Meta-epidemiologic review: blinding and sham treatment in clinical trial design for osteopathic manipulative treatment research

Objective

To analyze the consistency of study designs in osteopathic manipulative treatment (OMT) research, focusing on blinding protocols and the use of sham treatments.

Data Source and Study Selection

PubMed and CINAHL were searched in January 2022. A total of 83 research studies between 2009 and 2021 were selected based on the presence of a double- or single-blind study design and/or sham treatment.

Data Extraction and Analysis

Data regarding the primary outcome measures, blinding design, measures used to determine success of blinding, osteopathic technique used, and sham technique used for each eligible study were extracted and compared among different study designs.

Results

A total of 5968 subjects participated in the 83 trials. The study population mainly consisted of asymptomatic individuals (25%) and chronic back pain patients (19%). Light touch was employed most commonly (49%) as the sham treatment, followed by unrelated sham (20%) and incomplete maneuvers (20%). Most studies blinded the subjects (80%) or the outcome evaluator/data analyzer (71%), while only 20% studies blinded the osteopathic physicians.

Conclusions

Strict double-blinding is achievable for OMT clinical research by blinding the subjects and data collectors/analyzers rather than the osteopaths providing the actual treatment. The use of questionnaires to determine the success of blinding should be considered. Additionally, including OMT-naïve subjects is preferred to enhance blinding success. When designing a sham treatment, careful consideration should be given to blinding the data collector, accounting for the placebo effect, and incorporating an additional no-treatment control group to improve the rigor of the study design.

The effect of photobiomodulation on hearing loss: A systematic review

OBJECTIVES

To assess outcomes associated with photobiomodulation therapy (PBMT) for hearing loss in human and animal studies.

DESIGN

Systematic review and narrative synthesis in accordance with PRISMA guidelines.

SETTING

Data bases searched: MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov and Web of Science. No limits were placed on language or year of publication. Review conducted in accordance with the PRISMA 2020 statement.

PARTICIPANTS

All human and animal subjects treated with PBMT for hearing loss.

MAIN OUTCOME MEASURES

Pre- and post-PBMT audio metric outcomes.

RESULTS

Searches identified 122 abstracts and 49 full text articles. Of these, 17 studies met the inclusion criteria, reporting outcomes in 327 animals (11 studies), 30 humans (1 study), and 40 animal specimens (5 studies). PBMT parameters included 6 different wavelengths: 908 nm (1 study), 810 nm (1 study), 532 & 635 nm (1 study), 830 nm (3 studies), 808 nm (11 studies). The duration ranged from 4 to 60 minutes in a session, and the follow-up ranged from 5-28 days. Outcomes improved significantly when wavelengths within the range of 800-830 nm were used, and with greater duration of PBMT exposure. Included studies predominantly consisted of non-randomized controlled trials (10 studies).

CONCLUSIONS

Hearing outcomes following PBMT appear to be superior to no PBMT for subjects with hearing loss, although higher level evidence is required to verify this. PBMT enables concentrated, focused delivery of light therapy to the inner ear through a non-invasive manner with minimal side effects. As a result of heterogeneity in reporting PBMT parameters and outcomes across the included studies, direct comparison is challenging.

Fibroblasts Derived From Vestibular Schwannoma Express Protumorogenic Markers

BACKGROUND AND AIM

Vestibular schwannomas (VSs), despite being histologically benign, cause significant morbidity because of their challenging intracranial location and the propensity for growth. The role of the stroma and particularly fibroblasts, in the progression of VS, is not completely understood. This study examines the profile of fibroblasts in VS.

METHODS

Seventeen patients undergoing surgical excision of VS were recruited into the study. Reverse transcription with quantitative polymerase chain reaction (RT-qPCR) was performed on VS tissue samples and fibroblast-associated molecules examined. Immunofluorescence and immunohistochemistry in VS tissue were used to study the expression of fibroblast markers CD90 and podoplanin in situ. Fibroblast cultures were established from VS, and RT-qPCR analysis was performed on a panel of fibroblast markers on VS and control tissue fibroblasts.

RESULTS

Several fibroblast-associated molecules including members of galectin family and matrix metalloproteinases were found to be expressed in VS tissue on RT-qPCR analysis. In situ, expression of CD90 and podoplanin was observed in VS tissue both on immunohistochemistry and immunofluorescence. RT-qPCR analysis of fibroblasts from VS and control vestibular neuroepithelium (NE) showed a higher expression of several molecules of the galectin and matrix metalloproteinases family on VS fibroblasts compared with NE fibroblasts.

CONCLUSION

This work examines fibroblasts from VS and shows qualitative differences from NE fibroblasts on RT-qPCR. Further understanding of the fibroblast function in the progression of VS will potentially unveil new targets to manage VS growth.

The effect of photobiomodulation on tinnitus: a systematic review

OBJECTIVE

To establish outcomes following photobiomodulation therapy for tinnitus in humans and animal studies.

METHODS

A systematic review and narrative synthesis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The databases searched were: Medline, Embase, Cochrane Central Register of Controlled Trials ('Central'), ClinicalTrials.gov and Web of Science including the Web of Science Core collection. There were no limits on language or year of publication.

RESULTS

The searches identified 194 abstracts and 61 full texts. Twenty-eight studies met the inclusion criteria, reporting outcomes in 1483 humans (26 studies) and 34 animals (2 studies). Photobiomodulation therapy parameters included 10 different wavelengths, and duration ranged from 9 seconds to 30 minutes per session. Follow up ranged from 7 days to 6 months.

CONCLUSION

Tinnitus outcomes following photobiomodulation therapy are generally positive and superior to no photobiomodulation therapy; however, evidence of long-term therapeutic benefit is deficient. Photobiomodulation therapy enables concentrated, focused delivery of light therapy to the inner ear through a non-invasive manner, with minimal side effects.

Generating Operative Workflows for Vestibular Schwannoma Resection: A Two-Stage Delphi's Consensus in Collaboration with the British Skull Base Society. Part 2: The Translabyrinthine Approach

Objective  An operative workflow systematically compartmentalizes operations into hierarchal components of phases, steps, instrument, technique errors, and event errors. Operative workflow provides a foundation for education, training, and understanding of surgical variation. In this Part 2, we present a codified operative workflow for the translabyrinthine approach to vestibular schwannoma resection. Methods  A mixed-method consensus process of literature review, small-group Delphi's consensus, followed by a national Delphi's consensus was performed in collaboration with British Skull Base Society (BSBS). Each Delphi's round was repeated until data saturation and over 90% consensus was reached. Results  Seventeen consultant skull base surgeons (nine neurosurgeons and eight ENT [ear, nose, and throat]) with median of 13.9 years of experience (interquartile range: 18.1 years) of independent practice participated. There was a 100% response rate across both the Delphi rounds. The translabyrinthine approach had the following five phases and 57 unique steps: Phase 1, approach and exposure; Phase 2, mastoidectomy; Phase 3, internal auditory canal and dural opening; Phase 4, tumor debulking and excision; and Phase 5, closure. Conclusion  We present Part 2 of a national, multicenter, consensus-derived, codified operative workflow for the translabyrinthine approach to vestibular schwannomas. The five phases contain the operative, steps, instruments, technique errors, and event errors. The codified translabyrinthine approach presented in this manuscript can serve as foundational research for future work, such as the application of artificial intelligence to vestibular schwannoma resection and comparative surgical research.

Generating Operative Workflows for Vestibular Schwannoma Resection: A Two-Stage Delphi's Consensus in Collaboration with the British Skull Base Society. Part 1: The Retrosigmoid Approach

Objective  An operative workflow systematically compartmentalizes operations into hierarchal components of phases, steps, instrument, technique errors, and event errors. Operative workflow provides a foundation for education, training, and understanding of surgical variation. In this Part 1, we present a codified operative workflow for the retrosigmoid approach to vestibular schwannoma resection. Methods  A mixed-method consensus process of literature review, small-group Delphi's consensus, followed by a national Delphi's consensus, was performed in collaboration with British Skull Base Society (BSBS). Each Delphi's round was repeated until data saturation and over 90% consensus was reached. Results  Eighteen consultant skull base surgeons (10 neurosurgeons and 8 ENT [ear, nose, and throat]) with median 17.9 years of experience (interquartile range: 17.5 years) of independent practice participated. There was a 100% response rate across both Delphi's rounds. The operative workflow for the retrosigmoid approach contained three phases and 40 unique steps as follows: phase 1, approach and exposure; phase 2, tumor debulking and excision; phase 3, closure. For the retrosigmoid approach, technique, and event error for each operative step was also described. Conclusion  We present Part 1 of a national, multicenter, consensus-derived, codified operative workflow for the retrosigmoid approach to vestibular schwannomas that encompasses phases, steps, instruments, technique errors, and event errors. The codified retrosigmoid approach presented in this manuscript can serve as foundational research for future work, such as operative workflow analysis or neurosurgical simulation and education.

Ehrlichia canis rapid spread and possible enzooty in northern South Australia and distribution of its vector Rhipicephalus linnaei

Recent concerns have arisen in Australia regarding detections of the exotic bacterium Ehrlichia canis which has resulted in ehrlichiosis outbreaks. In Australia, it is spread by the tropical brown dog tick Rhipicephalus linnaei, formerly Rhipicephalus sanguineus sensu lato tropical lineage. Previously, the tick has been recorded in South Australia in the Coober Pedy and the Oodnadatta areas. This study, which includes historical specimens data held in historical Australian arthropod collections, along with 10 sampled remote communities, confirms the wide distribution range of this species within the State. E. canis was detected by PCR in the ticks. The percentage of dogs hosting PCR-positive ticks increased from 2.8% (95% confidence interval [CI]: 0.3 to 9.7) in November-December 2020 to 62.9% (95% CI: 44.9 to 78.5) end of February 2021, initially in two then in seven Anangu Pitjantjatjara Yankunytjatjara lands communities in the far northern regions of South Australia. Our results suggest a rapid spread of the pathogen. No evidence of E. canis was found in nine regional communities. The extended tropical brown dog tick distribution indicates a greater area where E. canis may occur and may require management to minimise the impacts of ehrlichiosis outbreaks. Without the implementation of effective detection and control programs, this extended distribution of R. linnaei is likely to result in the spread of the bacterium to other regions.

Balance testing: does it make a difference?

OBJECTIVE

This study aimed to analyse whether referral for specialist balance testing influences diagnosis and management of patients with dizziness.

METHOD

This was a retrospective study examining patients referred for vestibular function testing between 1 January 2018 and 30 June 2018.

RESULTS

A total of 101 patients were referred, with 69 patients (68.3 per cent) receiving a preliminary 'pre-vestibular function testing balance diagnosis', which included benign paroxysmal positional vertigo (32.7 per cent), Ménière's disease (13.8 per cent) and migraine (14.9 per cent). Following vestibular function testing, revised diagnoses were achieved for 54 patients (53.5 per cent), including benign paroxysmal positional vertigo (14.9 per cent), Ménière's disease (3.0 per cent) and migraine (10.9 per cent). Pre-vestibular function testing balance diagnoses were confirmed for 32.4 per cent of patients. If no pre-vestibular function testing suspected diagnosis was provided, vestibular function testing was significantly more likely to be inconclusive. Following vestibular function testing, 38.6 per cent were discharged, 21.7 per cent were referred to another specialty and treatment was commenced for 17.8 per cent of patients.

CONCLUSION

Referral for vestibular function testing has a role when attempting to answer a clear clinical question. Diagnosing the underlying aetiology of complex imbalance is challenging, but diagnosis can be assisted by judicious use of vestibular function testing.

Noise helps cochlear implant listeners to categorize vowels

Theoretical studies demonstrate that controlled addition of noise can enhance the amount of information transmitted by a cochlear implant (CI). The present study is a proof-of-principle for whether stochastic facilitation can improve the ability of CI users to categorize speech sounds. Analogue vowels were presented to CI users through a single electrode with independent noise on multiple electrodes. Noise improved vowel categorization, particularly in terms of an increase in information conveyed by the first and second formant. Noise, however, did not significantly improve vowel recognition: the miscategorizations were just more consistent, giving the potential to improve with experience.

Comparing Hearing Outcomes in Irradiated and Conservatively Managed Vestibular Schwannoma

OBJECTIVE

Compare hearing outcome for vestibular schwannoma patients following stereotactic radiosurgery (SRS) or conservative management.

STUDY DESIGN

Retrospective review.

SETTING

University Hospital.

PATIENTS

Patients with small- or medium-sized sporadic vestibular schwannoma (intracanalicular or with CPA component <2 cm) who were managed conservatively or underwent SRS with available clinical, radiological, and audiometric data from the time of presentation (or just before radiotherapy for the SRS group) and most recent follow-up; with the two sets of data to be compared being at least 3 years apart (minimum follow-up period).

INTERVENTIONS

SRS or observation.

MAIN OUTCOME MEASURE

Pure-tone averages, speech discrimination scores, and corresponding hearing classifications.

RESULTS

Two hundred forty-seven patients met our inclusion criteria; 140 were managed conservatively with a mean follow-up period of 5.9 ± 1.6 years and 107 underwent SRS with a mean follow-up period of 7.1 ± 1.9 years. There was significant deterioration of hearing measures for both groups; with the SRS group displaying consistently worse measures. SRS patients showed worse mean pure-tone averages and speech discrimination scores decline rates by 2.72 dB/yr and 2.98 %/yr, respectively, when compared with conservatively managed patients. Stratifying patients according to Tokyo's hearing classification revealed that 68.75% of conservatively managed patients who had baseline serviceable hearing preserved their hearing throughout the studied period compared with only 15.38% of the SRS patients.

CONCLUSION

Based on our data we conclude that patients with small- and medium-sized tumors will have a better hearing outcome if managed via an initial conservative approach with radiotherapy reserved for those demonstrating disease progression.

Congenital Mastoid Cholesteatoma

Background:

Congenital cholesteatomas account for just up to 5% of all cholesteatomas and most commonly arise in the petrous apex and middle ear. Congenital cholesteatomas arising in the mastoid are rare and typically present late.

Methods:

In this study, we report a case series of 3 cases managed in our department between 2006 and 2021 and present a summary of the current literature.

Results:

Congenital cholesteatomas arising in the mastoid is a rare finding and even among reported cases, not all are clearly mastoid in origin. Their location allows for considerable growth before symptoms develop. Pain and localized swelling in the temporal area are the most common presenting symptoms which can lead to diagnostic challenges. Our cases show that although surgery is often appropriate, conservative management may be suitable in certain situations.

Conclusion:

Congenital cholesteatoma of mastoid origin is rare and can present a diagnostic challenge. Greater awareness is important to facilitate early detection. A high index of suspicion is needed in those presenting with retro-auricular pain and swelling in the context of a normal ontological examination.

Electrical impedance guides electrode array in cochlear implantation using machine learning and robotic feeder

Cochlear Implant provides an electronic substitute for hearing to severely or profoundly deaf patients. However, postoperative hearing outcomes significantly depend on the proper placement of electrode array (EA) into scala tympani (ST) during cochlear implant surgery. Due to limited intra-operative methods to access array placement, the objective of the current study was to evaluate the relationship between EA complex impedance and different insertion trajectories in a plastic ST model. A prototype system was designed to measure bipolar complex impedance (magnitude and phase) and its resistive and reactive components of electrodes. A 3-DoF actuation system was used as an insertion feeder. 137 insertions were performed from 3 different directions at a speed of 0.08 mm/s. Complex impedance data of 8 electrode pairs were sequentially recorded in each experiment. Machine learning algorithms were employed to classify both the full and partial insertion lengths. Support Vector Machine (SVM) gave the highest 97.1% accuracy for full insertion. When a real-time prediction was tested, Shallow Neural Network (SNN) model performed better than other algorithms using partial insertion data. The highest accuracy was found at 86.1% when 4 time samples and 2 apical electrode pairs were used. Direction prediction using partial data has the potential of online control of the insertion feeder for better EA placement. Accessing the position of the electrode array during the insertion has the potential to optimize its intraoperative placement that will result in improved hearing outcomes.

A Capacitive Cochlear Implant Electrode Array Sensing System to Discriminate Fold-Over Pattern

Purpose During insertion of the cochlear implant electrode array, the tip of the array may fold back on itself and can cause serious complications to patients. This article presents a sensing system for cochlear implantation in a cochlear model. The electrode array fold-over behaviors can be detected by analyzing capacitive information from the array tip. Method Depending on the angle of the array tip against the cochlear inner wall when it enters the cochlear model, different insertion patterns of the electrode array could occur, including smooth insertion, buckling, and fold-over. The insertion force simulating the haptic feedback for surgeons and bipolar capacitance signals during the insertion progress were collected and compared. The Pearson correlation coefficient (PCC) was applied to the collected capacitive signals to discriminate the fold-over pattern. Results Forty-six electrode array insertions were conducted and the deviation of the measured insertion force varies between a range of 20% and 30%. The capacitance values from electrode pair (1, 2) were recorded for analyzing. A threshold for the PCC is set to be 0.94 that can successfully discriminate the fold over insertions from the other two types of insertions, with a success rate of 97.83%. Conclusions Capacitive measurement is an effective method for the detection of faulty insertions and the maximization of the outcome of cochlear implantation. The proposed capacitive sensing system can be used in other tissue implants in vessels, spinal cord, or heart.

Development and validation of an improved classification and risk stratification system for carotid body tumors: Multinational collaborative cohort study

BACKGROUND

This study aims to develop and validate a new classification system that better predicts combined risk of neurological and neurovascular complications following CBT surgery, crucial for treatment decision-making.

METHODS

Multinational retrospective cohort study with 199 consecutive cases. A cohort of 132 CBT cases was used to develop the new classification. To undertake external validation, assessment was made between the actual complication rate and predicted risk by the model on an independent cohort (n = 67).

RESULTS

Univariate analyses showed statistically significant associations between developing a complication and the following factors: craniocaudal dimension, volume, Shamblin classification, and Mehanna types. In the multivariate prognostic model, only Mehanna type remained as a significant risk predictor. The risk of developing complications increases with increasing Mehanna type.

CONCLUSIONS

We have developed and then validated a new classification and risk stratification system for CBTs, which demonstrated better prognostic power for the risk of developing neurovascular complications after surgery.

Systematic review of cochlear implantation in adults with asymmetrical hearing loss

BACKGROUND

Rapid advances in cochlear implantation has witnessed an expanding spectrum for candidacy worldwide. This includes a subgroup of adults with asymmetrical hearing loss who have a wide range in their hearing capacity between the two ears. As per guidelines they are not included in mainstream candidacy for CI across the world. Evidence is now emerging to support the benefits of CI in AHL.

METHODS

This review analyzed literature regarding the outcomes of CI in AHL. Primary outcome measure was to assess audiological benefits and secondary outcome measure was to assess hearing related quality of life. 15 relevant articles, published worldwide between 2009 and 2019 were chosen. CASP checklist for systematic reviews was used to ascertain the quality of literature. The strength of recommendations from each study was analyzed and classified as strong, moderate, weak or none based on GRADE guidelines.

RESULTS

Heterogeneity in samples was obvious and samples varied largely between the studies. The levels of evidence ranged from systematic review to expert opinion, but overall they reflected positively on both audiological and QOL benefits.

CONCLUSION

CI provides important auditory and QOL benefits in AHL, but there is no high level evidence as yet to strongly support CI for AHL. A long term multi-centric study is necessary to influence a change in practice for a growing population of AHL.Trial registration: ClinicalTrials.gov identifier: NCT03052920.

A hand-guided robotic drill for cochleostomy on human cadavers

Background

An arm supported robotic drill has been recently demonstrated for preparing cochleostomies in a pilot research clinical trial. In this paper, a hand-guided robotic drill is presented and tested on human cadaver trials.

Methods

The innovative smart tactile approach can automatically detect drilling mediums and decided when to stop drilling to prevent penetrating the endosteum. The smart sensing scheme has been implemented in a concept of a hand guided robotic drill.

Results

Experiments were carried out on two adult cadaveric human bodies for verifying the drilling process and successfully finished cochleostomy on three cochlea. The advantage over a system supported by a mechanical arm includes the flexibility in adjusting the trajectory to initiate cutting without slipping. Using the same concept as a conventional drilling device, the user will also be benefit from the lower setup time and cost, and lower training overhead.

Conclusion

The hand-guided robotic drill was recently developed for testing on human cadavers. The robotic drill successfully prepared cochleostomies in all three cases.

Ocular torsion responses to electrical vestibular stimulation in vestibular schwannoma

OBJECTIVES

We determined if eye movements evoked by Electrical Vestibular Stimulation (EVS) can be used to detect vestibular dysfunction in patients with unilateral vestibular schwannoma (VS).

METHODS

Ocular torsion responses to monaural sinusoidal EVS currents (±2 mA, 2 Hz) were measured in 25 patients with tumours ranging in size from Koos grade 1-3. For comparative purposes we also measured postural sway response to EVS, and additionally assessed vestibular function with the lateral Head Impulse Test (HIT). Patient responses were compared to age-matched healthy control subjects.

RESULTS

Patients exhibited smaller ocular responses to ipsilesional versus contralesional EVS, and showed a larger asymmetry ratio (AR) than control subjects (19.4 vs. 3.3%, p < 0.05). EVS-evoked sway responses were also smaller in ipsilesional ear, but exhibited slightly more variability than the eye movement response, along with marginally lower discriminatory power (patients vs. controls: AR = 16.6 vs 2.6%, p < 0.05). The HIT test exhibited no significant difference between groups.

CONCLUSIONS

These results demonstrate significant deficits in the ocular torsion response to EVS in VS patients.

SIGNIFICANCE

The fast, convenient and non-invasive nature of the test are well suited to clinical use.

Tumour risks and genotype-phenotype correlations associated with germline variants in succinate dehydrogenase subunit genes SDHB, SDHC and SDHD

BACKGROUND

Germline pathogenic variants in SDHB/SDHC/SDHD are the most frequent causes of inherited phaeochromocytomas/paragangliomas. Insufficient information regarding penetrance and phenotypic variability hinders optimum management of mutation carriers. We estimate penetrance for symptomatic tumours and elucidate genotype-phenotype correlations in a large cohort of SDHB/SDHC/SDHD mutation carriers.

METHODS

A retrospective survey of 1832 individuals referred for genetic testing due to a personal or family history of phaeochromocytoma/paraganglioma. 876 patients (401 previously reported) had a germline mutation in SDHB/SDHC/SDHD (n=673/43/160). Tumour risks were correlated with in silico structural prediction analyses.

RESULTS

Tumour risks analysis provided novel penetrance estimates and genotype-phenotype correlations. In addition to tumour type susceptibility differences for individual genes, we confirmed that the SDHD:p.Pro81Leu mutation has a distinct phenotype and identified increased age-related tumour risks with highly destabilising SDHB missense mutations. By Kaplan-Meier analysis, the penetrance (cumulative risk of clinically apparent tumours) in SDHB and (paternally inherited) SDHD mutation-positive non-probands (n=371/67 with detailed clinical information) by age 60 years was 21.8% (95% CI 15.2% to 27.9%) and 43.2% (95% CI 25.4% to 56.7%), respectively. Risk of malignant disease at age 60 years in non-proband SDHB mutation carriers was 4.2%(95% CI 1.1% to 7.2%). With retrospective cohort analysis to adjust for ascertainment, cumulative tumour risks for SDHB mutation carriers at ages 60 years and 80 years were 23.9% (95% CI 20.9% to 27.4%) and 30.6% (95% CI 26.8% to 34.7%).

CONCLUSIONS

Overall risks of clinically apparent tumours for SDHB mutation carriers are substantially lower than initially estimated and will improve counselling of affected families. Specific genotype-tumour risk associations provides a basis for novel investigative strategies into succinate dehydrogenase-related mechanisms of tumourigenesis and the development of personalised management for SDHB/SDHC/SDHD mutation carriers.

Lateral semicircular canal osteoma presenting as chronic postaural fistula

Temporal bone osteoma is an unusual pathology which can occur by birth or can be acquired and mostly involves the tympanomastoid segment of the temporal bone. Osteomas arising from the otic capsule are extremely rare, and there has been only one other report of a lateral semicircular canal osteoma in the literature. We report a similar case of an acquired lateral canal osteoma which presented as a chronic postaural fistula in an ear previously operated for paediatric cholesteatoma.

The Future of Cochlear Implant Design

This chapter discusses the multifaceted future of cochlear implant design. Current research is focused on novel strategies relating to the electrode array, aiming to improve the neuronal health and spatial selectivity, and reduce the power consumption. Future design iterations will most likely improve the neuronal health by reducing insertion trauma, minimizing the inflammatory pathway that follows electrode insertion or through the use of neurotrophins or stem cells. Improvements in spatial selectivity and in speech recognition in difficult listening environments can be achieved through changes in the electrode/neural interface. Designing an array that brings the electrodes closer to neural tissue, or changing the method of stimulation with current steering or even optical or piezoelectric stimulation are discussed. Increasing the MRI compatibility is an important consideration, and devices allowing remote programming have a huge impact on worldwide provision. Technology exists to realize the elusive goal of a fully implantable cochlear implant, allowing continuous and invisible hearing. Ultimately, future technologies will be integrated to allow tailoring of implant design to the individual, thereby addressing the broad variability in user performance. At the same time, there is an urgent requirement for a high quality, low cost, mass-produced implant for the developing world.

Evaluating the effectiveness and reliability of the Vibrant Soundbridge and Bonebridge auditory implants in clinical practice: Study design and methods for a multi-centre longitudinal observational study

Background

The Vibrant Soundbridge middle ear implant and the Bonebridge bone conducting hearing device are hearing implants that use radio frequency transmission to send information from the sound processor to the internal transducer. This reduces the risk of skin problems and infection but requires a more involved surgical procedure than competitor skin penetrating devices. It is not known whether more complex surgery will lead to additional complications. There is little information available on the reliability of these systems and adverse medical or surgical events. The primary research question is to determine the reliability and complication rate for the Vibrant Soundbridge and Bonebridge. The secondary research question explores changes in quality of life following implantation of the devices. The tertiary research question looks at effectiveness via changes in auditory performance.

Method

The study was designed based on a combination of a literature search, two clinician focus groups and expert review.A multi-centre longitudinal observational study was designed. There are three study groups, two will have been implanted prior to the start of the study and one group, the prospective group, will be implanted after initiation of the study. Outcomes are surgical questionnaires, measures of quality of life, user satisfaction and speech perception tests in quiet and in noise.

Conclusion

This is the first multi-centre study to look at these interventions and includes follow up over time to understand effectiveness, reliability, quality of life and complications.

Percutaneous pedestals in cochlear implantation

Percutaneous pedestals have been integral to the development of cochlear implants since 1969. By enabling direct electrical access to implanted electrodes or other devices, they allow optimization of control of stimulation strategies. Similarly, technology not validated for implantable use can be safely tested. These advantages have facilitated the development of cochlear implants and also resulted in their inclusion in trials investigating electronic implants developed for other organs. Surgery is straightforward, but post-operative care, in particular, skin-care is crucial to ensure complications are minimized. This review discusses the history of percutaneous pedestal use in cochlear implants and other electronic devices. Surgical technique, aftercare, and complications of surgery are discussed along with possibilities for future development.

Implantable microphones as an alternative to external microphones for cochlear implants

Totally implantable cochlear implants may be able to address many of the problems cochlear implant users have around cosmetic appearances, discomfort, and restriction of activities. The major technological challenges that need to be solved to develop a totally implantable device relate to implanted microphone performance. Previous attempts at implanting microphones for cochlear implants have not performed as well as conventional cochlear implant microphones, and in addition have struggled with extraneous body or surface contact noise. Microphones can be implanted under the skin or act as sensors in the middle ear; however, evidence from middle ear implants suggest body and contact noise can be overcome by converting ossicular chain movements into digital signals. This article reviews implantable microphone systems and discusses the technology behind them.

Screens and Sleep: Are Interactive Screen Activities Associated with Short and Inefficient Sleep?

BACKGROUND: Although sleep is essential for healthy development, school-aged children are not getting the recommended number of hours of sleep each night. There is evidence that screen-based activity use is associated with shorter sleep duration and poorer sleep quality in pediatric populations. Findings also suggest that using more interactive activities, such as video games, might be associated with shorter and less efficient sleep, when compared to more passive activities, such as watching television. Few studies have examined this connection in school-aged children and none have employed objective measurements of sleep.

OBJECTIVES: The aim of the present study was to assess the associations between devices that are different in their level of interactivity with quantity and quality of sleep. We hypothesized that more interactive screen activities will explain more of the variability in sleep efficiency and sleep duration compared to less interactive activities.

DESIGN/METHODS: Participants included 78 school-aged children (M=8.57, SD=1.81). Sleep was assessed objectively using actigraphy, a non-invasive device worn to examine sleep-wake patterns by measuring movement. Variables of interest included sleep duration and sleep efficiency. Time spent engaging in screen time activities was assessed via parental reports on the Children’s Leisure Activities Study Survey. Screen activities included time spent watching television/videos, playing video games, and using the computer.

RESULTS: Multiple linear regression analyses were performed to determine possible associations between screen activities and sleep variables. In the first analysis, longer time spent on computer use and playing video gameswas negatively associated with sleep duration (b= -0.04, p&lt;.01; b = -0.05, p&lt;.01, respectively) and the full model explained 24% of the variance. In a second analysis, using the computer was negatively associated with sleep efficiency (b = -0.01, p&lt;.05) and the full model explained 14% of the variance.

CONCLUSION: The current study found that interactive screen activities, including video games playing and computer use, but not watching television, were associated with significantly shorter sleep duration and poorer sleep efficiency. These findings support previous research in school-aged children that suggests video games and other interactive activities are associated with short and inefficient sleep.

Head-Jolting Nystagmus: Occlusion of the Horizontal Semicircular Canal Induced by Vigorous Head Shaking

IMPORTANCE

We report a new syndrome, which we are calling head-jolting nystagmus, that expands the differential diagnosis of head movement-induced paroxysmal vertigo.

OBSERVATIONS

Two male patients (65 and 58 years old) described rotational vertigo after violent and brief (1- to 2-second) oscillations of the head (head jolting) that triggered intense horizontal nystagmus lasting 45 seconds. Accelerations of the head required to induce these episodes could only be achieved by the patients themselves. In case 1, the episodes gradually disappeared over a 6-year period. In case 2, magnetic resonance imaging (3-T) suggested a filling defect within the left horizontal semicircular canal. He underwent surgical canal plugging in March 2013 that resolved the symptoms.

CONCLUSIONS AND RELEVANCE

We attribute head-jolting nystagmus to dislodged material within the horizontal semicircular canal and provide a mechanistic model to explain its origin.

HEAD JOLTING NYSTAGMUS: HEAD-SHAKING-INDUCED OCCLUSION OF THE HORIZONTAL SEMICIRCULAR CANAL

Background and aims

We report a new syndrome (head jolting nystagmus, HJN) that expands the differential diagnosis of head-movement induced paroxysmal vertigo.

Methods and results

Two male patients (65 and 58 yrs) described rotational vertigo after violent and brief (1–2 s) oscillations of the head (head jolting) that triggered intense horizontal nystagmus lasting 45s. Accelerations of the head required to induce these episodes could only be achieved by the patients themselves. In Patient 1 the episodes gradually disappeared over a 6–year period. In Patient 2, 3–Tesla MRI suggested a filling defect in the left horizontal semicircular canal. He underwent surgical canal plugging that resolved the symptoms.

Conclusion and relevance

We attribute HJN to dislodged material within the horizontal semicircular canal, and provide a mechanistic model to explain its origin.

Characterizing human vestibular sensory epithelia for experimental studies: new hair bundles on old tissue and implications for therapeutic interventions in ageing

Balance disequilibrium is a significant contributor to falls in the elderly. The most common cause of balance dysfunction is loss of sensory cells from the vestibular sensory epithelia of the inner ear. However, inaccessibility of inner ear tissue in humans severely restricts possibilities for experimental manipulation to develop therapies to ameliorate this loss. We provide a structural and functional analysis of human vestibular sensory epithelia harvested at trans-labyrinthine surgery. We demonstrate the viability of the tissue and labeling with specific markers of hair cell function and of ion homeostasis in the epithelium. Samples obtained from the oldest patients revealed a significant loss of hair cells across the tissue surface, but we found immature hair bundles present in epithelia harvested from patients >60 years of age. These results suggest that the environment of the human vestibular sensory epithelium could be responsive to stimulation of developmental pathways to enhance hair cell regeneration, as has been demonstrated successfully in the vestibular organs of adult mice.

Profiling of somatic mutations in phaeochromocytoma and paraganglioma by targeted next generation sequencing analysis

At least 12 genes (FH, HIF2A, MAX, NF1, RET, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and VHL) have been implicated in inherited predisposition to phaeochromocytoma (PCC), paraganglioma (PGL), or head and neck paraganglioma (HNPGL) and a germline mutation may be detected in more than 30% of cases. Knowledge of somatic mutations contributing to PCC/PGL/HNPGL pathogenesis has received less attention though mutations in HRAS, HIF2A, NF1, RET, and VHL have been reported. To further elucidate the role of somatic mutation in PCC/PGL/HNPGL tumourigenesis, we employed a next generation sequencing strategy to analyse "mutation hotspots" in 50 human cancer genes. Mutations were identified for HRAS (c.37G>C; p.G13R and c.182A>G; p.Q61R) in 7.1% (6/85); for BRAF (c.1799T>A; p.V600E) in 1.2% (1/85) of tumours; and for TP53 (c.1010G>A; p.R337H) in 2.35% (2/85) of cases. Twenty-one tumours harboured mutations in inherited PCC/PGL/HNPGL genes and no HRAS, BRAF, or TP53 mutations occurred in this group. Combining our data with previous reports of HRAS mutations in PCC/PGL we find that the mean frequency of HRAS/BRAF mutations in sporadic PCC/PGL is 8.9% (24/269) and in PCC/PGL with an inherited gene mutation 0% (0/148) suggesting that HRAS/BRAF mutations and inherited PCC/PGL genes mutations might be mutually exclusive. We report the first evidence for BRAF mutations in the pathogenesis of PCC/PGL/HNPGL.

Conservative management, surgery and radiosurgery for treatment of vestibular schwannomas: a model-based approach to cost-effectiveness

OBJECTIVE

To undertake a cost-effectiveness analysis comparing conservative management, surgery and radiosurgery for treating small-to-medium (1-20 mm)-sized vestibular schwannomas.

DESIGN

Model-based economic evaluation using individual-level data from a Birmingham-based longitudinal patient database and from published sources. Both a decision tree and state-transition (Markov) model were developed, from an National Health Service (NHS) perspective. Sensitivity analyses were also carried out.

SETTING

Secondary care treatment for patients with small-to-medium-sized vestibular schwannomas.

PARTICIPANTS

Three hypothetical cohorts of adult patients receiving conservative management, radiosurgery or surgery treatment, aged 58 years as starting age within model.

MAIN OUTCOME MEASURES

Cost-effectiveness based on cost per quality-adjusted life year (QALY).

RESULTS

Conservative management is the preferred strategy for the treatment of small-to-medium-sized vestibular schwannomas. Conservative management is both cheaper (-£ 722 and -£ 2764) and more effective (0.136 and 0.554 quality-adjusted life years) than both radiosurgery and surgery, respectively. A conservative strategy can therefore be considered as highly cost-effective. This result is sensitive to the assumed quality-of-life parameters in the model. Sensitivity analysis suggests that the probability of a conservative strategy being the most cost-effective approach compared with surgery and radiosurgery at a willingness to pay of £ 20 000/quality-adjusted life year gained is 80% and 55%, respectively.

CONCLUSIONS

A conservative approach is the preferred strategy for treatment of small-to-medium vestibular schwannomas. This result is sensitive to quality-of-life values used in the analysis. More research is required to assess the impact of treatment upon patients' health-related quality of life over time.

A comprehensive next generation sequencing-based genetic testing strategy to improve diagnosis of inherited pheochromocytoma and paraganglioma

CONTEXT

Pheochromocytomas and paragangliomas are notable for a high frequency of inherited cases, many of which present as apparently sporadic tumors.

OBJECTIVE

The objective of this study was to establish a comprehensive next generation sequencing (NGS)-based strategy for the diagnosis of patients with pheochromocytoma and paraganglioma by testing simultaneously for mutations in MAX, RET, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and VHL.

DESIGN

After the methodology for the assay was designed and established, it was validated on DNA samples with known genotype and then patients were studied prospectively.

SETTING

The study was performed in a diagnostic genetics laboratory.

PATIENTS

DNA samples from 205 individuals affected with adrenal or extraadrenal pheochromocytoma/head and neck paraganglioma (PPGL/HNPGL) were analyzed. A proof-of-principle study was performed using 85 samples known to contain a variant in 1 or more of the genes to be tested, followed by prospective analysis of an additional 120 samples.

MAIN OUTCOME MEASURES

We assessed the ability to use an NGS-based method to perform comprehensive analysis of genes implicated in inherited PPGL/HNPGL.

RESULTS

The proof-of-principle study showed that the NGS assay and analysis gave a sensitivity of 98.7%. A pathogenic mutation was identified in 16.6% of the prospective analysis cohort of 120 patients.

CONCLUSIONS

A comprehensive NGS-based strategy for the analysis of genes associated with predisposition to PPGL and HNPGL was established, validated, and introduced into diagnostic service. The new assay provides simultaneous analysis of 9 genes and allows more rapid and cost-effective mutation detection than the previously used conventional Sanger sequencing-based methodology.

Evaluation of SDHB, SDHD and VHL gene susceptibility testing in the assessment of individuals with non-syndromic phaeochromocytoma, paraganglioma and head and neck paraganglioma

OBJECTIVES

Research studies have reported that about a third of individuals with phaeochromocytoma/paraganglioma (PPGL) have an inherited predisposition, although the frequency of specific mutations can vary between populations. We evaluated VHL, SDHB and SDHD mutation testing in cohorts of patients with non-syndromic PPGL and head and neck paraganglioma (HNPGL).

DESIGN

Prospective, observational evaluation of NHS practice.

PATIENTS

Individuals with PPGL/HNPGL referred to a supraregional genetics testing service over a 10-year period.

MEASUREMENTS

Clinical (age, tumour site, malignancy, etc.), mutation frequencies and characteristics.

RESULTS

A total of 501 probands with PPGL (n = 413) or HNPGL (n = 88) were studied. Thirty-one percent of patients with PPGL presented had a pathogenic mutation in SDHB, SDHD or VHL. Mutation detection rates were highest in those with a positive family history (62%), malignancy (53%), multiple tumours (33%) or PGL (44%). Twenty-eight percent of individuals with a single sporadic phaeochromocytoma had a mutation. Overall, 63% of patients with HNPGL had a mutation (92% of those with a family history, 89% of those with multicentric tumours and 34% of those with a single sporadic HNPGL). Penetrance was calculated in 121 SDHB mutation-positive probands and 187 of their mutation-positive relatives. Most relatives were asymptomatic and lifetime penetrance in non-proband SDHB mutation carriers was <50%.

CONCLUSIONS

Practice-based evaluations of genetic testing in PPGL reveal high mutation detection rates. Although clinical criteria can be used to prioritize mutation testing, mutations were detected in 'low risk groups' indicating a need for comprehensive and inexpensive genetic testing strategies for PPGL and HNPGL.

Knowledge, awareness and compliance with universal precautions among health care workers at the University Hospital of the West Indies, Jamaica

BACKGROUND

Universal precautions are not well understood or implemented by health care practitioners, though crucial in the prevention and transmission of blood-borne pathogens like HIV.

OBJECTIVE

To assess knowledge, awareness and compliance of universal precautions among health care workers at the University Hospital of the West Indies, Jamaica.

METHODS

A cross-sectional survey was conducted in September and October 2007. A 28-item self-administered questionnaire was provided to 200 health care workers including medical doctors, medical technologists, nurses and porters to assess their knowledge, awareness and practice towards universal precautions.

RESULTS

Almost two-thirds (64.0%) of the respondents were very knowledgeable of universal precautions with significantly more females (75.4%) than males (42.9%) (p<0.0001). More nurses (90.0%), medical doctors (88.0%) and medical technologists (70%) were very knowledgeable of universal precautions (p<0.0001). More respondents (92.9%) who were employed in the health sector for 16 years and over reported high levels of awareness of universal precautions than those who were employed for less than five years (p<0.0001). 28.6% of males and only 6.2% of females reported that they do not use protective gear. More nurses reported frequent use of protective equipment followed by medical technologists and medical doctors (p<0.0001).

CONCLUSION

There was adequate knowledge and a fair level of awareness among medical doctors, medical technologists, and nurses towards universal precautions.

Management of the patient and family with neurofibromatosis 2: a consensus conference statement

A consensus conference on neurofibromatosis 2 (NF2) was held in 2002 at the request of the United Kingdom (UK) Neurofibromatosis Association, with particular emphasis on vestibular schwannoma (VS) surgery. NF2 patients should be managed at specialty treatment centres, whose staff has extensive experience with the disease. All NF2 patients and their families should have access to genetic testing because presymptomatic diagnosis improves the clinical management of the disease. Some clinical manifestations of NF2, such as ocular abnormalities, can be detected in infancy; therefore, clinical screening for at-risk members of NF2 families can start at birth, with the first magnetic resonance (MRI) scan at 10-12 years of age. Minimal interference, maintenance of quality of life, and conservation of function or auditory rehabilitation are the cornerstones of NF2 management, and the decision points to achieve these goals for patients with different clinical presentations are discussed.

Topical antibiotic ototoxicity: does it influence our practice?

INTRODUCTION

We hypothesised that general practitioners and ENT specialists manage discharging ears differently. This study was designed to investigate this further.

METHODS AND MATERIALS

Postal questionnaires were sent to all general practitioners in the Birmingham area and all UK consultants on the British Association of Otolaryngology-Head and Neck Surgery address list.

RESULTS AND DISCUSSION

In the presence of an intact tympanic membrane, 99 per cent of consultants and 90 per cent of general practitioners would use topical antibiotics. In the presence of a perforated tympanic membrane, 97 per cent of consultants would continue to use topical antibiotics, compared with only 43 per cent of general practitioners. This was attributed to a fear of ototoxicity. If a topical non-ototoxic antibiotic of proven efficacy could be made available, 93 per cent of consultants and 88 per cent of general practitioners in this study would seriously consider using it as first line treatment.

CONCLUSION

The majority of general practitioners would not use topical antibiotics in the presence of a perforated tympanic membrane. Most doctors would consider using a non-ototoxic topical antibiotic as first line treatment should one be made available.

Detection of Anaplasma platys and Babesia canis vogeli and their impact on platelet numbers in free-roaming dogs associated with remote Aboriginal communities in Australia

OBJECTIVE

To detect Anaplasma platys and Babesia canis vogeli infection, using polymerase chain reaction (PCR)-based assays, in free-roaming dogs associated with eight Aboriginal communities in remote areas of Australia and to determine the impact of infection through the assessment of platelet numbers.

PROCEDURES

Blood samples from 215 dogs were screened by PCR for A platys and B canis vogeli using established genus-specific DNA primers for the 16S and 18S rRNA genes respectively. Both A platys DNA and B canis vogeli DNA were confirmed from the screening PCR either by sequencing or by the use of species-specific primers. Peripheral blood films from 92 of the 215 dogs were used to estimate platelet numbers through an indirect method.

RESULTS

Of 215 dogs, 69 (32%) were positive for A platys, 22 (10%) for B canis vogeli and 24 (11%) for both. The two organisms were detected singularly and as coinfection in all communities. For the 92 dogs in which peripheral blood films were examined, the mean estimated platelet counts for the non-infected dogs was 318 x 10(9)/L, those infected with A platys alone was 256 x 10(9)/L, those with B canis vogeli alone was 276 x 10(9)/L and those infected with both parasites was 169 x 10(9)/L. In young dogs, infection produced significantly decreased mean platelet counts when compared to uninfected dogs. Thrombocytopenia (< 200 x 10(9)/L) was detected in 18 (51%) dogs infected with A platys alone, 3 (33%) dogs infected with B canis vogeli alone, 13 (72%) dogs coinfected, and 8 (27%) uninfected dogs.

CONCLUSIONS

A platys and B canis vogeli infection, either singularly or together, was widespread in free roaming dogs associated with remote Aboriginal communities in the Northern Territory and north-western New South Wales. Moreover, both A platys and B canis vogeli infections were associated with a reduction in mean platelet numbers in dog populations, particularly in young dogs. The fact that 51% of dogs infected with A platys alone and 72% dogs coinfected were thrombocytopenic compared to 27% of uninfected dogs suggests that the organism alone or in combination with B canis vogeli has the potential to cause thrombocytopenia and perhaps contribute to a clinical bleeding disorder in infected dogs.

Measles immunity and response to revaccination among secondary school children in Cumbria

The prevalence of antibody to measles virus in 759 children aged 11-18 years attending a secondary school in Cumbria was measured using a salivary IgG antibody capture assay. Serum IgG antibody levels were measured using a plaque reduction neutralization assay in subjects whose saliva was antibody negative. Vaccination histories were obtained from the child health computer and general practice record. A total of 662 pupils (87% of those tested) had detectable measles-specific IgG in saliva. Of the remaining 97, 82 provided blood samples and 29 had serum neutralizing antibody levels above 200 mIU/ml. Afer adjusting for non-participation rates, the proportion considered non-immune (no IgG in saliva and < or = 200 mIU/ml in serum) was 9% overall, ranging from 6% in vaccinated children to 20% in unvaccinated children. Measles-mumps-rubella vaccine was given to 50 children of whom 38 provided post-vaccination serum and 32 saliva samples. Thirty (79%) had a fourfold or greater rise in serum neutralizing antibody and 28 (88%) developed IgG antibody in saliva. Half of the children considered non-immune by antibody testing would have been overlooked in a selective vaccination programme targeted at those without a history of prior vaccination. A programme targeted at all school children should substantially reduce the proportion non-immune since a primary or booster response was achieved in three quarters of previously vaccinated children with low antibody levels and in all unvaccinated children. While it is feasible to screen a school-sized population for immunity to measles relatively quickly using a salivary IgG assay, a simple inexpensive field assay would need to be developed before salivary screening and selective vaccination could substitute for universal vaccination of populations at risk of measles outbreaks. The salivary IgG assay provided a sensitive measure of a booster response to vaccination.