scholarly journals Incomplete Partition type I: Radiological Evaluation of the Temporal Bone

Acta Medica ◽  
2021 ◽  
pp. 1-9
Author(s):  
Safak Parlak ◽  
Ayca Akgoz Karaosmanoglu ◽  
Sevtap Arslan ◽  
Levent Sennaroglu
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Correct Diagnosis ◽  
Semicircular Canals ◽  
Type I ◽  
Vestibular Aqueduct ◽  
Endolymphatic Duct ◽  
Incomplete Partition ◽  
Internal Acoustic Canal ◽  
Large Vestibular Aqueduct

Objective: Incomplete partition type I is an uncommon congenital anomaly of the inner ear, characterized by typical cystic cochleovestibular appearance. Incomplete partition type I was firstly defined as cystic cochlea and vestibule without large vestibular aqueduct; however, large vestibular aqueduct and/or enlarged endolymphatic duct could rarely be seen in incomplete partition type I anomaly. Correct diagnosis of the type of cochlear malformation and differentiation of incomplete partition type I is necessary for patient management and surgical approach. Our aim was to document the temporal bone imaging findings in a series of patients with incomplete partition type I. Materials and Methods: CT (n=85) and/or MRI (n=80) examinations of 99 ears in 59 incomplete partition type I patients were retrospectively evaluated. All structures of the otic capsule were retrospectively assessed. The appearances of cochlea and vestibule, vestibular aqueduct/endolymphatic duct, semicircular canals were qualitatively evaluated by an experienced neuroradiologist. The vertical dimension of vestibular aqueduct and/or endolymphatic duct (from the point where the duct arises from the vestibule) was measured on CT/MRI. Anterior-posterior diameter of the internal acoustic canal and the diameter of cochlear aperture were measured on CT. The cochleovestibular nerves were evaluated on sagittal-oblique high T2-weighted imaging. Results: All 99 ears had defective partition with unpartitioned cochlear basal turn and absent interscalar septae, separated but cystic cochlea. The vestibule was enlarged in all ears except one. Semicircular canals were usually dysplastic (92.9%). A total of 35 incomplete partition type I ears (35.3%) had large vestibular aqueduct and/or enlarged endolymphatic duct. Internal acoustic canal was wide in 21% of ears. Cochlear aperture was wide in 5.9% of ears. Cochlear nerve was either hypoplastic or aplastic in about a quarter of incomplete partition type I ears. Conclusion: In up to one-third of incomplete partition type I patients, an associated large vestibular aqueduct /endolymphatic duct could be seen accompanying typical inner ear findings. Although the cochlear nerves are normal in the majority of cases, auditory brainstem implantation may be necessary in certain cases of incomplete partition type I anomaly.

scholarly journals The Spectrum and Frequency of Inner Ear Anomalies in Patients with Congenital Hearing Impairment in Yakutia

2020 ◽  
Vol 101 (2) ◽  
pp. 90-102
Author(s):  
L. A. Klarov ◽  
N. A. Barashkov ◽  
F. M. Teryutin ◽  
G. P. Romanov ◽  
M. M. Popov ◽  
...  
Keyword(s):  
Inner Ear ◽  
Hearing Impairment ◽  
Temporal Bone ◽  
Semicircular Canals ◽  
Internal Auditory Meatus ◽  
X Ray ◽  
Vestibular Aqueduct ◽  
Incomplete Partition ◽  
Ear Anomalies ◽  
Congenital Hearing Impairment

Objective. To analyze the spectrum and frequency of inner ear anomalies in patients with congenital hearing impairment in Yakutia.Material and methods. A total of 165 patients with congenital hearing impairment were surveyed. All the patients were examined by an audiologist, an educational audiologist, and a neuropsychiatrist. All the patients underwent X-ray computed tomography (X-ray CT) of temporal bone structures (which was supplemented by magnetic resonance imaging (MRI) in some cases).Results. Based on modern ideas about inner ear anomalies and their classification, the authors first analyzed the spectrum and frequency of inner ear anomalies in patients with congenital hearing impairment in Yakutia. Inner ear malformations were identified in 16 (9.7%) of the 165 patients with hearing impairment, which corresponds to that in the previously studied samples of deaf people in different countries (from 3% to 35%). Of the inner ear structures, the cochlea and vestibule were more commonly affected. Abnormalities of the internal auditory meatus, semicircular canals, and vestibular aqueduct were less common. In general, the spectrum of anomalies was represented by 7 different malformations. Incomplete partition type II (IP-II) (34.3%) came first in incidence among all the abnormalities. Incomplete partition type III (IP-III) (18.7%) ranked second in incidence. The expansion of the internal auditory meatus (12.5%) and vestibular aqueduct (12.5%) occupied the third place. Inner ear anomalies occurred as concurrences that are difficult to interpret and classify in half (50%) of all the cases.Conclusion. Analysis of the spectrum and frequency of temporal bone abnormalities in Yakutia suggests that every 10 patients with congenital hearing impairment have one or another inner ear structural malformation (9.7%) and require accurate and timely diagnosis using up-to-date X-ray CT and MRI techniques.

scholarly journals Cystic Cochleovestibular Malformation (Incomplete Partition Type 1)

2010 ◽  
Vol 25 (1) ◽  
pp. 41-42 ◽  
Author(s):  
Nathaniel W. Yang
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Temporal Bone ◽  
Cochlear Implantation ◽  
Type I ◽  
Profound Hearing Loss ◽  
Increased Risk ◽  
Ear Malformations ◽  
Temporal Bone Imaging ◽  
Incomplete Partition

A 5-year old female with bilateral profound hearing loss underwent computerized tomographic imaging of the temporal bone as part of the work-up to determine the etiology of her deafness, and to delineate middle and inner ear anatomy prior to cochlear implantation. The examination revealed an inner ear malformation which, based on the newest classification of cochleovestibular malformations by Sennaroglu and Saatci, is called an incomplete partition type I (IP-1) or cystic cochleovestibular malformation. This condition is characterized by (1) a cochlea that is lacking the entire modiolus and cribriform area, resulting in a cystic appearance, and (2) a large cystic vestibule.1   Temporal bone imaging is among the most useful examinations in the etiological investigation of idiopathic sensorineural hearing loss in children, with up to 30%2 of the imaging studies showing an abnormality. The detection of inner ear malformations is important, as some abnormalities are associated with an increased risk of meningitis or progressive hearing loss following head trauma.3 Likewise, the approach to cochlear implantation may be influenced by the type of malformation. In this particular patient, the use of a cochlear implant with a full-band electrode design may be more appropriate, as the location of the neural elements within the cystic cochlea is not definitely known.

Role of Computed Tomography and Magnetic Resonance Imaging in detecting the Prevalence of inner ear anomalies among cochlear implant candidates

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Alaa Nasser Hussain Zaher ◽  
Tougan Taha Abd El Aziz ◽  
Ahmed Samy Abdelrahman
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Hearing Loss ◽  
Cochlear Implant ◽  
Inner Ear ◽  
Resonance Imaging ◽  
High Resolution Computed Tomography ◽  
Vestibular Aqueduct ◽  
Incomplete Partition ◽  
Ear Anomalies

Abstract Background Hearing loss management using cochlear implants in patients with inner ear anomalies has long been discussed in the otology community. Magnetic resonances imaging (B,/IRI) and Computed tomography (CT) play important roles in the preoperative assessment of inner ear abnormalities such as cochlear nerve deficiency and variant anatomy as these abnormalities may not only affect the decision of the implantation procedure or the patient's prognosis regarding auditory improvement, but also the risk of complications. Objective To examine the prevalence of inner ear anomalies among cochlear implant recipients in patients with congenital sensorineural hearing loss among the pediatric age group in the Demerdash hospital, Ain Shams university using High resolution computed tomography (HRCT) and MRI imaging. Methods A retrospective descriptive study over the course of 9 months that included all patients that are candidates for cochlear implant referred to the Radiology department, Ain Shams University Hospitals for a preoperative imaging in the form of CT and VIRI scans. Results CT and MRI scans of 33 patients who had congenital hearing loss and were candidates for cochlear implantation with total 66 ears were reviewed. Inner ear anomalies were identified in 8 patients representing a prevalence (24.2%) with 14 ear diseased. Anomalies were seen bilaterally in 6 patients and unilaterally in 2 patients. Among the 14 diseased ear, 9 ears (64.3%) were seen with incomplete partition Il, 7 ears (50%) were seen with enlarged vestibular aqueduct, 4 ears (28.6%) were seen with cochlear hypoplasia, 3 ears (21.4%) were seen with semicircular canal aplasia, 2 ears (14.3%) were seen with incomplete partition type I, 2 ears (14.3%) were seen with cochlear nerve aplasia, 2 ears with cochlear aplasia (14.3%), I ear (7.1%) was seen with common cavity ear (7.1%) with complete labyrinthine aplasia. Conclusion Prevalence of inner ear anomalies among cochlear implant candidates was 24.2%. This result is consistent with results worldwide and the most common anomalies were Incomplete partition Il and large vestibular aqueduct. Abbreviations Computed tomography (CT), Magnetic resonance imaging (MRI), High resolution computed tomography (HRCT), Internal auditory canal (IAC), Cerebellopontine angle (CPA).

The Semicircular Canals of the Inner Ear and the Pneumatization of the Temporal Bone

1986 ◽  
Vol 27 (3) ◽  
pp. 325-329
Author(s):  
C. Muren ◽  
H. Wilbrand
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Semicircular Canals ◽  
Petrous Bone ◽  
General Outline ◽  
Size And Shape ◽  
Wide Range

In an investigation of 94 plastic casts of temporal bone specimens a wide range of variations both in the general outline of the pyramid and in the anatomy of its specific structures was found. Attempts were made to estimate the transverse and vertical dimensions of the petrous bone. Both the mastoid and the perilabyrinthine pneumatization correlated to the dimensions of some structures, but not to the size and shape of the semicircular canals. References

Large Vestibular Aqueduct Syndrome: A Human Temporal Bone Study

2006 ◽  
Vol 116 (11) ◽  
pp. 2007-2011 ◽  
Author(s):  
Shigeo Hirai ◽  
Sebahattin Cureoglu ◽  
Patricia A. Schachern ◽  
Hideo Hayashi ◽  
Michael M. Paparella ◽  
...  
Keyword(s):  
Temporal Bone ◽  
Vestibular Aqueduct ◽  
Human Temporal Bone ◽  
Large Vestibular Aqueduct Syndrome ◽  
Large Vestibular Aqueduct

Volumetric Rendering of Human Inner Ear by MR Imaging

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P103-P103
Author(s):  
Jen-Fang Yu ◽  
Wei-Chung Chin ◽  
Che-Ming Wu ◽  
Shu-Hang Ng
Keyword(s):  
Mr Imaging ◽  
Inner Ear ◽  
3D Model ◽  
Semicircular Canals ◽  
Vestibular Aqueduct ◽  
3D Geometry ◽  
Large Vestibular Aqueduct Syndrome ◽  
Volumetric Rendering ◽  
Human Inner Ear

Problem To non-invasively measure in-vivo human inner ear by MRI and measure the geometry of vestibule by the reconstructed 3D model of inner ear for further diagnosis of large vestibular aqueduct syndrome (LVAS). Methods 3-T MR scanner, MAGNETOM Trio made by Siemens, was utilized. The TR/TE for MR imaging of 7 patients was 5.65/2.6 ms and the voxel size was 0.5 mm X 0.5 mm X 0.5 mm for single slice of 48 slices. The configuration of semicircular canals, vestibule and cochlea could be detected by threshold. The 3D geometry of inner ear was then computed based on the thickness of slice. Results The surface area and volume of semicircular canals for 7 normal ears were 217.85 square mm and 63.56 cubic mm; of vestibule were 105.88 square mm and 56.36 cubic mm; of cochlea were 171.84 square mm and 81.29 cubic mm respectively. The variation of volumes of vestibule and cochlea could be quantified non-invasively. The correlation between the volume and the level of LVAS will be analyzed once the number of volunteer reaches a statistically significant level. Conclusion The variation for the geometry of vestibule could be measured non-invasively. The grade of LVAS can be assessed by the obtained 3D model of semi-circular canal, vestibule and cochlea. Significance According to the 3D model, the geometry of inner ear can be measured, and the syndrome can be revealed directly to help clinical diagnosis of LVAS more accurately.

The ear

2021 ◽  
pp. 497-518
Author(s):  
Daniel R. van Gijn ◽  
Jonathan Dunne
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Middle Ear ◽  
Semicircular Canals ◽  
Lateral Wall ◽  
Oval Window ◽  
External Ear ◽  
Membranous Labyrinth ◽  
Stapes Footplate ◽  
Petrous Temporal Bone

The delicate yet definitive deflections of the pinna (wing/fin) of the external ear contribute to the collection of sound. The external acoustic meatus is responsible for the transmission of sounds to the tympanic membrane, which in turn separates the external ear from the middle ear. The middle ear is an air filled (from the nasopharynx via the eustachian tube), mucous membrane lined space in the petrous temporal bone. It is separated from the inner ear by the medial wall of the tympanic cavity – bridged by the trio of ossicles. The inner ear refers to the bony and membranous labyrinth and their respective contents. The osseus labyrinth lies within the petrous temporal bone. It consists of the cochlea anteriorly, semicircular canals posterosuperiorly and intervening vestibule – the entrance hall to the inner ear whose lateral wall bears the oval window occupied by the stapes footplate.

scholarly journals Clinical Investigation and Mechanism of Air-Bone Gaps in Large Vestibular Aqueduct Syndrome

2007 ◽  
Vol 116 (7) ◽  
pp. 532-541 ◽  
Author(s):  
Saumil N. Merchant ◽  
Hideko H. Nakajima ◽  
Christopher Halpin ◽  
Joseph B. Nadol ◽  
Daniel J. Lee ◽  
...  
Keyword(s):  
Inner Ear ◽  
Middle Ear ◽  
Bone Conduction ◽  
Distortion Product Otoacoustic Emission ◽  
Low Frequencies ◽  
Distortion Product ◽  
Vestibular Aqueduct ◽  
Acoustic Reflexes ◽  
Large Vestibular Aqueduct Syndrome ◽  
Large Vestibular Aqueduct

Objectives: Patients with large vestibular aqueduct syndrome (LVAS) often demonstrate an air-bone gap at the low frequencies on audiometric testing. The mechanism causing such a gap has not been well elucidated. We investigated middle ear sound transmission in patients with LVAS, and present a hypothesis to explain the air-bone gap. Methods: Observations were made on 8 ears from 5 individuals with LVAS. The diagnosis of LVAS was made by computed tomography in all cases. Investigations included standard audiometry and measurements of umbo velocity by laser Doppler vibrometry (LDV) in all cases, as well as tympanometry, acoustic reflex testing, vestibular evoked myogenic potential (VEMP) testing, distortion product otoacoustic emission (DPOAE) testing, and middle ear exploration in some ears. Results: One ear with LVAS had anacusis. The other 7 ears demonstrated air-bone gaps at the low frequencies, with mean gaps of 51 dB at 250 Hz, 31 dB at 500 Hz, and 12 dB at 1,000 Hz. In these 7 ears with air-bone gaps, LDV showed the umbo velocity to be normal or high normal in all 7; tympanometry was normal in all 6 ears tested; acoustic reflexes were present in 3 of the 4 ears tested; VEMP responses were present in all 3 ears tested; DPOAEs were present in 1 of the 2 ears tested, and exploratory tympanotomy in 1 case showed a normal middle ear. The above data suggest that an air-bone gap in LVAS is not due to disease in the middle ear. The data are consistent with the hypothesis that a large vestibular aqueduct introduces a third mobile window into the inner ear, which can produce an air-bone gap by 1) shunting air-conducted sound away from the cochlea, thus elevating air conduction thresholds, and 2) increasing the difference in impedance between the scala vestibuli side and the scala tympani side of the cochlear partition during bone conduction testing, thus improving thresholds for bone-conducted sound. Conclusions: We conclude that LVAS can present with an air-bone gap that can mimic middle ear disease. Diagnostic testing using acoustic reflexes, VEMPs, DPOAEs, and LDV can help to identify a non?middle ear source for such a gap, thereby avoiding negative middle ear exploration. A large vestibular aqueduct may act as a third mobile window in the inner ear, resulting in an air-bone gap at low frequencies.

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.

Sign in / Sign up

Export Citation Format

Share Document