Search results for "cochlea"

Characterization of nitric oxide synthase isoforms expressed in different structures of the guinea pig cochlea.

1997

Nitric oxide synthase (NOS) activity and NADPH diaphorase staining has previously been reported in mammalian cochlea. Here we demonstrate immunoreactivity for neuronal-type NOS I and endothelial-type NOS III in the cochlea of the guinea pig. NOS I immunoreactivity was seen in inner and outer hair cells, and spiral ganglion cells. Staining for NOS I was also shown in basal and intermediate cells of the stria vascularis, spiral ligament cells, and the media of vessels near the modiolus. An antibody to NOS III stained primarily vascular endothelial cells. Some NOS III immunoreactivity was also detected in spiral ganglion cells. An antibody to the inducible-type NOS II did not stain any structu…

Otoacoustic emissions: a new method to diagnose hearing impairment in children.

1993

Otoacoustic emissions (OAEs) are epiphenomena of sensitive, amplifying processes during hearing which can be detected in persons with normal inner ear function. They originate from the cochlea and are interpreted as an energy leakage of cochlear processes, perhaps resulting from active outer hair cell movements. OAEs travel from the cochlea through the middle ear to the external auditory canal where they can be detected using sensitive miniature microphones. Transient evoked (TEOAE) tests allow to otoacoustic emissions non-invasively check the integrity of the cochlea. In the neonatal period, registration of OAEs can be accomplished during natural sleep. In infants and neonates TEOAEs can b…

Dexamethasone prevents hearing loss by restoring glucocorticoid receptor expression in the guinea pig cochlea

2015

Objectives/Hypothesis Dexamethasone is widely used in the treatment of various inner ear diseases. However, knowledge about its direct impact on glucocorticoid receptor (GR) expression is still limited. Study Design Prospective animal study in male guinea pigs. Methods A therapeutic concentration of dexamethasone (8mg/mL) or a physiological concentration of NaCl (0.9% solution) were intratympanically injected into the ears of guinea pigs (n = 10 in each case) 14 hours prior to 90 dB noise exposure (1 hour). Eighteen ears were exposed to noise only. Seven untreated ears were used as controls. Auditory brainstem responses were recorded prior to noise exposure or treatment and 2 hours thereaft…

Habenular effect on hippocampal excitability is not cholinergically-mediated.

1989

Technique and value of gas and pantopaque cisternography in the diagnosis of cerebello-pontine angle tumours

1971

The techniques of gas and Pantopaque cisternography are described, as well as the various advantages and disadventages of these methods. Patients without neurological signs in whom a small tumour is suspected in the region of the cerebellopontine angle should be examined with Pantopaque. The examination can be carried out as an outpatient procedure. If definite neurological signs are present, gas cisternography is preferable in order to demonstrate secondary displacements of the ventricular system as well as the tumour itself.

Auditory Training in Deaf Children

2010

Deaf children are, earlier than in the past, identified and can benefit of new and highperformance devices (as cochlear implants or digital hearing aids). However, a great variability in their spoken language skills is observed (12) and first attributable to the well-known effect of the age of auditory rehabilitation (15, 16, 17, 18, 19, 20, 21, 22). The second assessment concerns the way speech disorders are treated: new technologies are not linked to any change in the way speech therapy is delivered, particularly in the field of auditory training. Auditory training constitutes an important part of the speech therapy addressed to the deaf children and must start as soon as possible. The go…

Imaging of inner ear malformations: a primer for radiologists

2021

AbstractIn the multidisciplinary management of patients with inner ear malformations (IEMs), the correct diagnosis makes the differences in terms of clinical and surgical treatment. The complex anatomical landscape of the inner ear, comprising several small structures, makes imaging of this region particularly challenging for general radiologists. Imaging techniques are important for identifying the presence and defining the type of IEM and the cochlear nerve condition. High-resolution magnetic resonance imaging (MRI) sequences and high-resolution computed tomography (HRCT) are the mainstay imaging techniques in this area. Dedicated MRI and HRCT protocols play an important role in the diagn…

Prospective Validation of Facial Nerve Monitoring to Prevent Nerve Damage During Robotic Drilling

2019

Facial nerve damage has a detrimental effect on a patient's life, therefore safety mechanisms to ensure its preservation are essential during lateral skull base surgery. During robotic cochlear implantation a trajectory passing the facial nerve at <0.5 mm is needed. Recently a stimulation probe and nerve monitoring approach were developed and introduced clinically, however for patient safety no trajectory was drilled closer than 0.4 mm. Here we assess the performance of the nerve monitoring system at closer distances. In a sheep model eight trajectories were drilled to test the setup followed by 12 trajectories during which the ENT surgeon relied solely on the nerve monitoring system and…

Akustikusneurinom als Ursache einer progredienten kindlichen Hörstörung

2003

Background: Neurinomas of the vestibulocochlear nerve unrelated to neurofibromatosis in children are extremely rare. Only 20 cases in children under the age of 16 are reported in the literature. Progressive unilateral hearing loss, tinnitus, vertigo and neurological deficits due to cranial nerve or brainstem compression are clinical signs. Patient and Results: We report on the case of a 12-years-old girl with an unilateral hearing loss, progressing to total deafness. Otoacoustic emissions were normal. In the MRI a large cerebellopontine angle tumor was found, identified as schwannoma of the vestibulocochlear nerve. Conclusions: The importance of MR Imaging in children with progressive unila…

Alteration of the Calcium Content in Inner Hair Cells of the Cochlea of the Guinea Pig after Acute Noise Trauma with and without Application of the O…

1999

Calcium ions are known to be important to the process of signal transduction across the apical and basal sides of the inner hair cells. Calcium channel antagonists have been demonstrated by light microscopy to provide protection against acoustic trauma. To evaluate the protective effect of calcium channel blocker on the inner ear cells to noise exposure, the amount of the histochemical reaction products formed in the cytoplasm of the inner hair cells of the guinea pig after application of pyroantimonate was measured by an image processing system connected to an energy-filtering transmission electron microscope (EFTEM). Compared to untreated control specimens (experimental animal group I) th…