Interactive effects of hearing aid use and cognitive function in patients with hearing loss.

BACKGROUND: There has been a significant increase in scientific investigations of the hearing-dementia association among the research on potentially modifiable risk factors for cognitive impairment. We tested two clinical questions. Analysis 1: does persistent hearing aid (HA) use decrease the decline in cognitive function caused by ageing? Analysis 2: does cognitive function at the time of HA fitting predict future persistent HA use? METHODS: This case-control study performed at two referral centres reported data obtained over a 4.5-year period. We recruited a group of patients with cognitive decline, aged 65 or older with or without hearing loss. The intervention consisted of the use of HAs. The primary outcome measures were adherence to continuous HA use and cognitive function measured using the Japanese version of the Mini-Mental State Examination Test and the Reading Cognitive Test Kyoto. RESULTS: Eighteen HA users and 18 controls were included in the first analysis. HA use was associated with a deceleration of cognitive decline 12 months later. In the second analysis, 11 participants with good adherence to HA use were compared with 12 participants who showed poor adherence to HA use. Among the variables employed in this study, cognitive function measured using the Reading Cognitive Test Kyoto was significantly lower in participants with poor adherence to HA. CONCLUSIONS: HA use in cognitively impaired individuals with hearing loss can slow age-related cognitive decline. Cognitively impaired people with hearing loss who fail to commit to HA use tend to have lower cognitive measurement scores before HA fitting. HA use is generally more challenging as people age and their cognitive abilities decline. Therefore, it is desirable that HAs be used when hearing loss and dementia are in their early stages.

Development of the Reading Cognitive Test Kyoto (ReaCT Kyoto) for Early Detection of Cognitive Decline in Patients with Hearing Loss.

BACKGROUND: Early detection of cognitive decline allows timely intervention to delay progression of dementia. However, current cognitive evaluation tools often include items delivered via verbal forms of instruction, which can cause poor performance in patients with hearing loss. OBJECTIVE: To develop and validate a cognitive screening battery, the Reading Cognitive Test Kyoto (ReaCT Kyoto), comprising test items given through non-verbal instruction. METHODS: A cross-sectional and multi-center study was conducted in the three medical institutes. ReaCT Kyoto was designed to evaluate domains of "registration," "repetition," "delayed recall," "visuospatial recognition," "orientation in time and place," and "executive function." The Japanese version of the Mini-Mental State Examination Test (MMSE-J) and ReaCT Kyoto were applied by experienced psychotherapists. Concurrent validity was evaluated between the ReaCT Kyoto Test and MMSE-J and between the ReaCT Kyoto Test and physician-diagnosed dementia. RESULTS: ReaCT Kyoto was validated in a sample of 115 participants. The mean age of subjects was 81.0±6.4 years, and the sample comprised 53.0% females. The area under the receiver operating curves was 0.95 for detecting physician-diagnosed dementia. When classifying patients in accordance with presence or absence of hearing loss, the AUCs were 0.93 and 0.97 for those with and without hearing loss, respectively. With a cut-off score of < 29 points for suspected dementia, ReaCT Kyoto correctly classified 90.4% of the subjects as belonging to the group with or without physician-diagnosed dementia. CONCLUSION: ReaCT Kyoto provides an appropriate solution for detection of cognitive impairment in persons with or without hearing loss.

Non-organic hearing loss.

CONCLUSION: Most non-organic hearing loss (NOHL) patients were young females. The discrepancy between the results of pure tone audiometry and objective auditory testing suggests NOHL. The diagnostic problem is that objective audiometry is not included in routine examinations and we have to suspect NOHL in order to perform further examination. The correct diagnosis can be difficult in patients who present with unilateral sudden hearing loss or who also have moderate to profound organic hearing loss. OBJECTIVE: Symptoms and results of auditory tests for NOHL patients were reviewed. PATIENTS AND METHODS: This study comprised 31 patients with NOHL. Age, symptoms, and the results of subjective and objective audiometry were collected. RESULTS: Twenty-four patients were female and 7 were male. The age at attendance ranged from 7 to 39 years old, with an average age of 16.6 years. Eight patients received steroids before the correct diagnosis was made. Six of them presented with unilateral sudden hearing loss, and the other two patients had accompanying bilateral organic hearing loss.

Vertigo as the sole presenting symptom of cerebellopontine angle meningioma.

We report a rare case of cerebellopontine angle (CPA) meningioma whose sole symptom was severe vertigo. A 39-year-old woman with right CPA meningioma was referred for surgery. She experienced severe vertigo for 2 years without any other symptoms. Caloric test indicated right canal paresis of 90%. Her audiogram was normal. After surgery, vertigo symptoms disappeared dramatically. The mechanisms of restoration from vertigo are discussed.

Clinical characteristics of delayed endolymphatic hydrops: long-term results of hearing and efficacy of hyperbaric oxygenation therapy.

CONCLUSION: Diuretics significantly improved hearing in patients with contralateral-type DEH, whereas they did not inpatients with ipsilateral-type DEH. OBJECTIVE: We report a review of 26 cases of DEH treated in recent 6 years. PATIENTS AND METHODS: The study group comprised 22 contralateral and 4 ipsilateral types of DEH. The efficacy of diuretics on the improvement in hearing was examined quantitatively. The efficacy of hyperbaric oxygenation therapy (HBO) on hearing was examined in six patients. RESULTS: The general properties of these cases were similar to those reported previously, except for the high proportion of patients with contralateral-type DEH. Diuretics significantly improved the hearing of patients with contralateral-type DEH. In contrast, no significant improvement by diuretics was noted in ipsilateral-type DEH.

Cochlear implants in post-lingually deafened patients.

CONCLUSION: Post-lingually deafened patients had good speech intelligibility scores with cochlear implantation. The age at the operation, duration of deafness, and the number of electrodes outside the cochlea showed only weak correlation with the postoperative performance, which warrants cochlear implantation in elderly patients and patients with a long history of deafness and leaving dummy electrodes outside the cochlea. Patients with cochlear obstruction showed comparable performance to patients with an open cochlea. OBJECTIVE: To evaluate the background and performance of post-lingually deafened cochlear implantation recipients. PATIENTS AND METHODS: Preoperative and intraoperative factors were collected for 109 cochlear implant subjects. Speech intelligibility scores were obtained and the effects of preoperative and intraoperative factors on postoperative performance were evaluated. RESULTS: The average speech intelligibility score was 85.1% for vowels, 41.1% for consonant-vowel (CV) syllables, and 80.4% for phrases. The correlation coefficient between the age at the operation, the duration of deafness, and the number of electrodes outside the cochlea and the postoperative performance was between 0.03 and -0.27. Patients with cochlear obstruction and patients with open cochlea did not show significant differences in speech intelligibility tests. The onset of deafness (progressive vs sudden) did not have an effect on the speech intelligibility test.

Bilateral congenital ossicular chain disruption mimicking otosclerosis.

A rare case of bilateral congenital ossicular chain disruption whose history and findings mimicked those of otosclerosis is reported. A 54-year-old male consulted us for slowly progressing hearing loss. Audiogram showed bilateral intermediate mixed hearing loss. The stapedial reflex was negative and the tympanogram was normal A-type. Based on the diagnosis of otosclerosis, stapes surgery was planned for the left side. Surgical findings revealed normal mobility of the stapes and a small disruption at the incudostapedial joint with connection of intact mucosa. The disruption was repaired with auto-bone columella. The patient's hearing improved after surgery. The surgery for the other side was performed successively, and similar ossicular disruption was observed. The mechanisms of findings that misled the preoperative diagnosis are discussed.

Stabilization technique for columella using trimmed autologous temporal fascia in type III and IV tympanoplasty--Muffler method.

CONCLUSION: High success rates of recovery of hearing level in type III and IV tympanoplasty could be achieved by this stabilization technique for columella using trimmed autologous temporal fascia. OBJECTIVE: The aim of this study was to evaluate a new stabilization technique for columella using trimmed autologous temporal fascia in type III and IV tympanoplasty. PATIENTS AND METHODS: A total of 55 patients (21 male, 34 female, aged 4-85 years) with chronic otitis media (n=16) and cholesteatoma (n=39) underwent tympanoplasty using this new stabilization technique for columella. Thirty-one patients underwent type III tympanoplasty and 24 patients underwent type IV tympanoplasty. Forty-two patients underwent a staged operation and 13 patients underwent a single operation. The observation period was 3.5 years from 6 months after the last operation. RESULTS: The overall success rates in type III and IV tympanoplasty were 87.1% (27/31) and 83.3% (20/24), respectively. Two of eight patients for whom the procedure was unsuccessful underwent reoperation and they acquired good hearing.

Induction of cell proliferation and beta-catenin expression in rat utricles in vitro.

Limited regenerative response occurs in mammalian vestibular epithelia, although vestibular hair cell regeneration in mammals has been demonstrated under a variety of experimental conditions. Beta-catenin is known to play an important role in both cell-cell adhesion and signal transduction associated with cell proliferation. This study evaluated cell proliferation activity in mammalian vestibular epithelia in organotypic culture and examined the involvement of beta-catenin in cell proliferation in vestibular epithelia. After 72 h of culture, utricles with or without induction of cell proliferation were examined. Cell proliferation was induced by brief exposure to forskolin and supplementation with fetal bovine serum. Cell proliferation activity was assessed by bromodeoxyuridine (BrdU) labeling. Immunohistochemistry was employed for analysis of cellular distribution of beta-catenin. In utricles cultured without induction of cell proliferation. BrdU labeling was not found in vestibular epithelia. Expression of beta-catenin was found in the area corresponding to the distribution of adherens junctions in vestibular epithelia. However, BrdU labeling was identified in sensory epithelia of utricles following induction of cell proliferation, although the number of BrdU-positive cells in sensory epithelia was very limited. Accumulation of beta-catenin was occasionally found in proliferating cells in sensory epithelia; however, it was not always found in BrdU-positive cells. The present findings suggest that beta-catenin may play a role in the induction of cell proliferation in mammal vestibular epithelia.

Transplantation of neural stem cells into explants of rat inner ear.

Damage and loss of hair cells in the inner ear is the most frequent cause of hearing loss and balance disorders. Mammalian hair cells do not regenerate in the conventional ways. To regenerate the hair cell in the mammalian inner ear we transplanted neural stem cells into explants of rat inner ear. The stem cells integrated successfully into the sensory epithelium of the vestibular organs, but not into the organ of Corti. This method is useful to investigate efficient ways to transplant stem cells into the inner ear.

Expression of calretinin by fetal otocyst cells after transplantation into damaged rat utricle explants.

Severe damage by acoustic overstimulation or ototoxins induces inner ear hair cell loss, resulting in permanent hearing loss and balance disorders because hair cell regeneration scarcely occurs in the inner ear sensory organs of mammals. In this study, to evaluate the possibilities of cell transplantation therapy for damaged inner ear sensory organs, dissociated cell cultures of fetal otocyst cells (FOCs) were established from embryonic day 12.5 (E12.5) rat inner ears, and transplanted into gentamicin-treated explants of vestibular sensory epithelia. Two weeks after transplantation, immunohistochemical analysis demonstrated that some of the grafted FOCs survived within the vestibular sensory epithelia and expressed epitopes of calretinin. one of the hair cell marker proteins. These findings indicate that FOCs have the potential to migrate into damaged vestibular epithelia and differentiate into hair cell immunophenotypes. Cell transplantation therapy may be available for functional regeneration in inner ear diseases.

Transplantation of bone marrow stromal cells into the cochlea of chinchillas.

This study aimed to evaluate the potential of bone marrow stromal cells for treatment of inner ear diseases. Autologous marrow cells labeled with Dil were implanted into the inner ear of five gentamicin-treated chinchillas. Histological analysis 3 weeks later revealed robust survival of grafted marrow cells in multiple regions within the cochlea. Marrow cells implanted in the basal turn of the cochlea migrated as far as the apical end or into the spiral ligament of the cochlea. Some grafted cells expressed a neuronal or glial cell marker, indicating their ability to differentiate into neuronal or glial cells. Survival, migrational mobility and differentiation of autologous marrow cells in damaged cochlea suggest their potential as transplants for treatment of various degenerative inner ear diseases.

Bidirectional synaptic plasticity in the cerebellum-like mammalian dorsal cochlear nucleus.

The dorsal cochlear nucleus integrates acoustic with multimodal sensory inputs from widespread areas of the brain. Multimodal inputs are brought to spiny dendrites of fusiform and cartwheel cells in the molecular layer by parallel fibers through synapses that are subject to long-term potentiation and long-term depression. Acoustic cues are brought to smooth dendrites of fusiform cells in the deep layer by auditory nerve fibers through synapses that do not show plasticity. Plasticity requires Ca(2+)-induced Ca(2+) release; its sensitivity to antagonists of N-methyl-d-aspartate and metabotropic glutamate receptors differs in fusiform and cartwheel cells.