Correlation between auditory function and internal auditory canal pressure in patients with vestibular schwannomas

2002 ◽  
Vol 96 (5) ◽  
pp. 872-876 ◽  
Author(s):  
Samir B. Lapsiwala ◽  
G. Mark Pyle ◽  
Ann W. Kaemmerle ◽  
Frank J. Sasse ◽  
Behnam Badie
Keyword(s):  
Hearing Loss ◽  
Tumor Growth ◽  
Tumor Size ◽  
Internal Auditory Canal ◽  
Auditory Evoked Potential ◽  
Cochlear Nerve ◽  
Content Type ◽  
Vascular Compromise ◽  
Brainstem Response ◽  
Fine Print

Object. Hearing loss is the most common presenting symptom in patients who harbor a vestibular schwannoma (VS). Although mechanical injury to the cochlear nerve and vascular compromise of the auditory apparatus have been proposed, the exact mechanism of this hearing loss remains unclear. To test whether pressure on the cochlear nerve from tumor growth in the internal auditory canal (IAC) is responsible for this clinical finding, the authors prospectively evaluated intracanalicular pressure (ICaP) in patients with VS and correlated this with preoperative brainstem response. Methods. In 40 consecutive patients undergoing a retrosigmoid—transmeatal approach for tumor excision, ICaP was measured by inserting a pressure microsensor into the IAC before any tumor manipulation. Pressure recordings were correlated with tumor size and preoperative auditory evoked potential (AEP) recordings. The ICaP, which varied widely among patients (range 0–45 mm Hg), was significantly elevated in most patients (median 16 mm Hg). Although these pressure measurements directly correlated to the extension of tumor into the IAC (p = 0.001), they did not correlate to total tumor size (p = 0.2). In 20 patients in whom baseline AEP recordings were available, the ICaP directly correlated to wave V latency (p = 0.0001), suggesting that pressure from tumor growth in the IAC may be responsible for hearing loss in these patients. Conclusions. Tumor growth into the IAC results in elevation of ICaP and may play a role in hearing loss in patients with VS. The relevance of these findings to the surgical treatment of these tumors is discussed.

Preservation of hearing in patients undergoing excision of acoustic neuromas and other cerebellopontine angle tumors

1985 ◽  
Vol 63 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Charles H. Tator ◽  
Julian M. Nedzelski
Keyword(s):  
Tumor Size ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Hearing Preservation ◽  
Cochlear Nerve ◽  
Consecutive Series ◽  
Speech Discrimination ◽  
Content Type ◽  
Acoustic Neuromas ◽  
Fine Print

✓ 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.

Determinants of tumor size and growth in vestibular schwannomas

2001 ◽  
Vol 94 (6) ◽  
pp. 922-926 ◽  
Author(s):  
Stephen L. Nutik ◽  
Michael J. Babb
Keyword(s):  
Growth Rate ◽  
Tumor Growth ◽  
Tumor Size ◽  
Internal Auditory Canal ◽  
Vestibular Schwannomas ◽  
Patient Age ◽  
Content Type ◽  
Patient Âgé ◽  
Cystic Tumors ◽  
Fine Print

Object. This study was undertaken to analyze factors associated with the size of unilateral vestibular schwannomas (VSs). Methods. A retrospective analysis of an unselected and sequential series of 433 patients with unilateral VSs was conducted. Tumor size was defined by the largest dimension of the tumor in the cerebellopontine angle, and the size was tested for a relationship with patient age and sex. In a subgroup of 231 patients in whom data were available, tumor size was also tested for a relationship with tumor cysts or the absence of an internal auditory canal (IAC) component. Some patients underwent a period of surveillance with serial imaging studies to monitor for tumor growth. Data from these patients, excluding those with cystic tumors, were analyzed to see if tumor growth was related to patient age, sex, or tumor size. Conclusions. Larger tumors were found in younger patients, in females, in the subgroup of cystic tumors, and in patients in whom there was no tumor component in the IAC. The probable explanations for these larger tumors are a faster growth rate and/or a delay in symptom onset. When untreated tumors are managed with observation, measurable growth is more often seen in larger tumors, although smaller tumors have a faster relative growth rate than larger ones.

Preservation of hearing in patients undergoing microsurgery for vestibular schwannoma: degree of meatal filling

2005 ◽  
Vol 102 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Gérard Mohr ◽  
Burak Sade ◽  
Jean-Jacques Dufour ◽  
Jamie M. Rappaport
Keyword(s):  
Vestibular Schwannoma ◽  
Tumor Size ◽  
Intraoperative Monitoring ◽  
Statistical Significance ◽  
Multivariable Analysis ◽  
Internal Auditory Canal ◽  
Magnetic Resonance Images ◽  
Content Type ◽  
Incomplete Filling ◽  
Fine Print

Object. Preservation of hearing has become a standard goal in selected patients undergoing surgery for a vestibular schwannoma (VS). This study was aimed at analyzing the role played by filling of the internal auditory canal (IAC) as well as those played by preoperative hearing quality, and tumor size in the postoperative preservation of serviceable hearing (SH). Methods. Three hundred eighty-six patients with VS were treated. Hearing preservation was attempted in 128 cases (33.2%) by using intraoperative monitoring and following a retrosigmoid approach. The maximal extrameatal size of the tumor, its extension within the IAC, and pre- and postoperative hearing quality, according to the Gardner—Robertson classification, were evaluated. Preservation of SH was achieved in 24.2% of the 128 patients. With respect to tumor size, SH was preserved in 39% of 77 patients harboring a tumor 15 mm wide or smaller and in 2% of 51 patients with lesions 16 mm wide or larger (p < 0.001). With regard to filling of the IAC, among 63 patients harboring a tumor 15 mm or smaller, in whom magnetic resonance images were available, SH was preserved in 52.8% of 36 patients with partial filling and in 25.9% of 27 patients with complete filling (p = 0.032). Concerning preoperative hearing quality, in the patients with tumors 15 mm or smaller, SH was preserved in 46.5% of 43 patients with Gardner—Robertson Class I hearing and 29.4% of 34 patients with Class II hearing (p = 0.126). Both tumor size and the extent of IAC filling proved statistically significant in a multivariable analysis (p < 0.001 and p = 0.026, respectively). Conclusions. Incomplete filling of the IAC and a tumor size of 15 mm or smaller are independent favorable factors in SH preservation. Excellent preoperative hearing appears to have a positive impact but does not have statistical significance. Intraoperative monitoring is useful in guiding the dissection; however, the surgeon's knowledge of topographical landmarks and meticulous surgical technique remain the essential factors of success.

The significance for postoperative hearing of preserving the labyrinth in acoustic neurinoma surgery

1992 ◽  
Vol 77 (5) ◽  
pp. 677-684 ◽  
Author(s):  
Marcos Tatagiba ◽  
Madjid Samii ◽  
Cordula Matthies ◽  
Mowaffak El Azm ◽  
Robert Schonmayr
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
Cochlear Nerve ◽  
Acoustic Neurinoma ◽  
Content Type ◽  
Acoustic Neurinomas ◽  
A Prospective Study ◽  
Fine Print

✓ Among 186 patients with preoperative hearing, a total of 189 acoustic neurinomas were removed through a lateral suboccipital approach with anatomical preservation of the cochlear nerve. Functional hearing was preserved in 92 (49%) of these patients; despite anatomical preservation of the cochlear nerve, deafness was the result in 51 % of the series. Many factors have been considered to cause hearing loss in patients whose cochlear nerve was intact after surgery; these include nerve retraction, nerve or cochlear ischemia, overheating and vibration damage to the nerve, and opening of the labyrinth. To evaluate the significance of injury to the labyrinth in postoperative hearing loss, a prospective study was undertaken. High-resolution computerized tomography studies through the inner ear with bone algorithm were performed pre- and postoperatively. The postoperative status of the labyrinth was classified into three patterns: intact, fenestrated, and widely opened. Injury to the labyrinth occurred in 30% of the cases. The most frequently injured labyrinth structures were the crus commune of the posterior and superior semicircular canals (52%), the posterior semicircular canal (23%). the vestibule (21%), and the superior semicircular canal (4%). A statistically significant relationship was found between injury to the labyrinth and deafness, elevated thresholds, and lower discrimination values at pure-tone audiograms and speech audiometry (p < 0.0001). The degree of the injury (comparison between fenestration and wide opening of the labyrinth) was also significantly related to postoperative deafness (p < 0.0001). Disturbance of the inner-ear fluids was considered to be the cause of the hearing loss. In 12 patients labyrinth injury was not associated with deafness. This finding may support the existence of mechanisms of cochlear protection. The homeostatic function of the endolymphatic sac was considered to play an important role in recovery of damaged hearing in these 12 cases.

Late course of preserved hearing and tinnitus after acoustic neurilemoma surgery

1992 ◽  
Vol 77 (5) ◽  
pp. 685-689 ◽  
Author(s):  
Atul Goel ◽  
Laligam N. Sekhar ◽  
Walter Langheinrich ◽  
Donald Kamerer ◽  
Barry Hirsch
Keyword(s):  
Tumor Recurrence ◽  
Tumor Resection ◽  
Internal Auditory Canal ◽  
Cochlear Nerve ◽  
Nerve Section ◽  
Preoperative Level ◽  
Content Type ◽  
Fine Print ◽  
Better Than

✓ The late course of preserved hearing and tinnitus following retrosigmoid transmeatal surgery for acoustic neurilemoma is reported. Over a period of 5 years, useful hearing was preserved in 15 patients after preservation was attempted in 42 patients. In five patients the hearing was better than the preoperative level; in three it was worse. Three patients developed delayed worsening and fluctuations of hearing in the surgically treated ear during a median follow-up period of 2½ years. While the exact reason for such worsening was not clear in two patients, in one patient it appeared that the muscle graft placed in the internal auditory canal after tumor resection resulted in fibrosis and compromise of the cochlear nerve. The causes of delayed worsening of hearing in the absence of tumor recurrence are analyzed, and possible treatment and methods of prevention of worsening are suggested. In six patients, tinnitus persisted after surgery in the ear with successful preservation of hearing, but hearing was not worsened and the tinnitus was not bothersome to the patient. In one patient with preoperative tinnitus, hearing was not preserved and tinnitus persisted sufficiently to necessitate re-exploration and cochlear nerve section.

Microvascular decompression for cochlear symptoms

2000 ◽  
Vol 93 (3) ◽  
pp. 421-426 ◽  
Author(s):  
Tomomi Okamura ◽  
Yasushi Kurokawa ◽  
Norio Ikeda ◽  
Seisho Abiko ◽  
Makoto Ideguchi ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Microvascular Decompression ◽  
Cranial Nerve ◽  
Cochlear Nerve ◽  
Auditory Brainstem Responses ◽  
Neurovascular Compression ◽  
Minimal Risk ◽  
Eighth Cranial Nerve ◽  
Content Type ◽  
Fine Print

Object. The object of this study was to evaluate the efficacy of a new neurovascular decompression technique in relieving symptoms of cochlear nerve dysfunction.Methods. Nineteen patients with slowly progressive hearing loss, low-frequency fluctuating hearing loss, and high-pitched tinnitus due to neurovascular compression (NVC) of the eighth cranial nerve in a triangular space between the seventh and eighth cranial nerves (the VII–VIII triangle) of the cerebellopontine angle (CPA) were treated using a new technique for microvascular decompression that was developed by anatomical study in 24 cadaver specimens of the CPA. In 12 of 19 patients the anterior inferior cerebellar artery (AICA) was observed to cause compression in the VII–VIII triangle and this vessel was easily mobilized medially for placement of a silicone sponge or Teflon cushion between the compressing artery and nerve. Postoperatively, hearing loss of 20 dB or more that was present in 11 of the 19 patients with NVC improved by more than 5 dB in seven (64%), including the patient with the most severe hearing loss. Of 18 patients presenting with tinnitus preoperatively, eight (44%) had no tinnitus and an additional nine (for a total of 94%) had good improvement in tinnitus after surgery and at long-term follow up.Conclusions. The microvascular decompression technique described is highly successful in treating symptoms due to direct or indirect compression of the cochlear nerve, with minimal risk of complications. Recordings of auditory brainstem responses confirmed the clinical diagnosis of NVC of the eighth cranial nerve and correlated with clinical results after microvascular decompression of the cochlear nerve.

Length of tumor–cochlear nerve contact and hearing outcome after surgery for vestibular schwannoma

2008 ◽  
Vol 108 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Raymund L. Yong ◽  
Brian D. Westerberg ◽  
Charles Dong ◽  
Ryojo Akagami
Keyword(s):  
Hearing Loss ◽  
Vestibular Schwannoma ◽  
Univariate Analysis ◽  
Internal Auditory Canal ◽  
Hearing Preservation ◽  
Magnetic Resonance Images ◽  
Auditory Evoked Potential ◽  
Cochlear Nerve ◽  
Hearing Outcome ◽  
Interpeak Latency

Object Tumor size is likely to be a major determinant of hearing preservation after surgery for vestibular schwannoma. Findings in some large case series have not supported this concept, possibly due to variation in the technique used for tumor measurement. The authors sought to determine if the length of tumor–cochlear nerve contact was predictive of hearing outcome in adults undergoing resection of a vestibular schwannoma. Methods Patients who underwent a hearing-preserving approach for resection of a vestibular schwannoma at one institution by a neurosurgeon/neurotologist team between 2001 and 2005 were screened. Patients with American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) Class A or B hearing preoperatively were included. Magnetic resonance images were reviewed and used to calculate the length of tumor–cochlear nerve contact. Tumors were also measured according to AAO-HNS guidelines. Results Thirty-one patients were included, 8 (26%) of whom had hearing preservation. Univariate analysis revealed that extracanalicular length of tumor–cochlear nerve contact (p = 0.0365), preoperative hearing class (p = 0.028), I–V interpeak latency of the brainstem auditory evoked potential (p = 0.021), and the interaural I–V interpeak latency difference (p = 0.018) were predictive of hearing outcome. Multivariate analysis confirmed the predictive value of extra-canalicular length of contact and preoperative hearing class (p = 0.041 and p = 0.0235, respectively). Conclusions Vestibular schwannomas with greater lengths of tumor–cochlear nerve contact increase a patient's risk for hearing loss after surgery with attempted hearing preservation. Involvement of the internal auditory canal produces a constant risk of hearing loss. Data from the experience of a single surgical team can be used to estimate the probability of good hearing outcome for any given patient with serviceable hearing and a vestibular schwannoma.

Gamma knife radiosurgery in the management of cavernous sinus meningiomas

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 68-73 ◽  
Author(s):  
Pierre-Hugues Roche ◽  
Jean Régis ◽  
Henry Dufour ◽  
Henri-Dominique Fournier ◽  
Christine Delsanti ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Tumor Growth ◽  
Gamma Knife ◽  
Cavernous Sinus ◽  
Gamma Knife Radiosurgery ◽  
Surgical Removal ◽  
Content Type ◽  
Cavernous Sinus Meningioma ◽  
The Mean ◽  
Fine Print

Object. The authors sought to assess the functional tolerance and tumor control rate of cavernous sinus meningiomas treated by gamma knife radiosurgery (GKS). Methods. Between July 1992 and October 1998, 92 patients harboring benign cavernous sinus meningiomas underwent GKS. The present study is concerned with the first 80 consecutive patients (63 women and 17 men). Gamma knife radiosurgery was performed as an alternative to surgical removal in 50 cases and as an adjuvant to microsurgery in 30 cases. The mean patient age was 49 years (range 6–71 years). The mean tumor volume was 5.8 cm3 (range 0.9–18.6 cm3). On magnetic resonance (MR) imaging the tumor was confined in 66 cases and extensive in 14 cases. The mean prescription dose was 28 Gy (range 12–50 Gy), delivered with an average of eight isocenters (range two–18). The median peripheral isodose was 50% (range 30–70%). Patients were evaluated at 6 months, and at 1, 2, 3, 5, and 7 years after GKS. The median follow-up period was 30.5 months (range 12–79 months). Tumor stabilization after GKS was noted in 51 patients, tumor shrinkage in 25 patients, and enlargement in four patients requiring surgical removal in two cases. The 5-year actuarial progression-free survival was 92.8%. No new oculomotor deficit was observed. Among the 54 patients with oculomotor nerve deficits, 15 improved, eight recovered, and one worsened. Among the 13 patients with trigeminal neuralgia, one worsened (contemporary of tumor growing), five remained unchanged, four improved, and three recovered. In a patient with a remnant surrounding the optic nerve and preoperative low vision (3/10) the decision was to treat the lesion and deliberately sacrifice the residual visual acuity. Only one transient unexpected optic neuropathy has been observed. One case of delayed intracavernous carotid artery occlusion occurred 3 months after GKS, without permanent deficit. Another patient presented with partial complex seizures 18 months after GKS. All cases of tumor growth and neurological deficits observed after GKS occurred before the use of GammaPlan. Since the initiation of systematic use of stereotactic MR imaging and computer-assisted modern dose planning, no more side effects or cases of tumor growth have occurred. Conclusions. Gamma knife radiosurgery was found to be an effective low morbidity—related tool for the treatment of cavernous sinus meningioma. In a significant number of patients, oculomotor functional restoration was observed. The treatment appears to be an alternative to surgical removal of confined enclosed cavernous sinus meningioma and should be proposed as an adjuvant to surgery in case of extensive meningiomas.

Stereotactic radiotherapy for the treatment of acoustic neuromas

2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 362-372 ◽  
Author(s):  
Michael T. Selch ◽  
Alessandro Pedroso ◽  
Steve P. Lee ◽  
Timothy D. Solberg ◽  
Nzhde Agazaryan ◽  
...  
Keyword(s):  
Stereotactic Radiotherapy ◽  
Tumor Size ◽  
Cranial Nerve ◽  
Target Volume ◽  
Tumor Control ◽  
Content Type ◽  
Seventh Cranial Nerve ◽  
Acoustic Neuromas ◽  
Fine Print

Object. The authors sought to assess the safety and efficacy of stereotactic radiotherapy when using a linear accelerator equipped with a micromultileaf collimator for the treatment of patients with acoustic neuromas. Methods. Fifty patients harboring acoustic neuromas were treated with stereotactic radiotherapy between September 1997 and June 2003. Two patients were lost to follow-up review. Patient age ranged from 20 to 76 years (median 59 years), and none had neurofibromatosis. Forty-two patients had useful hearing prior to stereotactic radiotherapy. The fifth and seventh cranial nerve functions were normal in 44 and 46 patients, respectively. Tumor volume ranged from 0.3 to 19.25 ml (median 2.51 ml). The largest tumor dimension varied from 0.6 to 4 cm (median 2.2 cm). Treatment planning in all patients included computerized tomography and magnetic resonance image fusion and beam shaping by using a micromultileaf collimator. The planning target volume included the contrast-enhancing tumor mass and a margin of normal tissue varying from 1 to 3 mm (median 2 mm). All tumors were treated with 6-MV photons and received 54 Gy prescribed at the 90% isodose line encompassing the planning target volume. A sustained increase greater than 2 mm in any tumor dimension was defined as local relapse. The follow-up duration varied from 6 to 74 months (median 36 months). The local tumor control rate in the 48 patients available for follow up was 100%. Central tumor hypodensity occurred in 32 patients (67%) at a median of 6 months following stereotactic radiotherapy. In 12 patients (25%), tumor size increased 1 to 2 mm at a median of 6 months following stereotactic radiotherapy. Increased tumor size in six of these patients was transient. In 13 patients (27%), tumor size decreased 1 to 14 mm at a median of 6 months after treatment. Useful hearing was preserved in 39 patients (93%). New facial numbness occurred in one patient (2.2%) with normal fifth cranial nerve function prior to stereotactic radiotherapy. New facial palsy occurred in one patient (2.1%) with normal seventh cranial nerve function prior to treatment. No patient's pretreatment dysfunction of the fifth or seventh cranial nerve worsened after stereotactic radiotherapy. Tinnitus improved in six patients and worsened in two. Conclusions. Stereotactic radiotherapy using field shaping for the treatment of acoustic neuromas achieves high rates of tumor control and preservation of useful hearing. The technique produces low rates of damage to the fifth and seventh cranial nerves. Long-term follow-up studies are necessary to confirm these findings.

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.

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