scholarly journals The Effect of Pulling Out Cochlear Implant Electrodes on Inner Ear Microstructures: A Temporal Bone Study

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Ingo Todt ◽  
Rainer O. Seidl ◽  
Arne Ernst
Keyword(s):  
Cochlear Implant ◽  
Inner Ear ◽  
Temporal Bone ◽  
Basilar Membrane ◽  
Temporal Sequence ◽  
Pull Out ◽  
Temporal Bones

The exchange of an cochlear implant or the re-positioning of an electrode have become more frequently required than a decade ago. The consequences of such procedures at a microstructural level within the cochlea are not known. It was the aim of the present study to further investigate the effects of an CI electrode pull-out. Therefore 10 freshly harvested temporal bones (TB) were histologically evaluated after a cochlear implant electrode pull-out of a perimodiolar electrode. In additional 9 TB the intrascalar movements of the CI electrode while being pulled-out were digitally analysed by video- capturing. Histologically, a disruption of the modiolar wall or the spiral osseous lamina were not observed. In one TB, a basilar membrane lifting up was found, but it could not be undoubtedly attributed to the pull-out of the electrode. When analyzing the temporal sequence of the electrode movement during the pull-out, the electrode turned in one case so that the tip elevates the basilar membrane. The pull- out of perimodiolarly placed CI electrodes does not damage the modiolar wall at a microstructural level and should be guided (e.g., forceps) to prevent a 90 o turning of the electrode tip into the direction of the basilar membrane.

Experimental Viral Infections of the Inner Ear II. Simian Virus 40 Induced Tumors of the Temporal Bone

1979 ◽  
Vol 88 (2) ◽  
pp. 198-204 ◽  
Author(s):  
Larry E. Davis ◽  
George T. Nager ◽  
Richard T. Johnson
Keyword(s):  
Inner Ear ◽  
Choroid Plexus ◽  
Temporal Bone ◽  
Viral Infections ◽  
Choroid Plexus Papilloma ◽  
Internal Auditory Canal ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Cochlear Aqueduct ◽  
Temporal Bones

Pathological and virological studies were performed on temporal bones of 23 hamsters which developed tumors subsequent to neonatal inoculation of simian virus 40 (SV40). Four to five months after viral inoculation, 22 hamsters developed undifferentiated sarcomas in the subcutaneous space adjacent to the temporal bone. Nine tumors invaded the temporal bone, occasionally extending to the subarachnoid space but not to the inner ear. Choroid plexus papillomas developed in four animals, with one tumor demonstrating invasion of the cochlear aqueduct, internal auditory canal, and cochlear modiolus. Cells grown from a sarcoma and a choroid plexus papilloma contained tumor antigen and established that the tumors were SV40 virus induced.

Temporal Bone Pathology in Scuba Diving Deaths

1993 ◽  
Vol 109 (3) ◽  
pp. 514-521 ◽  
Author(s):  
Patrick J. Antonelli ◽  
G. Joseph Parell ◽  
Gary D. Becker ◽  
Michael M. Paparella
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Round Window ◽  
Scuba Diving ◽  
Round Window Membrane ◽  
Bone Pathology ◽  
Rapid Ascent ◽  
Temporal Bones ◽  
Inner Ear Damage ◽  
Air Cells

Scuba diving has long been associated with otologic injuries; however, little is known about temporal bone pathology in diving-related deaths. We examined 18 temporal bones from 11 divers who died, primarily from complications of rapid ascent. Bleeding into the middle ear and mastoid air cells was nearly universal. Inner ear damage included hemorrhage around Reissner's membrane and the round window membrane and rupture of the utricle and saccule. Most of the observed inner ear damage was not surgically treatable. (OTOLARYNGOL HEAD NECK SURG 1993;109:514-21.)

Temporal Bone Findings in Cases of Salt Water Drowning

1983 ◽  
Vol 92 (2) ◽  
pp. 134-136 ◽  
Author(s):  
George Kelemen
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Middle Ear ◽  
Salt Water ◽  
Round Window ◽  
Scuba Diving ◽  
Serial Sections ◽  
Histopathological Findings ◽  
Histopathological Features ◽  
Temporal Bones

The otologic literature contains no description of the histopathological features of temporal bones of persons who perished in drowning accidents. Three temporal bones from two fatal cases of drowning were studied in serial sections. Two temporal bones were from a man aged 31 years who collapsed after scuba diving and died three days later. One temporal bone was from a 32-year-old man, serving in the navy, who drove his car, probably accidentally, into the sea and drowned in it. Histopathological findings appeared to be similar in the two cases. Diffuse hemorrhage was evident throughout the middle ear and inner ear. The tympanic and round window membranes appeared to be intact although hemorrhage had occurred within the tissue layers of the membranes. This finding contrasts with observations of ruptured membranes by other investigators.

scholarly journals Characteristics and clinical use of ocular and cervical vestibular evoked myogenic potentials for evaluating paediatric candidates for cochlear implants

2016 ◽  
Vol 131 (1) ◽  
pp. 56-63 ◽  
Author(s):  
X-D Xu ◽  
J Hu ◽  
Q Zhang ◽  
Y Zhang ◽  
X-T Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cochlear Implant ◽  
Inner Ear ◽  
Temporal Bone ◽  
Cochlear Implants ◽  
Bone Structure ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Myogenic Potential ◽  
Ear Malformations

AbstractObjective:This study aimed to define the characteristics and use of ocular and cervical vestibular evoked myogenic potentials for evaluating paediatric cochlear implant candidates.Methods:Ocular and cervical vestibular evoked myogenic potentials of 34 paediatric cochlear implant candidates were analysed. All patients also underwent a routine audiological examination, including computed tomography.Results:In all, 27 patients with normal inner-ear structures had absent or impaired vestibular evoked myogenic potential responses. In paediatric candidates with inner-ear malformations, ocular and cervical vestibular evoked myogenic potentials had lower thresholds and higher amplitudes. Vestibular evoked myogenic potential responses in this cohort were classified into three groups. There was significant concordance between vestibular evoked myogenic potentials and temporal bone computed tomography findings.Conclusion:Ocular and cervical vestibular evoked myogenic potential waveforms were different in paediatric candidates with normal and abnormal inner-ear structures. Therefore, vestibular evoked myogenic potential responses can indicate temporal bone structure.

Temporal Bone Histopathology in Charge Association

2002 ◽  
Vol 111 (5) ◽  
pp. 397-401 ◽  
Author(s):  
Shin-Ichi Haginomori ◽  
Makoto Miura ◽  
Isamu Sando ◽  
Margaretha L. Casselbrant
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Middle Ear ◽  
Congenital Heart ◽  
The Other ◽  
Otologic Surgery ◽  
Charge Association ◽  
Ear Anomalies ◽  
Temporal Bones ◽  
Central Nervous System Anomalies

Three temporal bones obtained at autopsy from 2 patients with CHARGE association (Coloboma, congenital Heart disease, Atresia of choanae, mental Retardation and/or central nervous system anomalies, Genital hypoplasia, and Ear anomalies) were examined histopathologically. Both temporal bones from 1 patient showed multiple anomalies in the middle ear, inner ear, and facial nerve. However, the temporal bone obtained from the other patient showed almost normal structures in the inner ear, middle ear, and eustachian tube. These results are different from those of 2 previous reports of temporal bone histopathology regarding CHARGE association. This difference suggests that CHARGE association may arise not from one etiopathogenetic factor, but from complex factors. Special attention to dehiscent facial canal and perilymphatic gusher during otologic surgery in patients with CHARGE association is discussed.

scholarly journals Validation of inner ear MRI in patients with Ménière’s disease by comparing endolymphatic hydrops from histopathologic specimens

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Young Sang Cho ◽  
Jong Sei Kim ◽  
Min Bum Kim ◽  
Sung Min Koh ◽  
Chang Hee Lee ◽  
...  
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Semicircular Canal ◽  
Endolymphatic Hydrops ◽  
Semicircular Canals ◽  
Meniere’S Disease ◽  
Ménière’S Disease ◽  
Affected Side ◽  
Mri Scans ◽  
Temporal Bones

AbstractIntravenous gadolinium-enhanced inner-ear magnetic resonance imaging (IV-Gd inner-ear MRI) has been used to visualize endolymphatic hydrops (EH) in clinical diagnosis of Ménière’s disease (MD). However, lack of histological validation has led to several concerns regarding how best to interpret the resulting images. Here, we compared hydropic changes in temporal bone specimens with the results of IV-Gd inner-ear MRI in patients with MD. Histopathologic images of temporal bones from 37 patients with MD and 10 healthy controls were collected from the National Temporal Bone Bank of the Massachusetts Eye and Ear Infirmary in the United States. The EH ratios in the vestibule and cochlea were calculated from temporal bones using the methods used for IV-Gd inner-ear MRI, and the degree to which the saccular and utricular hydrops contributed to vestibular hydrops was measured. The presence of hydropic change in each semicircular canal was assessed using temporal bone images and compared with IV-Gd inner-ear MRI scans of 74 patients with MD. Based on human temporal bone imagery, the EH ratios in the cochlea and the vestibule on the affected side were 0.314 and 0.757, respectively. In the healthy control group, the ratio was 0.064 for the cochlea and 0.289 for the vestibule; these values were significantly different from those for the affected side of MD patients. The values for the affected ear were similar to the ratios from the IV-Gd inner-ear MRI scans in MD patients. In the vestibule, saccular hydrops were more common than utricular hydrops. The average EH ratios in the saccule and utricle were 0.513 and 0.242, respectively. No significant hydropic change from each of three semicircular canals was evident in temporal bone histopathology. However, herniation of otolithic organs (saccule or utricle) into the lateral semicircular canal was found in 44.4% of the patients, with saccular herniation (24.8%) more common than utricular herniation (16.7%). Although IV-Gd inner-ear MRI might not reflect fully the results of actual histopathology due to the limited resolution of MRI and image-processing techniques, the measured EH ratios from temporal bone specimens and IV-Gd inner-ear MRI scans were similar. Hydropic change in the three semicircular canals was not significant at either the ampullated or nonampullated end. Canal invasion of vestibular hydrops seen on MRI also appeared in temporal bone histopathology, and saccular invasion was dominant.

Developmental Temporal Bone Anatomy and its Clinical Significance: Variations on Themes by H. F. Schuknecht

1984 ◽  
Vol 93 (4_suppl) ◽  
pp. 101-109 ◽  
Author(s):  
Gershon J. Spector
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Facial Canal ◽  
Sources Of Information ◽  
Tumor Extension ◽  
Developmental Anatomy ◽  
Bone Trauma ◽  
Temporal Bone Anatomy ◽  
Mechanisms Of Development ◽  
Temporal Bones

Fifty-eight fetal and neonatal temporal bones were studied to evaluate the mechanisms of development of the hiatus of the facial canal, hypotympanic fissures, periotic duct, tympanomeningeal fissures, and fetal inner ear vascularity. These were correlated with the clinical pathologic entities of temporal bone trauma, glomus jugulare tumor extension within the temporal bone, CNS-temporal septic conduits, and inner ear vascularity. Temporal bone developmental anatomy and histopathology provide rich sources of information on which to base the scientific and clinical study of otology.

scholarly journals CT Imaging Categorization and Biomarker Study of Anomalous Tympanic Segment of the Facial Nerves in Patients With Hearing Loss in the Absence of Microtia

2019 ◽  
Vol 98 (6) ◽  
pp. 340-345
Author(s):  
Nisa Oren ◽  
Daniel Thomas Ginat
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Temporal Bone ◽  
Charge Syndrome ◽  
Oval Window ◽  
High Resolution Computed Tomography ◽  
Facial Nerves ◽  
Ear Anomalies ◽  
Temporal Bones ◽  
Congenital Syndrome

The purpose of this study is to categorize anomalous tympanic facial nerve (FN) on high-resolution computed tomography (HRCT) and to determinate the significance of associated temporal bone anomalies and congenital syndromes without microtia in patients with hearing loss. A retrospective analysis of HRCT findings in 30 temporal bones in 18 patients with anomalous FN was performed. Abnormalities of the tympanic FN were categorized as follows: category 1: FN medially positioned, but above the oval window; category 2: FN in the oval window niche; and category 3: FN below the oval window. Potential associated findings that were assessed included stapes abnormalities, oval window atresia, and inner ear anomalies, as well as the presence of a known congenital syndrome with hearing loss. The most common type of anomalous tympanic FN was category 1 (67%, n = 20), following by group 2 (20%, n = 6) and group 3 (13%, n = 4). Stapes anomalies were detected in 77% of temporal bones (n = 23), oval window atresia was detected in 43% of temporal bones (n = 13), and inner ear anomalies were detected in 70% of temporal bones (n = 21). Anomalous tympanic facial nerves in temporal bone with conductive hearing loss were often (60%) not associated with oval window atresia. The combination of aberrant tympanic FN and inner ear anomalies was significantly ( P = .038) associated with a known congenital syndrome (6 patients), including CHARGE syndrome, oculo-auriculo-vertebral spectrum, Pierre-Robin sequences, and Down syndrome. Therefore, an anomalous tympanic FN in conjunction with inner ear anomalies appears to be a biomarker for certain congenital syndromes with hearing loss in the absence of microtia.

scholarly journals Three-Dimensional High-Resolution Temporal Bone Histopathology Identifies Areas of Vascular Vulnerability in the Inner Ear

2021 ◽  
pp. 1-11
Author(s):  
Bela Büki ◽  
Antonia Mair ◽  
Jacob M. Pogson ◽  
Nicholas S. Andresen ◽  
Bryan K. Ward
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Three Dimensional ◽  
Microvascular Disease ◽  
Clinical Findings ◽  
Vascular Compression ◽  
Otic Capsule ◽  
Vascular Disorders ◽  
Dimensional Reconstruction ◽  
Temporal Bones

<b><i>Objectives:</i></b> Hypothesized causes of vestibular neuritis/labyrinthitis include neuroinflammatory or vascular disorders, yet vascular disorders of the inner ear are poorly understood. Guided by known microvascular diseases of the retina, we developed 2 hypotheses: (1) there exist vascular vulnerabilities of artery channels in cases of hypothetical nerve swelling for the superior, inferior, and vestibulocochlear artery and (2) there are arteriovenous crossings that could compromise vascular flow in disease states. <b><i>Methods:</i></b> Two fully mounted and stained temporal bones were used to render three-dimensional reconstructions of the labyrinth blood supply. Using these maps, areas of potential vascular compression were quantified in 50 human temporal bones. <b><i>Results:</i></b> Although inner ear arteries and veins mostly travel within their own bony channels, they may be exposed (1) at the entrance into the otic capsule, and (2) where the superior vestibular vein crosses the inferior vestibular artery. At the entry into the otic capsule, the ratio of the soft tissue to total space for the superior vestibular artery was significantly greater than the inferior vestibular artery/cochleovestibular artery (median 44, interquartile range 34–55 vs. 14 [9–17], <i>p</i> &#x3c; 0.0001). <b><i>Conclusions:</i></b> Three-dimensional reconstruction of human temporal bone histopathology can guide vascular studies of the human inner ear. Studies of retinal microvascular disease helped identify areas of vascular vulnerability in cases of hypothetical nerve swelling at the entrance into the otic capsule and at an arteriovenous crossing near the saccular macula. These data may help explain patterns of clinical findings in peripheral vestibular lesions.

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