Imeglimin-mediated glycemic control in maternally inherited deafness and diabetes

Mitochondrial dysfunction causes maternally inherited deafness and diabetes (MIDD). Herein, we report improved glycemic control in a 47-year-old Japanese woman with MIDD using imeglimin without major adverse effects. Biochemical tests and metabolome analysis were performed before and after imeglimin administration. Blood glucose level fluctuations were determined. Sulfonylureas, dipeptidyl peptidase-4 inhibitors (DPP4is), and sodium glucose transporter-2 inhibitors (SGLT2i) were administered to evaluate the efficacy of their combination with imeglimin. Imeglimin decreased the HbA1c and ammonia levels and increased the time-in-range, C-peptide reactivity, and glucagon level. Elevated citrulline and histamine levels were decreased by imeglimin. The hypoglycemic effect was not enhanced by imeglimin when combined with sulfonylurea or DPP4i, but the blood glucose level was improved when combined with SGLT2i. Imeglimin improved glucose concentration-dependent insulin secretion and maximized the insulin secretory capacity by improving mitochondrial function and glutamine metabolism and urea circuit abnormalities by promoting glucagon secretion. Imeglimin could improve glycemic control in MIDD.

Imeglimin-mediated glycemic control in maternally inherited deafness and diabetes

Mitochondrial dysfunction causes maternally inherited deafness and diabetes (MIDD). Herein, we report improved glycemic control in a 47-year-old Japanese woman with MIDD using imeglimin without major adverse effects. Biochemical tests and metabolome analysis were performed before and after imeglimin administration. Blood glucose level fluctuations were determined. Sulfonylureas, dipeptidyl peptidase-4 inhibitors (DPP4is), and sodium glucose transporter-2 inhibitors (SGLT2i) were administered to evaluate the efficacy of their combination with imeglimin. Imeglimin decreased the HbA1c and ammonia levels and increased the time-in-range, C-peptide reactivity, and glucagon level. Elevated citrulline and histamine levels were decreased by imeglimin. The hypoglycemic effect was not enhanced by imeglimin when combined with sulfonylurea or DPP4i, but the blood glucose level was improved when combined with SGLT2i. Imeglimin improved glucose concentration-dependent insulin secretion and maximized the insulin secretory capacity by improving mitochondrial function and glutamine metabolism and urea circuit abnormalities by promoting glucagon secretion. Imeglimin could improve glycemic control in MIDD.

An Italian case series' description of thiamine responsive megaloblastic anemia syndrome: importance of early diagnosis and treatment

BACKGROUND

Individuals with thiamine-responsive megaloblastic anemia (TRMA) mainly manifest macrocytic anemia, sensorineural deafness, ocular complications, and nonautoimmune diabetes. Macrocytic anemia and diabetes may be responsive to high-dosage thiamine treatment, in contrast to sensorineural deafness. Little is known about the efficacy of thiamine treatment on ocular manifestations.

CASES PRESENTATION

Our objective is to report data from four Italian TRMA patients: in Cases 1, 2 and 3, the diagnosis of TRMA was made at 9, 14 and 27 months. In 3 out of 4 subjects, thiamine therapy allowed both normalization of hyperglycemia, with consequent insulin suspension, and macrocytic anemia. In all Cases, thiamine therapy did not resolve the clinical manifestation of deafness. In Cases 2 and 3, follow-up showed no blindness, unlike Case 4, in which treatment was started for megaloblastic anemia at age 7 but was increased to high doses only at age 25, when the genetic diagnosis of TRMA was performed.

CONCLUSIONS

Early institution of high-dose thiamine supplementation seems to prevent the development of retinal changes and optic atrophy in TRMA patients. The spectrum of clinical manifestations is broad, and it is important to describe known Cases to gain a better understanding of this rare disease.

A Case Report of Riboflavin Treatment and Cochlear Implants in a 4-Year-Old Girl with Progressive Hearing Loss and Delayed Speech Development: Brown-Vialetto-Van Laere Syndrome

BACKGROUND Brown-Vialetto-Van Laere (BVVL) syndrome is a rare autosomal recessive disorder caused by mutations in intestinal riboflavin transporter genes, resulting in a motor neuron disorder of childhood, which can be associated with sensorineural deafness. This report describes a 4-year-old Polish girl with progressive hearing loss and delayed speech development diagnosed with Brown-Vialetto-Van Laere syndrome who was treated with riboflavin (vitamin B2) and cochlear implants. CASE REPORT The case report concerns a girl from Poland who, at the age of 2 years 10 months, developed progressive atypical neurological symptoms of unknown etiology: ataxia of the upper and lower limbs, gait abnormalities, generalized muscle weakness, visual and hearing problems, and regression of speech development. A karyotype study (whole-exome sequencing) revealed alterations within SLC52A2, leading to the diagnosis of Brown-Vialetto-Van Laere syndrome and initiation of high-dose riboflavin treatment. As a 4-year-old child, she presented to the Institute of Physiology and Pathology of Hearing - World Hearing Center in Poland with progressive hearing loss and speech regression. Hearing tests revealed bilateral profound sensorineural hearing loss with auditory neuropathy. Surgical treatment was applied in the form of bilateral cochlear implantation. CONCLUSIONS This report shows the importance of genetic testing in infants who present with atypical symptoms or signs. In this case, the diagnosis of Brown-Vialetto-Van Laere syndrome resulted in timely correction of the genetic riboflavin (vitamin B2) deficiency and improved hearing following the use of cochlear implants.

Altering gene expression using antisense oligonucleotide therapy for hearing loss

Hearing loss affects more than 430 million people, worldwide, and is the third most common chronic physical condition in the United States and Europe (GBD Hearing Loss Collaborators, 2021; NIOSH, 2021; WHO, 2021). The loss of hearing significantly impacts motor and cognitive development, communication, education, employment, and overall quality of life. The inner ear houses the sensory organs for both hearing and balance and provides an accessible target for therapeutic delivery. Antisense oligonucleotides (ASOs) use various mechanisms to manipulate gene expression and can be tailor-made to treat disorders with defined genetic targets. In this review, we discuss the preclinical advancements within the field of the highly promising ASO-based therapies for hereditary hearing loss disorders. Particular focus is on ASO mechanisms of action, preclinical studies on ASO treatments of hearing loss, timing of therapeutic intervention, and delivery routes to the inner ear.

Investigational Medicinal Products for the Inner Ear: Review of Clinical Trial Characteristics in ClinicalTrials.gov

BACKGROUND

The previous 30 years have provided information on the mechanisms of cell death in the inner ear after noise exposure, ototoxic drug injury, and during aging, and clinical trials have emerged for all of these acquired forms of hearing loss. Sudden hearing loss is less well understood, but restoration of hearing after sudden hearing loss is also a long-standing drug target, typically using steroids as an intervention but with other agents of interest as well.

PURPOSE

The purpose of this review was to describe the state of the science regarding clinical testing of investigational medicinal products for the inner ear with respect to treatment or prevention of acquired hearing loss.

DATA COLLECTION AND ANALYSIS

Comprehensive search and summary of clinical trials listed in the National Library of Medicine (www.

CLINICALTRIALS

gov) database identified 61 clinical trials.

RESULTS

Study phase, status, intervention, and primary, secondary, and other outcomes are summarized for studies assessing prevention of noise-induced hearing loss, prevention of drug-induced hearing loss, treatment of stable sensorineural hearing loss, and treatment of sudden sensorineural hearing loss.

CONCLUSION

This review provides a comprehensive summary of the state of the science with respect to investigational medicinal products for the inner ear evaluated in human clinical trials, and the current challenges for the field.

A single-arm, open-label, intervention study to investigate the improvement of glucose tolerance after administration of the 5-aminolevulinic acid (5-ALA) in the patients with mitochondrial diabetes mellitus

BACKGROUND

Mitochondrial diabetes mellitus (MDM) is characterized by maternal inheritance, progressive neurosensory deafness, insulin secretory disorder, and progressive microvascular complications. Mitochondria are critical organelles that provide energy in the form of adenosine triphosphate (ATP). An impairment of ATP production in pancreatic β cells is regarded as the main cause of the insulin secretory disorder in patients with MDM, and these patients require insulin replacement therapy early after the diagnosis. The amino acid 5-aminolevulinic acid (5-ALA), a precursor of heme metabolites, is a non-proteinogenic δ amino acid synthesized in mitochondria. An addition of ferrous iron to 5-ALA enhances heme biosynthesis and increases ATP production through an upregulation of the respiratory complex. Several studies have reported that the administration of 5-ALA and ferrous iron to existing treatment improved the glycemic control in both patients with prediabetes and those with type 2 diabetes mellitus. The additional administration of 5-ALA and ferrous iron to MDM patients on insulin therapy may improve their insulin secretory capacity and glycemic control by improving their mitochondrial function. The findings of this study are expected to provide new treatment options for MDM and improve the patients' glycemic control and prognosis.

METHODS/DESIGN

This study is a single-arm, open-label pilot intervention study using clinical endpoints to investigate the effects of treatment with 5-ALA plus sodium ferrous citrate (SFC) to patients with MDM on their glucose tolerance. A total of 5 patients with MDM will be administered 5-ALA/SFC (200 mg/d) for 24 weeks. We will perform a 75-g oral glucose tolerance test before and at 24 weeks after the start of this 5-ALA/SFC treatment to evaluate glucose-dependent insulin responses.

DISCUSSION

To the best of our knowledge, this study will be the first assessment of the effects of 5-ALA/SFC in patients with MDM. This study will obtain an evidence regarding the effectiveness and safety of 5-ALA/SFC for patients with MDM.

TRIAL REGISTRATION

This study was registered with the University Hospital Medical Information Network (UMIN000040581) on July 1, 2020 and with the Japan Registry of Clinical Trials (jRCTs071200025) on August 3, 2020.

SUCLA2 Arg407Trp mutation can cause a nonprogressive movement disorder - deafness syndrome

SUCLA2 is a component of mitochondrial succinate‐CoA ligase and nucleotide diphosphokinase activities. Its absence results in Krebs cycle failure, mitochondrial DNA depletion, and a childhood‐fatal encephalomyopathy. We describe a purely neurologic allelic form of the disease consisting of deafness, putamenal hyperintensity on MRI and a myoclonic‐dystonic movement disorder unchanging from childhood into, so far, the late fourth decade. We show that succinate supplementation circumvents the Krebs cycle block, but does not correct the neurologic disease. Our patients’ Arg407Trp mutation has been reported in children with (yet) no MRI abnormalities. It remains possible that early succinate supplementation could impact the disease.

Genetic testing in the acute setting: a round table discussion

Genetic testing has historically been performed in the context of chronic disease and cancer diagnostics. The timelines for these tests are typically measured in days or weeks, rather than in minutes. As such, the concept that genetic information might be generated and then used to alter management in the acute setting has, thus far, not been feasible. However, recent advances in genetic technologies have the potential to allow genetic information to be generated significantly quicker. The m.1555A>G genetic variant is present in one in 500 individuals and predisposes to profound hearing loss following the administration of aminoglycoside antibiotics. These antibiotics are used frequently in cases of neonatal sepsis and it is estimated that approximately 180 neonates in the UK are at risk of antibiotic induced hearing loss each year because of this genetic change. Knowledge of this variant in the acute setting would allow clinicians to prescribe alternative antibiotics. The Pharmacogenetics to Avoid Loss of Hearing study will implement a genetic point of care test (POCT) for the m.1555A>G variant within two major UK based neonatal intensive care units. This represents the first trial of a genetic POCT aimed at altering management in the acute setting. This round table discussion outlines the novel ethical issues faced in the development of this trial and the legal barriers to implementation. We ask five stakeholders to provide their opinions on this trial and their perspectives on the concept of genetic testing in the acute setting.Trial registration numberISRCTN-13704894.

Fetal antisense oligonucleotide therapy for congenital deafness and vestibular dysfunction

Disabling hearing loss impacts ∼466 million individuals worldwide with 34 million children affected. Gene and pharmacotherapeutic strategies to rescue auditory function in mouse models of human deafness are most effective when administered before hearing onset, after which therapeutic efficacy is significantly diminished or lost. We hypothesize that preemptive correction of a mutation in the fetal inner ear prior to maturation of the sensory epithelium will optimally restore sensory function. We previously demonstrated that transuterine microinjection of a splice-switching antisense oligonucleotide (ASO) into the amniotic cavity immediately surrounding the embryo on embryonic day 13-13.5 (E13-13.5) corrected pre-mRNA splicing in the juvenile Usher syndrome type 1c (Ush1c) mouse mutant. Here, we show that this strategy only marginally rescues hearing and partially rescues vestibular function. To improve therapeutic outcomes, we microinjected ASO directly into the E12.5 inner ear. A single intra-otic dose of ASO corrects harmonin RNA splicing, restores harmonin protein expression in sensory hair cell bundles, prevents hair cell loss, improves hearing sensitivity, and ameliorates vestibular dysfunction. Improvements in auditory and vestibular function were sustained well into adulthood. Our results demonstrate that an ASO pharmacotherapeutic administered to a developing organ system in utero preemptively corrects pre-mRNA splicing to abrogate the disease phenotype.

The feasibility of an encapsulated cell approach in an animal deafness model

For patients with profound hearing loss a cochlear implant (CI) is the only treatment today. The function of a CI depends in part of the function and survival of the remaining spiral ganglion neurons (SGN). It is well known from animal models that inner ear infusion of neurotrophic factors prevents SGN degeneration and maintains electrical responsiveness in deafened animals. The purpose with this study was to investigate the effects of a novel encapsulated cell (EC) device releasing neurotrophic factors in the deafened guinea pig.

The results showed that an EC device releasing glial cell line-derived neurotrophic factor (GDNF) or brain-derived neurotrophic factor (BDNF) implanted for four weeks in deafened guinea pigs significantly preserved the SGNs and maintained their electrical responsiveness. There was a significant difference between BDNF and GDNF in favour of GDNF. This study, demonstrating positive structural and functional effects in the deafened inner ear, suggests that an implanted EC device releasing biologically protective substances offers a feasible approach for treating progressive hearing impairment.

Familial clustering of congenital deafness, patent ductus arteriosus, Eisenmenger complex, and differential cyanosis: A case report

RATIONALE

Few studies had reported syndromes that include patent ductus arteriosus (PDA) with Eisenmenger syndrome and congenital deafness clustered in male siblings without facial, skeletal, or mental abnormalities.

PATIENT CONCERNS

Two brothers, who were deaf and had PDA with Eisenmenger complex, were first seen at our Cardiology clinic at the ages of 25 and 41, respectively. They presented with progressive dyspnea on exertion. Upon physical examination, both brothers had clubbing and/or cyanotic toes, normal fingers, and without facial, skeletal, ophthalmological, or mental abnormalities.

DIAGNOSES AND INTERVENTIONS

Echocardiography and multidetector computed tomography revealed large PDAs in both brothers. Cardiac catheterization showed bidirectional shunting via the PDA.

OUTCOMES AND LESSONS

Familial clustering of Eisenmenger PDA and congenital deafness is rare. Further studies are warranted to define possible genetic links.

Improved Auditory Nerve Survival with Nanoengineered Supraparticles for Neurotrophin Delivery into the Deafened Cochlea

Cochlear implants electrically stimulate spiral ganglion neurons (SGNs) in order to provide speech cues to severe-profoundly deaf patients. In normal hearing cochleae the SGNs depend on endogenous neurotrophins secreted by sensory cells in the organ of Corti for survival. SGNs gradually degenerate following deafness and consequently there is considerable interest in developing clinically relevant strategies to provide exogenous neurotrophins to preserve SGN survival. The present study investigated the safety and efficacy of a drug delivery system for the cochlea using nanoengineered silica supraparticles. In the present study we delivered Brain-derived neurotrophic factor (BDNF) over a period of four weeks and evaluated SGN survival as a measure of efficacy. Supraparticles were bilaterally implanted into the basal turn of cochleae in profoundly deafened guinea pigs. One ear received BDNF-loaded supraparticles and the other ear control (unloaded) supraparticles. After one month of treatment the cochleae were examined histologically. There was significantly greater survival of SGNs in cochleae that received BDNF supraparticles compared to the contralateral control cochleae (repeated measures ANOVA, p = 0.009). SGN survival was observed over a wide extent of the cochlea. The supraparticles were well tolerated within the cochlea with a tissue response that was localised to the site of implantation in the cochlear base. Although mild, the tissue response was significantly greater in cochleae treated with BDNF supraparticles compared to the controls (repeated measures ANOVA, p = 0.003). These data support the clinical potential of this technology particularly as the supraparticles can be loaded with a variety of therapeutic drugs.

Neurotrophins and cochlear implants: a solution to sensorineural deafness?

OBJECTIVES

To review current trends for treating sensorineural deafness by enhancing spiral ganglion neuron (SGN) survival using neurotrophins combined with cochlear implants and identify areas for future research and development.

METHODS

A literature search was undertaken on PubMed and Google scholar using terms: neurotrophins, cochlear implants (CIs), and sensorineural to identify the most recent and significant publications. The abstracts were read to identify relevant papers; these were accessed in full and analysed for this review.

RESULTS

Neurotrophins have a known role in cochlear development and the maintenance of SGNs. So far experiments using osmotic pumps to deliver neurotrophins have been successful for short-term enhanced survival of SGN's following aminoglycoside ototoxicity in animal models. They have demonstrated the re-sprouting of radial nerve fibres from SGN's towards the source of delivery. In addition electrical stimulation, gene and cell-based therapy have increased SGN survival to varying degrees.

DISCUSSION

Osmotic pumps carry a high risk of infection therefore CIs coated in a drug containing polymer or hydrogel are a realistic alternative for sustained delivery of neurotrophins. Increased SGN survival combined with neuronal re-growth raises the possibility for CIs to stimulate discrete SGN populations. Unfortunately, the duration of treatment needed for long-term survival still remains unclear and further work is needed. Nevertheless the combination of regenerative medicine to CI technology presents a novel approach to developing CI technology.

[The treatment effects analysis of 164 patients with sudden sensorineural hearing loss]

OBJECTIVE

To explore the effective treatment of sudden sensorineural hearing loss and factors affecting its prognosis.

METHOD

The clinical data and follow-up results of 164 patients with sudden sensorineural hearing loss were analyzed retrospectively. All the 164 patients were given intravenous vasodilator, neurotrophic drugs treatment, oral prednisone treatment, and intratympanic dexamethasone injection. All patients were divided into low frequency hearing loss type,intermediate frequency hearing loss, high frequency hearing loss, all frequency hearing loss and total deafness group. Pure tone hearing threshold test were performed before and 3 months after treatment. All patients and different groups were compared before and after treatment damage frequency of average air conduction and various frequency air conduction hearing. Analysis of gender, age, process and hearing curve type, frequency hearing of impaired before treatment, the symptoms with or without vertigo.

RESULT

All the patients' hearing improved after treatment. The treatment efficiency was 46.3%, and low frequency hearing improvements were better than the high frequency hearing. Including age, process, frequency hearing of impaired before treatment, with or without vertigo isindependent factors influencing its prognosis.

CONCLUSION

Based on the regular treatment,oral and intratympanic injection glucocorticoid therapy are safe and effective for sudden hearing loss,The prognosis and age, course, impaired hearing before curve type, treatment frequency hearing level is closely related, with or without vertigo.

[Clinical analysis of Ginkgo biloba injection combined with traditional therapy in treatment of explosive deafness]

OBJECTIVE

To investigate the clinical efficacy of Ginkgo biloba injection combined with traditional therapy in the treatment of explosive deafness.

METHODS

Fifty-six (98 ears) participants who were all coal miners were selected. These patients were diagnosed with explosive deafness. and admitted to the otolaryngology department of our hospital from May 2010 to October 2013. They were.equally divided into control group and treatment group according to the therapeutic method. The patients in the control group only received traditional therapy, such as hyperbaric oxygen, while the patients in the treatment group were given Ginkgo biloba injection in addition to the therapy for the control group. The improvement in hearing was recorded and compared between the two groups.

RESULTS

The rate of improvement in tinnitus symptom in the treatment group was 78.0% (32/41), significantly higher than that in the control group (55.6%, 25/45) (χ2=4.857, P<0.05); compared with the treatment group (93.5%, 43/46), the control group had a significant lower overall response rate at 76.9% (40/52) (χ2=5.160, P<0.05).

CONCLUSION

Compared with traditional therapy alone, combined ginkgo biloba extract injection and traditional therapy can significantly improve tinnitus symptom and overall response rate in the treatment of explosive deafness in coal miners, which suggests that the combination therapy is worthy of clinical application.

Mesoporous silica supraparticles for sustained inner-ear drug delivery

Mesoporous silica supraparticles (MS-SPs) are prepared via self-assembly of mesoporous silica nanoparticles under capillary force action in confined droplets. The MS-SPs are effective carriers for sustained drug delivery. Animal studies show that these particles are suitable for chronic intracochlear implantation, and neurotrophins released from the MS-SPs can efficiently rescue primary auditory neurons in an in vivo sensorineural hearing loss model.

Effect of hypoglycemic anti-deafness capsules in diabetic patients with deafness and toxicological assessment in rats

OBJECTIVE

Through experiment on animals and clinical trials to explore the safety and efficacy of hypoglycemic anti-deafness capsules on diabetic patients with deafness.

METHODS

Total 296 patients with non-insulin dependent diabetes mellitus (NIDDM) were randomly divided into two groups. A treatment group of 164 patients (208 ears) was treated with hypoglycemic anti-deafness capsules based on TCM syndrome differentiation. A control group of 132 patients (184 ears) was treated with glibenclamide and conventional drug treatment for deafness. The following were observed: hearing, fasting plasma glucose (FPG), 2 h postprandial plasma glucose (2hPG), 24 h urine glucose (24hUG), improvement of main symptoms, platelet function, and changes in superoxide dismutase (SOD) and lipid peroxide (LPO) levels. In animal studies, Kunming mice, weighing 18-22 g were used. Half of the mice were males and half were females. Wistar rats, weighing 80-120 g were used. Half of the rats were males and half were females. Male Wistar rats, weighing 200-220 g, were also used. Their acute and chronic toxicity was studied.

RESULTS

The hearing improvement was 56.7% in the treatment group and 26.6% in the control group. FPG, 2hPG, and 24hUG were improved significantly (P < 0.05, P < 0.01, P < 0.01, respectively) in the treatment group and 2hPG and 24hUG improved significantly in the control group (P < 0.05, P < 0.05). The improvement in 2hPG and 24hUG in the treatment group was significantly greater than that in the control group P < 0.01).There was no significant difference in FPG between the two groups (P < 0.05). Main symptoms in the treatment group were significantly more improved than those in the control group (P < 0.05, P < 0.01). In the treatment group, platelet adhesion and aggregation, SOD, and LPO were all significantly improved from before treatment (P < 0.05, P < 0.01). However, in the control group, except LOP (P < 0.05), there were no significant differences from before treatment to after (P < 0.05). In animal studies, no obvious acute or long-term toxicity was observed from capsule administration.

CONCLUSION

Through experiment on animals and clinical trials, we can found that hypoglycemic anti-deafness capsules could decrease blood glucose and serum triglycerides of alloxan-induced diabetic rats. This herbal capsule is effective for safely treating diabetic patients with deafness.

Combining cell-based therapies and neural prostheses to promote neural survival

Cochlear implants provide partial restoration of hearing for profoundly deaf patients by electrically stimulating spiral ganglion neurons (SGNs); however, these neurons gradually degenerate following the onset of deafness. Although the exogenous application of neurotrophins (NTs) can prevent SGN loss, current techniques to administer NTs for long periods of time have limited clinical applicability. We have used encapsulated choroid plexus cells (NTCells; Living Cell Technologies, Auckland, New Zealand) to provide NTs in a clinically viable manner that can be combined with a cochlear implant. Neonatal cats were deafened and unilaterally implanted with NTCells and a cochlear implant. Animals received chronic electrical stimulation (ES) alone, NTs alone, or combined NTs and ES (ES + NT) for a period of as much as 8 months. The opposite ear served as a deafened unimplanted control. Chronic ES alone did not result in increased survival of SGNs or their peripheral processes. NT treatment alone resulted in greater SGN survival restricted to the upper basal cochlear region and an increased density of SGN peripheral processes. Importantly, chronic ES in combination with NTs provided significant SGN survival throughout a wider extent of the cochlea, in addition to an increased peripheral process density. Re-sprouting peripheral processes were observed in the scala media and scala tympani, raising the possibility of direct contact between peripheral processes and a cochlear implant electrode array. We conclude that cell-based therapy is clinically viable and effective in promoting SGN survival for extended durations of cochlear implant use. These findings have important implications for the safe delivery of therapeutic drugs to the cochlea.

Oral or topical nasal steroids for hearing loss associated with otitis media with effusion in children

BACKGROUND

Otitis media with effusion (OME) is common and may cause hearing loss with associated developmental delay. Treatment remains controversial.

OBJECTIVES

To examine the evidence for treating children with hearing loss associated with OME with systemic or topical intranasal steroids.

SEARCH STRATEGY

We searched the Cochrane ENT Group Trials Register; CENTRAL; PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; mRCT and additional sources for published and unpublished trials. The date of the most recent search was 26 August 2010.

SELECTION CRITERIA

Randomised controlled trials of oral and topical intranasal steroids, either alone or in combination with another agent such as an oral antibiotic. We excluded publications in abstract form only; uncontrolled, non-randomised or retrospective studies; and studies reporting outcomes by ears (rather than children).

DATA COLLECTION AND ANALYSIS

The authors independently extracted data from the published reports using standardised data extraction forms and methods. We assessed the quality of the included studies using the Cochrane 'Risk of bias' tool. We expressed dichotomous results as a risk ratio (RR) and continuous data as weighted mean difference (WMD), both with 95% confidence intervals (CI). Where feasible we pooled studies using a random-effects model and performed tests for heterogeneity between studies. In trials with a cross-over design, we did not use post cross-over treatment data.

MAIN RESULTS

We included 12 medium to high-quality studies with a total of 945 participants. No study documented hearing loss associated with OME prior to randomisation. The follow-up period was generally limited, with only one study of intranasal steroid reporting outcome data beyond six months. There was no evidence of benefit from steroid treatment (oral or topical) in terms of hearing loss associated with OME. Pooled data using a fixed-effect model for OME resolution at short-term follow up (< 1 month) showed a significant effect of oral steroids compared to control (RR 4.48; 95% CI 1.52 to 13.23; Chi² 2.75, df = 2, P = 0.25; I² = 27%). Oral steroids plus antibiotic also resulted in an improvement in OME resolution compared to placebo plus antibiotic at less than one month follow up, using a random-effects model (RR 1.99; 95% CI 1.14 to 3.49; five trials, 409 children). However, there was significant heterogeneity between studies (P < 0.01, I² = 69%). There was no evidence of beneficial effect on OME resolution at greater than one month follow up with oral steroids (used alone or with antibiotics) or intranasal steroids (used alone or with antibiotics) at any follow-up period. There was also no evidence of benefit from steroid treatment (oral or topical) in terms of symptoms.

AUTHORS' CONCLUSIONS

While oral steroids, especially when used in combination with an oral antibiotic, lead to a quicker resolution of OME in the short term, there is no evidence of longer-term benefit and no evidence that they relieve symptoms of hearing loss. We found no evidence of benefit from treatment of OME with topical intranasal steroids, alone or in combination with an antibiotic, either at short or longer-term follow up.

Enhanced auditory neuron survival following cell-based BDNF treatment in the deaf guinea pig

Exogenous neurotrophin delivery to the deaf cochlea can prevent deafness-induced auditory neuron degeneration, however, we have previously reported that these survival effects are rapidly lost if the treatment stops. In addition, there are concerns that current experimental techniques are not safe enough to be used clinically. Therefore, for such treatments to be clinically transferable, methods of neurotrophin treatment that are safe, biocompatible and can support long-term auditory neuron survival are necessary. Cell transplantation and gene transfer, combined with encapsulation technologies, have the potential to address these issues. This study investigated the survival-promoting effects of encapsulated BDNF over-expressing Schwann cells on auditory neurons in the deaf guinea pig. In comparison to control (empty) capsules, there was significantly greater auditory neuron survival following the cell-based BDNF treatment. Concurrent use of a cochlear implant is expected to result in even greater auditory neuron survival, and provide a clinically relevant method to support auditory neuron survival that may lead to improved speech perception and language outcomes for cochlear implant patients.

Neurotrophin therapy and cochlear implantation: translating animal models to human therapy

Cochlear implantation is a highly successful intervention for the treatment of deafness that depends on electrical stimulation of the inner ear's surviving spiral ganglion neurons. It is thought that some of the variability in hearing outcomes that is seen in patients receiving implants may be a reflection of the number or health of surviving neurons. A variety of studies have demonstrated a relationship between hair cell loss and degeneration of the spiral ganglion. This has been attributed to the loss of neurotrophin production with destruction of the spiral ganglion's target, the hair cell. Delivery of neurotrophins either through a device or through gene therapy has been shown to improve spiral ganglion survival after hair cell loss and additionally improves the function of cochlear implants in animal models. Translation of these observations to human therapy will require a clear understanding of the relationship between human spiral ganglion health and cochlear implant outcomes as well as the development of novel pre- and post-implantation outcomes measures.

Intraoperative brainstem auditory evoked potential pattern and perioperative vasoactive treatment for hearing preservation in vestibular schwannoma surgery

OBJECTIVE

In vestibular schwannoma surgery, four different intraoperative brainstem auditory evoked potential (BAEP) patterns (stable BAEP, abrupt loss, irreversible progressive loss, reversible loss) can be identified and correlated with postoperative hearing outcome. Patients with reversible loss significantly benefit from postoperative vasoactive treatment consisting of hydroxyethyl starch and nimodipine. The present study investigates the treatment effect in the remaining three BAEP patterns.

METHODS

A retrospective analysis was performed in 92 patients operated on for vestibular schwannoma between 1997 and 2005. Between 1997 and 2001, only patients with reversible loss of BAEP received vasoactive medication. Subsequently, all patients operated on between 2001 and 2005 received a 10 day course of therapy, regardless of the BAEP pattern. Serial audiological examinations before, after surgery and after 1 year were performed in all patients.

RESULTS

All 30 patients with reversible loss of BAEP received medication, and postoperative hearing preservation was documented in 21 patients. All 13 patients with stable waves showed hearing preservation, regardless of treatment. In all 24 patients with abrupt loss and in all 25 patients with irreversible progressive loss, postoperative anacusis was documented, regardless of treatment.

CONCLUSION

In patients with reversible loss of BAEP, a disturbed microcirculation of the cochlear nerve seems to be the underlying pathophysiological factor. In patients with abrupt or irreversible progressive loss, additional mechanical injury of nerve fibres determines hearing outcome. The study provides evidence that for the purpose of hearing preservation, only patients with reversible loss of BAEP benefit from vasoactive treatment.

[Prognosis and treatment of sudden sensorineural hearing loss with total and severe all frequency hearing loss]

OBJECTIVE

To evaluate the treatment and prognosis of sudden sensorineural hearing loss (SSHL) with total and severe all frequency hearing loss.

METHODS

Sixty-two patients diagnosed as SSHL (0.25, 0.5, 1, 2, 4 kHz pure tone average > or = 56 dB) were studied from January 2003 to October 2006, in which 18 of them were treated with Xueshuantong (Panax notoginseng saponins) while 19 of them treated with steroid and Xueshuantong, and 25 of them treated with steroid, DF-521 and Xueshuantong.

RESULTS

The hearing improvement rate of the patients treated with Xueshuantong was 22.2% (4/18) while the patients treated with steroid and Xueshuantong was 57.9% (11/19) and the patients treated with steroid, DF-521 and Xueshuantong was 68.0% (17/25). The good improvement rate of the patients treated with Xueshuantong was 5.6% (1/18) while the patients treated with steroid and Xueshuantong was 36.8% (7/19) and the patients treated with steroid, DF-521 and Xueshuantong was 60.0% (15/25). Over hearing improvement was significantly better in patients treated with steroid, defibrinogenation and Xueshuantong than in those treated with Xueshuantong only (P < 0.05). The patients of total hearing loss had a significantly higher vertigo rate and worse therapy effect.

CONCLUSIONS

The combined therapy include high-dose corticosteroids and defibrinogenation therapy is effective for the patients with total deafness and severe all frequency hearing loss. The prognosis of patients with total hearing loss was poor.

Delayed neurotrophin treatment following deafness rescues spiral ganglion cells from death and promotes regrowth of auditory nerve peripheral processes: effects of brain-derived neurotrophic factor and fibroblast growth factor

The extent to which neurotrophic factors are able to not only rescue the auditory nerve from deafferentation-induced degeneration but also promote process regrowth is of basic and clinical interest, as regrowth may enhance the therapeutic efficacy of cochlear prostheses. The use of neurotrophic factors is also relevant to interventions to promote regrowth and repair at other sites of nerve trauma. Therefore, auditory nerve survival and peripheral process regrowth were assessed in the guinea pig cochlea following chronic infusion of BDNF + FGF(1) into scala tympani, with treatment initiated 4 days, 3 weeks, or 6 weeks after deafferentation from deafening. Survival of auditory nerve somata (spiral ganglion neurons) was assessed from midmodiolar sections. Peripheral process regrowth was assessed using pan-Trk immunostaining to selectively label afferent fibers. Significantly enhanced survival was seen in each of the treatment groups compared to controls receiving artificial perilymph. A large increase in peripheral processes was found with BDNF + FGF(1) treatment after a 3-week delay compared to the artificial perilymph controls and a smaller enhancement after a 6-week delay. Neurotrophic factor treatment therefore has the potential to improve the benefits of cochlear implants by maintaining a larger excitable population of neurons and inducing neural regrowth.

Side selection for cochlear implantation in a case of Cogan's syndrome

Cogan's syndrome is a rare clinical entity that is characterised by non-syphilitic interstitial keratitis and audiovestibular symptoms. The cause of Cogan's syndrome is considered to be autoimmune disease, which is supported by the resolution of hearing loss after steroid treatment, and the association with other autoimmune diseases. The sensorineural hearing loss of Cogan's syndrome is progressive over a few months, and sudden, bilateral deafness often occurs, which may be an indication for cochlear implantation. This paper presents the case of a young woman suffering from Cogan's syndrome and sudden, bilateral deafness. With reference to this case, we describe problems regarding cochlear implantation for Cogan's syndrome and radiological findings aiding selection of cochlear implantation side.

Effects of antioxidants on auditory nerve function and survival in deafened guinea pigs

Based on in vitro studies, it is hypothesized that neurotrophic factor deprivation following deafferentation elicits an oxidative state change in the deafferented neuron and the formation of free radicals that then signal cell death pathways. This pathway to cell death was tested in vivo by assessing the efficacy of antioxidants (AOs) to prevent degeneration of deafferented CNVIII spiral ganglion cells (SGCs) in deafened guinea pigs. Following destruction of sensory cells, guinea pigs were treated immediately with Trolox (a water soluble vitamin E analogue)+ascorbic acid (vitamin C) administered either locally, directly in the inner ear, or systemically. Electrical auditory brainstem response (EABR) thresholds were recorded to assess nerve function and showed a large increase following deafness. In treated animals EABR thresholds decreased and surviving SGCs were increased significantly compared to untreated animals. These results indicate that a change in oxidative state following deafferentation plays a role in nerve cell death and antioxidant therapy may rescue SGCs from deafferentation-induced degeneration.

Recovery from deafness in a patient with Muckle-Wells syndrome treated with anakinra

Muckle-Wells syndrome (MWS) is a dominantly inherited autoinflammatory disease characterized by rashes, fever, arthralgia, sensorineural deafness, and the possible development of systemic AA amyloidosis. We used anakinra to treat a 22-year-old patient with MWS who had deafness and a high serum level of C-reactive protein (CRP). Following treatment with anakinra, the patient's CRP level normalized, and she recovered from deafness. The fact that this occurrence has never been previously reported strengthens the role of anakinra in MWS but also raises new questions about the physiopathology of such deafness.

Oral or topical nasal steroids for hearing loss associated with otitis media with effusion in children

BACKGROUND

Otitis media with effusion (OME) is common and may cause hearing loss with associated developmental delay. Treatment remains controversial.

OBJECTIVES

To examine evidence for or against treating children with hearing loss associated with OME with systemic or topical intranasal steroids.

SEARCH STRATEGY

We searched the Cochrane Ear, Nose and Throat Disorders Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library Issue 4 2005, MEDLINE (1966 to 2006), EMBASE (1974 to 2006), and the CINAHL, LILACS, Zetoc, IndMED, SAMED, KoreaMed, MEDCARIB and Cambridge Scientific Abstracts databases in January 2006.

SELECTION CRITERIA

Randomised controlled trials of oral and topical intranasal steroids, either alone or in combination with another agent such as an antibiotic, were included.

EXCLUSIONS

publications in abstract form only; uncontrolled, non-randomised or retrospective studies; studies reporting outcomes with ears (rather than children).

DATA COLLECTION AND ANALYSIS

Data were extracted from the published reports by the authors independently using standardised data extraction forms and methods. The methodological quality of the included studies was independently assessed by the authors as described in the Cochrane Handbook. Dichotomous results were expressed as an odds ratio using a fixed-effect model together with the 95% confidence intervals. Continuous data were analysed using the weighted mean difference in a fixed-effect model. Tests for heterogeneity between studies were performed using a Mantel-Haenszel approach. In trials with a cross-over design, post cross-over treatment data were not used.

MAIN RESULTS

No study prospectively documented hearing loss associated with OME prior to randomisation. Follow up was mainly short term. The odds ratio for OME persisting after short-term follow up in children treated with oral steroids compared to control was 0.22 (95% CI 0.08 to 0.63). The odds ratio for OME persisting after short-term follow up for children treated with oral steroids plus antibiotic compared to control plus antibiotic was 0.37 (95% CI 0.25 to 0.56). However, there was significant heterogeneity between studies included in the latter comparison (P < 0.01). Trends favoured steroids for most other comparisons, but confidence intervals included unity. There was no evidence of benefit for steroid treatment for OME or hearing loss associated with OME in the longer term.

AUTHORS' CONCLUSIONS

Both oral and topical intranasal steroids alone or in combination with an antibiotic lead to a quicker resolution of OME in the short term, however, there is no evidence of longer term benefit.

Resprouting and survival of guinea pig cochlear neurons in response to the administration of the neurotrophins brain-derived neurotrophic factor and neurotrophin-3

Degeneration of auditory neurons occurs after deafening and is associated with damage to the organ of Corti. The administration of neurotrophins can protect auditory neurons against degeneration if given shortly after deafening. However, it is not known whether the delayed administration of neurotrophins, when significant degeneration has already occurred, will provide similar protection. Furthermore, little is known about the effects of neurotrophins on the peripheral processes of the auditory neurons or whether these neurons can resprout. This study examined the morphological effects on auditory neurons following deafening and the administration of brain-derived neurotrophic factor and neurotrophin-3. Results showed that neurotrophins were effective in preventing death of auditory neurons if administered 5 days after deafening and were also effective in preventing the continued loss of neurons if the administration was delayed by 33 days. The peripheral processes of auditory neurons in cochleae that received neurotrophins were in greater number and had larger diameters compared with the untreated cochleae. Localized regions of resprouting peripheral processes were observed in deafened cochleae and were enhanced in response to neurotrophin treatment, occurring across wider regions of the cochlea. These findings have significant implications for an improvement in the performance of the cochlear implant and for future therapies to restore hearing to the deaf.

Steroid and Vasoactive Treatment for Acute Deafness after Attempted Hearing Preservation Acoustic Neuroma Surgery

OBJECTIVE

To investigate whether intravenous steroid and vasoactive therapy in the acute postoperative period improves hearing outcome in patients who develop acute deafness after attempted hearing preservation surgery for acoustic neuroma (AN) through a retrosigmoid or a middle cranial fossa approach.

STUDY DESIGN AND SETTING

Retrospective controlled study in a tertiary care center. Thirty-six patients who had developed acute deafness after hearing preservation surgery for treatment of an AN were reviewed. Preoperative AAOHNS hearing class was A in 2, B in 2 and D in 32 patients. Twenty-seven patients were treated with prednisolone, hydroxyethyl starch 3% and pentoxifylline intravenously for a period of at least 5 days. Nine patients (controls) did not receive any specific steroid or vasoactive therapy.

RESULTS

All patients in both groups remained deaf.

CONCLUSIONS

Intravenous therapy with prednisolone, hydroxyethyl starch 3% and pentoxifylline in the acute postoperative period does not improve hearing in patients who develop acute deafness after attempted hearing preservation surgery for AN.

Delayed neurotrophic treatment preserves nerve survival and electrophysiological responsiveness in neomycin-deafened guinea pigs

Benefits of cochlear prostheses for the deaf are dependent on survival and excitability of the auditory nerve. Degeneration of deafferented auditory nerve fibers is prevented and excitability maintained by immediate replacement therapy with exogenous neurotrophic factors, in vivo. It is important to know whether such interventions are effective after a delay following deafness, typical for the human situation. This study evaluated the efficacy of brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor axokine-1 analogue (CNTF Ax1) application, 2 or 6 weeks postdeafening, in preventing further degeneration and a decrease in excitability. Guinea pigs were deafened and implanted with intracochlear stimulating electrodes, a scala tympani cannula-osmotic pump system, and auditory brainstem response (ABR) recording electrodes. Subjects received BDNF + CNTF Ax1 or artificial perilymph (AP) treatment for 27 days, beginning at 2 or 6 weeks following deafening. Electrical (E) ABR thresholds increased following deafening. After 1 week, in the 2-weeks-delayed neurotrophic factor treatment group, EABR thresholds decreased relative to AP controls, which were statistically significant at 2 weeks. In the 6-week delay group, a tendency to enhanced EABR sensitivity began at 2 weeks of treatment and increased thereafter, with a significant difference between neurotrophic factor- and AP-treated groups across the treatment period. A clear, statistically significant, enhanced survival of spiral ganglion cells was seen in both neurotrophic factor treatment groups relative to AP controls. These findings demonstrate that BDNF + CNTF Ax1 can act to delay or possibly even reverse degenerative and, likely apoptotic, processes well after they have been activated. These survival factors can rescue cells from death and enhance electrical excitability, even during the period of degeneration and cell loss when the spiral ganglion cell population is reduced by >50% (6 weeks). It is noteworthy that this same degree of ganglion cell loss, secondary to receptor damage, is typically observed after a period equivalent to some years of deafness in humans.

Ocular manifestations of keratitis– ichthyosis–deafness (KID) syndrome

OBJECTIVE

Keratitis-ichthyosis-deafness (KID) syndrome is a rare congenital ectodermal dysplasia characterized by the association of hyperkeratotic skin lesions, moderate to profound sensorineural hearing loss and vascularizing keratitis. Mutations in the GJB2 gene coding for connexin 26, a component of gap junctions in epithelial cells, have been observed in several KID patients. Variable ocular manifestations of the disease in 3 patients with molecular genetically confirmed KID syndrome are reported.

DESIGN

Retrospective case series.

METHODS

Clinical examination and molecular genetic analysis for mutations in the GJB2 gene were performed in 3 patients with KID syndrome ages 5, 13, and 41 years.

RESULTS

Visual acuity ranged from normal to severe visual loss. The ocular signs included loss of eyebrows and lashes, thickened and keratinized lids, trichiasis, recurrent corneal epithelial defects, superficial and deep corneal stromal vascularization with scarring, keratoconjunctivitis sicca, and, in one patient, presumed limbal insufficiency. Whereas ocular surface integrity could be maintained with artificial tears in one patient, and an epithelial defect healed under conservative treatment in the second patient, multiple surgical procedures including superficial keratectomies, limbal allograft transplantation with systemic immunosuppression, amniotic membrane transplantation, lateral tarsorrhaphies, and lamellar keratoplasty could not preserve useful vision in the third patient.

CONCLUSIONS

KID syndrome may affect the ocular adnexae and surface with variable severity independent of the age of the patient. Lid abnormalities, corneal surface instability, limbal stem cell deficiency with resulting corneal complications, and dry eye are the main ocular manifestations.

Targeting the JNK Pathway as a Therapeutic Protective Strategy for Nervous System Diseases

The c-Jun N-terminal kinases (JNKs) are members of the family of mitogen activated protein kinases (MAPKs). While the functions of the JNKs under physiological conditions are diverse and not completely understood, there is increasing evidence that JNKs are potent effectors of apoptosis in both the brain and the mammalian inner ear following a variety of injuries. The activation of the inducible transcription factor c-Jun by N-terminal phosphorylation is a central event in JNK-mediated neural and inner ear hair cell death. A cell permeable peptide designed specifically to inhibit JNK signaling has proven successful in in vivo models of both neuronal degeneration following cerebral ischemia and auditory hair cell degeneration following exposure to either acoustic trauma or a toxic level of an aminoglycoside antibiotic. Here we discuss the evidence supporting the application of JNK inhibitors to prevent cellular degeneration in several central nervous system (CNS) and peripheral nervous system (PNS) diseases with an emphasis on traumatic ischemic damage to the CNS and acquired deafness in the PNS receptors.

The MAPK/JNK signalling pathway offers potential therapeutic targets for the prevention of acquired deafness

The c-Jun N-terminal kinases (JNKs) are also called stress activated protein kinases (SAPKs) and are members of the family of mitogen activated protein kinases (MAPKs). While the functions of the JNKs under physiological conditions are diverse and not completely understood, there is increasing evidence that JNKs are potent effectors of apoptosis of oxidative stress-damaged cells in both the brain and the mammalian inner ear following a trauma. The activation of the inducible transcription factor c-Jun by N-terminal phosphorylation is a central event in JNK-mediated apoptosis of oxidative stress-damaged auditory hair cells following exposure to either acoustic trauma or a toxic level of an aminoglycoside antibiotic and also the apoptosis of auditory neurons as a consequence of a loss of the trophic support provided by the auditory hair cells. In this review, we summarise what is known about the expression and activation of G-proteins, JNKs, c-Jun and c-Fos under oxidative stress conditions within the mammalian cochlea. A particular focus is put on a new peptide conjugate that is a promising protective agent(s) and pharmacological strategies for preventing cochlear damage induced by both acoustic trauma and aminoglycoside ototoxic damage.

Delayed neurotrophin treatment supports auditory neuron survival in deaf guinea pigs

As key factors in the development and maintenance of the auditory system, neurotrophins can prevent auditory neuron degeneration when applied within three to five days of deafening. We tested each of the neurotrophins BDNF, NT-3, NT-4/5 and NGF for their ability to support auditory neuron survival following a two-week period of deafness in guinea pigs, when approximately 15% auditory neuron degeneration has already occurred. Although delayed, the treatment with each neurotrophin prevented further degeneration with similar efficacy.

Marked hyperkeratosis of the soles in keratitis-ichthyosis-deafness syndrome: treatment with hydrocolloid dressing

Keratitis-ichthyosis-deafness (KID) syndrome is a rare congenital disorder that exhibits marked hyperkeratosis of the skin. We successfully treated cutaneous lesions on the soles of a patient with KID syndrome using hydrocolloid dressing.

Effects of nimodipine on salicylate ototoxicity

The purpose of this study was to examine the effects of nimodipine on salicylate ototoxicity in guinea pigs. The compound action potential (CAP) was recorded at the round window, and the cochlear blood flow (CBF) was measured simultaneously from the lateral wall of the basal turn of the cochlea by laser Doppler flowmetry. After administration of salicylate (100 mg/kg), the CAP thresholds were significantly elevated, by 5 to 20 dB (p < .05), and the CBF was significantly decreased (p < .05). After administration of nimodipine (2 mg/kg), the CAP thresholds were unchanged, but the CBF had increased significantly (p < .05), while systemic blood pressure had decreased significantly (p < .05). Simultaneous administration of both salicylate (100 mg/kg) and nimodipine (2 mg/kg) resulted in significant elevation of the CAP thresholds (p < .05), while the CBF did not decrease. These results suggest that nimodipine prevents the decrease in CBF induced by salicylate, but that nimodipine does not prevent the deterioration in the CAP.

Protection and regrowth of the auditory nerve after deafness: neurotrophins, antioxidants and depolarization are effective in vivo

Deafness, with loss of sensory (hair) cells, results in progressive pathophysiological changes ending in the degeneration of most auditory nerve neurons. It is now possible to consider these events in the broader context of anti-apoptotic survival factors in the peripheral and central nervous system. One consequence of deafferentation of a neuron is the loss of neurotrophins that can lead to a change in oxidative state (formation of free radicals), changes in intracellular Ca(2+), and an up-regulation of apoptotic genes. Interventions that can modify availability of neurotrophins, [Ca(2+)](I), and/or free radical formation or their destructive effects, may preserve the auditory nerve. Some interventions (neurotrophins) may also lead to a regrowth of neurites. Studies in this area are of basic value and also of immediate clinical interest for the application of the cochlear prosthesis to the severe and profoundly deaf, since the benefits of this prosthesis are directly dependent on auditory nerve survival and the proximity of stimulating electrode to neuron. We, and others, have found that auditory nerve degeneration can be prevented by chronic electrical stimulation. We have demonstrated in vivo that this effect can be blocked by tetrodotoxin, thus indicating that propagated action potentials are a necessary condition, and by verapamil (Ca(2+) channel blocker), supporting in vitro studies by others, indicating that L-type Ca(2+) channels are necessary for stimulation-induced rescue of the deafferented auditory nerve. The intensities of electrical stimulation required for rescue are at levels sufficient to express the intermediate-early gene c-fos which can initiate transcription of anti-apoptotic genes and pathways, and up-regulate expression of neurotrophins that may act in an autocrine manner to protect the nerve from death. We, and others, have found that chronic local delivery (osmotic pump and microcannulation of the inner ear fluid spaces) of individual neurotrophins and cocktails of factors can also enhance survival of the deafferented nerve, and some can also initiate a regrowth of degenerated peripheral processes of the nerve into the region of the destroyed sensory epitheliae. Recently, we have shown that this rescue can occur with delayed intervention, after degeneration of some neurons has begun, more closely mimicking the human clinical situation. Finally, we have shown that interventions with antioxidants may also be effective in preventing pathophysiological changes of the auditory nerve following deafness. These studies in the auditory periphery support the 'neurotrophic factor hypothesis' as proposed as a general mechanism underlying neurodegenerative and age-related pathology of the central nervous system. Additional animal studies can yield a rational scientific basis to justify human trials, with a goal to maintain auditory cell survival and initiate and direct fiber growth to the next generation of prosthesis. Intimate contact between electrode and a dense population of auditory neurons should greatly enhance the benefits of these devices for the profoundly deaf.

Cochleovestibular impairment in pediatric Cogan's syndrome

Cogan's syndrome is a rare, chronic inflammatory disorder that typically targets the eyes and vestibuloauditory apparatus, but it may also involve other organs. Three pediatric cases of Cogan's syndrome (ages 5, 13, and 18 years) are reported with long-term follow-up and complete and regular cochleovestibular functional evaluation and ophthalmologic and neurologic examinations. One case was a typical form (characterized by an interstitial keratitis and cochleovestibular impairment), whereas the other 2 cases were atypical forms with uveitis and polyarthritis. In all 3 cases, the first clinical sign was nonspecific eye redness misdiagnosed as a banal conjunctivitis, initially or secondarily associated with bilateral endocochlear sensorineural hearing loss and complete bilateral peripheral vestibular deficit. During the acute phase, early steroid treatment (prednisone, 1 mg/kg/day) was effective in treating the ocular lesions (3 of 3 cases) and improving hearing (2 of 3 cases) but less effective for the vestibular loss (2 of 3 cases). Adverse effects and dependence on the steroid occurred in 2 cases, and immunosuppressive drugs were necessary to avoid recurrences in 1 case. Over the long-term, the disease was controlled in 2 cases but continued to progress in the other. Cogan's syndrome in childhood should be suspected in cases of conjunctivitis associated with inner-ear symptoms; a prompt steroid treatment can avoid progressive impairment of multiple sensorineural functions (vision, balance, hearing). Long-term management involves limiting disease recurrences by adaptive therapies, screening for complications (aortitis in particular), and planning rehabilitation for the sensorial deficits.

Complete biotinidase deficiency presenting as reversible progressive ataxia and sensorineural deafness

Most symptomatic patients with biotinidase deficiency have both neurologic and cutaneous symptoms and typical organic aciduria. We encountered a previously healthy girl with complete biotinidase deficiency presenting initially at age 17 months with episodic ataxia that became severe progressive ataxia in 2 months, but without skin rash or typical organic aciduria, which resolved completely with biotin treatment. Additionally, moderate sensorineural deafness also improved to the normal range. Even without typical cutaneous findings or organic aciduria, biotinidase deficiency should be considered among the differential diagnosis in any child presenting with either episodic or progressive ataxia or sensorineural deafness as prompt diagnosis and treatment with biotin may induce an excellent recovery.

Oral or topical nasal steroids for hearing loss associated with otitis media with effusion in children

BACKGROUND

Otitis media with effusion (OME) is common and may cause hearing loss with associated developmental delay. Treatment remains controversial. The effectiveness of both systemic and topical intranasal steroids in promoting the resolution of effusions has been assessed by randomised controlled trials.

OBJECTIVES

To examine evidence for or against treating children with hearing loss associated with OME with systemic or topical intranasal steroids.

SEARCH STRATEGY

Searches were conducted in January 2002. We searched the Cochrane Controlled Trials Register using the terms 'otitis media', 'otitis media with effusion', 'glue ear', or 'OME', and 'steroids', 'glucocorticoids, synthetic', 'glucocorticoids, topical', 'anti-inflammatory agents, steroidal'. EMBASE and MEDLINE were also searched for additional information.

SELECTION CRITERIA

Randomised controlled trials of oral and topical intranasal steroids, either alone or in combination with another agent such as an antibiotic, were included.

EXCLUSIONS

publications in abstract form only since adequate appraisal was not possible; uncontrolled, non-randomised or retrospective studies; studies reporting outcomes with ears (rather than children) as the unit of analysis unless data were of sufficient detail to allow analysis by child.

DATA COLLECTION AND ANALYSIS

Data were extracted from the published reports by the two authors independently (CCB and JH van der V) using standardised data extraction forms and methods. The methodological quality of the included studies was independently assessed by the two authors using the scheme described in the Cochrane Handbook. Dichotomous results were expressed as an odds ratio using a fixed effects model together with the 95% confidence intervals. Continuous data were analysed using the weighted mean difference in a fixed effects model. Tests for heterogeneity between studies were performed using a Mantel-Haenszel approach. In trials with a cross over design, post crossover treatment data were not used.

MAIN RESULTS

No study prospectively documented hearing loss associated with OME prior to randomisation. Follow up was mainly short term. No serious or lasting adverse effects were reported in the six studies that did mention adverse effects. Most comparisons involved small numbers of subjects. The odds ratio for OME persisting after short term follow up in children treated with oral steroids compared to control was 0.22 (95% CI 0.08 to 0.63). The odds ratio for OME persisting after short term follow up for children treated with oral steroids plus antibiotic compared to control plus antibiotic was 0.32 (95% CI 0.20 to 0.52). However there was significant heterogeneity between studies included in the latter comparison (p<0.01). Trends favoured steroids for most other comparisons, but confidence intervals included unity. There was no evidence of benefit for steroid treatment for resolution of OME or of resolution of hearing loss associated with OME in the longer term.

REVIEWER'S CONCLUSIONS

Both oral and topical intranasal steroids alone or in combination with an antibiotic lead to a quicker resolution of OME in the short term. However, there is no evidence of a long term benefit from treating OME effusions or associated hearing loss with either oral or topical intranasal steroids. No serious adverse events were reported in the six studies that presented data on adverse effects. Future studies should document hearing loss associated with OME before the start of study treatment. Follow up should be longer and ideally include health related quality of life and hearing assessments. Data should not be presented only with ears as the unit of analysis.