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SUMMARY: The stylomastoid foramen is located on the inferior surface of the petrous part of the temporal bone between the base of the styloid process and mastoid processes. Through the stylomastoid foramen the facial nerve completes its intracranial part. The aim of this study was to analyze the morphometric parameters, shape and position of the stylomastoid foramen on the skulls in Serbian population, and to correlate it with gender and body side. The study included 44 dry adult skulls (88 stylomastoid foramen). After we determined the gender, the skulls were photographed, and then distances of the stylomastoid foramen from various important landmarks of the skull base were measured in programme ImageJ. The shape and position of the stylomastoid foramen were also noted. The statistical significance was found in male skulls between right and left side in relation to parameter (P2) the shortest distance from the upper end of the anterior margin of the mastoid process (MP) to the center of stylomastoid foramen (CSMF), and on the left side for parameter (P6) the shortest distance between CSMF and the line passing through the tip of the MP in relation to gender. The most common shape of the stylomastoid foramen was round in 46 (52.27 %) cases, and most common position was on the line passing through the upper end of the anterior margin of both MP in 36 (40.91 %) and medially to the line connecting the tips of the MP and styloid process in 88 (100 %) cases. The results of this study will be useful for neurosurgeons during surgeries on the facial nerve trunk or anesthetics to give facial nerve block near the foramen and prevent its complications.

El foramen estilomastoideo se encuentra en la superficie inferior de la parte petrosa del hueso temporal entre la base del proceso estiloides y el proceso mastoides. A través del foramen estilomastoideo el nervio facial completa su parte intracraneal. El objetivo de este estudio fue analizar los parámetros morfométricos, la forma y la posición del foramen estilomastoideo en cráneos de población serbia y correlacionarlos con el sexo y el lado del cuerpo. El estudio incluyó 44 cráneos adultos secos (88 forámenes estilomastoideos). Después de determinar el sexo, se fotografiaron los cráneos y luego se midieron en el programa ImageJ las distancias del foramen estilomastoideo desde varios puntos importantes de la base del cráneo. También se observó la forma y posición del foramen estilomastoideo. La significación estadística se encontró en cráneos de hombres entre el lado derecho e izquierdo en relación al parámetro (P2) la distancia más corta desde el extremo superior del margen anterior del proceso mastoides (PM) hasta el centro del foramen estilomastoideo (CFM), y en el lado izquierdo para el parámetro (P6) la distancia más corta entre CFM y la línea que pasa por la punta del PM en relación al sexo. La forma más común del foramen estilomastoideo era redonda en 46 (52,27 %) casos, y la posición más común estaba en la línea que pasa por el extremo superior del margen anterior de ambos PM en 36 (40,91 %) y medialmente a la línea que conecta las puntas del PM y el proceso estiloides en 88 (100 %) casos. Los resultados de este estudio serán útiles para los neurocirujanos durante las cirugías en el tronco del nervio facial o los anestésicos para bloquear el nervio facial cerca del foramen y prevenir sus complicaciones.

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BACKGROUND: Vestibular schwannomas (VS) are benign tumors arising from vestibular nerve's Schwann cells. Surgical resection via retrosigmoid (RS) or middle fossa (MF) is standard, but the optimal approach remains debated. This meta-analysis evaluated RS and MF approaches for VS management, emphasizing hearing preservation and Cranial nerve seven (CN VII) outcomes stratified by tumor size. METHODS: Systematic searches across PubMed, Cochrane, Web of Science, and Embase identified relevant studies. Hearing and CN VII outcomes were gauged using the American Academy of Otolaryngology-Head and Neck Surgery, Gardner Robertson, and House-Brackmann scores. RESULTS: Among 7228 patients, 56 % underwent RS and 44 % MF. For intracanalicular tumors, MF recorded 38 % hearing loss, compared to RS's 54 %. In small tumors (<1.5 cm), MF showed 41 % hearing loss, contrasting RS's lower 15 %. Medium-sized tumors (1.5 cm-2.9 cm) revealed 68 % hearing loss in MF and 55 % in RS. Large tumors (>3cm) were only reported in RS with a hearing loss rate of 62 %. CONCLUSION: Conclusively, while MF may be preferable for intracanalicular tumors, RS demonstrated superior hearing preservation for small to medium-sized tumors. This research underlines the significance of stratified outcomes by tumor size, guiding surgical decisions and enhancing patient outcomes.

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BACKGROUND: Facial nerve dysfunction can be a devastating trouble for post-parotidectomy patients. OBJECTIVE: To assess rehabilitation outcomes concerning patients with post-parotidectomy facial nerve dysfunction, comparing benign versus malignant neoplasms. METHODS: Prospective study enrolling adults who underwent parotidectomy with facial nerve sparing between 2016 and 2020. The Modified Sunnybrook System (mS-FGS) was used for facial assessments. Physiotherapy began on the first post-operative day with a tailored program of facial exercises based on Neuromuscular Retraining, to be performed at home 3 times/day. From the first outpatient consultation, Proprioceptive Neuromuscular Facilitation was added to the treatment of cases with moderate or severe facial dysfunctions. RESULTS: Benign and malignant groups had a statistically significant improvement in mS-FGS (p < 0.001 and p = 0.005, respectively). There was no significant difference between groups regarding treatment duration or number of physiotherapy sessions performed. The history of previous parotidectomy resulted in more severe initial dysfunctions and worse outcome. Age over 60 years and initially more severe dysfunctions impacted the outcome. CONCLUSION: Patients with benign and malignant parotid neoplasms had significant and equivalent improvement in postoperative facial dysfunction following an early tailored physiotherapy program, with no significant difference in the final facial score, treatment duration, or number of sessions required.

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Moebius syndrome (MBS) is a congenital cranial dysinnervation disorder (CCDD) characterized by a bilateral palsy of abducens and facial cranial nerves, which may coexist with other cranial nerves palsies, mostly those found in the dorsal pons and medulla oblongata. MBS is considered a "rare" disease, occurring in only 1:50,000 to 1:500,000 live births, with no gender predominance. Three independent theories have been described to define its etiology: the vascular theory, which talks about a transient blood flow disruption; the genetic theory, which takes place due to mutations related to the facial motor nucleus neurodevelopment; and last, the teratogenic theory, associated with the consumption of agents such as misoprostol during the first trimester of pregnancy. Since the literature has suggested the existence of these theories independently, this review proposes establishing a theory by matching the MBS molecular bases. This review aims to associate the three etiopathogenic theories at a molecular level, thus submitting a combined postulation. MBS is most likely an underdiagnosed disease due to its low prevalence and challenging diagnosis. Researching other elements that may play a key role in the pathogenesis is essential. It is common to assume the difficulty that patients with MBS have in leading an everyday social life. Research by means of PubMed and Google Scholar databases was carried out, same in which 94 articles were collected by using keywords with the likes of "Moebius syndrome," "PLXND1 mutations," "REV3L mutations," "vascular disruption AND teratogens," and "congenital facial nerve palsy." No exclusion criteria were applied.

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BACKGROUND: Facial nerve dysfunction is the principal postoperative complication related to parotidectomy. OBJECTIVE: To test the hypothesis that the modified Sunnybrook Facial Grading System (mS-FGS) is superior to the original S-FGS in the assessment of facial nerve function following parotidectomy. METHODS: Prospective, longitudinal study evaluating patients with primary or metastatic parotid neoplasms undergoing parotidectomy with facial nerve-sparing between 2016 and 2020. The subjects were assessed twice, on the first postoperative day and at the first outpatient evaluation, 20-30 days post-surgery. Facial assessments were performed using the original and modified (plus showing the lower teeth) versions of the Sunnybrook System and documented by pictures and video recordings. Intra- and inter-rater agreements regarding the assessment of the new expression were analyzed. RESULTS: 101 patients were enrolled. In both steps, the results from the mS-FGS were significantly lower (p < 0.001). Subjects with a history of previous parotidectomy and those who underwent neck dissection had more severe facial nerve impairment. The mandibular marginal branch was the most frequently injured, affecting 68.3% of the patients on the first postoperative day and 52.5% on the first outpatient evaluation. Twenty patients (19.8%) presented an exclusive marginal mandibular branch lesion. The inter-rater agreement of the new expression assessment ranged from substantial to almost perfect. The intra-rater agreement was almost perfect (wk = 0.951). CONCLUSION: The adoption of the Modified Sunnybrook System, which includes evaluation of the mandibular marginal branch, increases the accuracy of post-parotidectomy facial nerve dysfunction appraisal.

ANTECEDENTES: A disfunção do nervo facial é a principal complicação pós-operatória relacionada à parotidectomia. OBJETIVO: Testar a hipótese de que o sistema Sunnybrook de graduação facial modificado (mS-FGS) é superior ao S-FGS original na avaliação da função do nervo facial após parotidectomia. MéTODOS:: Estudo longitudinal prospectivo avaliando o pós-operatório de pacientes com neoplasias parotídeas primárias ou metastáticas, submetidos à parotidectomia com preservação do nervo facial, entre 2016 e 2020. Os indivíduos foram avaliados duas vezes, no primeiro dia de pós-operatório e na primeira avaliação ambulatorial, 20-30 dias após a cirurgia. As avaliações faciais foram realizadas usando as versões original e modificada (que incluem mostrar os dentes inferiores) do sistema Sunnybrook e documentadas por fotos e vídeos. Foram adicionalmente analisadas as concordâncias intra e interexaminadoras da avaliação da nova expressão. RESULTADOS: Cento e um pacientes foram incluídos. Em ambas as etapas, os resultados do mS-FGS foram significativamente menores (p < 0,001). Indivíduos com história de parotidectomia prévia e aqueles submetidos ao esvaziamento cervical apresentaram comprometimento mais grave do nervo facial. O ramo marginal mandibular foi o mais afetado, acometendo 68,3% dos pacientes no primeiro dia de pós-operatório e 52,5% na primeira avaliação ambulatorial. Vinte pacientes (19,8%) apresentaram lesão exclusiva do ramo marginal mandibular. A concordância interexaminadores da avaliação da nova expressão variou de substancial a quase perfeita. A concordância intraexaminador foi quase perfeita (wk = 0,951). CONCLUSãO:: A adoção do sistema Sunnybrook modificado, que inclui a análise do ramo marginal mandibular, aumenta a precisão da avaliação da disfunção do nervo facial pós-parotidectomia.

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OBJECTIVE: The objective was to evaluate whether the position of the nerves within the internal auditory canal (IAC) has any effect on preoperative and postoperative cochlear and facial nerve function in patients with intracanalicular vestibular schwannoma (VS) resected through the retrosigmoid transmeatal approach. METHODS: Forty-four patients with sporadic intracanalicular VS, from a series of 710 patients with VS who underwent operations from January 1993 to April 2022, were retrospectively reviewed. The pattern of displacement of the cranial nerves and tumor within the IAC was recorded. Tumors were divided into 2 types: type T1A lesions had only anteriorly displaced nerves, and type T1B had posteriorly displaced vestibular nerves and anteriorly displaced facial and cochlear nerves. Differences in surgical outcomes between groups in terms of facial nerve function and hearing preservation were evaluated. RESULTS: Thirty-five cases (79.5%) were T1A tumors and 9 were T1B (20.5%). Gross-total resection and anatomical preservation of the facial and cochlear nerves were achieved in all patients. Postoperatively, all patients with T1A VS maintained normal facial nerve function; however, among T1B VS patients, 6 (67%) retained House-Brackmann grade I, 2 worsened to grade II, and 1 worsened to grade III at 6 months (p = 0.006). The 27 T1A VS patients with serviceable hearing maintained this status, and an additional patient with nonserviceable hearing improved to serviceable hearing; among T1B VS patients, only 2 of the 5 patients with serviceable hearing remained as such, 2 evolved to nonserviceable hearing, and 1 lost hearing after surgery (p = 0.0022). T1B VS patients had a 24-fold risk of facial nerve deterioration (relative risk [RR] 25.2, 95% CI 1.42-448.57, p = 0.028) and a 32-fold risk of hearing deterioration (RR 32.7, 95% CI 1.93-553, p = 0.016) after surgery. CONCLUSIONS: In intracanalicular VS, postoperative cochlear and facial nerve function are directly related to the location of the tumor in relation to the nerves, with worse outcomes in cases where the tumor is located between the vestibular and facial-cochlear nerves.

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BACKGROUND: Early onset facial paralysis is usually managed with cross-face nerve grafts, however the low number of axons that reach the target muscle may result in weakness or failure. Multiple-source innervation, or 'supercharging', seeks to combine the advantages of different donor nerves while minimizing their weaknesses. We propose a combination of cross-face nerve grafts with local extra-facial nerve transfers to achieve earlier facial reanimation in our patients. METHODS: A retrospective cohort including all patients with early unilateral facial palsy (<12 months evolution) who underwent triple nerve transfer between 2019 and 2021 was conducted. We performed single-stage procedure including zygomatic-to-zygomatic and buccal-to-buccal cross-face grafts, a nerve-to-masseter to bucozygomatic trunk transfer, and a mini-hypoglossal to marginal branch transfer. Results were evaluated using the clinician-graded facial function scale (eFACE). RESULTS: Fifteen patients were included (eight females, seven males), mean age at the time of surgery was 48.9 ± 13.3 years. Palsy was right-sided in eight cases. The mean time from palsy onset to surgery was 5.5 ± 2.8 months. Patients showed improvement in static (70.8 ± 21.9 vs. 84.15 ± 6.68, p = 0.002) and dynamic scores (20 ± 16.32 vs. 74.23 ± 7.46, p < 0.001), as well as periocular (57.33 ± 15.23 vs. 74 ± 7.18, p = 0.007), smile (54.73 ± 11.93 vs. 85.62 ± 3.86, p < 0.001), mid-face (46.33 ± 18.04 vs. 95 ± 7.21, p < 0.001) and lower face scores (67.4 ± 1.55 vs. 90.31 ± 7.54, p < 0.001). CONCLUSION: The triple nerve transfer technique using cross-face nerve grafts, the nerve-to-masseter, and the hypoglossal nerve, is an effective and reproducible technique to obtain middle and lower face reanimation in cases of early facial palsy.

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SUMMARY: To clarify the path of the temporal branch of facial nerve (TB) crossing the zygomatic arch (ZA). Eighteen fresh adult heads specimens were carefully dissected in the zygomatic region, with the location of TB as well as its number documented. The hierarchical relationship between the temporal branch and the soft tissue in this region was observed on 64 P45 plastinated slices. 1. TB crosses the ZA as type I (21.8 %), type II (50.0 %,), and type III (28.1 %) twigs. 2. At the level of the superior edge of the ZA, the average distance between the anterior trunk of TB and the anterior part of the auricle is 36.36±6.56 mm, for the posterior trunk is 25.59±5.29 mm. At the level of the inferior edge of the ZA, the average distance between the anterior trunk of TB and the anterior part of the auricle is 25.77±6.19 mm, for the posterior trunk is 19.16±4.71 mm. 3. The average length of ZA is 62.06±5.36 mm. TB crosses the inferior edge of the ZA at an average of 14.67±6.45 mm. TB crosses the superior edge of the ZA at an average of 9.08±4.54 mm. 4. At the level of the ZA, TB passes on the surface of the pericranium while below the SMAS. The TB obliquely crosses the middle 1/3 part of the superior margin of the ZA and the junction of the middle 1/3 part and the posterior 1/3 part of the inferior margin of the ZA below the SMAS while beyond the periosteum. It is suggested that this area should be avoided in clinical operation to avoid the injury of TB.

El objetivo de estudio fue esclarecer el trayecto del ramo temporal del nervio facial (RT) que cruza el arco cigomático (AC). Se disecaron la región cigomática de 18 especímenes de cabezas sin fijar de individuos adultas y se documentó la ubicación del RT y su número de ramos. La relación jerárquica entre el ramo temporal y el tejido blando en esta región se observó en 64 cortes plastinados o P45. 1º El RT cruza el AC como tipo I (21,8 %), tipo II (50,0 %) y tipo III (28,1 %). 2º A nivel del margen superior del AC, la distancia promedio entre el tronco anterior de RT y la parte anterior de la aurícula fue de 36,36±6,56 mm, para el tronco posterior fue de 25,59±5,29 mm. A nivel del margen inferior del AC, la distancia promedio entre el tronco anterior del RT y la parte anterior de la aurícula era de 25,77±6,19 mm, para el tronco posterior era de 19,16±4,71 mm. 3º La longitud media de RT fue de 62,06±5,36 mm. EL RT cruzaba el margen inferior del AC a una distancia media de 14,67±6,45 mm. El RT cruzaba el margen superior del AC a una distancia media de 9,08±4,54 mm. 4º Anivel del AC, el RT pasaba por la superficie del pericráneo mientras se encuentra por debajo del SMAS. El RT cruza oblicuamente el tercio medio del margen superior del AC y la unión del tercio medio y el tercio posterior del margen inferior del AC por debajo del SMAS, más allá del periostio. Se sugiere que esta área debe evitarse en la operación clínica para evitar la lesión de la RT.

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Facial nerve injury in rats have been widely used to study functional and structural changes that occur in the injured motoneurons and other central nervous system structures related with sensorimotor processing. A decrease in long-term potentiation of hippocampal CA3-to-CA1 commissural synapse has recently been reported related to this peripheral injury. Additionally, it has been found increased corticosterone plasmatic levels, impairment in spatial memory consolidation, and hippocampal microglial activation in animals with facial nerve axotomy. In this work, we analyzed the neuronal morphology of hippocampal CA1 and CA3 pyramidal neurons in animals with either reversible or irreversible facial nerve injury. For this purpose, brain tissues of injured animals sacrificed at different postlesion times, were stained with the Golgi-Cox method and compared with control brains. It was found that both reversible and irreversible facial nerve injury-induced significant decreases in dendritic tree complexity, dendritic length, branch points, and spine density of hippocampal neurons. However, such changes' timing varied according to hippocampal area (CA1 vs. CA3), dendritic area (apical vs. basal), and lesion type (reversible vs. irreversible). In general, the observed changes were transient when animals had the possibility of motor recovery (reversible injury), but perdurable if the recovery from the lesion was impeded (irreversible injury). CA1 apical and CA3 basal dendritic tree morphology were more sensible to irreversible injury. It is concluded that facial nerve injury induced significant changes in hippocampal CA1 and CA3 pyramidal neurons morphology, which could be related to LTP impairments and microglial activation in the hippocampal formation, previously described.

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Objectives: To investigate the outcomes of cochlear re-implantation using multi-mode grounding stimulation associated with anodic monophasic pulses to manage abnormal facial nerve stimulation (AFNS) in cochlear implant (CI) recipients. Methods: Retrospective case report. An adult CI recipient with severe AFNS and decrease in auditory performance was re-implanted with a new CI device to change the pulse shape and stimulation mode. Patient's speech perception scores and AFNS were compared before and after cochlear re-implantation, using monopolar stimulation associated with cathodic biphasic pulses and multi-mode stimulation mode associated to anodic monophasic pulses, respectively. The insertion depth angle and the electrode-nerve distances were also investigated, before and after cochlear re-implantation. Results: AFNS was resolved, and the speech recognition scores rapidly increased in the first year after cochlear re-implantation while remaining stable. After cochlear re-implantation, the e15 and e20 electrodes showed shorter electrode-nerve distances compared to their correspondent e4 and e7 electrodes, which induced AFNS in the first implantation. Conclusions: Cochlear re-implantation with multi-mode grounding stimulation associated with anodic monophasic pulses was an effective strategy for managing AFNS. The patient's speech perception scores rapidly improved and AFNS was not detected four years after cochlear re-implantation.

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BACKGROUND: Frontal wrinkles are a cause of distress for many people as they age. Traditionally, these have been treated with botulinum toxin injections. However, this procedure is not free from complications and has a temporary result. This report describes a procedure involving temporal branch of facial nerve ablation, a novel and simple technique for the treatment and prevention of rhytids. OBJECTIVES: The objective of this study was to introduce this new technique of ablation for the treatment of frontal wrinkles after analyzing 3 options of approach based on the number of ablation lines. METHODS: Fifty-one patients with a mean age of 49 years underwent nerve ablation. The temporal nerve branches were located through electrostimulation. Through a skin puncture in the temporal region, an Abbocath, with part of the plastic coating removed at its base, was introduced. The nerve branches were cauterized in oblique lines with a monopolar electric scalpel. Patients were divided into 3 groups, depending on the number of ablation lines. RESULTS: The median follow-up period was 20 months (range, 1-50 months). Only 3 (5.7%) patients developed unilateral relapse of muscle activity in the frontal region. Group 6 was statistically superior to Group 1. There was no statistically significant difference between Group 4 and the other 2 groups. More than 70% of patients were satisfied or very satisfied with the results. CONCLUSIONS: Facial nerve branch ablation is a simple surgical technique for the treatment of forehead rhytids that produces less postoperative pain, features rapid recovery, and, above all, offers long-lasting results.

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INTRODUCTION: Compression of the labyrinthine segment of the facial nerve by edema has been considered as an important pathology in the majority of the cases of idiopathic facial nerve paralysis. Hence, it is suggested that total decompression of the facial nerve should also include the labyrinthine segment by a middle fossa approach. However, the middle fossa approach requires craniotomy and temporal lobe retraction, which increases the morbidity. The labyrinthine segment of the facial nerve can also be reached through mastoidectomy. However, many ear surgeons are not familiar with this approach due to the lack of anatomical data on this surgical area. OBJECTIVE: To study the anatomical limitations of decompression of the labyrinthine segment via transmastoid approach. METHODS: Complete mastoidectomy was performed in six adult cadavers heads. Dissection was extended in the zygomatic root and posterior bony wall of the external auditory canal to visualize the incudomallear joint completely. The bone between tympanic segment, lateral and superior semicircular canal's ampullas and middle fossa dural plate was removed. Fine dissection was carried out over tympanic segment of the facial nerve in an anterosuperomedial direction the labyrinthine segment was reached. RESULTS: All the mastoids were well pneumatized. Distances between the labyrinthine segment and middle fossa dura, and between the labyrinthine segment and superior semicircular canal, were 2.5 and 4.5 mm on average, respectively. In addition, distances between the middle fossa dura and dome of the lateral semicircular canal, and between the middle fossa dura and tympanic segment were 4.6 mm and 4.3 mm on average, respectively. CONCLUSION: It is possible to expose the labyrinthine segment of the facial nerve through mastoidectomy by dissecting the bone in the area between the tympanic segment of the facial nerve, middle fossa dural plate and ampullary ends of the lateral and superior semicircular canals.

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OBJECTIVE: To investigate microanatomic organizations of the extratemporal facial nerve and its branches, hypoglossal nerve, sural nerve, and great auricular nerve. METHODS: Nerve samples were dissected in 12 postmortem autopsies, and histomorphometric analyses were conducted. RESULTS: There was no significant difference between the right and left sides of the nerve samples for the nerve area, fascicle area, number of fascicles and average number of axons. The lowest mean fascicle number was found in the hypoglossal nerve (4.9 ±â€¯1.4) while the highest was in great auricular nerve (11.4 ±â€¯6.8). The highest nerve area (3,182,788 ±â€¯838,430 µm2), fascicle area (1,573,181 ±â€¯457,331 µm2) and axon number (14,772 ±â€¯4402) were in hypoglossal nerve (p < 0.05). The number of axons per unit nerve area was higher in the facial nerve, truncus temporofacialis, truncus cervicofacialis and hypoglossal nerve, which are motor nerves, compared to the sural nerve and great auricular nerve, which are sensory nerves (p < 0.05). The number of axons per unit fascicle area was also higher in motor nerves than in sensory nerves (p < 0.05). CONCLUSION: In the present study, it was observed that each nerve contained a different number of fascicles and these fascicles were different both in size and in the number of axons they contained. All these variables could be the reason why the desired outcomes cannot always be achieved in nerve reconstruction.

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OBJECTIVES: The benefit of corticosteroids following facial nerve neurorrhaphy in the setting of complete transection is questionable. This systematic review and meta-analysis aimed to evaluate corticosteroid efficacy on facial nerve regeneration and functional recovery after complete disruption and neurorrhaphy. METHODS: Randomized controlled trials on both human and animal models from Ovid MEDLINE and Ovid EMBASE studying corticosteroid efficacy in complete facial nerve disruption followed by neurorrhaphy were included. Data were extracted and pooled for meta-analysis. The outcomes were evaluated from electrophysiology, histology, and functional recovery. However, no randomized controlled trial in human was performed. Possibly, performing human trials with histopathology may not be feasible in clinical setting. RESULTS: Six animal studies (248 participants) met inclusion criteria. Electrophysiologic outcomes revealed no differences in latency (Standardized Mean Difference (SMD) = -1.97, 95% CI -7.38 to 3.44, p = 0.47) and amplitude (SMD = 0.37, 95% CI -0.44 to 1.18, p = 0.37) between systemic corticosteroids and controls. When analysis compared topical corticosteroid and control, the results provided no differences in latency (Mean Difference (MD) = 0.10, 95% CI -0.04 to 0.24, p = 0.16) and amplitude (SMD = 0.01, 95% CI -0.08 to 0.10, p = 0.81). In histologic outcomes, the results showed no differences in axon diameter (MD = 0.13, 95% CI -0.15 to 0.41, p = 0.37) between systemic corticosteroid and control; however, the result in myelin thickness (MD = 0.06, 95% CI 0.04 to 0.08, p < 0.05) favored control group. When comparing systemic corticosteroid with control in eye blinking, the results favored control (MD = 1.33, 95% CI 0.60 to 2.06, p =  0.0004). CONCLUSIONS: This evidence did not show potential benefits of systemic or topical corticosteroid deliveries after facial nerve neurorrhaphy in complete transection when evaluating electrophysiologic, histologic, and functional recovery outcomes in animal models.

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OBJECTIVES: The aim of this study was to assess the relationship between the stimulation amplitude and the distance to the facial nerve. METHODS: This study was designed as a prospective clinical study. A total of 20 patients (12 males, 8 females) were included. Partial superficial parotidectomy was performed in all patients with intraoperative facial monitoring. Measurements were made on the main trunk and major branches. Stimulation was started at 1 mA and incrementally increased to 2 and 3 mA's. The shortest distance creating a robust response (>100 mV) was recorded. RESULTS: At 1 mA, 2 mA and 3 mA stimulation intensity, the average distance between the tip of the stimulation probe and the main trunk was 2.20 ± 0.76 mm (range 1-3 mm), 3.80 ± 0.95 mm (range 2-5 mm), 4.80 ± 1.05 mm (range 3-7 mm) respectively. The stimulus intensity was inversely proportional in respect to the distance between the nerve and the tip of the stimulus probe (P < .00). The same relation was present in the facial nerve major branch measurements (P < .00). CONCLUSION: The proportional stimulation amplitude and distance to the facial nerve is thought to be a reliable auxillary method to assist the surgeon by facilitating the estimation of the distance to the facial nerve during extracapsular dissection and minimally invasive cases where the facial nerve isn't routinely dissected. LEVEL OF EVIDENCE: Level 3.

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OBJECTIVE: To analyze the morphofunctional regeneration process of facial nerve injury in the presence of insulin-like growth factor-1 and mesenchymal stem cells. METHODS: Fourteen Wistar rats suffered unilateral facial nerve crushing and were randomly divided into two groups. All received insulin-like growth factor-1 inoculation, but only half of the animals received an additional inoculation of mesenchymal stem cells. The animals were followed for 90 days and facial nerve regeneration was analyzed via spontaneous facial motor function tests and immunohistochemistry in the nerve motor nucleus. RESULTS: The group that received the growth factor and stem cells showed a statistically superior mean in vibrissae movements (p < 0.01), touch reflex (p = 0.05) and eye closure (p < 0.01), in addition to better immunohistochemistry reactivity. There was a statistically significant difference in the mean number of cells in the facial nerve nucleus between the experimental groups (p = 0.025), with the group that received the growth factor and stem cells showing the highest mean. CONCLUSION: The association between growth factor and stem cells potentiates the morphofunctional regeneration of the facial nerve, occurring faster and more effectively. LEVEL OF EVIDENCE: 4, degree of recommendation C.

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El síndrome de Moebius es una enfermedad congénita poco común que se caracteriza por el compromiso unilateral o bilateral del VI y VII par craneal, lo que compromete los músculos que controlan la oculomotricidad, produciendo una parálisis en la abducción del globo ocular y los músculos involucrados en la expresión facial. Su presentación clínica y grados de severidad son variables, puede presentar compromiso simétrico o asimétrico. Adicionalmente, gran parte de los casos se relacionan con trastornos del lenguaje, anomalías musculoesqueléticas y orofaciales. En el presente artículo se presenta el caso de una paciente femenina de 3 años producto de un embarazo trigemelar con diagnóstico clínico de síndrome de Moebius al nacer, confirmado por neuroimagen en la que se evidencia la ausencia bilateral del nervio facial en ángulos pontocerebelosos, adicionalmente con un defecto completo en los movimientos oculares de abducción y aducción lo que impide el estrabismo convergente común en estos pacientes.

Moebius syndrome is a rare congenital disease characterized by unilateral or bilateral involvement of the VI and VII cranial nerves, which compromises the muscles that control ocular motricity with paralysis in the abduction of the eyeball and the muscles involved in the facial expression. Its clinical presentation and degrees of severity are variable, and it can be symmetric or asymmetric. Additionally, most of the cases are related to language disorders, musculoskeletal and orofacial anomalies. This paper presents the case of a 3-year-old female patient, product of a trigemellar pregnancy with a clinical diagnosis of Moebius syndrome at birth, confirmed by neuroimaging, which shows the bilateral absence of the facial nerve in point-lateral angles. Additionally she has a complete defect in abduction and adduction eye movements, which prevents the common convergent strabismus in these patients.

A síndrome de Moebius é uma doença congênita rara caracterizada pelo envolvimento unilateral ou bilateral dos nervos cranianos VI e VII, que compromete os músculos que controlam a oculomotricidade com paralisia na abdução do globo ocular e dos músculos envolvidos na expressão facial. Sua apresentação clínica e graus de gravidade são variáveis, podendo ser um comprometimento simétrico ou assimétrico. Além disso, a maioria dos casos está relacionada a distúrbios de linguagem, anomalias musculoesqueléticas e orofaciais. Este paper apresenta o caso de uma paciente de 3 anos de idade, fruto de uma gravidez trigêmea com diagnóstico clínico de Síndrome de Moebius ao nascimento, confirmado por neuroimagem em que é evidente a ausência bilateral do nervo facial nos ângulos ponto-cerebelares. Além disso, ela tem um defeito completo nos movimentos oculares de abdução e adução, o que impede o estrabismo convergente comum nesses pacientes.

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PURPOSE: To describe the microsurgical anatomical aspects of the extratemporal facial nerve of Wistar rats under a high-definition video system. METHODS: Ten male Wistar rats (12-15 weeks old), without veterinary diseases, weighing 220-280 g, were used in this study. All animals in this study were submitted to the same protocol and by the same surgeon. A 10-mm incision was made below the bony prominence of the right or left ear, and extended towards the angle of the mandible. The dissection was performed and the main branches of the facial nerve were dissected. RESULTS: The main trunk of the facial nerve has a length of 0.88 ± 0.10 mm and a length of 3.81 ± 1.03 mm, measured from its emergence from the stylomastoid foramen to its bifurcation. Seven branches originating from the facial nerve were identified: posterior auricular, posterior cervical, cervical, mandibular, buccal, temporal, and zygomatic. CONCLUSIONS: The anatomy of the facial nerve is comparable to that of humans, with some variations. The most observed anatomical division was the distribution in posterior auricular, posterior cervical, cervical, mandibular, buccal, temporal, and zygomatic branches. There is no statistical difference between the thickness and distance of the structures compared to the contralateral side.

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Introducción. Las lesiones del nervio facial afectan la plasticidad a largo plazo en el hipocampo, así como la memoria de reconocimiento de objetos y la memoria espacial, dos procesos dependientes de esta estructura. Si bien se ha descrito una activación de la microglía en la corteza motora primaria asociada con esta lesión, no se conoce si ocurre algo similar en el hipocampo. Objetivo. Caracterizar en ratas el efecto de la lesión unilateral del nervio facial sobre la activación de células de la microglía en el hipocampo contralateral. Materiales y métodos. Se hicieron experimentos de inmunohistoquímica para detectar células de la microglía en el hipocampo de ratas sometidas a lesión irreversible del nervio facial. Los animales se sacrificaron en distintos momentos después de la lesión, para evaluar la evolución de la proliferación (densidad de células) y la activación (área celular) de la microglía en el tejido del hipocampo. Los tejidos cerebrales de los animales de control se compararon con los de animales lesionados sacrificados en los días 1,3, 7, 21 y 35 después de la lesión. Resultados. Las células de la microglía en el hipocampo de animales con lesión del nervio facial mostraron signos de proliferación y activación a los 3, 7 y 21 días después de la lesión. Sin embargo, al cabo de cinco semanas, estas modificaciones se revirtieron, a pesar de que no hubo recuperación funcional de la parálisis facial. Conclusiones. La lesión irreversible del nervio facial produce proliferación y activación temprana y transitoria de las células de la microglía en el hipocampo. Estos cambios podrían estar asociados con las modificaciones electrofisiológicas y las alteraciones comportamentales dependientes del hipocampo descritas recientemente.

Introduction: Facial nerve injury induces changes in hippocampal long-term synaptic plasticity and affects both object recognition memory and spatial memory consolidation (i.e., hippocampus-dependent tasks). Although facial nerve injury-associated microglíal activation has been described regarding the primary motor cortex, it has not been ascertained whether something similar occurs in the hippocampus. Peripheral nerve injury- associated microglíal changes in hippocampal tissue could explain neuronal changes in the contralateral hippocampus. Objective: To characterize the effect of unilateral facial nerve injury on microglíal proliferation and activation in the contralateral hippocampus. Materials and methods: Immunohistochemical experiments detected microglíal cells in the hippocampal tissue of rats that had undergone facial nerve injury. The animals were sacrificed at specific times after injury to evaluate hippocampal microglíal cell proliferation (cell density) and activation (cell area); sham-operated animals were compared to lesioned animals sacrificed 1,3, 7, 21, or 35 days after injury. Results: Facial nerve-injured rats' hippocampal microglíal cells proliferated and adopted an activated phenotype 3- to 21-days post-lesion. Such modifications were transient since the microglíal cells returned to their resting state five weeks after injury, despite the injury's irreversible nature. Conclusions: Facial nerve injury causes the transient proliferation and activation of microglíal cells in the hippocampus. This finding might partly explain the morphological and electrophysiological changes described for CA1 pyramidal neurons and the impairment of spatial memory consolidation which has previously been observed in facial nerve-injured rats.

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