Differentiation of geniculate ganglion venous malformation from schwannoma: dynamic T1-weighted imaging provides unique diagnostic value.

OBJECTIVE: To distinguish geniculate ganglion venous malformation (GGVM) from schwannoma (GGS) by using high-resolution CT (HRCT), routine MRI, and dynamic T1-weighted imaging (T1WI) characteristics. METHODS: Surgically confirmed GGVMs and GGSs between 2016 and 2021 were retrospectively included. Preoperative HRCT, routine MR, and dynamic T1WI were performed on all patients. Clinical data, imaging characteristics including lesion size, involvement of facial nerve (FN), signal intensity, enhancement pattern on dynamic T1WI, and bone destruction on HRCT were evaluated. Logistic regression model was developed to identify independent factors for GGVMs, and the diagnostic performance was accessed by receiving operative curve (ROC) analysis. Histological characteristics were explored for both GGVMs and GGSs. RESULTS: Twenty GGVMs and 23 GGSs with mean age of 31 were included. On dynamic T1WI, 18 GGVMs (18/20) showed "pattern A" enhancement (a progressive filling enhancement), while all 23 GGSs showed "pattern B" enhancement (a gradual whole-lesion enhancement) (p < 0.001). Thirteen GGVMs (13/20) showed the "honeycomb" sign whereas all GGS (23/23) showed extensive bone changes on HRCT (p < 0.001). Lesion size, involvement of FN segment, signal intensity on non-contrast T1WI and T2-weighted imaging (T2WI), and homogeneity on enhanced T1WI were obviously differed between two lesions (p < 0.001, p = 0.002, p < 0.001, p = 0.01, p = 0.02, respectively). Regression model showed the "honeycomb" sign and "pattern A" enhancement were independent risk factors. Histologically, GGVM was characterized by interwoven dilated and tortuous veins, while GGS was characterized by abundant spindle cells with dense arterioles or capillaries. CONCLUSIONS: The "honeycomb" sign on HRCT and "pattern A" enhancement on dynamic T1WI are the most promising imaging characteristics for differentiating GGVM from GGS. CLINICAL RELEVANCE STATEMENT: The characteristic sign and enhancement pattern on HRCT and dynamic T1-weighted imaging allow preoperative differentiation of geniculate ganglion venous malformation and schwannoma feasible, which will improve clinical management and benefit patient prognosis. KEY POINTS: • The "honeycomb" sign on HRCT is a reliable finding to differentiate GGVM from GGS. • GGVM typically shows "pattern A" enhancement (focal enhancement of the tumor on early dynamic T1WI, followed by progressive contrast filling of the tumor in the delayed phase), while "pattern B" enhancement (gradual heterogeneous or homogeneous enhancement of the whole lesion) is observed in GGS on dynamic T1WI.

Suprameatal-transzygomatic root endoscopic approach to the geniculate ganglion: an anatomical and radiological study.

PURPOSE: To describe the suprameatal-transzygomatic root endoscopic approach (STEA) to the geniculate ganglion (GG), the labyrinthine facial nerve (FN) and epitympanum. METHODS: The feasibility and limits of the STEA, maintaining the integrity of the ossicular chain, were analysed. Ten human cadaveric ears were dissected. Step-by-step description of the technique and relevant measurements were taken during the approach. The visualization and surgical working field on the anterior and posterior medial epitympanum, GG, greater superficial petrosal nerve, the labyrinthine FN and suprageniculate area were evaluated. The range of motion through the approach and the rate of the decompression of the GG and the labyrinthine portion of the FN were assessed as well. CT-scan measurements were compared with those obtained during the dissection. RESULTS: A complete exploration of the epitympanum was possible in every specimen. Decompression of the GG and first portion of the FN was achieved without any trauma to the ossicular chain in nine ears. The endoscope movements were mainly limited by the distance between bony buttress-short process of the incus-tegmen. The working space, during GG and labyrinthine FN decompression, was limited by the distance between malleus head-medial epitympanic wall and malleus head-GG. Radiologic measurements were consistent with those obtained during the dissections. CONCLUSION: The STEA is a promising minimally invasive approach for decompression of the GG and FN's labyrinthine portion. The applications of this corridor include the exploration and surgery of the medial epitympanum, preserving the ossicular chain.

Growth dynamic of the geniculate ganglion in children: a retrospective computed tomography study.

PURPOSE: The main aim of this retrospective computed tomography (CT) study was to examine the morphometric development of the geniculate ganglion (GG) in children aged between 1 and 18 years for surgical approaches. METHODS: This study was placed on 41 patients (20 females and 21 males) including cochlear implantation cases aged from one to 18 (at mean, 6.44 ± 5.79) years. All the measurements belonging to the length, width and area of GG were performed with a CT scanner. RESULTS: The morphometric values of GG were not different in terms of sex or side, statistically (p > 0.05). The length (p = 0.155) of GG was not correlated with the increasing ages from one to 18 years; however, its area (p < 0.001) and width (p = 0.003) were found to be increased in the childhood period. Linear functions for the length, width and area of GG were calculated as y = 2.028 + 0.011 × age (years), y = 1.496 + 0.014 × age (years), and y = 3.239 + 0.035 × Age (years), respectively. The dehiscence of GG was found in 22 (26.8%) out of 82 temporal bones. CONCLUSION: Our data suggested that the area and width of GG were progressively increasing with age in the childhood period. The calculated formula representing the growth dynamic of GG in children and the incidence of the presence of the dehiscent GG can be useful for radiologists and otologists to estimate its size and to avoid iatrogenic injury during early childhood surgeries.

Relation between volume of sphenoid sinuses and protrusion of Vidian nerve: possible applications to Vidian neurectomy.

PURPOSE: Vidian neurectomy is a surgical procedure applied to different pathological conditions, including chronic rhinitis and sphenopalatine neuralgia. The choice of the correct surgical approach depends upon the possible protrusion of Vidian nerve into the sphenoid sinuses. The present study analyzes the possible relationship between protrusion of Vidian nerve and volume of sphenoid sinuses. METHODS: In total, 320 maxillofacial CT-scans were retrospectively assessed. Subjects equally divided among males and females (age range 18-94 years) were divided into three groups according to the profile of Vidian nerve protrusion: type 1: Vidian nerve inside the sphenoid corpus; type 2: partially protruding into the sphenoid sinus; and type 3: entirely protruding into the sphenoid sinus through a stalk. Volume of sphenoid sinuses was extracted through the ITK-SNAP-free software and automatically calculated. Possible statistically significant differences in prevalence of the three types between males and females were assessed through Chi-squared test (p < 0.05). Differences in volume of sphenoid sinuses in subjects included within the three types were assessed through one-way ANOVA test (p < 0.05), separately for males and females. RESULTS: Type 2 was the most prevalent (46.5%), followed by type 1 (38.8%) and type 3 (14.7%), without significant differences according to sex (p > 0.05). Volume significantly increased passing from type 1 to type 3 both in males (p < 0.01) and in females (p < 0.01). CONCLUSIONS: The results prove the existence of a strict relationship between sphenoid sinuses pneumatization and protrusion of the Vidian canal and give a contribution to the knowledge of this important anatomical variant in endoscopic surgery.

Facial nerve hemangiomas at geniculate ganglion: preservation of nerve integrity is correlated with duration of facial palsy.

OBJECTIVE: To study preservation of nerve integrity in 16 cases with facial nerve hemangiomas at geniculate ganglion (GG). METHODS: 16 cases with facial nerve hemangiomas at GG, who presented with facial palsy, were included in the study. Preservation of nerve integrity was attempted by the same surgeon during surgical removal, and those who failed to preserve nerve integrity underwent nerve grafting. The patients were divided into longer duration group (>12months) and shorter duration group (≤12months) according to duration of facial palsy, and preservation of nerve integrity in the couple of groups was compared. RESULTS: Nerve integrity was preserved in 2 of 10 cases (20%) among longer duration group, while it was preserved in 5 of 6 cases (83.3%) among shorter duration group (p<0.05). All the cases with nerve integrity preserved recovered to grade III or better, among which 3 cases recovered to grade I or grade II, while only 3 of 9 cases (33.3%) with nerve grafting recovered to grade III at the best. CONCLUSIONS: Preservation of nerve integrity was correlated with duration of facial palsy in cases with hemangiomas at GG. Patients with nerve integrity preserved showed better outcomes of facial nerve.

Geniculate ganglion diverticulum: a potential imaging marker in patients with idiopathic intracranial hypertension.

PURPOSE: The diagnosis of idiopathic intracranial hypertension (IIH) is often challenging in patients who do not present with classic symptoms. Brain MRI can play a pivotal role, as several imaging findings, such as an empty sella appearance (ESA), have been shown to be associated with IIH. Yet, none of the MRI signs have been shown to have a high sensitivity and specificity. In this study, we tested the hypothesis that presence of a geniculate ganglion diverticulum (GGD) is a potential imaging marker for the detection of IIH. MATERIALS AND METHODS: This is an IRB-approved, single-institution, retrospective, observational study. Brain MRI examinations of patients referred to Radiology by Otology clinic over a period of 10 years were reviewed. 244 MRI exams fulfilling inclusion and exclusion criteria were independently screened for the presence of GGD and ESA by two Neuroradiology fellows. Electronic medical records (EMR) of patients in this study were reviewed for presence of clinical manifestations of IIH. Receiver operator characteristic (ROC) curves were generated to estimate the accuracy of each covariate in diagnosing IIH. The area under each ROC curve (AUC) was calculated to identify an accurate prognostic covariate. Statistical analysis was done using R programming language V 4.2.2. RESULTS: GGD was identified in MRI exams of 51 patients. A 2:1 propensity score (PS) matching for age, gender, and Body Mass Index (BMI) was used to select non-GGD control group for comparison with the GGD group. There was strong agreement between the 2 reviewers (kappa = 0.81, agreement = 95 %). Twelve patients in this study were diagnosed with IIH. There was a high incidence of GGD (OR = 12.19, 95 % CI (2.56, 58.10)) and ESA (OR = 4.97, 95 % CI (1.47, 16.74)) in IIH patients. The AUC observed in GGD for predicting IIH was 0.771 (0.655-0.888), specificity = 0.709 (0.638-0.780), and sensitivity = 0.833 (0.583-1). The AUC observed for ESA in predicting IIH was 0.682 (0.532-0.831), specificity = 0.780 (0.709-0.844), and sensitivity = 0.583 (0.333-0.833). CONCLUSION: GGD is potentially a novel imaging marker of IIH with sensitivity higher than and specificity comparable to that of ESA. CLINICAL RELEVANCE STATEMENT: Presence of GGD should raise the possibility of IIH.

Measurement and analysis of facial nerve on fully displayed multislice computed tomographic multiplanar reconstruction image.

The objectives of this study were to measure the length of horizontal segment of facial nerve (HFN), the length of vertical segment of facial nerve (VFN), and the angle between these 2 segments on a fully displayed multislice computed tomographic multiplanar reconstruction (MPR) images of HFN and VFN and to analyze the data with respects to side, sex, and age. Parameters of 234 patients (468 observations, 118 men and 116 women, aged 4-70 years) with intact temporal bone were measured on multislice computed tomographic multiplanar reconstruction images. The data gained were analyzed by statistical method. The left and right lengths of VFN were significantly different (P < 0.05). And the length of HFN, the length of VFN, and the angle between males and females were significantly different (P < 0.05). We divided the data into 3 groups to study correlations between measurements and age. In underaged group, there was a strong positive correlation between the length of VFN and age; the value of Pearson correlation was 0.645. And there was a weak correlation between the angle and the age; the value of Pearson correlation was 0.270. In older-aged group, there was a moderate negative correlation between the length of VFN and age; the value of Pearson correlation was -0.408. Our results are of high potential to expand the visual field to facial nerve and may provide more detailed information to surgeries of facial nerve, middle ear, and temporal bone.

Using greater superficial petrosal nerve and geniculate ganglion as the only two landmarks for identifying internal auditory canal in middle fossa approach.

The middle fossa approach is a surgical technique indicated for acoustic neuroma with advantages of complete tumor removal and hearing preservation. Various methods have been developed for identifying internal auditory canal (IAC). Here, we describe a new method, which uses greater superficial petrosal nerve (GSPN) and geniculate ganglion (GG) as the only two landmarks to identify IAC. In this study, the surgical anatomy and relations between GSPN, GG, petrous ridge, and IAC were measured on 20 temporal bone specimens and 40 HRCT scans of normal inner ear structures. The temporal bone study showed that the GSPN is nearly parallel to the petrous ridge, with an average angle of about 6 degrees. The line perpendicular to the GSPN from the tip of the GG to the petrous ridge reaches at the porus acousticus, with an average distance of 12.95 mm. The temporal bone HRCT scan study revealed that the length from the tip of the GG to the midpoint of the IAC portion on the line perpendicular to the petrous ridge is about 9.9 mm. We applied this method on 20 temporal bones by drilling the point away from the tip of the GG about 9.9 mm on a line angled with the GSPN about 96 degrees. All IACs were safely identified without damaging the cochlea, the labyrinthine portion of the facial nerve, or the vestibule. In conclusion, the GSPN and GG can be the only two landmarks for safely identifying the IAC without injury to the inner ear structures in the middle fossa approach.

Radioanatomic Assessment of the Geniculate Ganglion Dehiscence and Dimension: A Cadaveric Study.

OBJECTIVE: The main aim of this study placed on cadavers was to compare the data related to geniculate ganglion (GG) dehiscence and dimension obtained from computed tomography (CT) with dissection values. METHODS: This study was conducted on 20 temporal bones obtained from 10 cadavers (4 female, 6 male) aged between 45 and 92 (71.50 ± 15.98) years. All the measurements related to GG dimension were performed with a CT scanner and microdissection. RESULTS: The size of GG including its area, length, and width did not show statistically significant differences in terms of sex, side, and assessment method (CT and cadaveric dissections). The dehiscent GG was observed in 6 (30%) and 5 (25%) out of 20 temporal bones in CT and cadaveric dissections, respectively. The presence and absence of GG dehiscence in CT and dissection were similar in 75%. CONCLUSIONS: Our findings based on dissection data suggest that radiologic evaluation of dehiscent GG detection might be erroneous by 25%, which highlights that surgeons should be careful when lifting the dura to prevent GG injury during middle cranial fossa surgical approaches. On the other hand, there was no statistical difference between CT and dissection measurements related to GG dimension.

Is the Height of the Arcuate Eminence Related to Body Mass Index?

OBJECTIVES: To determine the relationship, if any, between body mass index (BMI) and attenuation of the arcuate eminence (AE). STUDY DESIGN: Case series with chart review. SETTING: Tertiary neurotologic referral center. SUBJECTS AND METHODS: Submillimeter distances were recorded from high-resolution temporal bone computed tomography (CT) scans of 50 patients (100 sides). The AE (defined as the superiormost location of the petrous bone over the otic capsule), the bony apex of the superior semicircular canal (SSC), and the geniculate ganglion (GG) were identified and 3-dimensional distances measured. The height of the AE relative to the bony apex of the superior semicircular canal was determined using Euclidean geometry using the fixed anatomical landmark of the GG as the origin. Correlations between AE and BMI were calculated using Pearson's, linear mixed effects, and sensitivity analysis models. RESULTS: The mean (SD) BMI was 30 (8.1) kg/m2, with 16 (30%) patients falling in the underweight/normal category (BMI <25 kg/m2), 10 (20%) overweight patients (25 kg/m2≤ BMI ≤ 30 kg/m2), and 24 (48%) patients considered obese (BMI >30 kg/m2). The mean (SD) AE heights for the left and right ears were 2.5 (1.11) and 2.6 (1.09), respectively. The results of the linear mixed-effects models indicated little evidence that BMI is associated with AE height when including all patients (partial R2 = 0.040) and when using BMI categories (partial R2 = 0.025). CONCLUSION: Contrary to other structures within the lateral skull base, the relative prominence of the arcuate eminence does not correlate with BMI or any other demographic variables.

Endoscopic Transcanal Approach to Geniculate Ganglion Hemangioma and Simultaneous Facial Nerve Reinnervation: A Case Report.

Hemangioma of the facial nerve (FN) is a very rare benign tumor whose origin is the vascular plexi that surround the nerve. The transpetrous, retrosigmoid, and middle cranial fossa (MCF) routes are the traditional and most widely used approaches to reach these lateral skull base neoformations. However, this very complex region can be reached through an exclusive transcanal endoscopic procedure in selected cases. One of these was a 42-year-old patient who had been presenting a worsening left FN paralysis (grade VI according to the House-Brackmann scale at the time of visit) for 22 months without a history of trauma or infection. Radiological studies showed a lesion in the region of the geniculate ganglion. A suprageniculate endoscopic approach was performed to remove the lesion, with the sacrifice of the FN and a simultaneous hypoglossal-facial anastomosis. The aim of this minimally invasive surgery is the complete excision of the disease, maintaining the hearing function intact and restoration of facial function, whenever possible, avoiding more invasive approaches.

Detectability of minute temporal bone structures with ultra-high resolution CT.

OBJECTIVE: Computed tomography (CT) is the imaging tool of choice in the diagnosis of temporal bone lesions. With the recent progress in imaging technology, CT with higher spatial resolution (Ultra-high resolution CT) has become available in the clinical setting. The purpose of this study is to evaluate the visibility of small temporal bone structures using ultra-high resolution CT. MATERIAL AND METHODS: The visibility of 27 minute temporal bone structures on ultra-high resolution CT images was evaluated. Non-helical axial scans were performed in 18 normal hearing ears without previous otologic diseases. Visibility was scored by an experienced radiologist and otologist. RESULTS: Minute temporal bone structures including the ossicular chain, the crus of the stapes, the greater superficial petrosal nerve, and the anterior malleolar ligament were clearly visualized on ultra-high resolution CT. The stapedius muscle tendon and the chorda tympani exiting the posterior canaliculus and coursing medial to the malleus could be visualized. CONCLUSION: Ultra-high resolution CT provides good visualization of small temporal bone structures in normal subjects.

Quantitative morphology of facial nerve based on three-dimensional reconstruction of temporal bone.

OBJECTIVE: To investigate an effective method of quantitative analysis of the facial nerve and its adjacent structures on the basis of three-dimensional (3D) CT image reconstruction of the temporal bone. METHODS: The inner structures of the temporal bone from CT images of 34 healthy adults were reconstructed. Precise measurement of the facial nerve and its adjacent structures were accomplished by using Able Software 3D-DOCTOR. RESULTS: 3D images of temporal bone structures, including facial nerve, tympanic annulus, cochleariform process, cochlea, semicircular canals, jugular fossa, and carotid artery, were reconstructed. Quantitative data of the facial nerve and its adjacent structures were analyzed, especially the detailed spatial relationships between the facial nerve and the surface of the mastoid process or tympanomastoid fissure. CONCLUSION: 3D reconstruction of CT images clearly displayed the detailed structures of the temporal bone. Quantitative data of the facial nerve and its adjacent structures are very useful for temporal bone surgery.

Radiographic Analysis of the Vidian Canal and Its Utility in Petrous Internal Carotid Artery Localization.

BACKGROUND: Endoscopic endonasal surgery of the skull base requires expert knowledge of the anatomy and a systematic approach. The vidian canal is regarded as a reliable landmark to localize the petrous internal carotid artery (pICA) near the second genu, which can be used for orientation in deep skull base approaches. There is controversy about the relationship between the vidian canal and the pICA. OBJECTIVE: To further establish the vertical relationship between the vidian canal and the pICA to aid in surgical approaches to the skull base. METHODS: We utilized a collection of institutional review board-approved computed tomographic (CT) angiograms (CTAs). Fifty CTAs were studied bilaterally for 100 total sides. The vidian canal was visualized radiographically to determine whether it terminates below, at, or above the level of the pICA. RESULTS: Sixty-six of 100 vidian canals terminated inferior to the pICA (66%), which was the most common relationship observed. The average distance inferior to the pICA was 1.01 mm on the right, 1.18 mm on the left, and 1.09 mm of the total 66 sides. Less commonly, the vidian canal terminated at the level of the pICA canal in 34 sides (34%). The vidian canal was not observed to terminate superior to the pICA in any of the 50 CTAs studied. CONCLUSION: The vidian canal terminates inferior to the pICA most commonly, but often terminates at the level of the pICA. Careful drilling clockwise inferior to superior around the vidian canal should allow for safe pICA localization in most cases.

Facial nerve neuroma in the geniculate ganglion extending into the internal auditory canal: A case report.

Facial nerve schwannoma is a very rare benign tumor representing less than 1% of intrapetrous lesions. Our patient is a forty-one year old female who has suffered from recurrent right facial palsy for the last six years. She was first misdiagnosed as having Bell's palsy and received corticosteroids which resulted in little improvement. She then had facial nerve decompression surgery which resulted in a partial improvement. Since then, she has suffered from recurrent attacks of facial palsy. Two years ago, she came to our hospital seeking further treatment options. The final diagnosis made by MRI was a possible facial nerve tumor. To obtain a better facial outcome, total tumor removal was performed through the middle cranial fossa approach along with facial-hypoglossal nerve end-to-side anastomosis through transmastoid approach. Her hearing was preserved, and she obtained a better facial outcome than that of her preoperative level. In conclusion, facial nerve schwannoma has the potential to be misdiagnosed as Bell's palsy which might lead to a delay in diagnosis, and end-to-side neurorrhaphy may be an effective alternative in a selected case.

Total Transcanal Endoscopic Facial Nerve Decompression for Traumatic Facial Nerve Palsy.

A few approaches can be used to decompress traumatic facial nerve paralysis including the middle cranial fossa approach or transmastoid approach depending on the site of injury. In some specific situation of treating traumatic facial nerve palsy whose injured site was confined from the geniculate ganglion to the second genu, transcanal endoscopic approach for facial nerve decompression can be used. We performed two cases of total endoscopic transcanal facial nerve decompression in patients with traumatic facial nerve palsy. After a six month follow-up, both patients showed improvement in facial function by 2 grades according to House-Brackmann grade system. In terms of treatment outcomes, total transcanal endoscopic facial nerve decompression for traumatic facial nerve palsy is an alternative for lesions limited to the tympanic segment I, and has an advantages of being minimally invasive and is cosmetically acceptable without an external scar or bony depression due to drilling.

Facial palsy and fallopian canal expansion associated with idiopathic intracranial hypertension.

OBJECTIVE: Describe neurotologic findings associated with idiopathic intracranial hypertension (IIH). STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: Case of IIH (>250 mm water) presenting with unilateral facial palsy and enlargement of the fallopian canal on computed tomography and magnetic resonance imaging. INTERVENTION(S): Oral acetazolamide, corticosteroids, and cerebrospinal fluid drainage. MAIN OUTCOME MEASURE(S): Intracranial pressure measurement, cranial nerve examination, audiometry, and symptom assessment. RESULTS: Audiometry revealed asymmetric sensorineural hearing loss. Enlargement of the fallopian canal with cerebrospinal fluid was evident on imaging studies. Partial resolution of IIH symptoms was achieved. CONCLUSION: IIH is an enigmatic disease entity. Increased intracranial pressure usually presents with headache and pulsatile tinnitus and is occasionally associated with cranial neuropathies. Abducens palsy is most common, producing diplopia. Cranial nerve involvement is often asymmetric, producing false localizing signs. Facial paralysis is an uncommon sequela of IIH. Treatment of IIH consists of reducing intracranial pressure. Corticosteroids are recommended for treatment of facial paralysis.

The radiographic prevalence of geniculate ganglion dehiscence in normal and congenitally thin temporal bones.

OBJECTIVE: To determine the prevalence of a dehiscent geniculate ganglion on routine temporal bone computed tomography (CT). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Two hundred seventy-eight consecutive temporal bone CT examinations for a total of 556 sides were reviewed. One hundred ninety-one sides were excluded. Reasons for exclusion included reconstructed coronal views, no coronal views, or a pathologic process, which involved the geniculate ganglion. Six examinations were from patients with clinical superior canal dehiscence confirmed by surgical repair or positive vestibular evoked myogenic potentials. Twenty-four scans were from patients with radiographic superior canal dehiscence confirmed by two independent readings. MAIN OUTCOME MEASURES: The incidence of geniculate ganglion dehiscence in patients with and without radiographic or clinical superior canal dehiscence. Dehiscent geniculate ganglion was defined as at least two consecutive cuts on a coronal CT showing no bone overlying the geniculate ganglion. RESULTS: The overall incidence of a dehiscent geniculate ganglion was 14.5% in the 365 sides reviewed. The incidence of a dehiscent geniculate ganglion is increased in patients with radiographic and clinical superior canal dehiscence as compared with normal patients and was significantly different by chi analysis (38.1 versus 11.4%). CONCLUSION: The presence of radiographic geniculate ganglion dehiscence is common. This finding has particular importance when the middle cranial fossa or subtemporal approach is used, as the facial nerve is more at risk especially when used to address superior canal dehiscence.

[Haemangiomas of the geniculate ganglion]. / Hemangiomas del ganglio geniculado.

About 60 cases have been published since Pulec first described hemangiomas of the geniculate ganglion. They usually cause facial weakness even when they are very small. In cases of insidious evolution of facial paralysis, MRI, and CT are very helpful to rule out these tumors. The treatment is based on complete surgical removal, although it has to be individualized, depending on preoperative facial function and the possibility of complete surgical removal with preservation of the facial nerve.