Tumors of Cerebellopontine Angle, Internal Auditory Canal, and Inner Ear

2004 ◽  
pp. 129-143
Author(s):  
B. De Foer
Keyword(s):  
Inner Ear ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal

scholarly journals 3D Real IR MR Findings in Acoustic Neuromas: Altered Perilymph Metabolism

2021 ◽  
pp. 014556132110471
Author(s):  
Suming Shi ◽  
Ping Guo ◽  
Wenquan Li ◽  
Wuqing Wang
Keyword(s):  
Inner Ear ◽  
Acoustic Neuroma ◽  
Intravenous Administration ◽  
Semicircular Canal ◽  
Signal Intensity ◽  
Cerebellopontine Angle ◽  
Endolymphatic Hydrops ◽  
Internal Auditory Canal ◽  
Control Side ◽  
Acoustic Neuromas

Objectives This study aimed to investigate the perilymph metabolism by analyzing the 3D real IR MR findings in acoustic neuroma (AN) after intravenous administration of gadolinium (Gd). Methods Eleven patients (6 men and 5 women) diagnosed with AN were included, and 3D real IR MRI was performed 4 hours after intravenous Gd injection. The signal intensity and details of inner ear, tumor, and internal auditory canal (IAC) by MRI were analyzed. Results Four patients had tumors confined to the IAC, and 5 had tumors that extended to the cerebellopontine angle cistern. The signal intensity of the cochlea, vestibule, and IAC fundus was conspicuously enhanced in 3D real IR images than the control side. One patient had a tumor in the cochlea, in which the signal intensity of the semicircular canal and vestibule was increased. One patient had an intravestibular tumor in which the signal intensity of the semicircular canal was increased and the cochlea had endolymphatic hydrops in the affected ear. Conclusions The synchronously increased signal intensity in the inner ear and IAC may indicate that IAC may serve as a channel for removal of the perilymph in the inner ear; the blockage by the tumor may have changed the hydrodynamics of the perilymph to cause a longer retention of Gd in the inner ear.

Microsurgical Treatment of Meningiomas of the Cerebellopontine Angle with Internal Auditory Canal Extension

Skull Base ◽  
2009 ◽  
Vol 19 (01) ◽  
Author(s):  
Martin Chovanec ◽  
Eduard Zverina ◽  
Jan Betka ◽  
Jiri Skrivan ◽  
Jan Kluh ◽  
...  
Keyword(s):  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Microsurgical Treatment

scholarly journals Cochlear Nerve Canal Stenosis: Association With MYH14 and MYH9 Genes

2021 ◽  
pp. 014556132199683
Author(s):  
Wenqi Liang ◽  
Line Wang ◽  
Xinyu Song ◽  
Fenqi Gao ◽  
Pan Liu ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Next Generation Sequencing ◽  
Inner Ear ◽  
Internal Auditory Canal ◽  
Cochlear Nerve ◽  
Transverse Diameter ◽  
Congenital Hearing Loss ◽  
Canal Stenosis ◽  
Ear Anomalies ◽  
Generation Sequencing

The bony cochlear nerve canal transmits the cochlear nerve as it passes from the fundus of the internal auditory canal to the cochlea. Stenosis of the cochlear nerve canal, defined as a diameter less than 1.0 mm in transverse diameter, is associated with inner ear anomalies and severe to profound congenital hearing loss. We describe an 11-month-old infant with nonsyndromic congenital sensorineural hearing loss with cochlear nerve canal stenosis. Next-generation sequencing revealed heterozygous mutations in MYH9 and MYH14, encoding for the inner ear proteins myosin heavy chain IIA and IIC. The patient’s hearing was rehabilitated with bilateral cochlear implantation.

Meningiomas Of the Internal Auditory Canal

Neurosurgery ◽  
2004 ◽  
Vol 55 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Makoto Nakamura ◽  
Florian Roser ◽  
Sharham Mirzai ◽  
Cordula Matthies ◽  
Peter Vorkapic ◽  
...  
Keyword(s):  
Cerebellopontine Angle ◽  
Clinical Symptoms ◽  
Management Strategies ◽  
Internal Auditory Canal ◽  
Signs And Symptoms ◽  
Vestibular Schwannomas ◽  
Additional Patient ◽  
Surgical Removal ◽  
Neurosurgical Department ◽  
Vestibulocochlear Nerve

Abstract OBJECTIVE: Meningiomas arising primarily within the internal auditory canal (IAC) are notably rare. By far the most common tumors that are encountered in this region are neuromas. We report a series of eight patients with meningiomas of the IAC, analyzing the clinical presentations, surgical management strategies, and clinical outcomes. METHODS: The charts of the patients, including histories and audiograms, imaging studies, surgical records, discharge letters, histological records, and follow-up records, were reviewed. RESULTS: One thousand eight hundred meningiomas were operated on between 1978 and 2002 at the Neurosurgical Department of Nordstadt Hospital. Among them, there were 421 cerebellopontine angle meningiomas; 7 of these (1.7% of cerebellopontine angle meningiomas) were limited to the IAC. One additional patient underwent surgery at the Neurosurgical Department of the International Neuroscience Institute, where a total of 21 cerebellopontine angle meningiomas were treated surgically from 2001 to 2003. As a comparison, the incidence of intrameatal vestibular schwannomas during the same period, 1978 to 2002, was 168 of 2400 (7%). There were five women and three men, and the mean age was 49.3 years (range, 27–59 yr). Most patients had signs and symptoms of vestibulocochlear nerve disturbance at presentation. One patient had sought treatment previously for total hearing loss before surgery. No patient had a facial paresis at presentation. The neuroradiological workup revealed a homogeneously contrast-enhancing tumor on magnetic resonance imaging in all patients with hypointense or isointense signal intensity on T1- and T2-weighted images. Some intrameatal meningiomas showed broad attachment, and some showed a dural tail at the porus. In all patients, the tumor was removed through the lateral suboccipital retrosigmoid approach with drilling of the posterior wall of the IAC. Total removal was achieved in all cases. Severe infiltration of the facial and vestibulocochlear nerve was encountered in two patients. There was no operative mortality. Hearing was preserved in five of seven patients; one patient was deaf before surgery. Postoperative facial weakness was encountered temporarily in one patient. CONCLUSION: Although intrameatal meningiomas are quite rare, they must be considered in the differential diagnosis of intrameatal mass lesions. The clinical symptoms are very similar to those of vestibular schwannomas. A radiological differentiation from vestibular schwannomas is not always possible. Surgical removal of intrameatal meningiomas should aim at wide excision, including involved dura and bone, to prevent recurrences. The variation in the anatomy of the faciocochlear nerve bundle in relation to the tumor has to be kept in mind, and preservation of these structures should be the goal in every case.

scholarly journals Trigeminal Nerve Schwannoma of the Cerebellopontine Angle

2018 ◽  
Vol 79 (S 05) ◽  
pp. S389-S390
Author(s):  
Maria Peris-Celda ◽  
Christopher Graffeo ◽  
Avital Perry ◽  
Lucas Carlstrom ◽  
Michael Link
Keyword(s):  
Trigeminal Nerve ◽  
Cerebellopontine Angle ◽  
Incidental Finding ◽  
Cranial Nerves ◽  
Internal Auditory Canal ◽  
Clinical History ◽  
Sensory Loss ◽  
Meckel’S Cave ◽  
Neurologic Deficits ◽  
Meckel's Cave

Introduction Large and even moderate sized, extra-axial cerebellopontine angle (CPA) tumors may fill this restricted space and distort the regional anatomy. It may be difficult to determine even with high resolution magnetic resonance imaging (MRI) if the tumor is dural-based, or what the nerve of origin is if a schwannoma. While clinical history and exam are helpful, they are not unequivocal, particularly since many patients present with a myriad of symptoms, or conversely an incidental finding. We present an atypical appearing, asymptomatic CPA tumor, ultimately identified at surgery to be a trigeminal schwannoma. Case History A 40-year-old man presented with new-onset seizure. MRI identified an incidental heterogeneously contrast-enhancing CPA lesion (Fig. 1A–D). The tumor was centered on the internal auditory canal (IAC) with no tumor extension into Meckel's cave, IAC or jugular foramen. Audiometry demonstrated 10db of relative left-sided hearing loss with 100% word recognition. Physical examination was negative for focal neurologic deficits. A retrosigmoid craniotomy was performed and an extra-axial, yellow-hued mass was encountered and resected, which was ultimately confirmed to originate from the trigeminal nerve (Video 1). Gross total resection was achieved, and the patient recovered from surgery with partial ipsilateral trigeminal sensory loss and no other new neurologic deficits. Conclusion Pure CPA trigeminal schwannomas are rare, but should be considered in the differential for enhancing CPA lesions. Although, Meckel's cave involvement is frequently observed, it is not universal, and pure CPA schwannomas of all cranial nerves IV–XII have been reported in the literature.The link to the video can be found at: https://youtu.be/AlodYCu70F8.

Endoscopically Assisted Drilling, Exposure of the Fundus through a Presigmoid Retrolabyrinthine Approach: A Cadaveric Feasibility Study

2017 ◽  
Vol 158 (1) ◽  
pp. 155-157 ◽  
Author(s):  
Thomas Muelleman ◽  
Matthew Shew ◽  
Sameer Alvi ◽  
Kushal Shah ◽  
Hinrich Staecker ◽  
...  
Keyword(s):  
Temporal Bone ◽  
Feasibility Study ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Entire Length ◽  
Retrolabyrinthine Approach

The presigmoid retrolabyrinthine approach to the cerebellopontine angle is traditionally described to not provide access to the internal auditory canal (IAC). We aimed to evaluate the extent of the IAC that could be exposed with endoscopically assisted drilling and to measure the percentage of the IAC that could be visualized with the microscope and various endoscopes after drilling had been completed. Presigmoid retrolabyrinthine approaches were performed bilaterally on 4 fresh cadaveric heads. We performed endoscopically assisted drilling to expose the fundus of the IAC, which resulted in exposure of the entire IAC in 8 of 8 temporal bone specimens. The microscope afforded a mean view of 83% (n = 8) of the IAC. The 0°, 30°, 45°, and 70° endoscope each afforded a view of 100% of the IAC in 8 of 8 temporal bone specimens. In conclusion, endoscopic drilling of the IAC of can provide an extradural means of exposing the entire length of the IAC while preserving the labyrinth.

scholarly journals Resection of a Dumbbell-Shaped Facial Nerve Schwannoma With Preservation of Facial Nerve Function Through the Extended Middle Fossa Approach: 2-Dimensional Operative Video

2021 ◽  
Author(s):  
Kaith K Almefty ◽  
Wenya Linda Bi ◽  
Walid Ibn Essayed ◽  
Ossama Al-Mefty
Keyword(s):  
Facial Nerve ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Growth Patterns ◽  
Geniculate Ganglion ◽  
Nerve Function ◽  
Middle Fossa ◽  
Facial Nerve Function ◽  
Large Tumor ◽  
Middle Fossa Approach

Abstract Facial nerve schwannomas are rare and can arise from any segment along the course of the facial nerve.1 Their location and growth patterns present as distinct groups that warrant specific surgical management and approaches.2 The management challenge arises when the facial nerve maintains good function (House-Brackmann grade I-II).3 Hence, a prime goal of management is to maintain good facial animation. In large tumors, however, resection with facial nerve function preservation should be sought and is achievable.4,5  While tumors originating from the geniculate ganglion grow extradural on the floor of the middle fossa, they may extend via an isthmus through the internal auditory canal to the cerebellopontine angle forming a dumbbell-shaped tumor. Despite the large size, they may present with good facial nerve function. These tumors may be resected through an extended middle fossa approach with preservation of facial and vestibulocochlear nerve function.  The patient is a 62-yr-old man who presented with mixed sensorineural and conductive hearing loss and normal facial nerve function. Magnetic resonance imaging (MRI) revealed a large tumor involving the middle fossa, internal auditory meatus, and cerebellopontine angle.  The tumor was resected through an extended middle fossa approach with a zygomatic osteotomy and anterior petrosectomy.6 A small residual was left at the geniculate ganglion to preserve facial function. The patient did well with hearing preservation and intact facial nerve function. He consented to the procedure and publication of images.  Image at 1:30 © Ossama Al-Mefty, used with permission. Images at 2:03 reprinted from Kadri and Al-Mefty,6 with permission from JNSPG.

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