Bilateral Hearing Loss and Unilateral Cochlear Ossification in a Patient With Chronic Myelogenous Leukemia.

Bilateral sensorineural deafness and unilateral cochlear ossification have rarely been described in patients with chronic myeloid leukemia (CML). A 21-year-old man presented to a hospital with right-sided sudden hearing loss and tinnitus. He was diagnosed with CML. Five days later, sudden hearing loss appeared in the other ear. Abnormality of the right-sided inner ear structure was revealed by preoperative magnetic resonance imaging; honeycomb-like cochlear ossification was observed during cochlear implant surgery in the right ear. The patient's auditory performance exhibited significant improvement after bilateral cochlear implantation in our hospital. Hematological disorders must be considered in patients with sensorineural hearing loss. Cochlear implantation is feasible in patients with CML who exhibit sensorineural deafness, but cochlear ossification should be carefully evaluated by means of preoperative imaging examinations.

Hipoacusia bilateral como forma de presentación en la carcinomatosis meníngea / Bilateral hearing loss as presentation in meningeal carcinomatosis

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Associations of Retinal Vessel Caliber With Hearing Status in Childhood and Midlife: A Cross-Generational Population-Based Study.

Importance: Microvascular phenotypes, which can be assessed using retinal imaging, may be informative about the life course pathogenesis of hearing loss. Objective: To investigate whether differences in retinal vessel caliber (specifically wider venules and narrower arterioles) are associated with hearing threshold and hearing loss in mid-childhood and midlife. Design, Setting, and Participants: A population-based cross-sectional study (Child Health CheckPoint) was nested within the Longitudinal Study of Australian Children. A total of 1281 children and 1255 attending parents were assessed using retinal microvasculature and air conduction audiometry data at a main assessment center in 7 large cities in Australia. Main Outcomes and Measures: Air conduction audiometry was used to calculate the high Fletcher index (mean threshold of 1, 2, and 4 kHz), and bilateral hearing loss was defined as a high Fletcher index greater than 15 dB hearing level in the better-hearing ear. Retinal arteriolar and venular caliber were measured from fundus photographs using validated computer-based software. Linear and logistic regression quantified the associations of retinal vessel caliber with hearing threshold and hearing loss, respectively. Results: Of the 1281 included children (mean age, 11.4 years; 49.1% boys), the mean (SD) high Fletcher index was 7.9 (5.8) dB hearing level. Of the 1255 included adults (mean age, 43.8 years; 86.6% women), the mean (SD) high Fletcher index was 13.0 (6.8) dB hearing level; 109 of 1281 children (8.5%) and 328 of 1255 adults (26.1%) had hearing loss. In adults, each 1-SD (18.6-µm) wider retinal venular caliber (worse) was associated with higher (worse) hearing threshold at lower individual frequencies (eg, 2 kHz: ß = 0.63; 95% CI, 0.10-1.17) and overall high Fletcher index (eg, 2 kHz: ß = 0.52; 95% CI, 0.07-0.96), as well as a 1.20-fold (95% CI, 1.03-1.40) higher odds of hearing loss. In children, patterns of venular associations were similar but smaller and less certain. Narrower retinal arteriolar caliber (worse) was associated with a 1.16-fold (95% CI, 1.00-1.37) higher odds of hearing loss in adults (per 1-SD [14.0-µm] narrower arteriolar caliber) but not in children. Conclusions and Relevance: Adverse retinal microvascular characteristics are associated with hearing loss by midlife, with venular associations possibly emerging by age 11 to 12 years. Microvascular health may contribute to the pathogenesis of hearing loss across the life course, warranting replication and mechanistic studies to inform causal inference and prevention efforts.

A Case of Gastric Meningeal Carcinomatosis Involving Bilateral Hearing Loss: The Difference between Clinical Images and Autopsy Findings.

We describe a rare case of meningeal carcinomatosis (MC) in a 66-year-old man who presented with bilateral deafness and vertigo, initially presumed to be neurofibromatosis type-2. Brain magnetic resonance imaging (MRI) of the patient revealed bilateral gadolinium enhanced masses at the cerebellopontine angle. However, multiple central nervous system symptoms, including loss of consciousness, gradually appeared. He had a history of gastric cancer; therefore, a lumbar puncture was performed. Cytological examination of the cerebrospinal fluid confirmed the presence of adenocarcinoma cells. The general condition of this patient worsened, and he died 46 days after the first onset of hearing loss. An autopsy was performed, and multiple infiltrations of adenocarcinoma cells in the brain were confirmed, though undetected by MRI. The prognosis of MC is extremely poor; therefore, rapid diagnosis is important to prevent mortality. Retrospectively, a lumbar puncture could have been conducted earlier to identify MC, especially in consideration of the clinical history of this patient.

A novel autosomal recessive GJB2-associated disorder: Ichthyosis follicularis, bilateral severe sensorineural hearing loss, and punctate palmoplantar keratoderma.

Ichthyosis follicularis, a distinct cutaneous entity reported in combination with atrichia, and photophobia has been associated with mutations in MBTPS2. We sought the genetic cause of a novel syndrome of ichthyosis follicularis, bilateral severe sensorineural hearing loss and punctate palmoplantar keratoderma in two families. We performed whole exome sequencing on three patients from two families. The pathogenicity and consequences of mutations were studied in the Xenopus oocyte expression system and by molecular modeling analysis. Compound heterozygous mutations in the GJB2 gene were discovered: a pathogenic c.526A>G; p.Asn176Asp, and a common frameshift mutation, c.35delG; p.Gly12Valfs*2. The p.Asn176Asp missense mutation was demonstrated to significantly reduce the cell-cell gap junction channel activity and increase the nonjunctional hemichannel activity in the Xenopus oocyte expression system. Molecular modeling analyses of the mutant Cx26 protein revealed significant changes in the structural characteristics and electrostatic potential of the Cx26, either in hemichannel or gap junction conformation. Thus, association of a new syndrome of an autosomal recessive disorder of ichthyosis follicularis, bilateral severe sensorineural hearing loss and punctate palmoplantar keratoderma with mutations in GJB2, expands the phenotypic spectrum of the GJB2-associated disorders. The findings attest to the complexity of the clinical consequences of different mutations in GJB2.

Regulation of KCNQ/Kv7 family voltage-gated K+ channels by lipids.

Many years of studies have established that lipids can impact membrane protein structure and function through bulk membrane effects, by direct but transient annular interactions with the bilayer-exposed surface of protein transmembrane domains, and by specific binding to protein sites. Here, we focus on how phosphatidylinositol 4,5-bisphosphate (PIP2) and polyunsaturated fatty acids (PUFAs) impact ion channel function and how the structural details of the interactions of these lipids with ion channels are beginning to emerge. We focus on the Kv7 (KCNQ) subfamily of voltage-gated K+ channels, which are regulated by both PIP2 and PUFAs and play a variety of important roles in human health and disease. This article is part of a Special Issue entitled: Lipid order/lipid defects and lipid-control of protein activity edited by Dirk Schneider.

A novel CHST3 allele associated with spondyloepiphyseal dysplasia and hearing loss in Pakistani kindred.

Skeletal dysplasias (SDs) are highly heterogeneous disorders composed of 40 clinical sub-types that are part of 456 well-delineated syndromes in humans. Here, we enrolled consanguineous kindred from a remote area of Sindh province of Pakistan, with 14 affected individuals suffering with short stature, kyphoscoliosis, joint dislocations, clubfoot, heart valve anomalies and progressive bilateral mixed hearing loss. To identify pathogenic variants in this family, whole exome sequencing (WES) was performed in one affected and one normal individual, which revealed a novel transversion mutation (c.802G>T; p.Glu268*) in CHST3 associated with the phenotype. CHST3 encodes a chondroitin 6-O-sulfotransferase-1 (C6ST-1) enzyme that is essential for the sulfation of proteoglycans found in cartilages. Previously, mutations in CHST3 have largely been reported in sporadic cases of SD, primarily with severe spinal abnormalities, joint dislocations, joint contractures, and clubfoot. Clinical and radiological examination of the affected individuals in this family provides new insights into phenotypic spectrum of CHST3 alleles and disease progression with age.

Positron Emission Tomography Imaging Reveals Auditory and Frontal Cortical Regions Involved with Speech Perception and Loudness Adaptation.

Considerable progress has been made in the treatment of hearing loss with auditory implants. However, there are still many implanted patients that experience hearing deficiencies, such as limited speech understanding or vanishing perception with continuous stimulation (i.e., abnormal loudness adaptation). The present study aims to identify specific patterns of cerebral cortex activity involved with such deficiencies. We performed O-15-water positron emission tomography (PET) in patients implanted with electrodes within the cochlea, brainstem, or midbrain to investigate the pattern of cortical activation in response to speech or continuous multi-tone stimuli directly inputted into the implant processor that then delivered electrical patterns through those electrodes. Statistical parametric mapping was performed on a single subject basis. Better speech understanding was correlated with a larger extent of bilateral auditory cortex activation. In contrast to speech, the continuous multi-tone stimulus elicited mainly unilateral auditory cortical activity in which greater loudness adaptation corresponded to weaker activation and even deactivation. Interestingly, greater loudness adaptation was correlated with stronger activity within the ventral prefrontal cortex, which could be up-regulated to suppress the irrelevant or aberrant signals into the auditory cortex. The ability to detect these specific cortical patterns and differences across patients and stimuli demonstrates the potential for using PET to diagnose auditory function or dysfunction in implant patients, which in turn could guide the development of appropriate stimulation strategies for improving hearing rehabilitation. Beyond hearing restoration, our study also reveals a potential role of the frontal cortex in suppressing irrelevant or aberrant activity within the auditory cortex, and thus may be relevant for understanding and treating tinnitus.

Susac syndrome: diverse clinical findings and treatment.

We report a case of a 19-year-old woman presenting bilateral neurosensorial hearing loss, mental abnormalities, and loss of visual field in the left eye. Visual acuity was 20/20 in OD and 20/25 in OS. Patient was examined systemically. Audiometry showed sensorineural hearing loss in both ears. The magnetic resonance imaging (MRI) of brain revealed multiple small lesions in the white matter in both cerebral hemispheres and at the corpus callosum. Fundoscopy showed bilateral normal optic disc and sheathing of the arterioles in the middle periphery of OD. Retinal edema and cotton-wool spots were observed. Fluorescein angiography showed bilateral peripheral occlusive arterial vasculopathy. The patient was diagnosed with Susac syndrome and treated with quetiapine fumarate, flunitrazepam, and prednisone, which resulted in stabile outcome. This case shows that a high index of suspicion leading to early recognition and treatment is important to avoid irreversible damage.

Susac syndrome: diverse clinical findings and treatment / Síndrome de Susac: achados clínicos diversos e tratamento

We report a case of a 19-year-old woman presenting bilateral neurosensorial hearing loss, mental abnormalities, and loss of visual field in the left eye. Visual acuity was 20/20 in OD and 20/25 in OS. Patient was examined systemically. Audiometry showed sensorineural hearing loss in both ears. The magnetic resonance imaging (MRI) of brain revealed multiple small lesions in the white matter in both cerebral hemispheres and at the corpus callosum. Fundoscopy showed bilateral normal optic disc and sheathing of the arterioles in the middle periphery of OD. Retinal edema and cotton-wool spots were observed. Fluorescein angiography showed bilateral peripheral occlusive arterial vasculopathy. The patient was diagnosed with Susac syndrome and treated with quetiapine fumarate, flunitrazepam, and prednisone, which resulted in stabile outcome. This case shows that a high index of suspicion leading to early recognition and treatment is important to avoid irreversible damage.

Relatamos o caso de uma mulher de 19 anos apresentando perda auditiva neurossensorial bilateral, anormalidades mentais e perda de campo visual no olho esquerdo. A acuidade visual era 20/20 em OD e 20/25 em OE. Paciente foi sistematicamente investigada, audiometria mostrou perda auditiva neurossensorial nos dois ouvidos e ressonância magnética nuclear (RNM) cerebral mostrou múltiplas pequenas lesões na substância branca em ambos os hemisférios cerebrais e no corpo caloso. A fundoscopia mostrou disco óptico normal bilateral, e embainhamento das arteríolas na média periferia do olho direito. Edema de retina e exsudatos algodonosos foram vistos. Angiofluoresceinografia mostrou vasculopatia arterial obstrutiva periférica bilateral. A paciente foi diagnosticada com síndrome Susac e tratada com fumarato de quetiapina, flunitrazepam e prednisona resultando em estabilização do quadro. Este caso mostra que um alto índice de suspeita levando ao reconhecimento precoce e tratamento é importante para evitar o diagnóstico tardio.

Delineation of EFTUD2 haploinsufficiency-related phenotypes through a series of 36 patients.

Mandibulofacial dysostosis, Guion-Almeida type (MFDGA) is a recently delineated multiple congenital anomalies/mental retardation syndrome characterized by the association of mandibulofacial dysostosis (MFD) with external ear malformations, hearing loss, cleft palate, choanal atresia, microcephaly, intellectual disability, oesophageal atresia (OA), congenital heart defects (CHDs), and radial ray defects. MFDGA emerges as a clinically recognizable entity, long underdiagnosed due to highly variable presentations. The main differential diagnoses are CHARGE and Feingold syndromes, oculoauriculovertebral spectrum, and other MFDs. EFTUD2, located on 17q21.31, encodes a component of the major spliceosome and is disease causing in MFDGA, due to heterozygous loss-of-function (LoF) mutations. Here, we describe a series of 36 cases of MFDGA, including 24 previously unreported cases, and we review the literature in order to delineate the clinical spectrum ascribed to EFTUD2 LoF. MFD, external ear anomalies, and intellectual deficiency occur at a higher frequency than microcephaly. We characterize the evolution of the facial gestalt at different ages and describe novel renal and cerebral malformations. The most frequent extracranial malformation in this series is OA, followed by CHDs and skeletal abnormalities. MFDGA is probably more frequent than other syndromic MFDs such as Nager or Miller syndromes. Although the wide spectrum of malformations complicates diagnosis, characteristic facial features provide a useful handle.

Bilateral internal acoustic canal mass.

We reported a case of bilateral internal acoustic canal mass. A 42-year-old man patient was previously treated for colon cancer. After surgery during chemotherapy signs as severe vertigo and bilateral sudden hearing loss occurred. Temporal bone magnetic resonance imaging (MRI) had bilateral internal acoustic canal masses.

Frequency discrimination in ears with and without contralateral cochlear dead regions.

OBJECTIVE: The purpose of this study was to test the ability to discriminate low-frequency pure-tone stimuli for ears with and without contralateral dead regions, in subjects with bilateral high-frequency hearing loss; we examined associations between hearing loss characteristics and frequency discrimination of low-frequency stimuli in subjects with high-frequency hearing loss. DESIGN: Cochlear dead regions were diagnosed using the TEN-HL test. A frequency discrimination test utilizing an adaptive three-alternative forced choice method provided difference limens for reference frequencies 0.25 kHz and 0.5 kHz. STUDY SAMPLE: Among 105 subjects with bilateral high-frequency hearing loss, unilateral dead regions were found in 15 subjects. These, and an additional 15 matched control subjects without dead regions, were included in the study. RESULTS: Ears with dead regions performed best at the frequency discrimination test. Ears with a contralateral dead region performed significantly better than ears without a contralateral dead region at 0.5 kHz, the reference frequency closest to the mean audiogram cut-off, while the opposite result was obtained at 0.25 kHz. CONCLUSIONS: Results may be seen as sign of a contralateral effect of unilateral dead regions on the discrimination of stimuli with frequencies well below the audiogram cut-off in adult subjects with bilateral high-frequency hearing loss.

Cochlear ossification in patients with profound hearing loss following bacterial meningitis.

CONCLUSION: Cochlear ossification following bacterial meningitis is related to causative pathogen, but not age at disease or time point of evaluation. However, progression may occur over time, especially in case of primary signs of ossification. OBJECTIVE: To investigate the occurrence and degree of cochlear ossification on CT and MRI in patients with bilateral profound hearing loss following bacterial meningitis, in relation to causative pathogen, age at disease, and time point of evaluation. Progression of ossification in cases that underwent more than one scan was evaluated. METHODS: In the period 1982-2008, 47 cochlear implantations were performed in 34 consecutive candidates suffering from bilateral profound hearing loss following bacterial meningitis. A retrospective review of patient files and preoperative CT and MR images was performed. RESULTS: Cochlear ossification was observed in 35% of patients and 26% of ears on CT. The corresponding values for MRI were 44 and 30% (difference not significant). Streptococcus pneumoniae infection caused ossification more frequently than Neisseria meningitidis. No difference was found between pediatric and adult cases, and the occurrence of ossification was not related to the time point of evaluation. Signs of progressive ossification were found in cases with two CT scans, especially if ossification was present at the first scan.

Phosphoribosylpyrophosphate synthetase superactivity and recurrent infections is caused by a p.Val142Leu mutation in PRS-I.

We identified a novel missense mutation, c.424G>C (p.Val142Leu) in PRPS1 in a patient with uric acid overproduction without gout but with developmental delay, hypotonia, hearing loss, and recurrent respiratory infections. The uric acid overproduction accompanying this combination of symptoms suggests that the patient presented with phosphoribosylpyrophosphate (PRPP) synthetase superactivity, but recurrent infections have not been associated with superactivity until now. However, recurrent infections are a prominent feature of patients with Arts syndrome, which is caused by PRPS1 loss-of-function mutations, indicating that the patient reported here has an intermediate phenotype. Molecular modeling predicts that the p.Val142Leu change affects both allosteric sites that are involved in inhibition of PRPS1 and the ATP-binding site, which suggests that this substitution can result both in a gain-of-function and loss-of-function of PRPP synthetase. This finding is in line with the normal PRPP synthetase activity in fibroblasts and the absence of activity in erythrocytes of the present patient. We postulate that the overall effect of the p.Val142Leu change on protein activity is determined by the cell type, being a gain-of-function in proliferating cells and a loss-of-function in postmitotic cells. Our results show that missense mutations in PRPS1 can cause a continuous spectrum of features ranging from progressive non-syndromic postlingual hearing impairment to uric acid overproduction, neuropathy, and recurrent infections depending on the functional sites that are affected.

Genome-wide SNP genotyping identifies the Stereocilin (STRC) gene as a major contributor to pediatric bilateral sensorineural hearing impairment.

Hearing loss is the most prevalent sensory perception deficit in humans, affecting 1/500 newborns, can be syndromic or nonsyndromic and is genetically heterogeneous. Nearly 80% of inherited nonsyndromic bilateral sensorineural hearing loss (NBSNHI) is autosomal recessive. Although many causal genes have been identified, most are minor contributors, except for GJB2, which accounts for nearly 50% of all recessive cases of severe to profound congenital NBSNHI in some populations. More than 60% of children with a NBSNHI do not have an identifiable genetic cause. To identify genetic contributors, we genotyped 659 GJB2 mutation negative pediatric probands with NBSNHI and assayed for copy number variants (CNVs). After identifying 8 mild-moderate NBSNHI probands with a Chr15q15.3 deletion encompassing the Stereocilin (STRC) gene amongst this cohort, sequencing of STRC was undertaken in these probands as well as 50 probands and 14 siblings with mild-moderate NBSNHI and 40 probands with moderately severe-profound NBSNHI who were GJB2 mutation negative. The existence of a STRC pseudogene that is 99.6% homologous to the STRC coding region has made the sequencing interpretation complicated. We identified 7/50 probands in the mild-moderate cohort to have biallelic alterations in STRC, not including the 8 previously identified deletions. We also identified 2/40 probands to have biallelic alterations in the moderately severe-profound NBSNHI cohort, notably no large deletions in combination with another variant were found in this cohort. The data suggest that STRC may be a common contributor to NBSNHI among GJB2 mutation negative probands, especially in those with mild to moderate hearing impairment.

Temporal bone histopathology in a case of sensorineural hearing loss caused by superficial siderosis of the central nervous system and treated by cochlear implantation.

OBJECTIVE: To evaluate the histopathology of the temporal bones of a patient with documented superficial siderosis of the central nervous system who underwent right cochlear implantation six years before death. BACKGROUND: Superficial siderosis of the central nervous system is due to chronic or repeated subarachnoid hemorrhage and results in sensorineural deafness in 95% of affected individuals in addition to other neurologic findings. The deposition of hemosiderin in the meninges and around cranial nerves is thought to be causative. There have been no previous reports of temporal bone pathology in this disorder.This 57 year old man developed progressive, bilateral hearing loss starting in his 30's with loss of pure tone thresholds and word recognition. He underwent a right cochlear implant at age 51 with full insertion of the device. METHODS: The temporal bones and brainstem were fixed in formalin and prepared for histologic study by standard techniques. Special stains, including Gomori stain for iron were performed on sections of the temporal bones and cochlear nucleus. RESULTS: There was severe bilateral degeneration of the organ of Corti, spiral ligament, stria vascularis, and spiral ganglion cells. Gomori stain revealed iron deposits within the spiral ligament, stria vascularis and in the subepithelial mesenchymal tissue of the maculae of the vestibular system. Evaluation of the cochlear nucleus revealed iron deposits within glial cells and larger cells, probably macrophages, near the CSF surface. On the right side, the track created by the cochlear implant entered the scala tympani and continued to mm17, as measured from the round window. DISCUSSION AND CONCLUSION: This is the first known case of superficial siderosis with documented temporal bone histopathology. Hearing loss was likely caused by severe degeneration of spiral ganglion cells in both ears, despite the presence of remaining hair cells in the middle and apical turns. This was consistent with cochlear neuronal degeneration and retrograde degeneration of spiral ganglion cells within the inner ear, or alternatively, consistent with primary degeneration of hair cells and neural structures within the cochlea. Despite the presence of neural degeneration, the patient achieved a word recognition score of 28% six months following implantation.

The therapeutic efficacy of human adipose tissue-derived mesenchymal stem cells on experimental autoimmune hearing loss in mice.

Autoimmune inner ear disease is characterized by progressive, bilateral although asymmetric, sensorineural hearing loss. Patients with autoimmune inner ear disease had higher frequencies of interferon-γ-producing T cells than did control subjects tested. Human adipose-derived mesenchymal stem cells (hASCs) were recently found to suppress effector T cells and inflammatory responses and therefore have beneficial effects in various autoimmune diseases. The aim of this study was to examine the immunosuppressive activity of hASCs on autoreactive T cells from the experimental autoimmune hearing loss (EAHL) murine model. Female BALB/c mice underwent ß-tubulin immunization to develop EAHL; mice with EAHL were given hASCs or PBS intraperitoneally once a week for 6 consecutive weeks. Auditory brainstem responses were examined over time. The T helper type 1 (Th1)/Th17-mediated autoreactive responses were examined by determining the proliferative response and cytokine profile of splenocytes stimulated with ß-tubulin. The frequency of regulatory T (Treg) cells and their suppressive capacity on autoreactive T cells were also determined. Systemic infusion of hASCs significantly improved hearing function and protected hair cells in established EAHL. The hASCs decreased the proliferation of antigen-specific Th1/Th17 cells and induced the production of anti-inflammatory cytokine interleukin-10 in splenocytes. They also induced the generation of antigen-specific CD4(+) CD25(+) Foxp3(+) Treg cells with the capacity to suppress autoantigen-specific T-cell responses. The experiment demonstrated that hASCs are one of the important regulators of immune tolerance with the capacity to suppress effector T cells and to induce the generation of antigen-specific Treg cells.

GJB2 allele variants and the associated audiologic features identified in Chinese patients with less severe idiopathic hearing loss.

AIMS: To explore possible correlations between the genotype of GJB2, the gene that encodes connexin 26 (Cx26), and its related audiogram features in Chinese patients with less severe nonsyndromic hearing loss (HL), we examined the pure tone audiograms and GJB2 coding region allele variants in 236 patients. RESULTS: Twelve of 34 (35.3%) patients with biallelic GJB2 mutations had totally asymmetric HL, a significantly higher prevalence than in patients with wild-type GJB2 (p = 0.027). In patients with biallelic GJB2 mutations, the percentages of cases with sloping, flat, and differently shaped audiograms between ears were 44.1%, 11.8%, and 35.3%, respectively; however, in patients with wild-type GJB2, the percentages were 72.4%, 3.4%, and 21.1%, respectively. Significant differences were found between patients with wild-type GJB2 and those with biallelic GJB2 mutations (p = 0.013) as well as those with single GJB2 mutations (p = 0.043). Threshold differences between ears were significantly higher in patients carrying GJB2 polymorphisms than in patients with wild-type GJB2 at 250-8000 Hz (p < 0.05). The threshold changes at adjacent octaves showed significant differences between groups at each adjacent frequency from 4000 to 8000 Hz (p = 0.04). CONCLUSIONS: The patients who carried biallelic pathogenic Cx26 mutations showed asymmetric HL compared with the patients who carried wild-type Cx26. The threshold difference and threshold changes at adjacent octaves between ears were higher in the patients with Cx26 polymorphisms.