Screening for congenital hearing impairment with brainstem evoked response audiometry in isolated orofacial cleft

Brainstem evoked response audiometry (BERA) is the most established and recommended objective audiometric method for the clinical diagnosis of hearing impairment in high-risk infants. It is unclear whether infants with orofacial clefts meet the criteria for the high-risk group. This retrospective cohort study evaluated the need for diagnostic BERA in infants with cleft palate with or without cleft lip by assessing the predisposition to and diagnosis of congenital hearing impairment. Data from 122 patients treated at a single cleft centre were evaluated. BERA was conducted at the time of palate repair at 4-6 months of age. Clinical follow-up was analysed up to 4 years. The presence of a syndrome was examined as a risk factor for congenital hearing impairment. Among the 122 patients, four had congenital sensorineural or mixed hearing loss requiring hearing aids. All affected patients had syndromes in addition to the cleft. Most patients with elevated hearing thresholds had transient conductive hearing loss. Most suspected sensorineural hearing loss initially diagnosed was refuted. However, a higher incidence of sensorineural hearing loss was found in patients with syndromic clefts, supporting the diagnostic use of BERA with initial surgery only in patients with syndromic clefts.

Eustachian Tube Balloon Dilation in Children: Short- and Long-Term Outcome

OBJECTIVE

Eustachian Tube Balloon Dilation (ETBD) represents an innovative therapeutic approach for chronic Eustachian tube dysfunction (CETD), a common disease in children. Some evidence of a benefit of ETBD in the adults exist in contrast to sparse reports in children. The objective was to analyze short- and long-term outcome of ETBD in children with CETD.

METHODS

A retrospective chart-review was performed in a cohort of 19 children (mean age 13 years, 7-17) who underwent ETBD. The following parameters were analyzed: tubomanometry (R-value), tympanogram, hearing (CPT-AMA, Air-bone gap [ABG]), Eustachian Tube Score (ETS and ETS-7), and Eustachian Tube Disease questionnaire (ETDQ).

RESULTS

Twenty-four ears were dilated (in 5 patients subsequently after successful first intervention) and grouped as A (17) without and B (7) with additional T-tube insertion. Most children suffered from either chronic otitis media with effusion or chronic perforation (12, 63%), the remainder comprising recurrent otitis media, adhesive otitis media and CETD with barotrauma. Mean duration of symptoms were 7/8.2 years and mean follow-up 13.7/11.1 months. Eighty percent of patients reported a subjective benefit. Accordingly, the R-value, ETS, and ETS-7 were significantly (P < .05) improved. Tympanometry, CPT-AMA and ABG showed a positive trend, but the result was not significant. Tympanic retraction remained largely the same; a spontaneous closure of a chronic tympanic perforation was seen in 1 of 3 cases.

CONCLUSIONS

The high subjective benefit and some significant objective improvement warrants further analysis of ETBD as part of the therapeutic management in pediatric CETD.

Pharmacokinetics-Based Pediatric Dose Evaluation and Optimization Using Saliva - A Case Study

Understanding pharmacokinetics (PK) in children is a prerequisite to determine optimal pediatric dosing. As plasma sampling in children is challenging, alternative PK sampling strategies are needed. In this case study we evaluated the suitability of saliva as alternative PK matrix to simplify studies in infants, investigating metamizole, an analgesic used off-label in infants. Six plasma and 6 saliva PK sample collections were scheduled after a single intravenous dose of 10 mg/kg metamizole. Plasma/saliva pharmacometric (PMX) modeling of the active metabolites 4-methylaminoantipyrine (4-MAA) and 4-aminoantipyrine (4-AA) was performed. Various reduced plasma sampling scenarios were evaluated by PMX simulations. Saliva and plasma samples from 25 children were included (age range, 5-70 months; weight range, 8.7-24.8 kg). Distribution of metamizole metabolites between plasma and saliva was without delay. Estimated mean (individual range) saliva/plasma fractions of 4-MAA and 4-AA were 0.32 (0.05-0.57) and 0.57 (0.25-0.70), respectively. Residual variability of 4-MAA (4-AA) in saliva was 47% (28%) versus 17% (11%) in plasma. A simplified sampling scenario with up to 6 saliva samples combined with 1 plasma sample was associated with similar PK parameter estimates as the full plasma sampling scenario. This case study with metamizole shows increased PK variability in saliva compared to plasma, compromising its suitability as single matrix for PK studies in infants. Nonetheless, rich saliva sampling can reduce the number of plasma samples required for PK characterization, thereby facilitating the conduct of PK studies to optimize dosing in pediatric patients.

Prospective Validation of Tubomanometry in Children With Normal Eustachian Tube Function

OBJECTIVES

Tubomanometry (TMM), described initially by Estève, is a relatively new manometric method for testing the eustachian tube function (ETF). This study presents the analysis of the measurement of ETF of healthy children by TMM, which has, to date, not been properly evaluated. The objectives of the study were to establish normative data for TMM and to demonstrate TMM as a reliable and valid method for measuring ETF in children.

DESIGN

The evaluation, after initial power analysis, comprised 35 children from 6 to 15 years of age with an intact tympanic membrane, no severe ET dysfunction, and less than three inflammations of the middle ear in their medical history. TMM was performed twice at three pressure levels for both ears. Statistical assessment of the various parameters of TMM was performed with emphasis on the R value and possible age dependency.

RESULTS

The 90th percentile for the R value was calculated to be 1.12. No clinically relevant age effect regarding the use of TMM as a screening method for children was found. Healthy children showed an opening within normal limits for the so-called R value in 88%; a delayed opening was measured in 6%, and rarely no opening was measured in 2%.

CONCLUSIONS

TMM is a reliable tool for measuring ETF in children. The normal limit for the R value should be set at 1.12. The proposed measuring algorithm and results can be used to calculate sensitivity and specificity in a future study.

Silastic sheeting in staged ear surgery: Is there still a role for this procedure?

OBJECTIVE

To review long-term outcomes for chronic otitis media with and without cholesteatoma in staged canal-wall-up tympanoplasty with temporary silastic sheeting and to compare hearing and recurrence results with the literature.

METHODS

Retrospective data analysis of all patients suffering from chronic otitis media with or without cholesteatoma (COMC/COM) and treated by staged canal-wall-up (CWU) technique with silastic insertion between 1992 and 2012. Literature analysis in PubMed 1990-2017.

RESULTS

74 cases were included in the analysis. In COMC (n = 47) a total of 2 (4%) recurrent and 14 (30%) residual cholesteatoma were documented. The postoperative hearing test showed a pure-tone-average (PTA) of 36 dB hearing level (HL) and an air-bone-gap (ABG) of 21 dB HL. A significant improvement was only observed for stage I disease (PTA 8 dB HL and ABG 9 dB HL). In COM (n = 27) postoperative PTA and ABG were significantly improved by 33 dB HL and 23 dB HL, respectively. Mean postoperative follow-up was 47 months (12-173) for COMC and 22 months (2-120) for COM.

CONCLUSIONS

The cholesteatoma recurrence rate in this study reflects contemporary published rates. Assessment of hearing outcome is difficult due to the low number of cases and very high heterogeneity of published data. Still, the staged CWU procedure with temporary silastic sheeting seems to bear some advantages in regard to hearing. The role of additional factors such as Eustachian Tube function to assess outcome should be considered. An internationally agreed upon reporting system should be followed, if various surgical approaches are to be compared.

LEVEL OF EVIDENCE

3.

Three Copies of Four Interferon Receptor Genes Underlie a Mild Type I Interferonopathy in Down Syndrome

Down syndrome (DS) is characterized by the occurrence of three copies of human chromosome 21 (HSA21). HSA21 contains a cluster of four interferon receptor (IFN-R) genes: IFNAR1, IFNAR2, IFNGR2, and IL10RB. DS patients often develop mucocutaneous infections and autoimmune diseases, mimicking patients with heterozygous gain-of-function (GOF) STAT1 mutations, which enhance cellular responses to three types of interferon (IFN). A gene dosage effect at these four loci may contribute to the infectious and autoimmune manifestations observed in individuals with DS. We report high levels of IFN-αR1, IFN-αR2, and IFN-γR2 expression on the surface of monocytes and EBV-transformed-B (EBV-B) cells from studying 45 DS patients. Total and phosphorylated STAT1 (STAT1 and pSTAT1) levels were constitutively high in unstimulated and IFN-α- and IFN-γ-stimulated monocytes from DS patients but lower than those in patients with GOF STAT1 mutations. Following stimulation with IFN-α or -γ, but not with IL-6 or IL-21, pSTAT1 and IFN-γ activation factor (GAF) DNA-binding activities were significantly higher in the EBV-B cells of DS patients than in controls. These responses resemble the dysregulated responses observed in patients with STAT1 GOF mutations. Concentrations of plasma type I IFNs were high in 12% of the DS patients tested (1.8% in the healthy controls). Levels of type I IFNs, IFN-Rs, and STAT1 were similar in DS patients with and without recurrent skin infections. We performed a genome-wide transcriptomic analysis based on principal component analysis and interferon modules on circulating monocytes. We found that DS monocytes had levels of both IFN-α- and IFN-γ-inducible ISGs intermediate to those of monocytes from healthy controls and from patients with GOF STAT1 mutations. Unlike patients with GOF STAT1 mutations, patients with DS had normal circulating Th17 counts and a high proportion of terminally differentiated CD8⁺ T cells with low levels of STAT1 expression. We conclude a mild interferonopathy in Down syndrome leads to an incomplete penetrance at both cellular and clinical level, which is not correlate with recurrent skin bacterial or fungal infections. The constitutive upregulation of type I and type II IFN-R, at least in monocytes of DS patients, may contribute to the autoimmune diseases observed in these individuals.

Appropriateness of antimicrobial prescribing in a Swiss tertiary care hospital: a repeated point prevalence survey

AIMS OF THE STUDY

Inappropriate use of antimicrobials is associated with the emergence of antimicrobial resistance and adverse events. Antimicrobial stewardship programmes may both optimise treatment of infections and reduce antimicrobial resistance but are implemented in only a minority of Swiss hospitals. In addition, data on prescribing patterns and quality are scarce. We conducted a repeated point prevalence survey to evaluate the quality of antimicrobial prescribing in a single tertiary care centre.

METHODS

Antimicrobial use was audited twice (summer 2017 and winter 2018) among all patients admitted to the University Hospital Basel, Switzerland. Data were collected from the electronic health record. Appropriateness of antimicrobial use was evaluated according to previously published rules and local national guidelines.

RESULTS

We evaluated 1112 patients of whom 378 (34%) received 548 prescriptions in total (30% for prophylaxis). Penicillins with &beta;-lactamase inhibitors were most commonly used (30%), followed by cotrimoxazole (12%) and ceftriaxone (7%). Intravenous administration was chosen in 56% of patients. Prior to antimicrobial therapy, blood cultures were collected in 69% of patients. Overall, 182 (33%) prescriptions were not appropriate; reasons included lack of indication (11%), incorrect dosing (7%), delay in intravenous to oral switch (9%) or non-adherence to local guidelines (15%). A minority of patients received antimicrobials despite documented allergies (2%). Almost 38% of empirical prescriptions were inappropriate, compared with only 19% of prophylactic and 20% of targeted prescriptions. Penicillins with &beta;-lactamase inhibitors and cephalosporins were most commonly involved in inappropriate prescribing (&gt;50%) followed by carbapenems (30%), narrow-spectrum penicillins (17%) and cotrimoxazole (6%), with oral administration being involved less frequently than intravenous administration (15 vs 37%). Infectious diseases consultation and presence of immunosuppression were associated with reduced odds (odds ratio [OR] 0.38, 95% confidence interval [CI] 0.21&ndash;0.70 and OR 0.31, 95% CI 0.17&ndash;0.54, respectively) of inappropriate prescription in the per-patient multivariable analysis, whereas being admitted to a surgical or intensive care unit was associated with increased odds (OR 1.83 and 5.67) compared with a medical unit.

CONCLUSION

Almost one third of prescriptions were inappropriate in our tertiary care centre despite local guidelines and an on-demand infectious diseases consultation service. Our results underscore the need for expanding current antimicrobial stewardship efforts, including national initiatives such as stewardship and prescribing guidelines, repeated surveys and identification of areas for improvement including timely intravenous to oral switches in order to reduce the consequences of inappropriate prescribing and of multidrug resistant organisms.

Dose evaluation of intravenous metamizole (dipyrone) in infants and children: a prospective population pharmacokinetic study

PURPOSE

The prodrug metamizole is prescribed intravenously for postoperative pain in children, including off-label use in infants < 1 year. We aimed to assess the pharmacokinetics of the main metabolites of metamizole in children aged 3-72 months.

METHODS

A single dose of 10 mg/kg metamizole was administered intravenously for postoperative analgesia. Pharmacokinetic samples were drawn at predefined time points. Pharmacokinetics of the main active metabolite 4-methylaminoantipyrine and three other metabolites was characterized by both non-compartmental and population pharmacokinetic analysis. AUC_0-inf of 4-methylaminoantipyrine was calculated by non-compartmental analysis for two age cohorts (3-23 months, 2-6 years) and compared with the 80-125% range of adult dose-adjusted reference exposure (AUC_ref). Population pharmacokinetic analysis investigated age and weight dependency of the pharmacokinetics and optimal dosing strategies to achieve equivalent adult exposure.

RESULTS

A total of 25 children aged 5 months-5.8 years (7.8-24.8 kg) with at least one concentration sample were included; 19 children had ≥ 5 predefined samples up to 10 h after metamizole dose administration. AUC_0-inf of 4-methylaminoantipyrine in children 2-6 years was 29.9 mg/L/h (95% CI 23.4-38.2), significantly lower than AUC_ref (80-125% range 39.2-61.2 mg/L/h). AUC_0-inf of 4-methylaminoantipyrine in infants < 2 years was 43.6 mg/L/h (95% CI 15.8-119.0), comparable with AUC_ref, while infants < 12 months showed increased exposure. Observed variability could be partially explained by covariates weight and age.

CONCLUSIONS

Age-related changes in pharmacokinetics of 4-methylaminoantipyrine requires reduced weight-based IV dosing in infants < 1 year compared with infants and children up to 6 years (5 versus 10-20 mg/kg) to achieve equivalent adult exposure.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02660177 .

Sialoblastoma of the submandibular gland: a distinct entity?

Sialoblastoma is a rare congenital malignant tumor of the salivary glands. A case of a submandibular sialoblastoma in a 1.5-year-old child is presented. A comparative analysis on 79 pediatric cases reported in the literature suggests a less aggressive behavior for submandibular sialoblastoma in comparison with other sites. Classically, diagnosis is confirmed by open biopsy, but fine-needle aspiration may offer an alternative with reduced morbidity. Expression of AFP and high levels of Ki-67 have been associated with poor prognosis. Whilst early surgical resection with negative margins is widely accepted as first-line treatment, there is no consensus on therapy of recurrence and follow-up. MRI and sonography represent valid tools for the follow-up, which is usually restricted to 3-5 years.Conclusion: Submandibular sialoblastomas may have a different biological profile in comparison with parotid tumors with the absence of metastasis and much lower rate of recurrence. Comprehensive diagnostics should include additional options such as fine-needle aspiration and markers to assess cell proliferation and AFP. Literature suggests that surgery alone is sufficient for the treatment of tumors with low malignancy. Follow-up should be tailored according to the tumor site and might be limited to 3-5 years. What is Known: • Sialoblastoma is a rare congenital malignant tumor with an unpredictable clinical outcome. What is New: • Sialoblastoma of submandibular origin seems to have a less aggressive behavior in comparison with other sites. • Fine-needle aspiration and markers to assess proliferation index (i.e., suggestive of potential more aggressive course/malignancy) should be strongly considered in the diagnostic work-up. • Radical surgery as first-line therapy and a 3-5-year follow-up are acceptable for tumors with a low malignancy.

Prosthetic valve endocarditis caused by Pseudomonas aeruginosa with variable antibacterial resistance profiles: a diagnostic challenge

Background

Infective endocarditis (IE) caused by gram-negative bacilli is rare. However, the incidence of this severe infection is rising because of the increasing number of persons at risk, such as patients with immunosuppression or with cardiac implantable devices and prosthetic valves. The diagnosis of IE is often difficult, particularly when microorganisms such as Pseudomonas aeruginosa, which rarely cause this infection, are involved. One of the mainstays for the diagnosis of IE are persistently positive blood cultures with the same bacteria, while polymicrobial bacteremia usually points to another cause, e.g. an abscess. The antimicrobial resistance profile of some P. aeruginosa strains may change, falsely suggesting an infection with several strains, thus further increasing the diagnostic difficulties.

Case presentation

A 66-year old male patient who had a transcatheter aortic valve implantation (TAVI) one year previously developed fever seven days after an elective inguinal hernia repair. During the following four weeks, P. aeruginosa with different antibiotic resistance profiles was repeatedly isolated from blood cultures. Repeated trans-esophageal echocardiograms (TEE) were negative and an infection by different P. aeruginosa strains was suspected. Extensive diagnostic workup for an infectious focus was performed with no results. Finally, an oscillating mass on the aortic valve was detected by TEE five weeks after the initial positive blood cultures. P. aeruginosa endocarditis was confirmed by culture of the surgically removed valve. Whole genome sequencing of the last two P. aeruginosa isolates (valve and blood culture) revealed identical strains, with genome mutations for AmpR, AmpD and OprD.

Conclusions

The diagnosis of prosthetic valve endocarditis is particularly difficult for several reasons. The modified Duke criteria have a lower sensitivity for patients with prosthetic valve endocarditis and the infection may be caused by “unusual” pathogens such as P. aeruginosa. Patients with repeatedly positive blood cultures should make clinicians suspicious for endocarditis even if imaging studies are negative and if isolated pathogens are “unusual”. Repeatedly positive blood cultures for P. aeruginosa should be considered as “persistent bacteremia” (suspicious for IE) even in the presence of different antibiotic susceptibility patterns, since P. aeruginosa might rapidly activate or deactivate resistance mechanisms depending on antibiotic exposition.

Sodium Polystyrene Sulfonate and Cytomegalovirus-Associated Hemorrhagic Duodenitis: More than Meets the Eye

Patient: Male, 56

Final Diagnosis: Hemorrhagic duodenitis

Symptoms: Abdominal pain • melena

Medication: —

Clinical Procedure: CT scan • gastroscopy • colonoscopy • blood transfusion

Specialty: General and Internal Medicine

Three-Dimensional Electronic Structure of the Type-II Weyl Semimetal WTe_{2}

By combining bulk sensitive soft-x-ray angular-resolved photoemission spectroscopy and first-principles calculations we explored the bulk electron states of WTe_{2}, a candidate type-II Weyl semimetal featuring a large nonsaturating magnetoresistance. Despite the layered geometry suggesting a two-dimensional electronic structure, we directly observe a three-dimensional electronic dispersion. We report a band dispersion in the reciprocal direction perpendicular to the layers, implying that electrons can also travel coherently when crossing from one layer to the other. The measured Fermi surface is characterized by two well-separated electron and hole pockets at either side of the Γ point, differently from previous more surface sensitive angle-resolved photoemission spectroscopy experiments that additionally found a pronounced quasiparticle weight at the zone center. Moreover, we observe a significant sensitivity of the bulk electronic structure of WTe_{2} around the Fermi level to electronic correlations and renormalizations due to self-energy effects, previously neglected in first-principles descriptions.

Bilateral congenital deafness: What investigations should be performed?

BACKGROUND

The introduction of newborn hearing screening has led to earlier identification of children with congenital sensorineural hearing loss (SNHL). Aetiological clarification offers several benefits. There is currently a lack of agreement on which examinations should be recommended.

OBJECTIVE

Descriptive review of the literature reporting investigations performed to establish the aetiology of congenital SNHL and comparison of the management policy in Swiss referral centres.

METHODS

PubMed Search from 1985 to March 2016 with specific search terms; study selection according to inclusion/exclusion criteria; narrative analysis by use of defined criteria and question-naire.

RESULTS

Ninety-two studies were finally included in this review. Forty studies investigated more than a single aetiology. Overall frequencies of aetiological parameters investigated were: genetic (47 studies), radiological (35), ophthalmic (35), serological (32), cardiac (25), renal (14), endocrine (12), neurological (8). Most of the studies were retrospective and various limitations such as poor population description, incomplete data or deficiencies in methodological quality were frequently detected. The variability detected in the investigative approach chosen by Swiss referral centres reflects the heterogeneous data seen in the literature.

CONCLUSIONS

The evidence in the literature regarding an appro-priate evaluation is mostly of low quality and difficult to assess owing to high heterogeneity. Nevertheless, imaging, genetic testing, neuropaediatric and ophthalmological evaluations, electrocardiograms and cytomegalovirus analysis have been identified as examinations to be included in the assessment of children with congenital SNHL. There is a need for international consensus on the various issues of such an evaluation, such as choice of investigations and diagnostic criteria.

Impact of MALDI-TOF-MS-based identification directly from positive blood cultures on patient management: a controlled clinical trial

OBJECTIVES

Rapid identification of pathogens directly from positive blood cultures (BC) in combination with an antimicrobial stewardship programme (ASP) is associated with improved antibiotic treatment and outcomes, but the effect of each individual intervention is less clear. The current study investigated the impact of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) versus conventional identification on antibiotic management in a setting with a well-established ASP and low resistance rates.

METHODS

In this single-centre open label, controlled clinical trial 425 patients with positive BCs were allocated by weekday during a 1-year period to either MALDI-TOF directly from positive BCs or conventional processing. ASP was identical throughout the study period. The primary outcome was duration of intravenous antimicrobial therapy and was analysed in an intention-to-treat approach.

RESULTS

In all, 368 patients were analysed (MALDI-TOF n = 168; conventional n = 200) with similar baseline characteristics. Mean duration of intravenous antimicrobial therapy (12.9 versus 13.2 days, p 0.9) and length of stay (16.1 versus 17.9 days, p 0.3) were comparable. In the clinically significant bloodstream infection subgroup (n = 242) mean time from Gram-stain to active treatment was significantly shorter (3.7 versus 6.7 h, p 0.003). Admission to the intensive care unit after bloodstream infection onset was less frequent in the MALDI-TOF group (23.1 versus 37.2%, p 0.02).

CONCLUSIONS

Rapid identification of contaminated BCs (n = 126) resulted in a shorter duration of intravenous antimicrobial therapy (mean 4.8 versus 7.5 days, p 0.04). Rapid identification using MALDI-TOF directly from positive BCs did not impact on duration of intravenous antimicrobial therapy, but provided fast and reliable microbiological results and may improve treatment quality in the setting of an established ASP.

Paediatric otogenic lateral sinus thrombosis: therapeutic management, outcome and thrombophilic evaluation

OBJECTIVE

Otogenic lateral sinus thrombosis (LST) in children represents a serious condition with potential long-lasting morbidity. The role of adjunct anticoagulation therapy and the benefit of an analysis of prothrombotic factors are unclear. The aim of the study was to report therapeutic management and outcome, analyze prothrombotic factors in children with otogenic LST treated with mastoidectomy/antibiotics/anticoagulation and to evaluate the results with a review of the literature.

METHODS

Retrospective chart review of 9 children with otogenic LST (2000-2009) and literature search in PubMed.

RESULTS

The most frequent sign was fever in 88%, while neurologic findings were seen in 55%. Streptococci was the most common bacteria (55%). Prothrombotic factors were normal in all children. All patients received therapeutic anticoagulation, without experiencing bleeding complications. Eight children made a full recovery, neurologic sequelae persisted in one. The literature review of 115 children identified fever as the most prominent sign, reported the absence of neurologic findings in almost 50% of cases and confirmed the major role of streptococci. Anticoagulation, as adjunct therapy, was given to 38% of patients in the therapeutic range with a trend towards better neurologic outcome. A prothrombotic analysis was reported in 5 studies with positive results in 2.

CONCLUSIONS

Surgery and antibiotics represent the mainstay of the therapy. Anticoagulation can be safely added in view of the high potential for morbidity and might reduce neurologic sequelae. Bacteria with thrombotic activity seem to be an important aetiology. In contrast, a prothrombotic disposition seems to play a minor role in the development of otogenic LST.

Mutation analysis of Netrin 1 and HMX3 genes in patients with superior semicircular canal dehiscence syndrome

CONCLUSION

In spite of its absence in the control population, there is questionable evidence for the alteration c.114C->T in the HMX3 gene being implicated in the development of superior semicircular canal dehiscence (SSCD). However, the concept of a complex disease is valid for SSCD and a possible molecular origin can neither be confirmed nor excluded by the results of this study.

OBJECTIVES

SSCD was first described in 1998 by Minor et al. While the etiology is not clear, findings from both temporal bone CT and histologic studies suggest a congenital or developmental origin. In recent years, a couple of genes regulating inner ear morphogenesis have been described. Specifically, Netrin-1 and HMX3 have been shown to be critically involved in the formation of the SCC. Molecular alterations in these two genes might lead to a disturbed development of this canal and might represent an explanation for SSCD.

METHODS

DNA was extracted from whole blood of 15 patients with SSCD. The coding sequences of Netrin-1 and HMX3 were amplified by PCR and sequenced.

RESULTS

One sequence alteration, heterozygous c.114C->T (conservative change without alteration of amino acid) in exon 1 of HMX3, was detected in 2 of 15 patients but not in 300 control chromosomes. The study was supported in part by the Emilia-Guggenheim-Schnurr-Foundation, Basel, Switzerland.

Role of ultrasound-guided core-needle biopsy in the assessment of head and neck lesions: a meta-analysis and systematic review of the literature

BACKGROUND

Core-needle biopsy (CNB) has occasionally been used in the work-up of head and neck lesions. However, no systematic review of this simple, minimally invasive method has yet been performed.

METHODS

A systematic review of the literature and meta-analysis of data extracted from 16 included studies were performed. A total of 1291 cervical lesions in 1267 patients were examined by CNB. This resulted in 1232 adequate samples, from which 554 were subsequently confirmed by excisional biopsy.

RESULTS

CNB was able to identify true neoplasms and detect malignancy in head and neck lesions with an overall accuracy of 94% and 96%, respectively, even though there was a significant difference between the histologically verified and all adequate samples. CNB provided a correct specific diagnosis in 87% of cases without major complications and achieved a higher accuracy than that of fine-needle aspiration in detecting malignancy.

CONCLUSIONS

This meta-analysis confirms that CNB is an excellent method in the assessment of salivary gland lesions and lymphadenopathies inclusive of malignant lymphoma, but it is not ideal for evaluating thyroid lesions.

High homogeneity in auditory outcome of pediatric CI-patients with mutations in Gap-Junction-Protein Beta2

OBJECTIVES

A controversy exists in the literature regarding better auditory performance of cochlear implanted children with mutations in the Gap-Junction-Protein Beta2 (GJB2) gene. This is partially due to insufficient numbers, lack of proper statistics, etc. As this represents a very important issue for the counselling clinician, the aim of the study was to analyze auditive outcome in GJB2-related hearing loss in relation to other causes and review the literature.

METHODS

Retrospective study. 44 children with unilateral cochlea implants were assigned into 3 groups according to their cause of deafness: group A contained 13 patients with GJB2-related deafness, group B 15 with hereditary hearing loss and negative GJB2-screening, and group C 16 with a nonhereditary cause. The auditory outcome performance was evaluated by pure-tone audiograms (PTA), the Monosyllabic-Trochee-Polysyllabic-Word Test (MTP) and the Listening Progress Profile (LiP) according to the EARS-protocol (Evaluation of Auditory Response to Speech) pre- and postoperatively up to 6.5 years. Additionally the educational setting was considered. Statistical analysis included direct comparison by using mixed models and computing the variance to test for homogeneity.

RESULTS

A trend towards better performance for the GJB2 group (vs. the other groups combined) was observed regarding PTA, even more pronounced for LiP/MTP. However, a significant p-value was not reached. A high homogeneity, expressed by a significant difference in the variance of MTP and LiP was observed in the GJB2 group. Differences in educational setting were not significant.

CONCLUSIONS

The results of the study seem to support a better auditory performance of GJB2-patients with cochlea implants due to a cochlear origin of the defect. The significant homogeneity for this group is of paramount issue for the counselling clinician and a very important observation.

Mutation analysis of the Cx26, Cx30, and Cx31 genes in autosomal recessive nonsyndromic hearing impairment

CONCLUSION

Biallelic Cx26 mutations are the most common cause of autosomal recessive nonsyndromic hearing impairment (ARNHI) in Switzerland. Mutations in Cx30 and 31, digenic mutations as well as large deletions/duplications, are unlikely to be a major cause of hearing loss in Swiss patients with ARNHI. Multiplex ligation-dependent probe amplification (MLPA) is a highly accurate screening method for detection of c.del(GJB6-D13S1830).

OBJECTIVES

The intent of this study was to investigate the prevalence of the point and digenic mutations including large deletions and duplications in the Cx26, 30, and 31 genes in a Swiss patient cohort with ARNHI and cochlear implant.

PATIENTS AND METHODS

The coding regions of Cx26, 30, and 31 were sequenced in 32 patients. Large deletions/duplications were assessed by MLPA.

RESULTS

In one patient digenic heterozygous mutations involving Cx26 (c.35delG) and Cx30 (c.del(GJB6-D13S1830)) were identified. Biallelic Cx26 mutations were detected in 31%. One putative mutation (c.94C>T) was found in Cx31. MLPA analysis did not reveal any additional deletion or duplication in all three Cx genes, except for the heterozygous c.del(GJB6-D13S1830) deletion.

Ultrasound-guided core-needle biopsy in the diagnosis of head and neck lesions

This article describes the technique of ultrasound-guided core-needle biopsy in the head and neck, and also warns of its risks. In contrast to fine-needle aspiration, this minimally invasive procedure has the advantage of supplying a histological specimen rather than a cytological smear. Therefore, it could be used as an additional diagnostic tool in the investigation of head and neck lesions, and can be carried out within the out-patients clinic.

A de novo PABPN1 germline mutation in a patient with oculopharyngeal muscular dystrophy

BACKGROUND

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset autosomal dominantly inherited disorder characterized by dysphagia, ptosis, and proximal limb weakness and is caused by germline mutations (triplet repeat expansions) in the polyadenylate binding protein nuclear 1 (PABPN1) gene.

OBJECTIVE

To describe a 70-year-old female patient with OPMD on the clinical and molecular genetic level and to develop a rapid and efficient molecular genetic screening method to study large patient groups.

METHODS

Detailed family history and clinical assessment of the OPMD patient were followed by mutation analysis of the PABPN1 gene by direct DNA sequencing and by our newly developed method, fluorescent PABPN1 polymerase chain reaction (PCR) product (flPPP) method. A cohort of 50 healthy Swiss probands was screened using the flPPP to assess the frequency of the (GCG)7 allele in the Swiss population. Cricopharyngeal myotomy was performed as treatment for dysphagia.

RESULTS

A heterozygous (GCG)9 triplet repeat expansion in PABPN1 was identified. Since the family history proved to be negative, the mutation is likely to have occurred de novo. The frequency of the (GCG)7 allele among healthy Swiss controls amounted to 1%. The flPPP method showed a sensitivity and specificity of 100%. Two years after cricopharyngeal myotomy, the patient is still relieved of dysphagia.

CONCLUSIONS

An otolaryngologist should include OPMD in the differential diagnosis of a patient presenting with dysphagia, as this symptom can be the first sign of the disease and family history can be negative. Molecular genetic testing represents a highly accurate and rapid way to confirm the clinical diagnosis of OPMD. Cricopharyngeal myotomy relieves the patient of dysphagia in the majority of cases.

Two families with nonsyndromic low-frequency hearing loss harbor novel mutations in Wolfram syndrome gene 1

Although hereditary hearing loss is highly heterogeneous, only a few loci have been implicated with low-frequency hearing loss. Mutations in one single gene, Wolfram syndrome 1 (WFS1), have been reported to account for most familial cases with this type of hearing impairment. This study was conducted to determine the cause of nonsyndromic low-frequency hereditary hearing impairment in two large families. Two large families from Switzerland and United States with low-frequency hearing loss were identified. Genomewide linkage analysis was performed followed by mutation screening in the candidate gene WFS1 with direct DNA sequencing and restriction fragment analysis. Both families were linked to DFNA6/14/38 with lod scores>3. Two novel heterozygous missense mutations in WFS1 were identified: c.2311G>C leading to p.D771H in the Swiss family and c.2576G>C leading to p.R859P in the US family. The sequence alteration was absent in 100 control chromosomes. Nonsyndromic low-frequency hereditary hearing impairment seems to be predominantly a monogenic disorder due to WFS1. We confirm that most mutations in WFS1 associated with isolated low-frequency hearing loss are clustered in the C-terminal protein domain coded by exon 8.

Audiologic testing and molecular analysis of 12S rRNA in patients receiving aminoglycosides

BACKGROUND

Pathogenic mutations in the mitochondrial genome are associated with a wide variety of maternally inherited human diseases including sensorineural hearing loss (HL). A specific mutation, m.1555A>G in the mitochondrial 12S rRNA gene, is associated with predisposition to aminoglycoside ototoxicity and HL. Mutation screening in this gene has been recommended before use of aminoglycosides as a preventative strategy to reduce the risk of ototoxicity.

OBJECTIVE

To study the incidence of mutations in the 12S rRNA gene in patients being treated with aminoglycosides and its correlation with ototoxicity.

METHODS

Patients undergoing treatment with aminoglycosides were prospectively enrolled in this study (n = 27). Total dosage administered and therapeutic levels of the antibiotic were noted. All patients underwent high-frequency pure-tone audiometry pre- and posttherapy and sequencing of the 12S rRNA gene. In addition, 12S rRNA gene was also sequenced in 50 controls to characterize population specific polymorphisms.

RESULTS

Five of 27 patients suffered from HL involving the high frequencies: four mild and one moderate. Only one of the five patients with ototoxicity harbored two sequence alterations in 12S rRNA of uncertain pathogenicity. The m.1555A>G and m.961delTInsCn mutations were not detected.

CONCLUSIONS

High-frequency pure-tone audiometry is critical for detection of aminoglycoside-induced HL. In the Swiss population, screening for mutations in the 12S rRNA gene, before the initiation of aminoglycoside therapy, is not supported by this limited study. A larger multicenter and multicultural study is warranted to more definitively address this critical clinical issue.

Rate of false-positive results for threshold shifts during initial treatment with aminoglycosides

Specific recommendations from the American Speech-Language Hearing Association (1994) exist for the audiometric surveillance of patients receiving aminoglycoside therapy. However, these recommendations are not based primarily on test-retest repeatability in often seriously ill patients. The probability of ototoxicity is very low during the first three days of aminoglycoside therapy, and significant threshold shifts can be assumed to represent a false-positive result. Baseline thresholds were measured in 28 patients before or not later than 24 h after the beginning of aminoglycoside therapy. These measurements were repeated in 22 patients during the first three days of the drug administration. Three out of 22 patients fulfilled the American Speech-Language-Hearing Association's (1994) criteria for cochleotoxicity making up a false-positive rate of 13%. In actual patients, the false-positive rate of audiometric surveillance during ototoxic drug administration may be substantially higher than in healthy subjects when these criteria are used.

DFNA54, a third locus for low-frequency hearing loss

Nonsyndromic hereditary hearing impairment (NSHHI) is a highly heterogeneous disorder with more than 90 loci mapped, of which nearly one-half of the responsible genes are identified. In dominant NSSHI hearing loss is typically biased towards the high frequencies while low-frequency hearing loss is unusual. Only two NSHHI loci, DFNA1 and DFNA6/14/38, are associated with predominantly low-frequency loss. We mapped the loci harboring the gene responsible for autosomal dominant low-frequency hearing loss in a multigenerational family. The pedigree of a Swiss family with low-frequency hearing loss was established. Using genomic DNA, DFNA1 and DFNA6/14/38 were excluded by linkage analysis or by direct sequencing of the responsible gene. Genome-wide linkage analysis was performed using commercially available microsatellite markers. Two-point linkage analysis demonstrated linkage to chromosome 5q31, the locus for DFNA15, with a lod score of 6.32 at recombination fraction theta=0 for marker D5S436. Critical recombinations were seen at markers D5S1972 and D5S410. Sequencing of the corresponding gene POU4F3 yielded no pathogenic mutation segregating with the affected members. In addition to Wolfram syndrome gene 1 (DFNA6/14/38) and diaphanous (DFNA1) there is evidence for a third gene involved in low-frequency hearing loss located at DFNA15. Because of the differences in auditory phenotype and the absence of pathogenic mutation in the coding region of POU4F3 it is likely that there is a second gene in 5q31, designated DFNA54, associated with NSHHI.

GJB2 Mutations in the Swiss Hearing Impaired

OBJECTIVE

Mutations in the GJB2 gene encoding connexin 26 (Cx26) protein are a major cause for nonsyndromic autosomal recessive and sporadic deafness. However, its contribution to hearing impairment in Switzerland remains undefined. To determine the frequency and type of GJB2 mutations in the Swiss hearing-impaired population diagnosed under the age of 2 yr and at 2 yr and older and to assess the effectiveness of denaturing high-performance liquid chromatography (DHPLC) in screening for mutation in GJB2.

METHODS

Thirty-four patients with hearing impairment underwent mutation screening of the single coding exon of GJB2 with DHPLC followed by bidirectional sequencing to identify sequence alterations.

RESULTS

GJB2 mutations were more common in children diagnosed with hearing impairment under the age of 2 yr compared to the group 2 yr and older. In patients under age 2 yr, 9 of 20 (45%) harbored 13 GJB2 mutations including a common 313del14nt mutation; four of these patients were homozygous or compound heterozygous for GJB2 mutations. In contrast, 2 of 14 patients in the 2 yr and older group (14%) had a single mutation in GJB2. The 35delG mutation was exclusively found in 5 patients under the age of 2 yr. DHPLC for mutation screening was 100% sensitive and 83% specific for detecting sequence alterations in GJB2.

CONCLUSIONS

In Switzerland, GJB2 mutations are a major cause of nonsyndromic hearing impairment in children under the age of 2. Similar to other populations, GJB2 mutations are uncommon in the affected Swiss patients identified after 2 yr. Although 35delG mutation is common in the hearing-impaired children under the age of 2, it was absent in patients diagnosed with hearing impairment after the age of 2. DHPLC is a highly sensitive tool for detection of GJB2 mutations.

Molekulargenetische Aspekte in der Otorhinolaryngologie

In der HNO-Heilkunde hat die Molekulargenetik in den letzten zehn Jahren vor allem in der Otologie und bei den Kopf-Hals-Tumoren einen enormen Aufschwung erlebt. Die ersten Resultate dieser Grundlagenforschung beginnen nun, im klinischen Alltag Fuß zu fassen. Auf dem Gebiet der otologischen Forschung wurde dank der Molekulargenetik das Verständnis der auditiven Funktion wesentlich erweitert. Die hereditäre Schwerhörigkeit, welche die syndromale und nicht-syndromale Form unterscheidet, wird mehr und mehr entschlüsselt. So sind mittlerweile viele den verschiedenen Syndromen zugrunde liegende Gendefekte identifziert. Dadurch kann die Diagnostik verbessert und können die betroffenen Patienten besser beraten werden. Der Aufwand dieser Analysen zwingt zur restriktiven Abklärung, sodass bis heute allein die häufigste syndromale Form, das Pendred-Syndrom, in unserer Klinik routinemäßig molekulargenetisch untersucht wird. Bei der nicht-syndromalen Schwerhörigkeit zeigt sich eine Vielfalt von Genen und Mutationen. In zwei Fällen wird in der Klinik die Indikation zur Abklärung empfohlen: einerseits die Analyse von Gap-Junction-Protein Beta2, welche das Protein Connexin 26 (Cx26) kodiert, bei Patienten mit kongenitaler nicht-syndromaler Schwerhörigkeit, da Cx26 den häufigsten Gendefekt in dieser Gruppe darstellt mit einer hohen Prävalenz von etwa 20% in der Schweiz; andererseits die Mutationssuche im Wolfram-Syndrom-Gen-1 bei Familien, deren Mitglieder eine Tieftonschwerhörigkeit aufweisen, da dieses Gen bei diesem Typ des Hörverlustes die häufigste Ursache zu sein scheint. Eine Gentherapie zur Behandlung der Schwerhörigkeit ist noch nicht in Sicht. Bei den Kopf-Hals-Tumoren hat die Molekulargenetik ebenfalls viel zum Verständnis der Tumorentstehung beigetragen. Die klinische Anwendung konzentriert sich darauf, ein Risikoprofil für die individuelle Tumorentwicklung erstellen zu können, die Prognose besser abzuschätzen und neue Therapiemodalitäten auf genetischer Basis zu entwickeln. Richtlinien zur molekulargenetischen Tumorabklärung können noch keine abgegeben werden, da die Studienresultate nicht einheitlich sind. Auf dem Gebiet der Gentherapie hingegen sind bereits klinische Versuche im Gang.

Etiology of syndromic and nonsyndromic sensorineural hearing loss

The past 10 years have seen an explosive gain in our understanding of molecular mechanisms of hearing and deafness. This has already resulted in improved diagnosis for the population with hereditary hearing loss. For syndromic hearing loss, we will see a shift from the historical terminology to a more precise genetic definition based on specific genetic abnormality. Functional studies of nonsyndromic deafness genes will elucidate the complex functional and hemostatic mechanisms in the inner ear. Ultimately, availability of gene therapy for the affected patients will bring to closure the circle of detection, identification, and correction of the disease.

[Is there clinical evidence for the aging of the peripheral vestibular organ?]

The ageing process of hearing is well known. Age-dependent normative data are established for pure tone audiometry. It seems logical to suppose that the peripheral vestibular system undergoes a similar ageing process. To support this hypothesis we investigated subjects aged 50-82 with presbyacusis demonstrated by pure tone audiometry. Asymmetry of the peripheral vestibular system was ruled out by symmetrical thermal excitation rate. Slow-phase velocity of nystagmus induced by rotating-chair stimulation was compared with pure tone audiometry. We found no significant correlation and thus our approach failed to bear out the hypothesis.