A Lack of Association between Human Herpes Viridiae (HHV) and Vestibular Schwannoma: Analysis of 121 Cases

Objectives:

Vestibular schwannoma (VS) is a benign tumor thatarises from the Schwann cells of the vestibular nerve. Human herpes virus (HHV) 1 and 2 have been found within the parenchyma of virtually all the organs of the body and the dorsal root ganglia of the spinal cord in humans. HHV has been shown to replicate within Schwann cells, and infection by HHV has been shown to mimic VS on magnetic resonance imaging. Others hypothesized that the likely cause of VS is HHV infection and that prior exposure to HHV-3 is a potential risk factor in VS development. Our objective wasto assess for the presence of HHV viral DNA using immunohistochemical techniques in surgically excised vestibular schwannoma samples.

Methods:

Tissue microarrays (TMAs) representing sporadic and NF2-associated vestibular schwannomas from 121 patients, as well as both positive and negative controls, were studied. TMA sections were immunostained-using antibodies directed against HHV-1, HHV-2, HHV-3, HHV-5, and HHV-8.

Results:

There was no immunohistochemically detectable HHV (HHV-1, HHV-2, HHV-3, HHV-5, HHV-8) in any of the 121 cases of sporadic or NF2 cases analyzed.

Conclusions:

These data offer no support for an association between HHV and the development of sporadic or NF2 associated VS in humans.

Prevalence of MT-RnR1 in the General Population

Objective: Review the prevalence of MT-RNR1 genetic mutation and assess the need for neonatal screening prior to gentamicin therapy. A comprehensive search of MEDLINE, EMBASE, Cochrane Library, Clinical Evidence, and Cochrane Central Register of Trials was performed. The reference lists were cross-referenced. Review was restricted to human studies in English language.

Method: Studies describing the prevalence/incidence of MT-RNR1 gene mutations (A1555G, C1494T, A7445G) in the population. Relevant studies screening for presence for MT-RNR1 in patients receiving aminoglycoside therapy were included.

Results: Twenty-two articles out of 67 full papers and 206 abstracts from 1948 to November 2011 met the inclusion criteria. These included 9 prospective case-control studies, 12 case series, and a case report. There is weak evidence that MT-RNR1 is globally prevalent with racial bias especially in Chinese and Spanish populations. The prevalence/incidence ranged from 0.09%-2.9% in general population to 17% in the high-risk population. Weak evidence of neonatal sensorineural hearing loss following aminoglycoside exposure was also seen.

Conclusion: There is a need for large national epidemiological studies to assess the prevalence of MT-RNR. Some evidence of a global prevalence of MT-RNR1 with racial bias and link between aminoglycoside exposure and NSHL among at risk group. It is difficult to justify routine screening of patients for MT-RNR1 with the available literature.

Systematic review and meta-analysis of the risk factors for sudden sensorineural hearing loss in adults

OBJECTIVES/HYPOTHESIS

To review the medical literature evidence of potential risk factors for sudden sensorineural hearing loss (SSNHL) in the adult general population.

STUDY DESIGN

Systematic review of prospective and retrospective studies; meta-analysis of case-controlled studies.

METHODS

Three researchers independently reviewed MEDLINE (January 1, 1950-November 30, 2010), Embase (January 1, 1980-November 30, 2010), and Evidence-Based Medicine Reviews databases in addition to conducting a manual reference search. Randomized controlled trials, prospective cohort studies, consecutive/nonconsecutive case series, and retrospective reviews in which a clear definition of SSNHL was stated were included in the study. Researchers individually extracted data regarding patient information and the presumed risk factors. Discrepancies were resolved by mutual consensus.

RESULTS

Twenty-two articles met the inclusion criteria. Cardiovascular risk factors (smoking, increased alcohol consumption) appeared to be associated with a higher risk of developing SSNHL. A low level of serum folate may also be implicated as a risk factor. Factor V Leiden and MTHFR gene polymorphisms were found to occur more frequently in patients with SSNHL in several studies, suggesting these inherited prothrombophilic mutations could be independent risk factors of SSNHL.

CONCLUSIONS

Acquired and inherited cardiovascular risk factors appeared to be associated with an increased risk of developing SSNHL.

Avoiding the “Deadly Sins” of Humanitarian Missions: How to “Do Good” Better

Program Description: Over the past several decades, the numbers of North American physicians and surgeons engaged in international humanitarian missions has increased dramatically. Such trips often provide an opportunity for needy individuals and communities to receive care that would otherwise be unavailable to them. They also provide the opportunity for participants to “give back” through providing direct patient care and teaching in an environment of extreme need. Personal motivations, level of ability of the individual practitioner, sophistication of the mission organization, as well as level of connectedness to “in country” providers varies dramatically among mission groups. This variability has contributed to some unfortunate patient outcomes. Accusations that “surgical safaris” represent a “form of Neo-colonialism” have cast doubt on the motivations of participants and brought significant scrutiny to the true benefits arising from these efforts. This interactive miniseminar will explore “deadly sins” which are common to medical humanitarian efforts as well as issues which are unique to surgical humanitarian missions. Panelists will discuss available data and areas in which there is a lack of data concerning humanitarian efforts. Finally, “best practices” for humanitarian missions will be discussed. Issues to be discussed include appropriate standard of care, duration, follow-up, conduct of research, resident trainee participation in surgical procedures, role of the media, and integration with local care systems.

Educational Objectives: 1) Identify common problems encountered during medical and surgical humanitarian mission trips. 2) Understand ethical concerns arising during international humanitarian efforts. 3) Apply best practices for conduct of humanitarian mission trips in which they are involved.

Prospective, randomized controlled assessment of the short- and long-term efficacy of a hearing conservation education program in Canadian elementary school children

OBJECTIVE

To assess the efficacy of a hearing conservation program in changing acoustic risk-taking and hearing conservation behaviors in elementary school children.

STUDY DESIGN

Prospective, randomized, mixed design controlled study.

METHODS

Participants were grade-six students from 16 Vancouver School Board schools. Differences between the intervention and control group responses on a behavioral questionnaire were measured at baseline, and then at 2 weeks and 6 months after administration of a hearing conservation program (Sound Sense™).

RESULTS

The intervention resulted in significant interactions for improved earplug use at dances (P = .019), rock concerts (P = .001), with percussion musical instruments (P = .002), and electric guitars (P = .028) at 2 weeks postintervention relative to baseline. Improvements in children's earplug use at dances (P = .041), rock concerts (P = .0024), and with power lawn mowers (P = .043) at 6 months postintervention relative to baseline were also observed. Behavior in the intervention group compared to control group improved in earplug use with any "other noises" at 2 weeks (P = .001), and 6 months (P = .022) relative to baseline. There was a tendency in the intervention group to reduce the duration of use of personal music devices at 2 weeks and 6 months after the hearing conservation program, which was nonsignificant.

CONCLUSION

The Sound Sense™ hearing conservation program improved earplug use practices in elementary school children in the short and long term. The development, implementation and evaluation of a community-based health promotion project around hearing loss can serve as a tremendous opportunity for students to develop their knowledge and skills in health advocacy.

Systematic review of the evidence for the etiology of adult sudden sensorineural hearing loss

OBJECTIVES/HYPOTHESIS

To determine the evidence for different etiologies of sudden sensorineural hearing loss (SSNHL) identified by clinical diagnostic tests in the adult population.

STUDY DESIGN

Systematic literature review.

METHODS

Review of MEDLINE (1950-October 2009), EMBASE (1980-October 2009), and EBM Review databases in addition to manual reference search of identified papers. Randomized controlled trials, prospective cohort studies, and retrospective reviews of consecutive patients in which a clear definition of SSNHL was stated and data from consecutive patients were reported with respect to etiology of hearing loss. Three researchers independently extracted data regarding patient demographic information, diagnostic tests employed, and the identified presumed etiologies. Discrepancies were resolved by mutual consensus.

RESULTS

: Twenty-three articles met the inclusion criteria. The first group of papers searched for different etiologies among patients with SSNHL. Multiple etiologies were identified, including viral infection, vascular impairment, autoimmune disease, inner ear pathology, and central nervous system anomalies. The diagnosis for the majority of patients remained idiopathic. The second group of papers evaluated SSNHL patients with specific diagnostic tests such as autoimmune markers, hemostatic parameters, and diagnostic imaging.

CONCLUSIONS

The suspected etiologies for patients suffering sudden sensorineural hearing loss included idiopathic (71.0%), infectious disease (12.8%), otologic disease (4.7%), trauma (4.2%), vascular or hematologic (2.8%), neoplastic (2.3%), and other causes (2.2%). Establishment of a direct causal link between SSNHL and these etiologies remains elusive. Diagnostic imaging is a useful method for identification of temporal bone or intracranial pathology that can present with SSNHL as a primary symptom.

Holiday review. How random is the toss of a coin?

BACKGROUND

The toss of a coin has been a method used to determine random outcomes for centuries. It is still used in some research studies as a method of randomization, although it has largely been discredited as a valid randomization method. We sought to provide evidence that the toss of a coin can be manipulated.

METHODS

We performed a prospective experiment involving otolaryngology residents in Vancouver, Canada. The main outcome was the proportion of "heads" coin tosses achieved (out of 300 attempts) by each participant. Each of the participants attempted to flip the coin so as to achieve a heads result.

RESULTS

All participants achieved more heads than tails results, with 7 of the 13 participants having significantly more heads results (p<or=0.05). The highest proportion of heads achieved was 0.68 (95% confidence interval 0.62-0.73, p<0.001).

INTERPRETATION

Certain people are able to successfully manipulate the toss of a coin. This throws into doubt the validity of using a coin toss to determine a chance result.

Primary middle ear Epstein-Barr virus-related lymphoepithelial carcinoma: case reports and systematic review

OBJECTIVES/HYPOTHESIS

To report two cases of primary lymphoepithelial carcinoma in the middle ear and to determine the optimal treatment for such lesions.

STUDY DESIGN/METHODS

Case reports and a systematic review of the literature.

RESULTS

Primary lymphoepithelial carcinoma in the middle ear is an exceptionally rare condition with only two other cases reported in the literature. There appears to be an association with Epstein-Barr virus infection and in those patients originating from the Guangdong province of China, much as is the case for similar lesions found in the nasopharynx. Piecemeal rather than en bloc excision, in combination with adjuvant radiotherapy, appears to adequately control the disease.

CONCLUSIONS

Primary lymphoepithelial carcinoma of the middle ear is a rare lesion, which when treated has a good prognosis.

Toward the development of evidence-based guidelines for the management of methicillin-resistant Staphylococcus aureus otitis

OBJECTIVES

(1) To determine the causative bacteriology of discharging ears in a case series from a tertiary/quaternary academic centre serving an urban population and from a review of the literature and (2) to develop treatment guidelines for methicillin-resistant Staphylococcus aureus (MRSA) otorrhea based on the best available evidence.

METHODS

A retrospective analysis of all "ear" cultures from the microbiology laboratory at St. Paul's Hospital, Vancouver, was performed to ascertain a qualitative analysis on the susceptibility and bacteriology data. A systematic review of the literature was performed for all studies examining the bacteriology, susceptibility, and treatment for any MRSA infection producing otorrhea.

RESULTS

Staphylococcus aureus and Pseudomonas aeruginosa (PA) were present in 39.7% and 13.5%, respectively, of ear cultures obtained at our institution versus 9.9 to 54.1% and 25.0 to 48.6% in identified studies in the literature. Methicillin-sensitive Staphylococcus aureus (MSSA) was present more frequently than MRSA (31.2% vs 8.5% at our institution; 16.9% vs 6.9% in the literature). MRSA isolates were often resistant to gentamicin (14.8%) and ciprofloxacin (7.7%) but susceptible to trimethoprim-sulfamethoxazole (TMP-SMX) (85.3%) and fusidic acid (96.3%), suggesting a preponderance of the "community strain" of MRSA.

CONCLUSION

The susceptibility of MRSA to antibiotics in commonly used otic drops (ie, gentamicin and ciprofloxacin) is low. Based on the available data, we suggest an evidence-based approach to the management of MRSA otorrhea considering whether the strain is community or hospital acquired and whether the tympanic membrane is intact.

A systematic review of pediatric sensorineural hearing loss in congenital syphilis

INTRODUCTION

Congenital syphilis is a known cause of progressive sensorineural hearing loss. The prevalence of syphilitic sensorineural hearing loss (SNHL) in childhood is not clearly defined.

OBJECTIVE

To determine the frequency and characteristics of pediatric SNHL following intrauterine infection with or exposure to Treponema pallidum in order to develop evidence-based guidelines for audiologic monitoring.

DATA SOURCES

Medline (1950-March 2008), EMBASE (1980-March 2008), CINAHL (1982-March 2008), BIOSIS Previews (1969-March 2008), and Cochrane databases. Manual search of references of identified articles and book chapters.

STUDY SELECTION

Articles with an inception cohort of children infected with T. pallidum during pregnancy, positive serological identification of syphilis infection in the antenatal period or pathognomonic clinical signs of congenital syphilis infection, and longitudinal serial audiologic evaluations to identify the prevalence and progression of SNHL.

DATA EXTRACTION

Patient information, maternal and infant serologic status, and audiometric data extracted in an independent fashion. Discrepancies resolved through mutual consensus.

DATA SYNTHESIS

Descriptive statistics.

RESULTS

One prospective cohort study met the inclusion criteria. No cases of SNHL in infants with early congenital syphilis treated with antibiotics in the neonatal period were identified.

CONCLUSIONS

There have been no reports of children with confirmed congenital SNHL secondary to in utero syphilis infection. Newborns with positive syphilis serology should have hearing screening performed at birth and receive treatment with an appropriate course of penicillin therapy. Longitudinal hearing screening is recommended for all pediatric patients with congenital syphilis, as further studies documenting longitudinal audiometric data for patients previously treated either fully or partly for congenital syphilis are required.

A systematic review of neonatal toxoplasmosis exposure and sensorineural hearing loss

INTRODUCTION

The Joint Committee on Infant Hearing 2007 Position Statement includes in utero toxoplasmosis infection as a risk indicator for delayed-onset or progressive sensorineural hearing loss. It is recommended that children with congenital toxoplasmosis infection undergo audiologic monitoring to identify congenital and delayed-onset sensorineural hearing loss.

OBJECTIVE

To determine the prevalence of sensorineural hearing loss and to develop evidence-based guidelines for audiologic monitoring of children born with congenital toxoplasmosis infection.

DATA SOURCES

Systematic search of Medline, EMBASE and Cochrane databases and manual search of references.

STUDY SELECTION

Longitudinal studies reporting an inception cohort identified at birth, with serologic confirmation of toxoplasmosis infection, and long-term serial audiometric evaluation.

DATA EXTRACTION

Independent extraction of patient and audiometric data.

DATA SYNTHESIS

Descriptive statistics.

CONCLUSION

The five studies meeting our inclusion criteria report a prevalence of toxoplasmosis-associated hearing loss from 0% to 26%. Improved treatment regimens for toxoplasmosis may account for this range. Three treatment groups were identified and a subgroup analysis of the compiled data was performed. In children receiving limited or no treatment, the prevalence of toxoplasmosis-associated SNHL was found to be 28%. In children prescribed 12 months of antiparasitic treatment but in whom treatment was not confirmed to have started prior to 2.5 months of age and in whom compliance was not ensured, the prevalence of SNHL was 12%. In children treated with 12 months of antiparasitical therapy initiated prior to 2.5 months of age with serologically-confirmed compliance, the prevalence of SNHL was 0%. Only two longitudinal studies were identified and neither reported any cases of delayed-onset or progressive toxoplasmosis-associated SNHL. Children who have received a 12-month course of antiparasitical therapy initiated prior to 2.5 months with serologically-confirmed compliance should have repeat audiometric evaluation at 24-30 months of age. Children with congenital toxoplasmosis that had no treatment, partial treatment, delayed onset of treatment, or compliance issues should undergo annual audiologic monitoring until able to reliably self-report hearing loss.

Objective findings with malpositioning of a nucleus 24RE(CA) cochlear implant

BACKGROUND

Proper intracochlear placement of cochlear implant electrode arrays is believed to be important for optimum speech perception results. However, objective tests of cochlear implant function typically provide little or no information about the intracochlear placement of the array. We report the results for a variety of objective tests, including averaged electrode voltage (AEV) measurements, in a patient where the electrode array had folded up on itself during insertion.

PURPOSE

To determine whether any of the objective measures provided evidence of incorrect electrode placement.

RESEARCH DESIGN

Objective test data are reported for a patient with an incorrectly positioned electrode array, prior to and following reimplantation, and compared to data obtained in 42 patients with normal insertions.

STUDY SAMPLE

One patient with an incorrectly placed electrode array, prior to and following reimplantation, and a sample of 42 implant recipients with correct insertions.

INTERVENTION

The patient with the malpositioned electrode array was explanted and reimplanted. The results for the first and the second implant, with regards to objective test results, are compared. The results are also compared to the data obtained on 42 implant recipients with normal insertions.

DATA COLLECTION AND ANALYSIS

The objective test data (primarily AEV data) are compared with AEV results obtained in 42 patients with normal electrode insertions.

RESULTS AND CONCLUSIONS

Although the electrode array had folded up on itself during insertion, intraoperative electrode impedances and VIII nerve responses, as well as postoperative electrically evoked auditory brainstem responses, were within normal limits. However, averaged electrode voltages, obtained with the Nucleus Crystal Integrity Test system, were abnormal and consistent with a low-impedance pathway between the apical and middle portions of the electrode array.

Cross-sectional survey of hearing impairment and ear disease in Uganda

OBJECTIVE

To determine the prevalence and causes of disabling hearing loss in adults and children in Uganda.

STUDY DESIGN

Cross-sectional survey of ear disease and hearing impairment.

SETTING

A random cluster sample design of the population from the Masindi district of Uganda following the World Health Organization (WHO) guidelines, using a modified version of the WHO Ear Disease Survey Protocol.

MAIN OUTCOME MEASURE

The prevalence of disabling hearing impairment using the WHO definitions (excluding 0.5 kHz owing to high background noise levels).

RESULTS

In the study, 6041 participants were enrolled and underwent audiometric evaluation and an ear examination. The prevalence of disabling hearing impairment was 11.7% in adults and 10.2% in children. A further 2.3% of children in whom thresholds could not be measured were deemed to have significant hearing loss based on screening questions and/or sound-field stimuli. Correctable causes such as dry perforations, cerumen impaction, and chronic suppurative otitis media resulted in disabling hearing loss in 17% of adult subjects and 41% of children. Preventable hearing loss, such as meningitis and noise-induced hearing loss, was present in a further significant percentage of subjects.

CONCLUSIONS

Ear disease and hearing impairment were found to be important health problems in the Ugandan population. Preventable ear disease is a major cause of hearing loss in the population. It is hoped that the findings of this study will draw attention to the problem in Uganda and will lead to proper allocation of resources for the prevention and treatment of hearing loss and ear disease.

Meta-analysis: prophylactic drainage and bleeding complications in thyroid surgery

OBJECTIVE

To conduct a comprehensive systematic review and high-quality meta-analysis to determine whether prophylactic drain placement reduces adverse bleeding events in thyroid surgery.

DATA SOURCES

MEDLINE (OVID and PubMed), CENTRAL, CDSR, ACP Journal Club, DARE, EMBASE, PREMEDLINE, OLDMEDLINE, CINAHL, BIOSIS Previews, LILACS, KOREAMED, SAMED, IndMED, SIGLE, ScienceDirect, and INGENTACONNECT.

REVIEW METHODS

Studies for evaluation included all prospective trials assessing the use of drainage in thyroid surgery. We excluded case studies, retrospective studies, reviews, and studies that had a "selective" method of postoperative drainage that was not defined or was based on surgeon preference. Search strategies were broad and based on Cochrane Collaboration search filters. There was no language restriction. Article selection was conducted by two independent reviewers under QUORUM guidelines.

RESULTS

Four hundred sixty-two articles were identified by the search strategy used, and 16 articles were included in the final review. Ten studies were randomized controlled trials, with 8 used for quantitative meta-analysis. No study showed a statistically significant benefit or harm with drain use. Meta-analysis of data estimated an odds ratio of 1.47 for reoperation for bleeding and 0.88 for visible hematoma for suction drains versus no drains. The results were not statistically significant, and 95% confidence intervals were wide.

CONCLUSION

The literature has insufficient evidence to recommend routine drainage in thyroid surgery. It is possible that drains may increase the risk of reoperation for bleeding, although the data are not statistically significant. If there is a benefit to drainage, absolute risk reductions of bleeding outcomes may not warrant routine use.

A systematic review of the incidence of sensorineural hearing loss in neonates exposed to Herpes simplex virus (HSV)

OBJECTIVE

To develop evidence-based guidelines for appropriate audiological monitoring of children born following exposure to or infection with Herpes simplex virus (HSV) for development of immediate or delayed-onset of sensorineural hearing loss (SNHL).

DATA SOURCES

A Medline search of the 1966-July 2007 database was supplemented by search of the additional database Embase (1980-July 2007). Manual search was conducted of references of identified papers and book chapters.

STUDY SELECTION

Articles were sought that were longitudinal in design, to include an inception cohort of children infected with (or exposed to) HSV who were entered at a similar point at birth and followed over time with serial audiometry to identify hearing loss if it developed.

DATA EXTRACTION

Patient information and audiometric data extraction from relevant articles was performed independently by all three researchers. Discrepancies were resolved by mutual consensus.

DATA SYNTHESIS

Data was analyzed using descriptive statistics.

RESULTS

Three papers reported five children with SNHL following apparent disseminated HSV-2 infections in which other obvious clinical sequelae of HSV infection and co-morbid conditions were present. Audiometric information is lacking regarding onset and progression. There are no reports of delayed-onset SNHL following perinatal or asymptomatic HSV infection.

CONCLUSIONS

The development of SNHL in children with exposure to HSV occurs rarely. Routine serological screening for HSV infection in otherwise healthy neonates newly diagnosed with SNHL is unjustified. There is insufficient data to define the incidence and natural history of SNHL in children with HSV infections. Carefully designed and conducted studies are needed to address this issue.

Systemic absorption of topical gentamicin sinus irrigation

OBJECTIVE

Evidence surrounding systemic absorption of gentamicin during intraoperative irrigation of the paranasal sinuses is lacking. The objectives of this study were to determine (1) if topical gentamicin is absorbed from the paranasal sinuses, (2) if hearing loss occurs following topical administration of gentamicin, and (3) if gentamicin placed within the sinuses travels retrograde (against mucociliary clearance) up the auditory tube to the middle ear.

DESIGN

Consecutive, prospective case series.

SETTING

Tertiary centre.

METHODS

A series of patients undergoing sinus surgery were identified. Fluorescein-stained gentamicin was used to irrigate the sinus cavities intraoperatively. Otoscopy using a filtered light source was performed 30 minutes postoperatively.

MAIN OUTCOME MEASURES

(1) Serum gentamicin levels preirrigation and at 30 minutes postirrigation and (2) change in pure-tone average and threshold at 8 kHz pre- and postoperative audiograms.

RESULTS

Twenty patients were enrolled. Serum gentamicin levels were detectable in three patients. Fluorescein irrigation solution was not visualized in the middle ear space. No significant hearing loss was observed in any of the patients.

CONCLUSIONS

Gentamicin may be absorbed from the nasal mucosa during intraoperative irrigation of the sinuses. However, detectable serum levels were well below therapeutic levels. The clinical significance of this finding requires further study to determine if topical sinus irrigation with gentamicin is a safe procedure.

Prevalence of new-onset vestibular symptoms following cochlear implantation

OBJECTIVE

To identify the prevalence of new-onset balance symptoms in adult patients who have undergone cochlear implantation (CI).

DESIGN

A retrospective, questionnaire-based prevalence study of 227 consecutive adults (age > 16 years) who have undergone CI. The control group comprised patients awaiting CI.

SETTING

Tertiary hospital, Vancouver, British Columbia.

METHODS

All patients implanted at the study centre were contacted. A questionnaire regarding their past medical history and the presence and character of pre- and post-CI dizziness was completed. Patients were divided into four groups based on the presence or absence of their symptoms in relation to the time of implantation. Patients with vestibular symptoms further completed the Dizziness Handicap Inventory (DHI).

MAIN OUTCOME MEASURES

Incidence of balance symptoms pre- and post-CI and associated DHI scores.

RESULTS

One hundred ten of 227 patients (48%) responded. Fifty-three (48.3%) had dizziness prior to CI and 64 patients (58.2%) postimplantation. Forty-one patients (37.3%) noted new onset of balance symptoms or a change in their symptoms post-CI. The onset was immediate (within 1 week post-CI) in the majority of this group (63.4%). DHI scores were generally low across all groups.

CONCLUSIONS

Delayed- and late-onset new balance-related symptoms occur in approximately 5 and 9% of CI patients, respectively, and the self-perceived handicapping effects of these symptoms may be greater compared with patients with symptoms prior to implantation.

Ethical considerations in resource allocation in a cochlear implant program

OBJECTIVE

To review processes of resource allocation and the ethical considerations relevant to the fair allocation of a limited number of cochlear implants to increasing numbers of potential recipients.

DESIGN

Review of relevant considerations.

SETTING

Tertiary referral hospital.

METHODS

Editorial discussion of the ethical issues of resource allocation.

MAIN OUTCOME MEASURES

Heterogeneity of audiometric thresholds, self-reported disability of hearing loss, age of the potential cochlear implant recipient, cost-effectiveness, access to resources, compliance with follow-up, social support available to the recipient, social consequences of hearing impairment, and other recipient-related factors.

RESULTS

In a publicly funded health care system, there will always be a need for decision-making processes for allocation of finite fiscal resources. All candidates for cochlear implantation deserve fair consideration. However, they are a heterogeneous group in terms of needs and expected outcomes consisting of traditional and marginal candidates, with a wide range of benefit from acoustic amplification.

CONCLUSIONS

We argue that implant programs should thoughtfully prioritize treatment on the basis of need and potential benefit. We reject queuing on the basis of "first-come, first-served" or on the basis of perceived social worth.

Natural history of hearing loss in children with enlarged vestibular aqueduct syndrome

OBJECTIVE

To determine the natural history of hearing loss in children with enlarged vestibular aqueduct (EVA) syndrome.

DESIGN

(1) Retrospective cohort study and (2) systematic literature review.

SETTING

Tertiary pediatric centre.

METHODS

(1) Charts of children assessed by one physician between 1993 and 2000 were reviewed. (2) Source articles were identified by a search of Medline, Embase, and the Cochrane Library of the English-language literature through January 2006, with manual review of references. The search was limited to English, human, and age less than 18 years.

MAIN OUTCOME MEASURES

Pure-tone average. Hearing was classified as stable, progressive and fluctuating.

RESULTS

(1) Twenty-one children (39 ears) with EVA were identified. Eighty-two percent of ears had stable hearing, and 18% of ears demonstrated progressive hearing loss. (2) Seven source articles were identified and combined with the present data for a total of 310 ears with a mean follow-up of 4 years. Bilateral EVA was found to be six times more common than unilateral EVA, and there was an equal male to female ratio. Stable hearing was found in 67% of ears and progressive hearing loss in 33% of ears. Subgroup analysis demonstrated hearing fluctuations in 50% of progressive hearing loss ears and 34% of stable ears.

CONCLUSIONS

Stable hearing is observed in 67% of ears with EVA of which 34% will demonstrate fluctuations in hearing. Progression of hearing loss is seen in 33% of ears of which half will demonstrate fluctuations.

Length of tumor–cochlear nerve contact and hearing outcome after surgery for vestibular schwannoma

Object

Tumor size is likely to be a major determinant of hearing preservation after surgery for vestibular schwannoma. Findings in some large case series have not supported this concept, possibly due to variation in the technique used for tumor measurement. The authors sought to determine if the length of tumor–cochlear nerve contact was predictive of hearing outcome in adults undergoing resection of a vestibular schwannoma.

Methods

Patients who underwent a hearing-preserving approach for resection of a vestibular schwannoma at one institution by a neurosurgeon/neurotologist team between 2001 and 2005 were screened. Patients with American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) Class A or B hearing preoperatively were included. Magnetic resonance images were reviewed and used to calculate the length of tumor–cochlear nerve contact. Tumors were also measured according to AAO-HNS guidelines.

Results

Thirty-one patients were included, 8 (26%) of whom had hearing preservation. Univariate analysis revealed that extracanalicular length of tumor–cochlear nerve contact (p = 0.0365), preoperative hearing class (p = 0.028), I–V interpeak latency of the brainstem auditory evoked potential (p = 0.021), and the interaural I–V interpeak latency difference (p = 0.018) were predictive of hearing outcome. Multivariate analysis confirmed the predictive value of extra-canalicular length of contact and preoperative hearing class (p = 0.041 and p = 0.0235, respectively).

Conclusions

Vestibular schwannomas with greater lengths of tumor–cochlear nerve contact increase a patient's risk for hearing loss after surgery with attempted hearing preservation. Involvement of the internal auditory canal produces a constant risk of hearing loss. Data from the experience of a single surgical team can be used to estimate the probability of good hearing outcome for any given patient with serviceable hearing and a vestibular schwannoma.

Medical management of middle ear disease in children less than 2 years of age with sensorineural hearing loss

OBJECTIVE

With emerging early hearing detection and communication development programs, physicians are increasingly requested to review young children with sensorineural hearing loss (SNHL) and associated conductive hearing loss (CHL). The purpose of this critical review is to develop an evidence-based approach to the management of the child less than 2 years of age with fluctuating CHL and coexisting SNHL.

METHODS

A critical review of the 1966-2002 MEDLINE database was performed to address the diagnosis, natural history, and management of otitis media with effusion (OME) and the management of acute otitis media (AOM) in the child under 2 years of age with underlying SNHL.

RESULTS

Pneumatic otoscopy should be used to diagnose middle ear effusion. Clearance of OME may be prolonged in children with craniofacial abnormalities. Antibiotics provide a small short-term increase in the resolution of OME and may be warranted in children with coexisting SNHL and OME for 4 to 6 weeks. If OME persists for 8 to 12 weeks, bilateral myringotomy and tube placement (BM&T) with short-term tubes will improve hearing and help resolve OME. AOM in children less than 2 years of age should be treated with a 10-day course of antibiotics. Prophylactic antibiotics may be useful in avoiding tube placement in children less than 2 years of age with recurrent AOM. BM&T with short-term tubes are recommended if recurrent AOM persists. Pneumococcal vaccination can decrease episodes of AOM by 6 to 7%.

CONCLUSIONS

An evidence-based algorithm for the management of fluctuating CHL in children less than 2 years of age with an underlying SNHL is presented.