scholarly journals Radiologic and Functional Evaluation of Electrode Dislocation from the Scala Tympani to the Scala Vestibuli in Patients with Cochlear Implants

2014 ◽  
Vol 36 (2) ◽  
pp. 372-377 ◽  
Author(s):  
N. Fischer ◽  
L. Pinggera ◽  
V. Weichbold ◽  
D. Dejaco ◽  
J. Schmutzhard ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Functional Evaluation ◽  
Scala Tympani ◽  
Scala Vestibuli

Scala vestibuli cochlear implantation in patients with partially ossified cochleas

2002 ◽  
Vol 116 (11) ◽  
pp. 946-950 ◽  
Author(s):  
Stefano Berrettini ◽  
Francesca Forli ◽  
Emanuele Neri ◽  
Giovanni Segnini ◽  
Stefano Sellari Franceschini
Keyword(s):  
Cochlear Implants ◽  
Systemic Vasculitis ◽  
Electrode Array ◽  
Common Finding ◽  
Scala Tympani ◽  
Inferior Segment ◽  
Cochlear Ossification ◽  
Alternative Site ◽  
Current Report ◽  
Scala Vestibuli

Partial cochlear obstruction is a relatively common finding in candidates for cochlear implants and frequently involves the inferior segment of the scala tympani in the basal turn of the cochlea. In such patients, the scala vestibuli is often patent and offers an alternative site for implantation. The current report describes two patients with such partial obstruction of the inferior segment of the basal cochlear turn, caused in one case by systemic vasculitis (Takayasu’s disease) and in the other by obliterative otosclerosis. A scala vestibuli implantation allowed for complete insertion of the electrode array. No problems were encountered during the surgical procedures and the good post-operative hearing and communicative outcomes achieved were similar to those reported in patients without cochlear ossification.The importance of accurate pre-operative radiological study of the inner ear is underscored, to disclose the presence and define the features of the cochlear ossification and ultimately to properly plan the surgical approach.

Na and nonelectrolyte entry into inner ear fluids of the rat

1987 ◽  
Vol 253 (1) ◽  
pp. F50-F58 ◽  
Author(s):  
O. Sterkers ◽  
E. Ferrary ◽  
G. Saumon ◽  
C. Amiel
Keyword(s):  
Cerebrospinal Fluid ◽  
Inner Ear ◽  
Lateral Ventricle ◽  
Endothelial Barrier ◽  
Scala Tympani ◽  
Epithelial Secretion ◽  
Kinetics Of ◽  
Hydrophilic Solutes ◽  
Inner Ear Fluids ◽  
Scala Vestibuli

Kinetics of hydrophilic solute entry into endolymph (EL), perilymph (PL), and cerebrospinal fluid (CSF) were studied after intravenous administration (sodium, urea, glycerol, mannitol, sucrose) and cerebral lateral ventricle injection (urea, sucrose) of tracers in anesthetized rats. Samples of cochlear EL, PL of scala vestibuli (PLV), PL of scala tympani (PLT), and cisternal CSF were obtained. The data showed slow entry of tracers in PLV, PLT, and CSF as follows: Na greater than urea greater than mannitol approximately sucrose; slower entry of mannitol and sucrose in PLT and CSF than in PLV; 1 h delayed peak of radioactivity in PLV compared with the immediate peaks in PLT and CSF after CSF injection, and the value of PLV peak was 13% that in CSF; extremely slow entry of nonelectrolytes in EL. These results indicate that PLV originates mainly from plasma across a blood-perilymph barrier that restricts the entry of small hydrophilic solutes. The blood-perilymph barrier is most likely composed of an endothelial barrier associated with an epithelial secretion. The latter could be located at the vasculo-epithelial zone of the spiral limbus.

K, Cl, and H2O entry in endolymph, perilymph, and cerebrospinal fluid of the rat

1982 ◽  
Vol 243 (2) ◽  
pp. F173-F180 ◽  
Author(s):  
O. Sterkers ◽  
G. Saumon ◽  
P. Tran Ba Huy ◽  
C. Amiel
Keyword(s):  
Cerebrospinal Fluid ◽  
Potassium Chloride ◽  
Intravenous Administration ◽  
Compartmental Analysis ◽  
Water Entry ◽  
Scala Tympani ◽  
Rapid Turnover ◽  
Kinetics Of ◽  
Scala Vestibuli

The kinetics of radioactive potassium, chloride, and water entry into endolymph, perilymph, and cerebrospinal fluid were studied after intravenous administration of tracers in anesthetized and nephrectomized rats. Samples of cochlear endolymph, perilymph of scala vestibuli, perilymph of scala tympani, and cisternal cerebrospinal fluid were obtained. The data showed: 1) a rapid turnover of water in endolymph, perilymph, and cerebrospinal fluid, since 3H2O equilibrated with plasma in a few minutes; 2) a slow entry of 42K and 36Cl in perilymph, since 36Cl equilibrated with plasma after 2 h and 42K did not at 6 h; 3) an extremely slow entry of 42K and 36Cl in endolymph, since no equilibrium with plasma was obtained within the 5 h of the experiments. The comparison of the compartmental analysis of our data with the results of other studies using perilymphatic perfusion of tracers indicated that perilymph rather than plasma may be considered as the precursor of endolymph.

Facilitated transfer of glucose from blood into perilymph in the rat cochlea

1987 ◽  
Vol 253 (1) ◽  
pp. F59-F65 ◽  
Author(s):  
E. Ferrary ◽  
O. Sterkers ◽  
G. Saumon ◽  
P. Tran Ba Huy ◽  
C. Amiel
Keyword(s):  
Cerebrospinal Fluid ◽  
Linear Function ◽  
Intravenous Administration ◽  
Glucose Concentration ◽  
Concentration Ratio ◽  
Facilitated Transport ◽  
Scala Tympani ◽  
Glucose Transfer ◽  
Rat Cochlea ◽  
Scala Vestibuli

The transport of glucose into cochlear endolymph, perilymph of scala vestibuli and perilymph of scala tympani, and cerebrospinal fluid (CSF) was studied after intravenous administration of tracers of D-glucose, L-glucose, and 3-O-methyl-D-glucose in anesthetized rats. The data showed that D-glucose concentrations in perilymph of scala vestibuli, perilymph of scala tympani, and CSF were approximately 50%, and in endolymph less than 10%, that in plasma; D-glucose concentration in perilymph of scala vestibuli, perilymph of scala tympani, and CSF increased as a linear function of that in plasma; D-glucose entry into perilymph of scala vestibuli, perilymph of scala tympani, and CSF was more rapid than that of L-glucose; after infusion of 3-O-methyl-D-glucose, but not after that of mannitol, both the D-glucose concentration ratio of perilymph over plasma and D-glucose transfer into perilymph were lowered. These results indicate that D-glucose enters into perilymph of scala vestibuli by a facilitated transport, possibly located at the blood-perilymph barrier.

Evaluation of the HiFocus® electrode array with positioner in human temporal bones

2003 ◽  
Vol 117 (7) ◽  
pp. 527-531 ◽  
Author(s):  
Antje Aschendorff ◽  
Thomas Klenzner ◽  
Bernhard Richter ◽  
Ralf Kubalek ◽  
Heiner Nagursky ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Electrode Array ◽  
Scala Tympani ◽  
X Ray ◽  
Temporal Bones ◽  
Scala Vestibuli

The aim of the study presented was to assess the insertion mode and possible intracochlear trauma after implantation of the HiFocus® electrode with positioner in human temporal bones. The study was performed in five freshly frozen temporal bones. The position of electrodes was evaluated using conventional X-ray analysis, rotational tomography and histomorphological analysis. Insertion of the HiFocus® electrode with positioner resulted in considerable trauma to fine cochlear structures including fracture of the osseous spiral lamina, dislocation of the electrode array from the scala tympani into the scala vestibuli and fracture of the modiolus close to the cochleostomy. The implication of the results regarding clinical outcome will be discussed.

Use of Multichannel Cochlear Implants in Obstructed and Obliterated Cochleas

1988 ◽  
Vol 98 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Bruce J. Gantz ◽  
Brian F. Mccabe ◽  
Richard S. Tyler
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implants ◽  
Middle Ear ◽  
External Auditory Canal ◽  
Single Channel ◽  
Scala Tympani ◽  
Radiographic Evidence ◽  
Early Experiences ◽  
Channel Electrode ◽  
Gain Access

Obstruction that occurs within the scala tympani (after meningitis or otosclerosis) has been considered a contraindication for placement of a multichannel cochlear implant electrode. Two patients who exhibited radiographic evidence of intracochlear narrowing and obliteration were implanted with multichannel electrodes. Implantation involved creation of a channel for the electrode to wrap around the modiolus. The middle ear cavity and the external auditory canal also had to be removed to gain access. The response of one of the patients was similar to that of patients with normal cochlear anatomy who use multichannel devices. These early experiences, along with one case in which a single-channel electrode was placed, is presented.

scholarly journals Evaluation of the Relationship between the NRT-Ratio, Cochlear Anatomy, and Insertions Depth of Perimodiolar Cochlear Implant Electrodes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Philipp Mittmann ◽  
Grit Rademacher ◽  
Sven Mutze ◽  
Frederike Hassepass ◽  
Arneborg Ernst ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Electrode Array ◽  
Scala Tympani ◽  
Flat Panel ◽  
Insertion Depth ◽  
Tomography System ◽  
Neural Response Telemetry ◽  
Auditory Performance ◽  
The Relationship ◽  
Scala Vestibuli

The position of the cochlear implant electrode array within the scala tympani is essential for an optimal postoperative hearing benefit. If the electrode array changes in between the scalae intracochlearly (i.e., from scala tympani to scala vestibuli), a reduced auditory performance can be assumed. We established a neural response telemetry-ratio (NRT-ratio) which corresponds with the scalar position of the electrodes but shows within its limits a variability. The aim of this study was to determine if insertion depth angle or cochlea size influences the NRT-ratio. The intraoperative electrophysiological NRT data of 26 patients were evaluated. Using a flat panel tomography system, the position of the electrode array was evaluated radiologically. The insertion depth angle of the electrode, the cochlea size, and the NRT-ratio were calculated postoperatively. The radiological results were compared with the intraoperatively obtained electrophysiological data (NRT-ratio) and statistically evaluated. In all patients the NRT-ratio, the insertion depth angle, and the cochlea size could be determined. A significant correlation between insertional depth, cochlear size, and the NRT-ratio was not found. The NRT-ratio is a reliable electrophysiological tool to determine the scalar position of a perimodiolar electrode array. The NRT-ratio can be applied independent from insertion depth and cochlear size.

Comparative Impacts of Scala Vestibuli Versus Scala Tympani Cochlear Implantation on Auditory Performances and Programming Parameters in Partially Ossified Cochleae

2018 ◽  
Vol 39 (6) ◽  
pp. 700-706 ◽  
Author(s):  
Mathieu Trudel ◽  
Mathieu Côté ◽  
Daniel Philippon ◽  
David Simonyan ◽  
Noémie Villemure-Poliquin ◽  
...  
Keyword(s):  
Cochlear Implantation ◽  
Scala Tympani ◽  
Scala Vestibuli

Acute labyrinthitis associated with systemicCandida albicansinfection in ageing mice

1996 ◽  
Vol 110 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Robert B. Ashman ◽  
John M. Papadimitriou ◽  
Alma Fulurija
Keyword(s):  
Risk Factor ◽  
Candida Albicans ◽  
Inner Ear ◽  
Inbred Mice ◽  
Semicircular Canals ◽  
Systemic Infection ◽  
Opportunistic Pathogen ◽  
Scala Tympani ◽  
Membranous Labyrinth ◽  
Scala Vestibuli

AbstractThe yeastCandida albicansis an important opportunistic pathogen that has been associated with disease of the inner ear. This study describes the histopathology of acute labyrinthitis caused by systemic infection with C.albicansin ageing inbred mice. Within four days after infection, yeast and hyphal forms of C.albicanswere found in the membranous labyrinth. The utricle and the adjacent parts of the ampullary regions of the semicircular canals were most severely affected, but damage was also seen in the scala media, the Scala tympani, the saccule, and the scala vestibuli. In the utricle, the lining epithelium of the membranous labyrinth was disrupted, and the lining cells of the vestibular membrane showed foci in which the membrane was disrupted. The data suggest that age may represent a risk factor for fungal labyrinthitis.

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