Idiopathic Sensorineural Hearing Research Articles

ステロイド併用少用量免疫抑制剤治療を施行した特発性両側性感音難聴例

ステロイド併用少用量免疫抑制剤治療を施行した特発性両側性感音難聴例

Blood flow in the ears of patients receiving cochlear implants.

We measured cochlear blood flow (CBF) in 55 patients who received cochlear implants, using a laser-Doppler probe placed over the site of drilling in the cochlear bony wall. The subjects included 29 patients with congenital deafness of unknown cause, 8 with idiopathic progressive sensorineural hearing loss, 4 with postmeningitic deafness, 3 with Waardenburg's syndrome, 3 with congenital cytomegalovirus infection, and 8 whose deafness had other causes. There was a wide range of CBF values in patients with congenital deafness of unknown cause. In the patients with idiopathic progressive sensorineural hearing loss, the CBF was significantly lower in patients more than 40 years old. Intracochlear calcification following meningitis appears to be associated with a reduced CBF.

Genotypic and phenotypic correlations of DFNB1-related hearing impairment in the Midwestern United States.

To determine the genotypic and phenotypic correlations of hearing impairment (HI) in a midwestern US population related to autosomal recessive nonsyndromic hearing loss locus 1 (DFNB1). A retrospective review. Tertiary care children's hospital. A total of 160 consecutive children diagnosed with idiopathic sensorineural hearing loss. GJB2 genotype and audiometric phenotype. The prevalence of subjects with HI having biallelic GJB2-related mutations was 15.3% (24/157). Of these 24 patients, 9 (38%) were homozygous 35delG, 6 (25%) had other biallelic nonsense mutations, and 9 (38%) had a missense mutation of at least 1 allele. The allelic prevalence of 35delG was 8.6% (27/314) in the study population and 48% (23/48) in the DFNB1 group. The M34T allele mutation was next most prevalent at 2.2% (7/314) in the study population and 10% (5/48) in the DFNB1 group. Severe to profound HI occurred in 59% of DFNB1 subjects. Genotypes with biallelic nonsense mutations had a high risk of severe to profound HI (88%). DFNB1-related HI was usually bilateral, symmetric, nonprogressive, and had flat audiograms. However, asymmetric HI (22%), sloping audiograms (26%), and even borderline-normal hearing in 1 ear was observed, and these were associated with the presence of at least 1 missense mutation. Two novel mutations, K15T and L90V, were identified. A subject presenting to our clinic with severe to profound HI had a 40% risk of biallelic GJB2 mutation. Our population represents a consecutively enrolled clinic population with sensorineural hearing loss. In our DFNB1-related HI cohort, the 35delG mutation and severe to profound HI rates were lower than previously reported. Our missense mutation and M34T allelic prevalence rates were higher than expected and were associated with a less severe hearing loss. The presence of biallelic nonsense mutations was associated with severe to profound hearing loss in nearly 90% of cases. Mild asymmetric HI and sloping audiograms were more often associated with missense mutations.

Photochemically Induced Double Lateral Wall Lesions in the Guinea Pig Cochlea

ObjectiveMultiple patches of atrophy have been reported in the stria vascularis (SV) in elderly persons with presbycusis The aim of this study was to investigate the correlation between sensorineural hearing loss and this strial condition.Material and MethodsWe established a new animal model comprising two small lesions in the SV in the second turn of the cochlea by means of photochemical reaction. Using this model, we investigated morphological and physiological changes in the cochlea at 3, 7 and 14 days after SV damage.ResultsScanning electron microscopy studies revealed that the strial cells between the two damaged areas of the SV remained intact, although the outer hair cells (OHCs) facing the intact SV area were damaged. Furthermore, damage to the first and second rows of OHCs gradually progressed throughout the 14-day observation period. The endocochlear potential (EP) measured at a point midway between the 2 lesions at 3 and 7 days was found to be significantly lower compared with control values, but had returned to a normal level at 14 daysConclusionThe reversible EP change and localized OHC loss seen in the present investigation may help to understand acute idiopathic or progressive sensorineural hearing loss.

Evaluation of the Vestibular Aqueduct in Vestibulocochlear Disorders by Magnetic Resonance Imaging

The visibility of the vestibular aqueduct (VA) was examined using magnetic resonance imaging (MRI) in 95 patients: 15 patients with Meniere's disease, 4 with vestibular Meniere's disease, 4 with cochlear Meniere's disease and 72 patients with other vestibular and/or cochlear disorders. In order to visualize the VA, the T 2 -weighted image (T 2 WI) and the proton-density weighted image (PDWI) were obtained in the sagittal plane with a head coil. The visibility of the VA was classified into 4 grades, i.e. grade 0 (not visible), grade 1 (partially visible with PDWI), grade 2 (partially visible with T 2 WI) and grade 3 (clearly visible with T 2 WI). The visibility of the VA was significantly lower bilaterally in Meniere's disease, vestibular Meniere's disease, cochlear Meniere's disease and idiopathic bilateral sensorineural hearing loss (IBSNHL) than in the other diseases. The differences among Meniere's disease, vestibular Meniere's disease and cochlear Meniere's disease were not significant. The significance of decreased visibility in IBSNHL is unknown so far. The VA studies using MRI strongly suggest that the pathogenesis of Meniere's disease, vestibular Meniere's disease, cochlear Meniere's disease and IBSNHL is, at least in part, related to the findings of the VA.

感音難聴と加齢 特発性両側性感音難聴と加齢

感音難聴と加齢 特発性両側性感音難聴と加齢

Detection of inner ear disease autoantibodies by immunoblotting.

To define further the character of autoantibodies against the inner ear in patients with inner ear disease, Autoantibodies in sera from 82 patients with inner ear disease were investigated by immunoblotting. The inner ear antigens were extracted from Hartley guinea pigs. Brain, kidney, lung, heart and liver extracts were also prepared. Antibodies against the inner ear were found in 32 of 82 (39%) patients with inner ear disease. These sera reacted with the 30 and 58 kDa bands of the inner ear extracts. The 30 kDa band was detected in sera from patients with various inner ear diseases, while the 58 kDa band reacted with sera of patients with idiopathic progressive sensorineural hearing loss. Only two of the 52 normal control sera had a very faint band at 30 kDa. Sixteen of 32 positive sera were then used to probe Western blots of the brain, kidney, lung heart and liver extracts. The 58 kDa band was also found in the protein extracts of the brain, the lung, and the liver. On the other hand, preliminary purification of the 30 and 58 kDa proteins from the inner ear extracts were achieved by anion exchange chromatography. These results show that antibodies in sera from patients with inner ear disease reacted with at least two polypeptide bands (30 and 58 kDa) of guinea pig inner ear extracts, and the 58 kDa antigenic epitope was not cochlea specific.

Study on the Distribution of Hearing Levels in Idiopathic Bilateral Sensorineural Hearing Loss

The pattern of aggravation in hearing was investigated in 105 patients who were diagnosed as having idiopathic bilateral sensorineural hearing loss at the Hearing Loss Clinic, Department of Otolaryngology, Kitasato University Hospital. Audiograms were taken 1,069 times from the 105 cases over more than 3 years, and were used to obtain the distribution of hearing levels at each test frequency. The clinical course of idiopathic bilateral sensorineural hearing loss was divided into three stages: Stages I, II and III, based on the pattern of aggravation. The pattern of distribution of hearing levels at different stages was compared with each other with reference to peaks or clustering points. Similar peaks were noted at Stage II and Stage III as aggravation proceeded from Stage I. Another peak was noted in the zone of scale-out.

特発性両側性感音難聴の検討

特発性両側性感音難聴の検討

特発性両側性感音難聴の聴力変動について

特発性両側性感音難聴の聴力変動について

特発性両側性感音難聴の検討（成人型と若年型について）

特発性両側性感音難聴の検討（成人型と若年型について）

特発生両側性感音難聴（特難）の域値上検査 （第２報）

特発生両側性感音難聴（特難）の域値上検査 （第２報）