Search results for "cochlea"
showing 10 items of 135 documents
Tinnitus e ipertensione neurogena da conflitto neurovascolare: descrizione di un caso
2008
The term neurovascular conflict (NVC) has been introduced to describe the anatomic situation where a nerve makes contact with a blood vessel, artery or vein, at the exit zone from the brain’s trunk. The NVC between the VIII nerve and a blood vessel is clinically associated with tinnitus, vertigo (disabling positional vertigo, DPV), and unilateral sensorineural hearing loss. The blood vessels which most frequently make contact with the VIII nerve are the anterior-inferior cerebellar artery, then the posterior-inferior cerebellar artery and the basilar artery. The authors present an unusual case in which both vertebral arteries (one of which crosses the midline) create a NVC with left acousti…
Augmented reality based middle and inner ear surgical procedures
2020
Otologic procedures involve manipulation of small, delicate and complex structures in the temporal bone anatomy which are in close proxmity of critical nerves and blood vessels. Augmented reality (AR) can highly benefit the otological domain by providing supplementary anatomical and navigational information unified on a single display. However, despite being composed of mainly rigid bony structures, the awareness and acceptance of possibilities of AR systems in otology is fairly low. This project aims at developing video-based AR solutions for middle and inner ear surgical procedures.We propose two applications of AR in this regard. In the first application, information about middle ear cle…
Augmented Reality in minimally invasive otologic surgery and transmodiolar cochlear implantation
2021
Optimal exposure is necessary for minimally invasive otologic surgery. Augmented reality allows to enrich the real environment by adding data without replacing it by a virtual environment and to view this information on a single screen by combining the vision of the operating field and the imaging. This technique is very little described in otology in the literature. This project aims to develop augmented reality solutions for otological surgeries and transmodiolar implantation. To prepare this augmented reality project, we studied the visualization of the middle ear by a virtual endoscope based on preoperative high resolution CT-scans. Then, we worked on the application of augmented realit…
Hierarchical imaging and computational analysis of three-dimensional vascular network architecture in the entire postnatal and adult mouse brain
2021
The formation of new blood vessels and the establishment of vascular networks are crucial during brain development, in the adult healthy brain, as well as in various diseases of the central nervous system. Here, we describe a step-by-step protocol for our recently developed method that enables hierarchical imaging and computational analysis of vascular networks in postnatal and adult mouse brains. The different stages of the procedure include resin-based vascular corrosion casting, scanning electron microscopy, synchrotron radiation and desktop microcomputed tomography imaging, and computational network analysis. Combining these methods enables detailed visualization and quantification of t…
Diagnosis and therapy of vestibular schwannoma.
2009
MRI studies are of paramount importance for diagnosis and follow-up measurements during conservative and postinterventional management of vestibular schwannomas (VS). MRI findings that convey important information for hearing-preservation VS surgery are: length of tumor-cochlear nerve contact, involvement of the internal auditory canal, incomplete filling of internal auditory canal, tumor size less than 15 mm and the intralabyrinthine signal intensity on 3DFT-CISS gradient-echo images. Functional neuro-otologic studies of facial nerve function, hearing and vestibular/balance function provide a valuable means of assessment of the actual impairment of the functional status of the VS patient. …
On the Function of the Spiral Prominence
1967
The suppression of hematic circulation of the internal auditory artery of a guinea-pig causes the necrosis of all anatomic formations of the cochlear duct, with the exception of the organ of Corti of the vestibular segment. The author confirms his hypothesis about the origin of the cochlear endolymph and thinks that the prominence provides the vegetative life of the organ of Corti.
Development and evolution of inner ear sensory epithelia and their innervation
2002
The development and evolution of the inner ear sensory patches and their innervation is reviewed. Recent molecular developmental data suggest that development of these sensory patches is a developmental recapitulation of the evolutionary history. These data suggest that the ear generates multiple, functionally diverse sensory epithelia by dividing a single sensory primordium. Those epithelia will establish distinct identities through the overlapping expression of genes of which only a few are currently known. One of these distinctions is the unique pattern of hair cell polarity. A hypothesis is presented on how the hair cell polarity may relate to the progressive segregation of the six sens…
A suggested role for secondary flow in the stimulation of the cochlear hair cell
1985
The mammalian Corti organ and the reptilian basilar papilla are structures with a curved surface, which vibrate in a fluid medium. This paper is concerned with the role played by the geometric shape of these organs in cochlear hydrodynamics. In association with vibrating structures such as these organs, it can be expected that a stationary current will be initiated due to a nonlinear phenomenon in the boundary layer known as secondary flow. This phenomenon may explain the source of the mechanical nonlinearity in the cochlea.
Intralabyrinthine neurinoma: Management, exeresis and auditory restoration with cochlear implant
2021
Abstract Background and objective Vestibular schwannoma is a benign tumour that originates in the eighth cranial nerve. It is termed intralabyrinthine schwannoma (ILS) when it develops in the inner ear, this being a rare origin. We present our experience in the management of three patients with ILS. Materials and methods The results of tumour excision and cochlear implantation were evaluated in three patients with ILS: two intracochlear schwannomas (ICS) and one intravestibular schwannoma (IVS). Results Prior to surgery, all patients presented progressive sensorineural hearing loss and tinnitus. Complete tumour resection and cochlear implantation was possible in all patients, with favourabl…
Ascorbic acid reduces noise-induced nitric oxide production in the guinea pig ear.
2008
Objectives: Noise-induced hearing loss can be caused, among other causes, by increased nitric oxide (NO) production in the inner ear leading to nitroactive stress and cell destruction. Some studies in the literature suggest that the degree of hearing loss (HL) could be reduced in an animal model through ascorbic acid supplementation. To identify the effect of ascorbic acid on tissue-dependent NO content in the inner ear of the guinea pig, we determined the local NO production in the organ of Corti and the lateral wall separately 6 hours after noise exposure. Study Design: Prospective animal study in guinea pigs. Methods: Over a period of 7 days, male guinea pigs were supplied with minimum (…