Cochlear Implantation in Children with Enlarged Vestibular Aqueduct: A Systematic Review of Surgical Implications and Outcomes.

OBJECTIVES: This study investigated age at implantation, improvement in hearing and speech perception outcomes, as well as surgical complications in pediatric cochlear implant recipients with Pendred Syndrome (PS) or non-syndromic enlarged vestibular aqueduct (NSEVA). DESIGN: A systematic review of the literature between 1984 and 2021 was performed. Two independent reviewers performed abstract and full-text screening using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The inclusion criteria were: English language, cochlear implant, age at implantation available, age <18 years, PS, Mondini malformation, and enlarged vestibular aqueduct. Full-text analysis was completed using the National Institute of Health assessment tool for case series and case-control studies. Studies were also graded according to the Oxford Centre for Evidence-Based Medicine grading system. RESULTS: In total, 198 studies were identified and screened, and 55 studies were included for analysis. Audiological outcomes were available in 46 studies, and the four-frequency pure-tone audiogram average improved by 60 to 78 dB HL due to cochlear implantation. Auditory performance and speech intelligibility scores increased by 44%. The overall average implantation age was 60 months. The implantation age was 21 months lower in the studies where individuals were implanted after the year 2000 compared with those implanted before the year 2000. Perilymph gusher/oozing was the most common surgical incident reported, occurring in 187 of 1572 implantations. CONCLUSIONS: In children with PS/NSEVA, cochlear implantation improves pure-tone average by 60 to 78 dB HL and capacity of auditory performance/speech intelligibility by 44%. The implantation age for these children has decreased during the last two decades but is still somewhat higher than reported for unselected pediatric cochlear implantation. Perilymph gusher/oozing is the most common surgical complication.

Cochlear implantation in adults and pediatrics with enlarged vestibular aqueduct: a systematic review on the surgical findings and patients' performance.

PURPOSE: Cochlear implantation (CI) has been considered a safe and effective management option for patients with severe to profound hearing loss. Patients with enlarged vestibular aqueduct (EVA) could be challenging with some variations in surgical approaches, intraoperative surgical notes, and clinical outcomes. This study aimed to  review the surgical and clinical outcomes of cochlear implantation among patients with EVA. MATERIALS AND METHODS: A systematic literature search was carried out in five major databases. All original studies reporting cochlear implantation in patients with EVA were included for qualitative data synthesis. The risk of bias was independently assessed through the National Intuitional of Health tool. The review protocol was registered in PROSPERO (reference number: CRD42021225900). RESULTS: A total of 34 studies with 4035 subjects were included. Of them, 853 (21.14%) had EVA and underwent CI. Mondini malformation was the most frequently associated anomaly (n = 78, 11.1%). Unilateral implantation was performed in 258 cases while bilateral in 119 subjects. Postoperative complications included CSF/perilymph gusher (n = 112), CSF oozing (n = 18), and partial electrode insertion (n = 6). Closing the cochleostomy with temporalis fascia, muscle, connective tissue, or fibrin glue was the most frequently reported approach to manage CSF/perilymph gusher (n = 67, 56.7%) while packing was performed in six patients. CONCLUSION: Patients with EVA demonstrated audiometric and speech performance improvement after CI. However, many patients had intra- or postoperative complications. Further research is needed as the outcomes may be affected by associated temporal bone pathology, the timing of implant, and hearing condition.

Endoscopic assistance in retrosigmoid transmeatal approach to intracanalicular vestibular schwannomas - An alternative for middle fossa approach. Technical note.

BACKGROUND: Complete surgical removal of intracanalicular vestibular schwannomas with nerve VII and VIII sparing and without worsening patient's status is challenging. Also the choice of an optimal surgical technique, which is usually limited to selection between retrosigmoid transmeatal (RT) and middle fossa (MF) approach, can be a challenge. Although many previous studies documented superiority of RT to MF approach and vice versa, still no consensus has been reached regarding an optimal approach to intracanalicular vestibular schwannomas. In this technical note, we present RT approach with an endoscopic assistance and highlight its advantages over MF approach in surgical management of pure intracanalicular vestibular schwannomas. METHOD: RT approach with an endoscopic assistance is presented as an optimal surgical treatment for intracanalicular vestibular schwannomas, and its advantages are compared to those offered by MF approach. RESULTS: Under an endoscopic guidance, we found a residual tumor in the fundus of the inner acoustic canal and performed its gross total resection. CONCLUSIONS: RT approach is an excellent technique suitable for safe radical surgical treatment of T1 vestibular schwannomas; this technique is associated with lower morbidity risk than MF approach.

Image-guided, microsurgical topographic anatomy of the endolymphatic sac and vestibular aqueduct via a suboccipital retrosigmoid approach.

The endolymphatic sac (ES) and the vestibular aqueduct (VA) are often in the surgical field when posterior fossa lesions are targeted using retrosigmoid approaches. The purpose of this work is to validate neuronavigator accuracy in predicting VA location as well as to give guidelines to preserve the ES and VA. A retrosigmoid approach was performed bilaterally in six specimens in the semisitting position. Preoperatively, we registered in the CT scans the position of the VA genu (virtual genu). After the approach execution, ES and VA genu topographic relationships with evident posterolateral cranial base structures were measured using neuronavigation. Next, we exposed the VA genu: its position coincided with the virtual VA genu in all the specimens. On the average, the ES was 17.93 mm posterosuperolateral to the XI nerve in the jugular foramen, 12.26 mm posterolateral to the internal acoustic meatus, 20.13 mm anteromedial to the petro-sigmoid intersection at a point 13.30 mm inferior to the petrous ridge. The VA genu was located 7.23 mm posterolateral to the internal acoustic meatus, 18.11 mm superolateral to the XI nerve in the jugular foramen, 10.27 mm inferior to the petrous ridge, and 6.28 mm anterolateral to the endolymphatic ledge at a depth of 3.46 mm from the posterior pyramidal wall. Our study demonstrates that is possible to use neuronavigation to reliably predict the location of the VA genu. In addition, neuronavigation may be effectively used to create a topographical framework that may help maintaining the integrity of the ES/VA during retrosigmoid approaches.

Endovascular treatment of symptomatic vestibular aqueduct dehiscence as a result of jugular bulb abnormalities.

A new endovascular treatment consisting of stent-assisted coil implantation is described for jugular bulb abnormalities causing symptomatic vestibular aqueduct dehiscence. Three patients presenting with vertigo associated with pulsatile tinnitus or hearing loss were treated. This technique cured the vertigo and pulsatile tinnitus in all patients and preserved normal cerebral venous drainage with no side effects.

New treatment of vertigo caused by jugular bulb abnormalities.

OBJECTIVE: Jugular bulb abnormalities can induce tinnitus, hearing loss, or vertigo. Vertigo can be very disabling and may need surgical treatments with risk of hearing loss, major bleeding or facial palsy. Hence, we have developed a new treatment for vertigo caused by jugular bulb anomalies, using an endovascular technique. PATIENTS: Three patients presented with severe vertigos mostly induced by high venous pressure. One patient showed downbeat vertical nystagmus during the Valsalva maneuver. The temporal-bone computed tomography scan showed a high rising jugular bulb or a jugular bulb diverticulum with dehiscence and compression of the vestibular aqueduct in all cases. INTERVENTION: We plugged the upper part of the bulb with coils, and we used a stent to maintain the coils and preserving the venous permeability. RESULTS: After 12- to 24-month follow-up, those patients experienced no more vertigo, allowing return to work. The 3-month arteriographs showed good permeability of the sigmoid sinus and jugular bulb through the stent, with complete obstruction of the upper part of the bulb in all cases. CONCLUSION: Disabling vertigo induced by jugular bulb abnormalities can be effectively treated by an endovascular technique. This technique is minimally invasive with a probable greater benefit/risk ratio compare with surgery.

Programming Levels and Speech Perception in Pediatric Cochlear Implant Recipients With Enlarged Vestibular Aqueduct or GJB2 Mutation.

OBJECTIVE: To determine the relationship between hearing loss etiology, cochlear implant (CI) programming levels, and speech perception performance in a large clinical cohort of pediatric CI recipients. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary care hospitals. PATIENTS: A total of 136 pediatric CI recipients (218 ears) were included in this study. All patients had diagnoses of either enlarged vestibular aqueduct (EVA) or GJB2 (Connexin-26) mutation confirmed via radiographic data and/or genetic reports. All patients received audiologic care at either Boston Children's Hospital or Massachusetts Eye and Ear in Boston, MA, between the years 1999 and 2020. MAIN OUTCOME MEASURES: Electrode impedances and programming levels for each active electrode and speech perception scores were evaluated as a function of etiology (EVA or GJB2 mutation). RESULTS: Children with EVA had significantly higher impedances and programming levels (thresholds and upper stimulation levels) than the children with GJB2 mutation. Speech perception scores did not differ as a function of etiology in this sample; rather, they were positively correlated with duration of CI experience (time since implantation). CONCLUSIONS: Differences in electrode impedances and CI programming levels suggest that the electrode-neuron interface varies systematically as a function of hearing loss etiology in pediatric CI recipients with EVA and those with GJB2 mutation. Time with the CI was a better predictor of speech perception scores than etiology, suggesting that children can adapt to CI stimulation with experience.

Cochlear Implantation in Pediatric Patients With Enlarged Vestibular Aqueduct: A Systematic Review.

OBJECTIVE(S): To describe cochlear implantation (CI) outcomes, with speech perception, auditory, language, and parent-reported auditory and speech behaviors, in children with an enlarged vestibular aqueduct (EVA) and incomplete partition type 2 (IP-II) and compare to control children without inner ear malformations (IEMs) and to determine cerebrospinal fluid gusher rates and effect on outcomes. STUDY DESIGN: Systematic review and meta-analysis. METHODS: MEDLINE, Embase, Cochrane, and CINAHL databases were searched from inception to February 2020. Studies reporting relevant outcomes in children with EVA or EVA + IP-II and controls without IEMs undergoing CI were included. Mean differences in speech perception, auditory, and language scores between cases and controls were meta-analyzed. Gusher rates were determined by proportion meta-analyses. RESULTS: Of 214 identified articles, 42 met inclusion criteria, evaluating 775 cases and 2,191 controls. Of -cases, 578 (74.6%) had EVA and 197 (25.4%) had EVA + IP-II. Cases showed a significant improvement in speech perception, auditory and language performance, comparable to controls. Parent-reported auditory and speech production behaviors outcomes were positive among cases and comparable to controls. Pooled gusher proportions in EVA and EVA + IP-II cases were 27.7% (95% CI: 17.6-39.1) and 48.6% (95% CI: 28.6-69.0), respectively, with a proportion difference of 20.9% (95% CI: 11.0-30.1). Gusher occurrence did not impact speech perception or language outcomes. CONCLUSION: Outcomes in children with EVA or EVA + IP-II undergoing CI are favorable and largely comparable to outcomes in children with hearing loss undergoing CI without IEMs. Intraoperative gusher is more prevalent among children with EVA + IP-II as compared to iEVA. Gusher does not influence speech perception and language development outcomes. LEVEL OF EVIDENCE: NA Laryngoscope, 132:1459-1472, 2022.

Early Elevation and Normalization of Electrode Impedance in Patients With Enlarged Vestibular Aqueduct Undergoing Cochlear Implantation.

OBJECTIVE: To characterize early changes in impedance in patients undergoing cochlear implantation with and without enlarged vestibular aqueducts (EVA). METHODS: Case-control retrospective study of patients undergoing cochlear implantation with and without EVA. Impedance was measured across all channels intraoperatively and within 24 hours of surgery. All patients received the same electrode array. RESULTS: Ten patients with EVA (and matched controls were identified). The average intraoperative impedance across all electrodes was significantly higher in patients with EVA (13.1 ±â€Š1.4 kΩ) than in controls (9.6 ±â€Š2.5 kΩ, p  < 0.001). At 24-hour activation, the average impedance across all electrodes was roughly equal in both groups (6.8 ±â€Š2.7 kΩ versus 6.5 ±â€Š2.1 kΩ, p  = 0.72). CONCLUSIONS: This study is the first identify differences in intraoperative impedance between patients with and without EVA. In addition, these data demonstrate rapid normalization within 24 hours of surgery. Such findings can give a window of insight into both the intracochlear microenvironment of patients with EVA and the important early electrode-fluid-tissue interface changes that occur within hours of surgery for all patients.

Characteristics of electrically evoked auditory brainstem response in children with large vestibular aqueduct syndrome after cochlear implantation.

BACKGROUND: The vestibular aqueduct (VA) width may affect the auditory conduction pathway of large vestibular aqueduct syndrome (LVAS) children. OBJECTIVE: Analyzing the electrically evoked auditory brainstem response (EABR) after cochlear implantation (CI) in severe to profound sensorineural hearing loss (SNHL) children with LVAS. MATERIALS AND METHODS: Fifty-four children with SNHL who received CI were selected, including 21 children with LVAS and 33 children without inner ear malformations (IEMs). The VA width was measured in LVAS children. The post-operative EABRs were recorded in all children. RESULTS: For the LVAS group, the VA width was positively correlated with wave III (eIII) latency of EABR at the No. 2 electrode (E2), E5, E8, and E11, the VA width was positively correlated with wave V (eV) latency of EABR at E2, E5, E8, and E11. Only the eV latency of E2 showed a significant difference between the two groups. CONCLUSION AND SIGNIFICANCE: SNHL children with LVAS and no IEMs have similar conduction of the auditory pathway. In the LVAS group, the conduction of the auditory pathway becomes better with the decrease of VA width. Rational use of post-operative EABRs and the measurement of anatomical parameters can effectively assess the development of part auditory pathways in LVAS children, which may be helpful in predicting post-operative speech and hearing recovery.

Enlarged Vestibular Aqueduct: Disease Characterization and Exploration of Potential Prognostic Factors for Cochlear Implantation.

OBJECTIVES: There is an unmet need to match the anticipated natural history of hearing loss (HL) in enlarged vestibular aqueduct (EVA) with clinical management strategies. The objectives of this study are therefore to provide a detailed case characterization of an EVA cohort and explore the relationship between candidate prognostic factors and timing of cochlear implant (CI) surgery. STUDY DESIGN: A multicenter retrospective review of patients diagnosed with EVA. SETTING: Patient data recruitment across three CI centers in the UK. PATIENTS: One hundred fifty patients with a radiological diagnosis of EVA from January 1995 to January 2021. MAIN OUTCOME MEASURES: Age at audiological candidacy for CI and age at first implant surgery. RESULTS: EVA was predominately a bilateral condition (144/ 150) with increased prevalence in women (M:F, 64:86). 51.7% of patients failed new-born hearing screening, with 65.7% having HL diagnosed by 1 year. Initial moderate to severe and severe to profound HL were reported most frequently. In 123 patients, median age that audiological candidacy for CI was met for at least one ear was 2.75 years. Median age at first CI was 5 years (140/150).Pendred syndrome (confirmed in 73 patients) and ethnicity, were not significantly associated with earlier CI surgery. Multivariate linear regression demonstrated that male patients have first CI surgery significantly earlier than females (coefficient -0.43, 95% CI [-0.82, -0.05), p-value = 0.028). CONCLUSIONS: This large UK EVA cohort provides evidence that patients should be closely monitored for CI candidacy within the first 3 years of life. Significantly, male gender is emerging as an independent prognostic factor for earlier assessment and first CI surgery.

Cochlear implants in forty-eight children with cochlear and/or vestibular abnormality.

CT and MRI scans for 48 children with cochlear and/or vestibular abnormality were classified in decreasing severity; common cavity, Mondini plus enlarged vestibular aqueduct, Mondini dysplasia alone and enlarged vestibular aqueduct alone. No significant relationship between degree of cochlea abnormality and surgical issues (cerebrospinal fluid gusher, depth of insertion, number of electrodes) or speech perception/language outcomes was found. A significant relationship was observed between cerebrospinal fluid gusher and partial electrode insertion, fewer active electrodes and poorer sentence understanding. Optimum language outcomes were associated with younger age at implant.

Enlarged Vestibular Aqueduct: Hearing Progression and Cochlear Implant Candidacy in Pediatric Patients.

HYPOTHESIS/OBJECTIVE: Investigate the rate of hearing loss progression and incidence of cochlear implant candidacy in children with enlarged vestibular aqueduct (EVA). BACKGROUND: EVA is the most common congenital malformation of the inner ear, is responsible for a large percentage of children with hearing loss, and is associated with hearing loss progression. Rates and degree of progression of hearing loss to cochlear implantation candidacy have not been well described. METHODS: Review of children with EVA who presented to a single academic medical center. Audiometric data were reviewed to determine subjects who met criteria for cochlear implantation (≥75 dB pure-tone average) at presentation. For those not meeting criteria, serial audiometric data were reviewed for progression to candidacy. RESULTS: A total of 257 ears met inclusion criteria. One hundred ninety-two (74.7%) met cochlear implant candidacy criteria by age 12, yet only 117 ears (60.9%) actually received implants before turning 13. One hundred fifty-three ears (59.5%) met implant candidacy criteria at presentation. Nearly 50% of those not initially meeting implantation criteria had a ≥15 dB shift in pure-tone average by age 12, with 37.5% of this subgroup meeting implant candidacy criteria before their teen years at an average age of 7.10 years. CONCLUSION: The majority of children with EVA reach cochlear implant candidacy before reaching adulthood, yet implantation rates for candidate ears remain at 60% and delay in implantation persist. Parents of children with EVA should be counseled on the likelihood of progression and closely monitored for cochlear implant candidacy.

Vestibular impairment in cochlear implanted children presenting enlarged vestibular aqueduct and enlarged endolymphatic sac.

Enlarged vestibular aqueduct (EVA) is a common finding in tomodensitometry. When cranial MRI is performed, enlarged endolymphatic sac (EES) can also be found. Profound hearing loss is a common finding in these patients but a few studies have investigated vestibular function after cochlear implantation (CI) in EVA and EES patients. Our main objective was to find out whether in EVA children candidates to CI, a higher endolymphatic sac (ES) volume was predictive for higher rates of postsurgical vestibular complications. METHODS: We retrospectively included EVA children who benefited from CI, during the last 2 years. Two groups were constituted according to the presence or not of a vestibular impairment (decrease in the VOR gain on the VHIT test on one of the semicircular canals and/or a loss of cVEMPs) 6 months after CI. Endolymphatic volume of both VA and ES was measured for each patient. RESULTS: Fifteen patients were included. The mean endolymph volume was significantly higher in the impaired group (0.40 cm3 ± 0.23, range 0.08-0.70) than in the non-impaired group (0.11 cm3 ± 0.07, range 0.04-0.29; p = 0.029). Four children of the impaired group were followed during one year. At the end of vestibular rehabilitation, all children recovered a lateral canal function and a saccular function. CONCLUSION: In EVA children, a combined EES appears to increase the risk of severe post CI vestibular impairment. To minimize this risk prior CI surgery, besides tomodensitometry, MRI measurement of the ES volume should be systematically performed.

Enlarged vestibular aqueduct: Intraoperative electrocochleography findings during cochlear implantation.

Enlarged vestibular aqueduct (EVA) is the most frequent inner ear abnormality found on computed tomography in children with sensorineural hearing loss. The effects EVA abnormalities have on electrocochleography (ECochG) are unknown. Positive deflections in summation potential evoked by tone bursts were observed in 3/5 subjects, while a large negative deflection, similar to endolymphatic hydrops (EH), was observed for 2/5 subjects. The presence of an enlarged summation potential, with and without a compound action potential, was observed in response to a broadband click stimulus. Results suggest likely effects of a third window on ECochG responses and presence of EH in EVA.

Cochlear Implant Outcomes in Large Vestibular Aqueduct Syndrome-Should We Provide Cochlear Implants Earlier?

OBJECTIVE: Examine postoperative speech perception outcomes in a large vestibular aqueduct syndrome (LVAS) patients at a major cochlear implantation center. STUDY DESIGN: Retrospective analysis of the Sydney Cochlear Implant Centre (SCIC) database and medical records from January 1994 to December 2015 was performed. SETTING: Tertiary referral center. PATIENTS: Patients with a diagnosis of LVAS who received a cochlear implant (CI). Only those with speech perception outcomes recorded at least 12 months post implant were included in our analysis. INTERVENTION(S): Therapeutic. MAIN OUTCOME MEASURE(S): Postoperative speech perception scores. RESULTS: Between 1994 and 2015, 176 adult and pediatric patients with a diagnosis of LVAS underwent cochlear implantation at SCIC. Postoperative Bamford-Kowal Bench (BKB) sentence test scores were obtained for 97 patients. The postoperative median BKB score was 93% with a lower quartile score of 85% and an upper quartile score of 98%. Smaller numbers were available for post-CI City University of New York (CUNY) and Consonant-Nucleus-Consonant (CNC) word scores yet similar excellent results were seen. CONCLUSIONS: Our study results suggest the CI should be considered when BKB scores have dropped to 85%. We suggest that rather than LVAS cases representing a challenge to cochlear implantation, they are amongst the best candidates for surgery, and should receive a CI at an earlier stage in hearing loss, when they have better speech perception. This allows stable hearing to be established earlier along with excellent speech perception outcomes.

Cochlear implantation in a 10-year old boy with Pendred syndrome and extremely enlarged endolymphatic sacs.

A 10-year-old boy with fluctuating sensorineural hearing loss (SNHL) and biallelic mutations in the SLC26A4 gene and with inner ear anomalies received a cochlear implantation. SLC26A4 mutations are associated with variable degrees of SNHL and enlarged vestibular aqueducts (EVA), identified either as non-syndromic EVA or classic Pendred syndrome; the latter also associated with thyroid dysfunction. The inner ear malformations in this group of patients have been considered a relative contraindication against cochlear implantation because of the potential per- and postoperative complications such as peroperative cerebrospinal fluid leak or postoperative vestibular symptoms. In the current case there were no surgical or postoperative complications, indicating that extremely enlarged endolymphatic sacs are not as such a contraindication for cochlear implantation. This case also illustrates the management dilemma of an appropriate timing for cochlear implantation.

The vestibular aqueduct: site of origin of endolymphatic sac tumors.

OBJECT: Although endolymphatic sac tumors (ELSTs) frequently destroy the posterior petrous bone and cause hearing loss, the anatomical origin of these neoplasms is unknown. To determine the precise topographic origin of ELSTs, the authors analyzed the imaging, operative, and pathological findings in patients with von Hippel-Lindau disease (VHL) and ELSTs. METHODS: Consecutive VHL patients with small (

Enlarged Vestibular Aqueduct and Cochlear Implants: The Effect of Early Counseling on the Length of Time Between Candidacy and Implantation.

OBJECTIVE: To determine if discussing cochlear implantation (CI) with patients with enlarged vestibular aqueducts (EVA) and their families before reaching audiological criteria for CI candidacy effects the length of time between reaching audiological candidacy and CI surgery, and to describe the universal newborn hearing screening (UNHS) results and communication modality in this sample. PATIENTS: Forty-two patients (25 females) with confirmed EVA and cochlear implants. INTERVENTION(S): Diagnostic CI visit. MAIN OUTCOME MEASURES: The primary outcome measure is the difference in length of time between reaching audiological candidacy for CI and surgical implantation between those who had preliminary discussions regarding CI with their medical and healthcare providers before reaching audiological candidacy versus who had discussions after reaching candidacy. The secondary outcome measure is the result of the UNHS and primary mode of communication used by each patient. RESULTS: Discussing CI before reaching audiological candidacy was associated with a significantly shorter duration between reaching audiological candidacy and receiving CI (median = 3.1 mo; interquartile range [IQR] = 1.7-5.4) as compared with discussing CI after reaching candidacy (median = 5.8 mo; IQR = 3.2-11.2; p = 0.012). Participants born after the implementation of the UNHS, 16 of 24 patients referred on one or both ears. Communication modalities were evenly divided between utilizing sign-support English and oral/aural communicators only. CONCLUSIONS: Discussion of CI in patients with EVA before reaching audiological candidacy reduces the amount of time the child is without adequate auditory access and contributes to a constructive and interactive preparatory experience.

Intracanalicular meningioma: clinical features, radiologic findings, and surgical management.

OBJECTIVE: Intracanalicular meningiomas are extremely rare, and only 36 cases have been reported to date. The aim of this study is to describe the clinical, radiologic, and histopathologic features of 13 intracanalicular meningiomas highlighting important aspects of tumor diagnosis and treatment. STUDY DESIGN: Retrospective study. SETTING: Quaternary referral otology and cranial base private center. PATIENTS: Thirteen consecutive patients with pathologically confirmed intracanalicular meningioma surgically treated between December 1988 and July 2006. The follow-up of the series ranged from 13 to 60 months. INTERVENTIONS: Nine patients with unserviceable hearing were operated on through the translabyrinthine approach. Four patients underwent enlarged middle cranial fossa approach with the intention of preserving their hearing. RESULTS: Total tumor removal was achieved in all cases. The postoperative facial nerve function was either excellent or good (House-Brackmann Grade I or II) in 10 cases (77%) and acceptable (Grade III) in one case. Two patients with preoperative facial paresis showed no improvement in their facial nerve function. In patients who underwent surgery via the enlarged middle cranial fossa, hearing was preserved at the preoperative level in two cases, but serviceable hearing was lost in the remaining two. CONCLUSION: Primary meningiomas of the internal auditory canal are extremely rare. On account of a lack of specific symptoms and the limited diagnostic findings, preoperative diagnosis of intracanalicular meningioma still represents a diagnostic challenge. Intraoperative findings may help in differentiating meningiomas from other intracanalicular lesions.