Course Of Facial Nerve Research Articles

Surface Anatomy of the Middle Division of the Facial Nerve

The anatomy of the facial nerve and its branches has been well documented. The course of the extratemporal facial nerve, its anatomical planes, and the surface landmarks of the temporal division and marginal mandibular division are well known. However, the surface landmark of the middle division of the facial nerve has not been studied to date. Eighteen hemifacial dissections in 10 fresh human cadavers were performed through a preauricular face-lift incision. An 18-gauge needle with brilliant green dye was used to mark the nerve through the skin before dissection. The exact location of the middle division branches of the facial nerve was documented in relation to the transcutaneous marking. The middle division branches of the facial nerve were found to lie at a mean of 2.3 mm from the tattooed point, with a range of 0 to 6 mm. A nerve branch was found directly tattooed by the needle seven of 18 times, inferior to the tattoo five of 18 times, and superior to the tattoo six of 18 times. The zygomatic/buccal motor branch that innervates the zygomaticus major muscle can be reliably found at the midway point on a line drawn from the root of the helix and the lateral commissure of the mouth. This study will help guide surgeons to the middle division of the facial nerve as it applies to facial surgery.

Two Cases of Malleostapedotomy in Congenital Oval Window Atresia

Congenital anomaly of the oval window with an abnormal facial nerve course is an uncommon embryological defect, which is related to the underdevelopment of second branchial arch derivatives. Some treatments for improving hearing levels are available; these include hearing aids, vestibulotomy, neo-oval window formation, and stapes surgeries, including incudostapedotomy and malleostapedotomy. However, surgery for congenital anomalies of the oval window has rarely been described, usually in very small series of patients. We describe two cases of congenital anomalies of the oval window with aberrant facial nerve courses. One was a 40-year-old male diagnosed with unilateral congenital oval window atresia; the other was a 10-year-old male diagnosed with bilateral congenital oval window atresia. We also describe the clinical manifestations and treatment outcomes of malleostapedotomy for congenital anomalies of the oval window with aberrant facial nerve courses.

Evaluation of Variation in the Course of the Facial Nerve, Nerve Adhesion to Tumors, and Postoperative Facial Palsy in Acoustic Neuroma

Objective To investigate the variation in the course of the facial nerve (FN) in patients undergoing acoustic neuroma (AN) surgery, its adhesion to tumors, and the relationship between such adhesions and postoperative facial palsy. Methods The subjects were 356 patients who underwent AN surgery in whom the course of the FN could be confirmed. Patients were classified into six groups: ventro-central surface of the tumor (VCe), ventro-rostral (VR), ventro-caudal (VCa), rostral (R), caudal (C), and dorsal (D). Results The FN course was VCe in 185 cases, VR in 137, VCa in 19, R in 10, C in 4, and D in one. For tumors < 1.5 cm, VCe was most common. For tumors ≥ 1.5 cm, the proportion of VR increased. No significant difference was observed between the course patterns of the FN in terms of postoperative FN function, but for tumors > 3.0 cm, there was an increasing tendency for the FN to adhere strongly to the tumor capsule, and postoperative facial palsy was more severe in patients with stronger adhesions. Conclusions The VCe pattern was most common for small tumors. Strong or less strong adhesion to the tumor capsule was most strongly associated with postoperative FN palsy.

Anatomía quirúrgica de nervios facial y auricular mayor del conejo como modelo experimental

Objetivo: describir la anatomía quirúrgica de los nervios facial y auricular mayor del conejo como modelo experimental. Técnica quirúrgica: disección bilateral de los dos nervios en doce conejos. Se describen el patrón de distribución, reparos quirúrgicos y similitudes y diferencias con humanos. Resultados: el facial viaja por debajo del sistema musculoaponeurótico superficial y de la parótida, para dividirse en tres ramas principales: orbitaria, bucal y marginal. El auricular mayor es posterior al facial y la vena retrofacial es el reparo principal. Ambos son nervios polifasciculares. Conclusiones: el facial del conejo es un modelo para estudios de regeneración nerviosa dada su configuración polifascicular semejante al humano. El nervio auricular mayor, para injerto, es accesible en el mismo campo quirúrgico.

Congenital Oval or Round Window Anomaly With or Without Abnormal Facial Nerve Course

To describe the audiometric results in a consecutive series of patients with congenital ossicular aplasia (Class 4a) or dysplasia of the oval and/or round window (Class 4b), which might include a possible anomalous course of the facial nerve. Retrospective chart study. Tertiary referral center. A tertiary referral center study with a total of 14 patients with congenital minor ear anomalies as part of a consecutive series (n = 89) who underwent exploratory tympanotomies (15 ears). Audiometric results. In 8 of 15 ears, ossicular reconstruction was attempted. In the short term (1 mo), there was a serviceable hearing outcome (air-bone gap closure to within 25 dB) in 4 ears. However, the long-term results showed deterioration because of an increased air-bone gap in all but 1 ear. No facial nerve lesion was observed postoperatively. Congenital dysplasia or aplasia of the oval and/or round window is an uncommon congenital minor ear anomaly. Classical microsurgical opportunities are rare in this group of anomalies. Newer options for hearing rehabilitation, such as the osseointegrated passive bone conduction devices, have become viable alternatives for conventional air conduction hearing devices. In the near future, upcoming active bone conduction devices might become the most preferred surgical option. In cases in which the facial nerve is only partially overlying the oval window, a type of malleostapedotomy procedure might result in a serviceable postoperative hearing level.

Intraoperative CT-guided cochlear implantation in congenital ear deformity

Conclusions: Intraoperative computed tomography (iCT)-guided cochlear implantation is practical and effective for correct electrode placement in the cochlea of patients with congenital inner ear and/or complex middle ear malformation. Objectives: The operation in patients with inner ear and/or complex middle ear malformation including abnormal facial nerve course is difficult. This study evaluated the efficacy of cochlear implantation under the guidance of iCT to insure correct electrode placement. Methods: This was a prospective interventional case series. Ten patients with severe to profound sensorineural hearing loss due to ear malformations were enrolled, and iCT was used to confirm the right placement of electrodes. Results: Intraoperative CT was performed three times in one patient, twice in two, and once in the others. Interruption of the surgical process for each iCT until resumption of surgery was 9.64 ± 0.63 min. iCT revealed incorrectly positioned cochlear implants in two patients, which were immediately corrected. There were no reoperations due to misplacement of electrodes. iCT helped locate the cochlea in the middle ear of one patient with an abnormal facial nerve course. The overall intervention rate based on iCT findings was 30%. Level of evidence: level 4.

First Branchial Cleft Anomaly: Clinical Insight into its Relevance in Otolaryngology with Pediatric Considerations

First branchial cleft anomalies (FBCA) represent a small subset of congenital malformations in neck. Prime objective of this study is to share our experience with FBCA, emphasize its relevance in otolaryngology and deal with its pediatric perspective. Embryology, pathologic anatomy and varied spectra of clinical presentations of FBCA are discussed. Along with this we have illustrated three different cases; all of them were of pediatric age group and were misdiagnosed by their treating specialists elsewhere. In this article we have also laid special emphasis on its pediatric considerations. FBCA are mostly misdiagnosed due to their unfamiliar clinical signs and symptoms. Swellings may masquerade as other neck masses. Majority of patients give a history of previous incision and drainage. While dealing with pediatric patients the important factors to be kept in mind are the age of child, superficial course of facial nerve, any associated agenesis of parotid gland. Alteration in surgical technique may be required in children. A thorough medical examination with high index of clinical suspicion should be kept in mind while dealing with such anomalies. Owing to their complex presentation and close relation with facial nerve they are challenging lesions for surgeons.

Congenital aural atresia treated with floating mass transducer on the round window: 5 years of imaging experience

The aim of this paper is to illustrate imaging features of patients affected by congenital aural atresia (CAA) before and after treatment with a Vibrant SoundBridge (VSB) device implanted on the round window. Ten patients (5 males and 5 females; mean age 22.1 years) with CAA underwent preoperative high-resolution computed tomography (HRCT) to estimate the degree of involvement of the middle- and inner-ear structures and highlight radiological landmarks useful for surgical planning. Bilateral CAA, mostly of the mixed type, was present in 7 patients and ossicular chain abnormalities in 16 ears (94% of cases). The round window region was normal in all patients, whereas facial-nerve course and/or caliber abnormalities were present in 6 ears (35.3%). The tympanic cavity was small in 13 ears (76.5%), whereas the mastoid was well pneumatized in 8/17 (47%). HRCT provides accurate information about anatomy and malformations of the middle and inner ear and can thus assist the surgeon in planning the procedure.

Case 171: Facial Nerve Hemangioma

The patient’s imaging features, especially the honeycomb pattern of ossific changes in the geniculate fossa, were virtually pathognomonic for ossifying hemangioma of the facial nerve.

3D Double-Echo Steady-State with Water Excitation MR Imaging of the Intraparotid Facial Nerve at 1.5T: A Pilot Study

The intraparotid facial nerve is difficult to delineate using conventional MR sequence. Our aim was to assess the value of 3D DESSWE MR imaging in depicting the normal anatomy of the intraparotid facial nerve. A 3D-DESSWE sequence was performed with optimum parameters in 18 healthy volunteers on a 1.5T MR imaging unit. The data obtained were reconstructed in relation to the course of the facial nerve by using the MPR and thin-section MIP programs. Images acquired were analyzed by 2 neuroradiologists. They made the initial evaluations independently but resolved inconsistencies by collaborative review and consensus agreement. The certainty of identifying the intraparotid facial nerve was scored and recorded on an arbitrary scale of 0-2. The lengths of the facial nerves were measured; CNRs of the facial nerves and parotid ducts were calculated. Statistical evaluation of the results was achieved by the 2-tailed Wilcoxon test, ANOVA, and a paired t test. In all subjects, 3D DESSWE images provided a reliable definition of the normal facial nerve anatomy bilaterally. There were no significant differences between scores, lengths, and CNRs of bilateral facial nerves (P > .05). The intraparotid facial nerve, parotid ducts, and retromandibular vein showed high signal intensity while the surrounding soft tissue showed relatively low signal intensity. The signal intensity between the facial nerves and parotid ducts was significantly different (P < .01); but no differences could be obtained for the CNRs between the 2 structures (P > .05). The 3D DESSWE sequence can display the intraparotid course of the normal facial nerve, including the relationship between the facial nerve and the parotid duct.

Aberrant course of the intracranial facial nerve in cases of atresia of the internal auditory canal (IAC)

The aim of this study is to describe the morphology of the rare malformation that is atresia of the internal auditory canal (IAC) and determine the course of the facial nerve in cases of normal facial nerve function. Index cases were retrospectively selected from our electronic database in which all inner ear malformations presenting to a tertiary referral center between 1995 and 2010 are collected. Computed tomography (CT) data and magnetic resonance (MR) images were reviewed by two neuroradiologists. An otolaryngologist analyzed the patients' clinical data. Nine ears of six patients (three bilateral, three unilateral) with atresia of the IAC were identified. All patients presented with sensory neural hearing loss. Two of these unilaterally affected patients had facial nerve palsy. In the other seven cases of complete atresia of the IAC, the facial nerve was dislocated in its cisternal segment close to the trigeminal nerve. Where the nerve fibers enter the Gasserian ganglion, the facial nerve takes a sharp lateral turn and enters a minute canal by which it reaches the geniculate ganglion. In the two ears with facial nerve palsy, this pathway could not be identified. In atresia of the IAC, the facial nerve takes a ventral and superior course, with its own canal starting at the point where the trigeminal nerve enters the Gasserian ganglion. Facial nerve palsy points to absence of this aberrant temporal facial nerve canal.

Facial nerve lying lateral to ossicles in one case of congenital aural atresia

An abnormal facial nerve (FN) course can be found in a significant number of patients with congenital aural atresia. However, the literature does not include any cases in which the tympanic portion of the FN was displaced lateral to ossicles. We report a unique case of unilateral congenital aural atresia with this rare FN displacement. A review of the existing literature and a discussion are also provided.

Neuro-ophthalmologic Complications and Manifestations of Upper and Lower Motor Neuron Facial Paresis

The facial nerve (cranial nerve VII) courses a long pathway beginning in the precentral gyrus and ending at the facial muscles, lacrimal and salivary glands, and structures of the inner ear. Lesions along this pathway, clinically divided into upper and lower motor neuron lesions, present with unique characteristics that assist the physician in identifying the lesion site. The sequelae particularly of peripheral CN VII palsies, may result in significant and chronic damage to the cornea that may be challenging for the physician and patient.

What Is Expected of the Facial Nerve in Michel Aplasia? Anatomic Variation

We sought better understanding about the facial nerve anatomy in the rare inner ear Michel anomaly to help better define this aplasia and prevent potential complications in surgery on these patients. The data from computed tomography scans and magnetic resonance images of six Michel aplastic ears (three patients) were evaluated for a facial nerve course. Facial nerve course and anatomic landmarks were noted. Based on data obtained from this group of very rare patients, three different facial nerve anatomies were encountered. The first patient had normal-looking mastoid cells, normal middle ear ossicles, and a completely formed facial nerve canal through the middle ear. The second patient had pneumatized mastoid air cells despite an anomalous ossicular chain. This patient also had a facial nerve canal but not through the middle ear. In the third patient, although mastoid cells were present, neither ossicles nor a definite facial nerve canal could be detected. With guidance provided by the anatomy of the other parts of the ear, such as air cells and the ossicular chain, the danger zones posing a high probability of facial nerve injury can be predicted. Although all Michel aplasias may have aplastic petrous bone in common, there are some degrees of variation.

Proximal and distal Facial nerve exploration during superficial parotidectomy

One of the most technique sensitive surgeries in the maxillofacial region is the parotid gland surgery owing to the close relation between the gland and the extra-cranial course of facial nerve. Facial nerve is generally located by means of a proximal surgical identification technique aimed at identifying the facial nerve at its point of exit from the stylomastoid foramen to its entry into the posteromedial surface of parotid gland. There are reports in the literature on distal nerve identification techniques, either as a choice or in cases where proximal nerve identification is difficult. The present report deals with personal clinical experience, describing both the techniques for detection of the facial nerve in 17 cases reported. The technique mainly chosen was conventional proximal nerve identification technique in 16 cases. Distal exploration of the buccal branch was undertaken only in one case, on account of difficulty in locating the main trunk intraoperatively, due to the presence of a post inflammatory fibrosis. The decision to resort to the identification of the buccal nerve is supported by the regular course and adequate size of this branch of facial nerve in its peripheral area co-located with stenson's duct, which enable it to be easily identified during surgery.

Facial nerve mapping and monitoring in lymphatic malformation surgery

Objective Establish the efficacy of preoperative facial nerve mapping and continuous intraoperative EMG monitoring in protecting the facial nerve during resection of cervicofacial lymphatic malformations. Methods Retrospective study in which patients were clinically followed for at least 6 months postoperatively, and long-term outcome was evaluated. Patient demographics, lesion characteristics (i.e., size, stage, location) were recorded. Operative notes revealed surgical techniques, findings, and complications. Preoperative, short-/long-term postoperative facial nerve function was standardized using the House-Brackmann Classification. Mapping was done prior to incision by percutaneously stimulating the facial nerve and its branches and recording the motor responses. Intraoperative monitoring and mapping were accomplished using a four-channel, free-running EMG. Neurophysiologists continuously monitored EMG responses and blindly analyzed intraoperative findings and final EMG interpretations for abnormalities. Results Seven patients collectively underwent 8 lymphatic malformation surgeries. Median age was 30 months (2–105 months). Lymphatic malformation diagnosis was recorded in 6/8 surgeries. Facial nerve function was House-Brackmann grade I in 8/8 cases preoperatively. Facial nerve was abnormally elongated in 1/8 cases. EMG monitoring recorded abnormal activity in 4/8 cases—two suggesting facial nerve irritation, and two with possible facial nerve damage. Transient or long-term facial nerve paresis occurred in 1/8 cases (House-Brackmann grade II). Conclusions Preoperative facial nerve mapping combined with continuous intraoperative EMG and mapping is a successful method of identifying the facial nerve course and protecting it from injury during resection of cervicofacial lymphatic malformations involving the facial nerve.

Study of intratemporal course of facial nerve and its variations — 25 temporal bones dissection

Facial nerve is the longest nerve in a bony canal. Three dimensional anatomical knowledge provides the foundation for safe and skillful dissection of the very complex temporal bone and tortuous facial nerve. A small surgical area and a fair incidence of anatomical variations makes the facial nerve prone to injury. Inspite of the problems presented, the nerve serves as an excellent landmark and guide to the competent otological surgeon who studies it deligently, the neophyte on the other hand lives in constant fear of finding the nerve inadvertently. The present study was undertaken to explore the microanatomy of tympano-mastoid segment of facial nerve. The current study was conducted at Dept of E.N.T, temporal bone lab, J.N.M.C Sawangi, Wardha. 25 temporal bones were dissected to study the various parameters of the tympano-mastoid segments of the facial nerve, its relations with the important middle ear structures and their anomalies. Mean length of tympanic segment was 9.28mm and that of the mastoid segment was 13.7mm. Mean depth of second genu from the cortex was 19.72mm. Amongst the variations noted commonest were the variations in the tympanic segment of about 12 %. An overhang in the region of oval window and a hump at the second genu was noted in one specimen each. The variations in the tympanomastoid segment occur with sufficient frequency showing not much racial and geographical variance.

Another Cause for Conductive Hearing Loss With Present Acoustic Reflexes

There are numerous potential causes of conductive hearing loss (HL). It is important to obtain a thorough history and perform a complete examination, including audiometric testing and radiographic evaluation when necessary. In this report, we present a patient with an intact tympanic membrane, no history of ear disease or trauma who as an adult developed progressive, conductive HL because of an anomalous course of a dehiscent facial nerve. In the patient with a conductive HL and at least partially intact reflexes, superior semicircular canal dehiscence, fracture of the stapes superstructure proximal to the tendon, other third window phenomena, and now dehiscence of the facial nerve resulting in decreased mobility of the ossicular chain must be considered.

Infantile facial nerve course in an adult patient with congenital aural dysplasia

Infantile facial nerve course in an adult patient with congenital aural dysplasia

Recurrent facial nerve palsy caused by a facial cyst

Mr B first presented to the authors' department in 2001 complaining of right-sided facial weakness. He was diagnosed with a grade 2 facial nerve palsy for which no obvious cause was identified. He was actively treated with aciclovir and steroids and his symptoms resolved completely. Over the next 2 years, he suffered two similar episodes that responded well to similar treatment. One year later, he was referred to the clinic with a grade 3 facial nerve palsy. A computed tomography scan showed no abnormality along the course of the right facial nerve. Genetic tests showed no genetic cause for the recurrent facial nerve palsy. His symptoms initially resolved but 6 months later he was readmitted with a grade 4 facial nerve palsy. A magnetic resonance imaging scan showed inflammation of the tympanic and mastoid sections of the facial nerve and facial nerve decompression surgery was planned. Intra-operatively, mild oedema was evident along the intratemporal course of the facial nerve. During decompression of the mastoid (horizontal) segment of the facial nerve (Figure 1), a significant amount of mucoid fluid in keeping with a benign cyst was drained (Figure 2). His facial palsy fully resolved and a magnetic resonance imaging scan performed 1 year after surgery showed no evidence of recurrence or other pathology. At 3-year follow up, there was no recurrence of symptoms.