Microfissure between the round Window Niche and Posterior Canal Ampulla

1977 ◽  
Vol 86 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Yasumasa Okano ◽  
Eugene N. Myers ◽  
David R. Dickson
Keyword(s):  
Round Window ◽  
Pathological Finding ◽  
Anatomical Structure ◽  
Fetal Life ◽  
Human Fetuses ◽  
Posterior Canal ◽  
Mesenchymal Tissue ◽  
One Year ◽  
Round Window Niche ◽  
Temporal Bones

The microfissure between the round window niche and the posterior canal ampulla was examined in fetal, child, and adult human temporal bones. The communication which was filled with mesenchymal tissue and blood vessels extending from the middle ear, was observed between the round window niche and the posterior canal ampulla in 10 to 15-week human fetuses. The mesenchymal tissue in the communication was replaced by cartilage with advancing age of the fetus. No communication was observed at birth. From newborn to 12 months of age, no microfissure was observed. After one year of age, the microflssure was first observed and the frequency of the observation increased with increasing age of the patient. After six years of age, the microfissure was observed bilaterally in 100% of cases studied. The microflssure has its origin from the communication between the round window niche and the posterior canal ampulla in fetal life, and is a normal developmental and anatomical structure, and not a pathological finding.

Locating the scala media in the fixed human temporal bone for therapeutic access: a preliminary study

2006 ◽  
Vol 120 (11) ◽  
pp. 914-915 ◽  
Author(s):  
H Pau ◽  
P Fagan ◽  
S Oleskevich
Keyword(s):  
Temporal Bone ◽  
Round Window ◽  
Oval Window ◽  
Horizontal Line ◽  
Point Of Entry ◽  
Anterior Edge ◽  
Human Temporal Bone ◽  
Round Window Niche ◽  
Temporal Bones ◽  
A Site

Objective: To investigate the location of the scala media in relation to the round window niche in human temporal bones.Design: Ten human temporal bones were investigated by radical mastoidectomy and promontory drill-out.Setting: Temporal bone laboratory.Outcome measures: The distance from the scala media to the anterior edge of the round window niche, measured by Fisch's stapedectomy measuring cylinders.Results: The scala media was identified at the transection point of a vertical line 1.6 to 2.2 mm (mean=1.8 mm; standard deviation=0.2) anterior to the anterior edge of the round window niche and a horizontal line 0.2 mm inferior to the lower border of the oval window.Conclusion: This report demonstrates the point of entry into the scala media via the promontory in fixed temporal bone models, which may provide a site of entry for stem cells and gene therapy insertion.

Middle-ear endoscopy and trans-tympanic drug delivery using an interventional sialendoscope: feasibility study in human cadaveric temporal bones

2010 ◽  
Vol 124 (12) ◽  
pp. 1263-1267 ◽  
Author(s):  
G Peters ◽  
J Lin ◽  
M A Arriaga ◽  
D W Nuss ◽  
B Schaitkin ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Eustachian Tube ◽  
Middle Ear ◽  
Guide Wire ◽  
Round Window ◽  
Human Cadavers ◽  
Incudostapedial Joint ◽  
Round Window Niche ◽  
Temporal Bones ◽  
Inferior Quadrant

AbstractObjective:This study aimed to assess the feasibility of using a 1.3 mm, semi-rigid, interventional salivary endoscope for middle-ear endoscopy, and as a trans-tympanic route for delivery of medication, in human cadaveric temporal bones.Study design:Human cadaveric study.Methods:Five temporal bones harvested from human cadavers were examined. A 1.3 mm, interventional sialendoscope was used to make endoscopy-assisted myringotomy incisions in the postero-inferior quadrant (n = 5) and the antero-inferior quadrant (n = 3).Results:Middle-ear examination was successful in all specimens (n = 5). Access to the round window niche and adequate visualisation of the round window were achieved in all five temporal bones (100 per cent). A guide wire could be navigated to the round window niche without difficulty. Other structures identified in all specimens included the incudostapedial joint, stapedius tendon, pyramidal eminence and facial nerve via an extended myringotomy incision. The anterior middle-ear space was also successfully examined through an endoscope-guided anterior myringotomy. The opening to the eustachian tube was visualised and cannulated with a guide wire in all preparations in which this was attempted (n = 3).Conclusions:The 1.3 mm, interventional sialendoscope allowed adequate visualisation of the eustachian tube, middle-ear space and round window niche, with interventional capabilities, in a cadaveric model. Our result validates the feasibility of its use for trans-tympanic drug delivery.

The Crista Fenestra and Its Impact on the Surgical Approach to the Scala Tympani during Cochlear Implantation

2017 ◽  
Vol 22 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Roberto D. Angeli ◽  
Joel Lavinsky ◽  
Enio T. Setogutti ◽  
Luiz Lavinsky
Keyword(s):  
High Resolution ◽  
Cochlear Implantation ◽  
Round Window ◽  
Ct Scanning ◽  
Round Window Membrane ◽  
Scala Tympani ◽  
High Resolution Computed Tomography ◽  
High Resolution Ct ◽  
Round Window Niche ◽  
Temporal Bones

Objective: The aim of this work was to describe the dimensions of the crista fenestra and determine its presence by means of high-resolution computed tomography (CT) for the purpose of cochlear implantation via the round window approach. Methods: A series of 10 adult human temporal bones underwent high-resolution CT scanning and were further dissected for microscopic study of the round window niche. Results: In all of the specimens, the round window membrane was fully visualized after the complete removal of bony overhangs. The crista fenestra was identified as a sharp bony crest located in the anterior and inferior borders of the niche; its area ranged from 0.28 to 0.80 mm2 (mean 0.51 ± 0.18). The proportion of the area occupied by the crista fenestra in the whole circumference of the round window ranged from 23 to 50% (mean 36%). We found a moderate positive correlation between the area of the niche and the dimensions of the crista fenestra (Spearman rho: 0.491). In every case, high-resolution CT scanning was unable to determine the presence of the crista fenestra. Conclusion: The crista fenestra occupies a variable but expressive area within the bony round window niche. Narrower round window niches tended to house smaller crests. The presence of the crista fenestra is an important obstacle to adequate access to the scala tympani. Nevertheless, a high-resolution CT scan provides no additional preoperative information with regard to its presence for the purpose of surgical access to the scala tympani via the round window niche.

Microfissure in the Oval Window Area

1981 ◽  
Vol 90 (2) ◽  
pp. 174-180 ◽  
Author(s):  
Takehiko Harada ◽  
Isamu Sando ◽  
Eugene N. Myers
Keyword(s):  
Temporal Bone ◽  
Round Window ◽  
Vertical Plane ◽  
Careful Analysis ◽  
Oval Window ◽  
Annular Ligament ◽  
Round Window Niche ◽  
Window Area ◽  
Most Probable Explanation ◽  
Temporal Bones

Examination of 331 human temporal bones revealed the presence of a microfissure in the oval window area in 25%. The youngest temporal bone in which the microfissure was observed was from a child eight years old and the oldest temporal bone was from an individual 102 years old. It appears that the microfissure in this area occurs extremely rarely before 10 years of age, that it begins to be observed after the age of 10, and that the incidence of this fissure increases sharply at about age 40. In 61% of the bones in which the microfissure was observed, it was present both superior and inferior to the oval window in almost the same vertical plane. In none of the bones, however, did it extend beyond the annular ligament to the footplate. The histological appearance of the microfissure in this area was quite similar to that of the microfissure between the posterior canal ampulla and round window niche, although the latter appeared to be wider in general. The histogenesis of the microfissure is still unknown, but upon careful analysis of the results of this study and literature review, the authors consider nontraumatic spontaneous fracture by mechanical stress to be the most probable explanation for its occurrence. Possible clinical significance of the microfissure is also discussed.

Mesenchyme Remaining in Human Temporal Bones

1986 ◽  
Vol 95 (3_part_1) ◽  
pp. 349-357 ◽  
Author(s):  
Tetsuo Takahara ◽  
Isamu Sando ◽  
Yoshie Hashida ◽  
Yoshihiro Shibahara
Keyword(s):  
Middle Ear ◽  
Round Window ◽  
Oval Window ◽  
The Body ◽  
First Year ◽  
Sinus Tympani ◽  
Hematoxylin And Eosin ◽  
Round Window Niche ◽  
Temporal Bones ◽  
Middle Ear Cleft

This study was conducted in order to gain basic information about mesenchyme remaining in the middle ear cleft in normal infants. Because no previous report has objectively described the quantity or quality of such postnatal remnants in normal infants, it has not been possible to accurately evaluate the significance of mesenchyme remaining in the middle ears of infants with pathologic conditions, such as otitis media and congenital anomalies. Thus, 53 temporal bones obtained from 41 individuals reported upon here—from 26 weeks' gestation to 8 years of age—will be controls for future studies of pathologic conditions. The children from whom these temporal bones were obtained had no anomalies of the ear (or any other known part of the body); nor did they have any pathologic conditions in the ear. The temporal bones were prepared for histologic study with hematoxylin and eosin staining and were examined under the light microscope. After areas of the mesenchyme in the histologic sections were projected and illustrated for each of 19 portions in the middle ear cleft under the microprojector, those areas were measured by compensating polar planimetry. The findings obtained in this study were as follows: (1) The amount of mesenchyme remaining in the days after birth seemed to gradually decrease in volume with increased maturity and had nearly disappeared within the first year in normal infants. Where mesenchyme was noted in the temporal bones of infants over 1 year of age, it was usually present only in small niches. (2) Most mesenchyme found in temporal bones of normal infants was seen in the mastoid antrum; it was also found in the aditus ad antrum, the epitympanum, the hypotympanum, the sinus tympani, the round window niche, the oval window niche, and the mesotympanum.

Transection of the Posterior Ampullary Nerve for the Relief of Benign Paroxysmal Positional Vertigo

1974 ◽  
Vol 83 (5) ◽  
pp. 596-605 ◽  
Author(s):  
Richard R. Gacek
Keyword(s):  
Hearing Loss ◽  
Benign Paroxysmal Positional Vertigo ◽  
Round Window ◽  
Signs And Symptoms ◽  
Round Window Membrane ◽  
Careful Study ◽  
Positional Vertigo ◽  
One Year ◽  
Round Window Niche ◽  
Paroxysmal Positional Vertigo

Five patients with incapacitating benign paroxysmal positional vertigo (BPPV) for one year or longer were managed surgically by transection of the posterior ampullary nerve. An approach to this nerve was devised based upon a careful study of the posterior ampullary nerve in temporal bone dissections and specimens of the inner ear. Using the round window membrane as the principal landmark, the singular canal was exposed in the round window niche via a tympanotomy approach under local anesthesia. Transection of the posterior ampullary nerve promptly and completely relieved the signs and symptoms of BPPV in all five patients. A severe sensorineural hearing loss was produced in one case as a result of traumatic labyrinthitis. Transection of the posterior ampullary nerve in the round window niche is recommended to: 1) relieve severe BPPV of one or more years duration, and 2) add to the completeness of transcanal labyrinthectomy by denervating the inaccessible posterior canal crista.

Crista Neglecta in Man

1978 ◽  
Vol 87 (3) ◽  
pp. 306-312 ◽  
Author(s):  
Yasumasa Okano ◽  
Isamu Sando ◽  
Eugene N. Myers
Keyword(s):  
Nerve Fibers ◽  
Transitional Epithelium ◽  
Fetal Life ◽  
Main Trunk ◽  
Average Width ◽  
Posterior Canal ◽  
Small Branch ◽  
Sensory Hair Cells ◽  
Temporal Bones ◽  
The Relationship

— The prevalence, location, and size of the crista neglecta in man were investigated by examining the histological sections of 223 human temporal bones (137 cases). The relationship between the crista neglecta and the singular nerve was also described. The crista neglecta was observed in 17 cases, ranging in age from 15-week fetal life to 76 years. This structure was located on the wall of the anterolateral quadrant of the posterior canal ampulla, close to the cribriform area of the singular nerve in the area between the utriculoampullar duct and the intermediate portion of the posterior canal crista. The average width, length, and height of the crista neglecta were described. The crista neglecta had a mound-like shape and contained nerve fibers, transitional epithelium, sensory hair cells, and a cupula. The nerve fibers from the crista neglecta were joined to a small branch of the singular nerve at the cribriform area in 5 of 17 crista neglecta cases, and to the main trunk of the singular nerve in the remaining 12 cases.

Mucopolysaccharidosis I-H (Hurler's Syndrome) and Human Temporal Bone Histopathology

1984 ◽  
Vol 93 (1) ◽  
pp. 65-69 ◽  
Author(s):  
P. A. Schachern ◽  
D. A. Shea ◽  
M. M. Paparella
Keyword(s):  
Otitis Media ◽  
Stria Vascularis ◽  
Round Window ◽  
Enzyme Analysis ◽  
Mucopolysaccharidosis I ◽  
Human Temporal Bone ◽  
Hurler’S Syndrome ◽  
Round Window Niche ◽  
Temporal Bones ◽  
Histopathologic Findings

Six temporal bones from three patients with mucopolysaccharidosis I-H are described. All three patients were diagnosed as having mucopolysaccharidosis I-H by enzyme analysis, and all fit the phenotypic criteria of this disease. Family histories of the three cases described were negative for mycopolysaccharide-storage diseases. All three of the patients suffered chronic recurrent otitis media from infancy through death. Common histopathologic findings include otitis media, residual mesenchyme in the round window niche, partial occlusion of the middle ear cavity, and basophilic concretions within the stria vascularis. The common severe histopathologic changes observed in this study and similar findings in the temporal bones described in other studies lead the authors to believe that ear involvement in this disease may be more common than was previously suspected.

scholarly journals Cochlear Implantation Following Explorative Tympanotomy in Patients With Sudden Sensorineural Hearing Loss: Surgical Features and Audiological Outcomes

2021 ◽  
pp. 014556132110091
Author(s):  
Robin Rupp ◽  
Joachim Hornung ◽  
Matthias Balk ◽  
Matti Sievert ◽  
Sarina Müller ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Connective Tissue ◽  
Sensorineural Hearing Loss ◽  
Cochlear Implantation ◽  
Round Window ◽  
Sudden Sensorineural Hearing Loss ◽  
Sensorineural Hearing ◽  
Round Window Membrane ◽  
Hearing Results ◽  
Round Window Niche

Objective: To investigate the anatomical status of the round window niche and hearing outcome of cochlear implantation (CI) after explorative tympanotomy (ExT) with sealing of the round window membrane in patients with sudden sensorineural hearing loss at a tertiary referral medical center. Methods: Between January 1, 2007, and July 30, 2020, 1602 patients underwent CI at our department. Out of these, all patients previously treated by ExT with sealing of the round window membrane because of unilateral sudden hearing loss were included in the study. A retrospective chart review was conducted concerning method of round window membrane sealing, intraoperative findings during CI, postoperative imaging, and hearing results. Results: Twenty one patients (9 females; 8 right ears; 54.3 years [± 12.9 years]) underwent ExT with sealing of the round window membrane with subsequent CI after 26.6 months (± 32.9 mo) on average. During CI, in 76% of cases (n = 16), the round window niche was blocked by connective tissue due to the previous intervention but could be removed completely in all cases. The connective tissue itself and its removal had no detrimental effects on the round window membrane. Postoperative computed tomography scan showed no electrode dislocation. Mean postoperative word recognition score after 3 months was 57.4% (± 17.2%) and improved significantly to 73.1% (± 16.4%, P = .005) after 2 years. Conclusion: Performing CI after preceding ExT, connective tissue has to be expected blocking the round window niche. Remaining tissue can be removed safely and does not alter the round window membrane allowing for a proper electrode insertion. Short- and long-term hearing results are satisfactory. Consequently, ExT with sealing of the round window membrane in patients with sudden sensorineural hearing loss does not impede subsequent CI that can still be performed safely.

Contribution of auditory nerve fibers to compound action potential of the auditory nerve

2014 ◽  
Vol 112 (5) ◽  
pp. 1025-1039 ◽  
Author(s):  
Jérôme Bourien ◽  
Yong Tang ◽  
Charlène Batrel ◽  
Antoine Huet ◽  
Marc Lenoir ◽  
...  
Keyword(s):  
Action Potential ◽  
Auditory Nerve ◽  
Computational Simulation ◽  
Round Window ◽  
Hearing Threshold ◽  
Compound Action Potential ◽  
Nerve Fibers ◽  
Auditory Nerve Fibers ◽  
Round Window Niche ◽  
Compound Action

Sound-evoked compound action potential (CAP), which captures the synchronous activation of the auditory nerve fibers (ANFs), is commonly used to probe deafness in experimental and clinical settings. All ANFs are believed to contribute to CAP threshold and amplitude: low sound pressure levels activate the high-spontaneous rate (SR) fibers, and increasing levels gradually recruit medium- and then low-SR fibers. In this study, we quantitatively analyze the contribution of the ANFs to CAP 6 days after 30-min infusion of ouabain into the round window niche. Anatomic examination showed a progressive ablation of ANFs following increasing concentration of ouabain. CAP amplitude and threshold plotted against loss of ANFs revealed three ANF pools: 1) a highly ouabain-sensitive pool, which does not participate in either CAP threshold or amplitude, 2) a less sensitive pool, which only encoded CAP amplitude, and 3) a ouabain-resistant pool, required for CAP threshold and amplitude. Remarkably, distribution of the three pools was similar to the SR-based ANF distribution (low-, medium-, and high-SR fibers), suggesting that the low-SR fiber loss leaves the CAP unaffected. Single-unit recordings from the auditory nerve confirmed this hypothesis and further showed that it is due to the delayed and broad first spike latency distribution of low-SR fibers. In addition to unraveling the neural mechanisms that encode CAP, our computational simulation of an assembly of guinea pig ANFs generalizes and extends our experimental findings to different species of mammals. Altogether, our data demonstrate that substantial ANF loss can coexist with normal hearing threshold and even unchanged CAP amplitude.

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