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

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.

1978 ◽  
Vol 87 (6) ◽  
pp. 815-820 ◽  
Author(s):  
Kenneth D. Dolan ◽  
Richard W. Babin ◽  
Charles G. Jacoby

During the past five years, nine patients with “significant” unilateral enlargement of one internal auditory canal by polytomography were subsequently found to have freely filling canals on contrast posterior fossa myelography. The radiographic appearance of the enlarged canals varied greatly and included all the various configurations usually suggestive of acoustic neuroma. Likewise, the clinical presentation varied greatly from asymptomatic to highly suggestive of cerebellopontine angle tumor. This series underscores the essential nature of posterior fossa studies in the evaluation of potential acoustic neuromas and the variability of the normal architecture of the internal auditory meatus.


1996 ◽  
Vol 115 (1) ◽  
pp. 46-48 ◽  
Author(s):  
Ltc Moises Arriaga ◽  
Maj Michael Gorum

A subset of patients with acoustic neuromas and useful hearing have tumors that are inadequately approached by both middle fossa and retrosigmoid techniques. The enhanced retrosigmoid technique combines the hearing preservation of posterior semicircular canal ablation to achieve lateral internal auditory canal exposure with the ample cerebellopontine angle exposure of the standard retrosigmoid technique.


Neurosurgery ◽  
2004 ◽  
Vol 54 (2) ◽  
pp. 391-396 ◽  
Author(s):  
John Diaz Day ◽  
Douglas A. Chen ◽  
Moises Arriaga

Abstract THE TRANSLABYRINTHINE APPROACH has been popularized during the past 30 years for the surgical treatment of acoustic neuromas. It serves as an alternative to the retrosigmoid approach in patients when hearing preservation is not a primary consideration. Patients with a tumor of any size may be treated by the translabyrinthine approach. The corridor of access to the cerebellopontine angle is shifted anteriorly in contrast to the retrosigmoid approach, resulting in minimized retraction of the cerebellum. Successful use of the approach relies on a number of technical nuances that are outlined in this article.


1985 ◽  
Vol 63 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Charles H. Tator ◽  
Julian M. Nedzelski

✓ Microsurgical techniques have made it possible to identify and preserve the cochlear nerve from its origin at the brain stem and along its course through the internal auditory canal in patients undergoing removal of small or medium-sized acoustic neuromas or other cerebellopontine angle (CPA) tumors. In a consecutive series of 100 patients with such tumors operated on between 1975 and 1981, an attempt was made to preserve the cochlear nerve in 23. The decision to attempt to preserve hearing was based on tumor size and the degree of associated hearing loss. In cases of unilateral acoustic neuroma, the criteria for attempted preservation of hearing were tumor size (2.5 cm or less), speech reception threshold (50 dB or less), and speech discrimination score (60% or greater). In patients with bilateral acoustic neuromas or tumors of other types, the size and hearing criteria were significantly broadened. All patients were operated on through a suboccipital approach. Hearing was preserved postoperatively in six (31.6%) of the 19 patients with unilateral acoustic neuromas, although the cochlear nerve was preserved in 16. Of the six patients with postoperative hearing, three retained excellent hearing, and the other three had only sound awareness and poor discrimination. Hearing was preserved in three cases with other CPA tumors, including an epidermoid cyst and small petrous meningiomas in the internal auditory canal. Of the two cases with bilateral tumors, hearing was preserved in one. Of the 23 patients in whom hearing preservation was attempted, nine (39.1%) had some postoperative hearing, which in six was equal to or better than the preoperative level. Thus, it is worthwhile to attempt hearing preservation in selected patients with CPA tumors.


1997 ◽  
Vol 106 (8) ◽  
pp. 657-661 ◽  
Author(s):  
Anthony G. Zeitouni ◽  
David Zagzag ◽  
Noel L. Cohen

Meningiomas are the second most common tumor to involve the cerebellopontine angle (CPA), but controversy exists as to whether they can arise within the internal auditory canal (IAC) or whether involvement of the IAC occurs secondarily by extension from the CPA. This paper reports on a patient with an enhancing IAC meningioma that then grew and on subsequent scans was found to involve the CPA. This case demonstrates that these tumors can arise within the IAC and can grow out to involve the CPA. These findings are discussed within the context of meningioma tumor genetics and the histologic evidence for precursor cells in the IAC. The radiologic findings useful in distinguishing an acoustic neuroma from a meningioma are reviewed in the light of this case. While an enhancing mass projecting into the IAC is most often an acoustic neuroma, this radiologic finding is not pathognomonic.


1981 ◽  
Vol 89 (5) ◽  
pp. 861-866 ◽  
Author(s):  
William N. Hanafee

Computerized tomographic (CT) scanning for intracanalicular tumors requires air as a contrast agent within the internal auditory canal and special computer manipulations of the image to visualize small tumors. The same computer manipulations of CT scans provide detail of the middle and inner ear structures not available by non-CT tomographic techniques. The demonstration of horizontal semicircular canal fistula is one area in which CT scanning is clearly superior. Some pitfalls of the technique and interpretation of it will be discussed.


Author(s):  
Aditi Akhuj ◽  
Snehal Samal ◽  
Rakesh Krishna Kovela ◽  
Ragini Dagal ◽  
Rebecca Thimoty

Introduction: Acoustic neuromas are most common tumors of CP angle, accounting more than 90% of all such tumors. Meningioma, primary cholesteratoma and facial nerve schwanoma are the different type of tumors. Acoustic neuroma is a benign tumor situates in CP angle which has a fibrous growth and originates from the division of vestibulochochlear nerve. Aim: Impact of Balance Training and Co-ordination Exercises in Post-Operative Left Cerebellopontine Angle Tumor Case Presentation: A 40 year old male with right hand dominance was referred to physiotherapy department. On examination he presented mild impairment in balance and co-ordination, assisted walking. Discussion: This case report is an important to the published literature on rehabilitation of a patient witha CPA tumor, as it presents the sequential management in the patients post CPA tumor. Conclusion: Acoustic neuroma is most common CPA tumor. Management of CPA tumor is important to improve quality of life. As per the reference articles and the exercises planned can progressively improve balance and co-ordination of patients.


1993 ◽  
Vol 109 (1) ◽  
pp. 88-95 ◽  
Author(s):  
Anil K. Lalwani ◽  
Robert K. Jackler

Preoperative differentiation between acoustic neuroma (AN) and meningioma of the cerebellopontine angle (CPA) is important in selection of the surgical approach, successful tumor removal, and preservation of hearing and facial nerve. We retrospectively reviewed the magnetic resonance imaging (MRI) findings associated with 30 meningiomas involving the CPA (MCPA) encountered between 1987 to 1991 at the University of California, San Francisco. Magnetic resonance imaging was critical in differentiating meningioma from AN in the CPA. Typical findings on MRI associated with MCPA, differentiating them from ANs, Include: Meningiomas are sessile, possessing a broad base against the petrous face, whereas ANs are globular; they are often extrinsic and eccentric to the internal auditory canal (IAC); when involving the IAC, they usually do not erode the IAC; MCPAs demonstrate hyperostosis of the subjacent bone and possess intratumoral calcification; they involve adjacent intracranial spaces and structures; and meningiomas are characterized by a distinctive dural “tail” extending away from the tumor surface. While any one finding may not be diagnostic by itself, taken together the constellation of these findings is strongly Indicative of meningioma. In our experience, MRI with gadolinium enhancement was able to distinguish MCPA from AN in nearly every case.


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