 150 kg can be easily managed.

Relationship between Doppler left ventricular diastolic filling indexes and the electrocardiographic criteria for left atrial enlargement

Traditional electrocardiographic (ECG) criteria for left atrial enlargement (LAE) emphasize the increased amplitude and width of the corresponding component of the hypertrophied atrium. Although a correlation exists between LAE and ECG criteria, a cause-and-effect relationship has not been conclusively demonstrated. Because the diastolic properties of the left ventricle directly influence left atrial emptying, these properties might also influence the ECG diagnosis of LAE. Therefore, the authors hypothesized that the ECG criteria for LAE are influenced by diastolic properties of the left ventricle as defined by Doppler-derived parameters.

Thrombocytopenia following sustained-release procainamide

Procainamide hydrochloride-induced thrombocytopenia has infrequently been reported in the past. We report six cases of thrombocytopenia following the administration of the sustained-release form of procainamide. Three of these cases had platelet counts of less than 15,000/microL. The mean time to onset of thrombocytopenia from drug administration was 40 days (range, nine to 71 days). The mean time until normalization of the platelet counts after the drug therapy was stopped was 7.8 +/- 3.1 days (range, four to nine days). Oral prednisone therapy had little apparent benefit. The thrombocytopenia was not part of a systemic lupus erythematosus syndrome. We believe that thrombocytopenia is an important side effect of sustained-release procainamide therapy.

A report on The National Council of Community Mental Health Centers

The National Council of Community Health Centers represents a professional development of great interest to clergy. Because mental health centers collaborate with community agencies and systems, their interventions on behalf of community mental health provide an occasion to work toward common goals. Their policy of shared responsibility with community leaders and consumers provides a unique opportunity for a practical integration of religious systems and the public arena. A number of pastors and mental health trained clergy are actively participating in this common effort on behalf of the nation's mental health.

Physical disorders among emergency psychiatric patients

An examination of patients with physical disorders requiring immediate treatment or investigation was undertaken in the Psychiatric Emergency Service of the Royal Ottawa Hospital and found to comprise 7% of the patient population, or one visit per day. Those with physical problems differed from the rest of the emergency patients in that a greater number were over age 60 and were diagnosed as alcoholic or chronic organic brain syndrome. Socio-demographic characteristics were examined as well. The presenting problem was accurate regarding a physical basis in only two-thirds and the disorder could, in some way, be related to a psychiatric diagnosis in 75% of the patients. Emphasis is placed on the fairly high frequency of immediate physical attention required by these patients who come to the psychiatrist. Consequently, psychiatric assessment and management is not the priority for this group and other skills of the psychiatrist are necessary in treating the patient.

The mother tongue in psychotherapy

The psychotherapy of three women with neurotic and adaptational problems was conducted using their mother tongue, German, and emphasis is placed on the facilitation of the therapeutic process by this method. It is felt that transference may be readily formed, there is less resistance to examining conflict areas, and the use of the acquired language as a defense against anxiety can be avoided. Several other authors have noted similar effects of therapy in the mother tongue. Various aspects of the literature are discussed, particularly focusing on the affective and cognitive differences between the primary and acquired languages as they may influence the psychotherapy.

Frontal lobe lesions masquerading as psychiatric disturbances

This paper presents three cases of frontal lobe lesions from the author's experience (subdural hematoma, meningioma and astrocytoma) which initially appeared as schizophrenia or depression. Attention is drawn, in the absence of specific neurological signs, to the importance of headache and somnolence in offering clues to the presence of a lesion. Disturbances in thought, affect and perception cannot always be assessed as purely functional.