Variants of the Anterior Subtemporal Approach to the Gasserian Ganglion and Related Structures: An Anatomical Study With Relevant Implications for Keyhole Surgery.

BACKGROUND: The advantages and limitations of different craniotomy positions and approach trajectories to the gasserian ganglion (GG) and related structures using an anterior subtemporal approach have not been studied systematically. Knowledge of these features is of importance when planning keyhole anterior subtemporal (kAST) approaches to the GG to optimize access and minimize risks. METHODS: Eight formalin-fixed heads were used bilaterally to assess temporal lobe retraction (TLR), trigeminal exposure, and relevant anatomical aspects of extra- and transdural classic anterior subtemporal (CLAST) approaches compared with slightly dorsally and ventrally allocated corridors. RESULTS: TLR to the GG and foramen ovale was found to be lower via the CLAST approach (P < 0.001). Using the ventral variant, TLR to access the foramen rotundum was minimized (P < 0.001). The overall TLR was maximal using the dorsal variant (P < 0.001) owing to interposition of the arcuate eminence. An extradural CLAST approach required wide exposure of the greater petrosal nerve (GPN) and middle meningeal artery (MMA) sacrifice. Both maneuvers were spared using a transdural approach. Using CLAST, medial dissection >39 mm can enter the Parkinson triangle, jeopardizing the intracavernous internal carotid artery. The ventral variant enabled access to the anterior portion of the GG and foramen ovale without the need for MMA sacrifice or GPN dissection. CONCLUSIONS: The CLAST approach provides high versatility to approach the trigeminal plexus, minimizing TLR. However, an extradural approach jeopardizes the GPN and requires MMA sacrifice. The risk of cavernous sinus violation exists when progressing medially beyond 4 cm. The ventral variant has some advantages to access the ventral structures and avoid MMA and GPN manipulation. In contrast, the usefulness of the dorsal variant is rather limited owing to the greater TLR required.

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.

EGR4 is critical for cell-fate determination and phenotypic maintenance of geniculate ganglion neurons underlying sweet and umami taste.

The sense of taste starts with activation of receptor cells in taste buds by chemical stimuli which then communicate this signal via innervating oral sensory neurons to the CNS. The cell bodies of oral sensory neurons reside in the geniculate ganglion (GG) and nodose/petrosal/jugular ganglion. The geniculate ganglion contains two main neuronal populations: BRN3A+ somatosensory neurons that innervate the pinna and PHOX2B+ sensory neurons that innervate the oral cavity. While much is known about the different taste bud cell subtypes, considerably less is known about the molecular identities of PHOX2B+ sensory subpopulations. In the GG, as many as 12 different subpopulations have been predicted from electrophysiological studies, while transcriptional identities exist for only 3 to 6. Importantly, the cell fate pathways that diversify PHOX2B+ oral sensory neurons into these subpopulations are unknown. The transcription factor EGR4 was identified as being highly expressed in GG neurons. EGR4 deletion causes GG oral sensory neurons to lose their expression of PHOX2B and other oral sensory genes and up-regulate BRN3A. This is followed by a loss of chemosensory innervation of taste buds, a loss of type II taste cells responsive to bitter, sweet, and umami stimuli, and a concomitant increase in type I glial-like taste bud cells. These deficits culminate in a loss of nerve responses to sweet and umami taste qualities. Taken together, we identify a critical role of EGR4 in cell fate specification and maintenance of subpopulations of GG neurons, which in turn maintain the appropriate sweet and umami taste receptor cells.

Surgical management of symptomatic hemangioma of the geniculate ganglion: fascicular-sparing resection or grafting?

Geniculate ganglion hemangioma (GGH) is rarely presented in the neurosurgical literature. It extends extradurally on the middle fossa floor and displaces the intratemporal part of the facial nerve. Surgical treatment is advisable at early symptoms. Proposed techniques include fascicular-sparing resection or nerve interruption with grafting. No definitive conclusions exist about the superiority of a certain technique in preserving facial nerve integrity and function. Through the description of a surgically managed symptomatic GGH, we herein discuss literature data about the surgical results of fascicular-sparing resection versus grafting. A PRISMA-based literature search was performed on the PubMed database. Only articles in English and published since 1990 were selected and furtherly filtered based on the best relevance. Statistical comparisons were performed with ANOVA. One hundred sixteen GGHs were collected, 56 were treated by fascicular-sparing resection, and 60 were treated by grafting. The facial function was improved, or unchanged, in 53 patients of the fascicular-sparing group and 30 patients of the grafting one. Sixty-five patients achieved a good (House-Brackmann (HB) grade III) postoperative facial outcome, of which 47 and 18 belonged to the fascicular-sparing and grafting group, respectively. Greater efficacy of the fascicular-sparing technique in the achievement of a better facial outcome was found (p = 0.0014; p = 0.0022). A surgical resection at the earliest symptoms is critical to preserve the facial nerve function in GGHs. Fascicular-sparing resection should be pursued in symptomatic cases with residual facial function (I-III HB). Conversely, grafting has a rationale for higher HB grades (V-VI). Broader studies are required to confirm these findings and turn them into new therapeutic perspectives.

[Imaging study of anatomical parameters related to pterygoid canal neurotomy].

Objective:Measuring the important anatomic parameters related to vidian neurectomy to locate the vidian nerve accurately and prevent the surgical complications. Methods:High resolution CT（HRCT） was used to measure the distance parameters between the important anatomic landmarks in 50 patients （100 sides） with chronic rhinosinusitis, sinus cyst or allergic rhinitis et al. The distance from the posterior opening of the palatovaginal canal to the upper edge of the sphenoidal process of palatine bone, the upper edge of the sphenoidal process of palatine bone to the external opening of the vidian canal, the external opening of the vidian canal to the greater palatine canal, and the external opening of the vidian canal to the foramen rotundus were measured. Results:The posterior opening of the palatovaginal canal, the upper edge of the sphenoidal process of palatine bone, the external opening of the vidian canal, the greater palatine canal, and the foramen rotundum are of great value in locating vidain nerve and preventing surgical complications. The distance from the posterior opening of the palatovaginal canal to the upper edge of the sphenoidal process of palatine bone, the upper edge of the sphenoidal process of palatine bone to the external opening of the vidian canal, the external opening of the vidian canal to the greater palatine canal, and the external opening of the vidian canal to the foramen rotundus were（12.46±1.19） mm, （3.23±0.36） mm, （6.09±0.75） mm and（7.6±1.16） mm respectively. Conclusion:HRCT can be used as a powerful tool for preoperative localization of the external pterygoid nerve orifice and its related important anatomical landmarks, and the preoperative distance parameters obtained are valuable for intraoperative localization of the pterygoid nerve to prevent the occurrence of complications.

Three-dimensional structure of the facial canal and related blood vessels and nerves in the temporal bone.

PURPOSE: There are only limited anatomical data on nerves, veins, and arteries in the temporal bone. More detailed anatomical data are required to improve planning of treatments targeting the temporal bone region. Herein, we performed a detailed analysis of the facial canal (FC) and the related carotid artery and vein. METHODS: We examined the bony structure of the middle ear and FC, jugular foramen, and carotid canal in 30 Japanese elderly donor cadavers. Three-dimensional reconstruction of the canal structure was achieved using cone beam computed tomography, while macroscopic and histological analyses were also performed. RESULTS: The FC form was classified as either straight (28%) or bent (72%). There were significant differences in the diameter of the FC and the distance between the internal jugular vein, other FC branches, and the FC. Principal component analysis (PCA) was performed for the FC using 29 factors. Two principal components significantly explained 30.9% (component 1, 18.6%; component 2, 12.3%) of the FC. Histological observation showed numerous ganglion cells and shrunken neurons in the geniculate ganglion of the facial nerve of elderly samples. CONCLUSION: FC diameter is an important contributor to the relationship between the FC and the jugular foramen. The FC and the internal jugular vein are located close to each other, which is useful information for the trans-canal surgery of the otology. Furthermore, the geniculate ganglion contains numerous ganglion cells and shrunken neurons, which may affect the FC structure during bone matrix remodeling with aging.

Gânglio Geniculado

The sensory ganglion of the facial (7th cranial) nerve. The geniculate ganglion cells send central processes to the brain stem and peripheral processes to the taste buds in the anterior tongue, the soft palate, and the skin of the external auditory meatus and the mastoid process.

Ganglio sensorial del nervio facial (7mo par craneal).Las células del ganglio geniculado envían procesos centrales hacia el tallo cerebral y procesos periféricos a los bulbos gustativos en la lengua anterior, el paladar blando, y la piel del meato auditivo externo y el proceso mastoideo.

Gânglio sensitivo do nervo facial (VII par craniano). As células do gânglio geniculado enviam processos centrais para o tronco encefálico e processos periféricos para os corpúsculos gustativos na parte anterior da língua, palato mole, pele do meato acústico externo e processo mastoide.

Totally endoscopic transcanal facial nerve decompression in patients with traumatic facial nerve paralysis: from geniculate ganglion to mastoid segment.

OBJECTIVE: The current study evaluated the effectiveness of endoscopic transcanal facial nerve decompression in patients with post-traumatic facial nerve paralysis. METHODS: This retrospective study included 10 patients with post-traumatic complete facial nerve paralysis who underwent endoscopic transcanal facial nerve decompression. The surgical technique was explained step by step, and the surgical complications, hearing status and facial nerve function 12 months post-operatively were reported. RESULTS: Endoscopic transcanal facial nerve decompression allowed exposure of the geniculate ganglion to the mastoid segment. The facial nerve function improved from House-Brackmann grade VI to grades I and II in 8 of 10 (80 per cent) patients, and 2 patients experienced partial recovery (House-Brackmann grades III and IV). No severe complication was reported. CONCLUSION: Endoscopic transcanal facial nerve decompression, involving the nerve from the geniculate ganglion to the mastoid segment, is a safe and effective approach in patients with post-traumatic facial nerve paralysis.

Schwannomas of the greater superficial petrosal nerve - case series, discussion of surgical techniques, and review of literature.

BACKGROUND: Facial nerve schwannomas account for about 0.8% of all petrous mass lesions. Schwannomas of the greater superficial petrosal nerve (GSPN) are a rare subtype with few case-reports up to date. CASE PRESENTATIONS: A retrospective analysis of clinical outcomes, radiographic findings and postoperative complication between June 2007 and December 2020 was performed. Four cases of GSPN schwannomas were reported. The presenting symptoms were facial nerve palsy and hearing loss. Imaging studies showed a subtemporal mass on the anterosuperior aspect of the petrous bone, in one case with extraordinary petrous bone and mastoid infiltration and destruction. Three cases were removed through a subtemporal extra- or intradural approach, one case via a combined pre- and retrosigmoid approach. Improvement of facial nerve palsy occurred in one case; new hearing loss was observed in another case. Xeropthalmia was a short-term temporary deficit in three cases. Short- to mid-term follow-up of the patients has not shown any tumor recurrence. CONCLUSIONS: GSPN schwannomas are rare entities presenting with heterogenous symptoms. Our surgical findings emphasize safe resection. Complete remission is possible by GTR. Since the small data set limits the expressiveness of statements regarding standard of care and alternative therapy options, additional data is needed.

Oral Sensory Neurons of the Geniculate Ganglion That Express Tyrosine Hydroxylase Comprise a Subpopulation That Contacts Type II and Type III Taste Bud Cells.

Oral sensory neurons of the geniculate ganglion (GG) innervate taste papillae and buds on the tongue and soft palate. Electrophysiological recordings of these neurons and fibers revealed complexity in the number of unique response profiles observed, suggesting there are several distinct neuronal subtypes. Molecular descriptions of these subpopulations are incomplete. We report here the identification of a subpopulation of GG oral sensory neurons in mice by expression of tyrosine hydroxylase (TH). TH-expressing geniculate neurons represent 10-20% of oral sensory neurons and these neurons innervate taste buds in fungiform and anterior foliate taste papillae on the surface of the tongue, as well as taste buds in the soft palate. While 35-50% of taste buds on the tongue are innervated by these TH+ neurons, 100% of soft palate taste buds are innervated. These neurons did not have extragemmal processes outside of taste buds and did not express the mechanosensory neuron-associated gene Ret, suggesting they are chemosensory and not somatosensory neurons. Within taste buds, TH-expressing fibers contacted both Type II and Type III cells, raising the possibility that they are responsive to more than one taste quality. During this analysis we also identified a rare TH+ taste receptor cell type that was found in only 12-25% of taste buds and co-expressed TRPM5, suggesting it was a Type II cell. Taken together, TH-expressing GG oral sensory neurons innervate taste buds preferentially in the soft palate and contact Type II and Type III taste bud receptor cells.

[Clinical observation of highly selective vidian neurectomy guided by the palatovaginal canal].

Objective:Summarize the safety and feasibility of highly selective vidian neurectomy guided by the palatovaginal canal. Methods:Hypothermal plasma surgery was performed on 53 patients with perennial allergic rhinitis （PAR）. Remove the soft tissue covering the anterior wall of the sphenoid process of palatine bone using the Coblation system. Find the palatovaginal canal and cut off the neurovascular bundle in the palatovaginal canal. Expose the anterior orifice of the vidian canal and cut off the vidian nerve. Results:53 PAR patients have conducted the novel vidian neurectomy without sphenopalatine artery trunk damage. No secondary hemorrhage and hard palate numbness happened. The symptoms of nasal obstruction, sneeze, nasal discharge, and rhinocnesmus were relieved significantly. Conclusion:The simple and safe approach of highly selective vidian neurectomy guided by the palatovaginal canal provides an alternative surgical option for clinicians.

[Differential diagnosis and management of hemangioma at geniculate ganglion].

Objective: To investigate the clinical characteristics, differential diagnosis, treatments and prognosis of facial nerve hemangioma and schwannoma at genicular ganglion, so as to provide reference for clinical diagnosis and treatments of facial nerve tumor at genicular ganglion. Methods: Clinical data of 13 patients with facial nerve tumors at genicular ganglion confirmed by postoperative pathology in the Ninth People's Hospital affiliated to Shanghai Jiaotong University School of Medicine from March 2018 to April 2020 were retrospectively analyzed, including seven cases of hemangioma and six cases of schwannoma. There were eight males and five females. Their ages ranged from 20 to 65, with an average age of 40. The course of disease ranged from 3 to 118 months, with an average of 52 months. All the patients underwent preoperative HRCT of the temporal bone and facial nerve dynamic contrast-enhanced(DCE) MRI examinations. All the patients had detailed surgical procedures and at least one-year postoperative follow-up. Results: On HRCT of the temporal bone, (4/7) hemangioma at geniculate ganglion showed characteristic honeycomb appearance, while 6/6 schwannoma and 3/7 hemangiomas showed expansive bone changes. On DCE-MRI, geniculate ganglion hemangioma (7/7) showed characteristic "point-to-surface" enhancement, and schwannoma (6/6) showed characteristic "face-to-surface" enhancement. For five hemangioma-patients with HB-Ⅱ-Ⅳ before surgery, the facial nerve anatomy was completely preserved through transcanal endoscopic approach(TEA), and the facial nerve function improved one year after surgery (two cases of HB-I, two cases of HB-Ⅱ, and one case of HB-Ⅲ). For two patients, with preoperative facial nerve function HB-Ⅴ-Ⅵ, since their tumors was inseparable from the nerves, they were performed with facial nerve anastomosis during the surgery, and the facial nerve function was improved to HB-Ⅳ level one year after surgery. For six patients with meningioma whose facial nerve function was greater than or equal to HB-Ⅲ, based on the preoperative hearing level, the involved segments, and duration of facial paralysis, three of them were conducted surgeries through middle cranial fossa approach, one by translabyrinthine approach, and one via mastoid approach. Two patients among them with complete facial paralysis over three years preoperatively were not performed facial nerve anastomosis after total resections of the tumors, and there was no improvement in facial nerve function one year after surgery. Three patients underwent facial nerve anastomosis after total tumor resections, and their facial nerve function was HB-Ⅲ in one patient, HB-Ⅳ in two patients one year after surgery. One patient (preoperative HB-Ⅲ) had a normal hearing level preoperatively, and the tumor involved the labyrinth segment. To protect the hearing, partial tumor was resected through the middle cranial fossa approach, and facial nerve function improved to HB-Ⅱ one year after surgery. Conclusions: Temporal bone HRCT combined with DCE-MRI are useful for the differential diagnosis of hemangioma and schwannoma at geniculate ganglion and provide references for preoperative clinical decision makings. It is extremely necessary to select the appropriate surgical approach based on the patient's hearing and involved segments. For geniculate ganglion hemangioma, early surgery can improve the possibilities of anatomical integrity of facial nerve, thereby improving facial nerve function postoperatively.TEA is a kind of surgical method worth consideration, with the characteristics of minimally invasive, favorable postoperative features, and so on. For schwannoma, one-stage functional reconstruction of the facial nerve is recommended during the resection of the tumors because of the inevitable damage to the anatomical integrity of the facial nerve.

Sphenoid sinus pneumatization: the good, the bad, and the beautiful.

PURPOSE: To study different types of extension of sphenoid sinus pneumatization detected by CT and examine their correlation with other anatomical variants. METHODS: Sphenoid sinus pneumatization was characterized (780 hemi-sinuses) on CT scans. Its incidence and correlations with related anatomical variants were evaluated. Dimensions of surgical window were measured in the lateral type, where pneumatization extends beyond a line connecting Vidian (pteregoid) canal (VC) and foramen rotundum (FR). RESULTS: The lateral recess of the sphenoid sinus was pneumatized in 27.3% of patients with a mean width of 7.59 mm. The distance separating the FR and the VC correlated strongly with the depth of the lateral recess. There was significant positive correlation between pneumatization of lateral recess and Vidian nerve prominence to other pneumatization patterns (lesser sphenoid, frontal, and Maxillary sinuses) (p < 0.0001). Lateral recess pneumatization in coronal cuts was also significantly correlated with anterior-posterior sphenoid pneumatization in sagittal cuts (p < 0.0001). CONCLUSION: Pre-operative assessment of sphenoid sinus pneumatization is essential in the endoscopic approach to skull base structures to facilitate surgical access and avoid injury of the nearby structures. Our study showed significant correlation among anatomical variants and different measurements which allows the surgeon to predict abnormal anatomy with high accuracy.

Development of the Geniculate Ganglion in Human Fetuses.

AIM: To present the quantitative development of the geniculate ganglion (GG) in foetal cadavers. MATERIAL AND METHODS: This study focused on 60 temporal bones of 30 (15 female and 15 male) foetuses aged 18?30 weeks of gestation (mean age, 22.83 ± 3.49 weeks) to measure the length, width and area of the GG. RESULTS: According to gestational weeks and months, the ganglion length (1.21 ± 0.41 mm), width (1.03 ± 0.28 mm) and area (1.24 ± 0.61 mm < sup > 2 < /sup > ) did not change. In terms of sexes or sides, ganglion dimensions were not significantly different. Positive correlation was found between the length and width (p=0.033, r=0.276), between the length and area (p < 0.001, r=0.762) and between the width and area (p < 0.001, r=0.622). Linear functions were calculated for the ganglion area (y=0.355 + 0.039 × weeks), length (y=0.636 + 0.025 × weeks) and width (y=0.634 + 0.017 × weeks). CONCLUSION: The ganglion size did not change in foetal cadavers aged 18?30 weeks of gestation. This finding may be important for anatomists and embryologists in performing morphometric studies and understanding the development of the GG and for neurootologists and neurosurgeons in achieving greater success in skull base surgeries.

Decompression of the geniculate ganglion and labyrinthine segments of the facial nerve through a middle cranial fossa approach using an ultrasonic surgical system: an anatomic study.

PURPOSE: The aim of this study is to evaluate the feasibility and the safety of a novel, alternative method for bone tissue management in facial nerve decompression by a middle cranial fossa approach. Several applications of Piezosurgery technology have been described, and the technique has recently been extended to otologic surgery. The piezoelectric device is a bone dissector which, using micro-vibration, preserves the anatomic integrity of soft tissue thanks to a selective action on mineralized tissue. METHODS: An anatomic dissection study was conducted on fresh-frozen adult cadaveric heads. Facial nerve decompression was performed by a middle cranial fossa approach in all specimens using the piezoelectric device under a surgical 3D exoscope visualization. After the procedures, the temporal bones were examined for evidence of any injury to the facial nerve or the cochleovestibular organs. RESULTS: In all cases, it was possible to perform a safe dissection of the greater petrosal superficial nerve, the geniculate ganglion, and the labyrinthine tract of the facial nerve. No cases of semicircular canal, cochlea, or nerve damage were observed. All of the dissections were carried out with the ultrasonic device without the necessity to replace it with an otological drill. CONCLUSION: From this preliminary study, surgical decompression of the facial nerve via the middle cranial fossa approach using Piezosurgery seems to be a safe and feasible procedure. Further cadaveric training is recommended before intraoperative use, and a wider case series is required to make a comparison with conventional devices.

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.

Morphometric properties of the fallopian canal: comparison of two nations with different ethnic origins.

PURPOSE: To determine the widths of fallopian canal segments (labyrinthine segment, geniculate ganglion, tympanic segment mastoid segment and stylomastoid foramen), in two nations with different ethnic origins, and to analyze the differences in between. METHODS: We retrospectively analyzed temporal computerized tomographies of 102 individuals including 38 Turks and 64 Syrians. The widths of right and left labyrinthine (LS), tympanic (TS), mastoid (MS), geniculate ganglion (GG) and stylomastoid foramen (SF) segments of the fallopian canal were measured. RESULTS: The narrowest segment was LS (right: 1.04 ± 0.23 mm, left: 1.03 ± 0.22 mm) and the widest segment was SF (right: 1.82 ± 0.41 mm, left: 1.85 ± 0.35 mm). From the widest to the narrowest, the widths of the FC segments were sorted as SF > GG > MS > TS > LS. The widths of the fallopian canal segments were similar between right and left sides, and between males and females (p > 0.05). Our results indicated that both right and left GG were significantly wider in Turks (p < 0.001 for both), however right LS (p < 0.001) and left TS (p = 0.005) were significantly wider in Syrian refugees. Two groups did not show any differences for the widths of other FC segments (p > 0.05). CONCLUSIONS: Nations of different ethnic origins may have differences concerning the widths of some segments of the fallopian canal. Further studies with a larger sample size including clinical data of the patients are needed to clarify our findings, and to determine whether these differences have any clinical implications.

Síndrome de Ramsay Hunt: reporte de un caso clínico / Ramsay Hunt Syndrome: clinical case report

El virus varicela zoster produce cuadros clínicos por reactivación del mismo en años posteriores a la primoinfección, en sujetos con condiciones particulares, como situaciones de estrés, inmunodepresión, radioterapia, estados infecciosos que cursen con fiebre, entre otros. El síndrome de Ramsay Hunt es uno de ellos. Se caracteriza por una tríada de parálisis facial periférica, vesículas herpéticas en oído externo y otalgia. Objetivo: pr esentar un caso típico del síndr ome de Ramsay Hunt, métodos diagnósticos y tratamiento realizado. Presentación de caso clínico: paciente femenina, de 21 años, originaria de Tegucigalpa, Honduras, se presentó al Hospital Escuela Universitario por cuadro de seis días de evolución, de cambios inflamatorios en el oído externo izquierdo, en la región del pabellón auricular y el conducto auditivo externo, con presencia de vesículas herpéticas eritematosas con costras y restos hemáticos, otorrea, hiperemia, prurito y otalgia intermitente. También refirió parálisis de hemicara izquierda de cuatro días de evolución. Examen físico: conducto auditivo externo izquierdo presentaba vesículas con costras. Hubo ptosis palpebral izquierda e incapacidad para realizar las mímicas faciales. Tratamiento intrahospitalario: aciclovir 800 mg vía oral cada 6 horas, dexametasona 8 mg IV cada 8 horas, diclofenaco 75 mg IV cada 12 horas; citidina-5- monofosfato disódico, más uridin-5-trifosfato trisódico, 1 comprimido cada 12 horas; mupirocina ungüento al 1Universidad Nacional Autónoma de Honduras, Facultad de Ciencias Médicas, Tegucigalpa, Honduras. ORCID 0000-0002-2346-4209 2Universidad Nacional Autónoma de Honduras, Facultad de Ciencias Médicas. Departamento de Cirugía. Tegucigalpa, Honduras. 3Hospital Escuela Universitario, Departamento de Cirugía, Tegucigalpa, Honduras. Autor de correspondencia: Paola Andrea Hincapié Gaviria, paolahincapie23@gmail.com Recibido: 10/07/2020 Aceptado: 03/03/2021 al 2%, aplicado en oído externo cada 8 horas y ejercicios de fisioterapia. Conclusión: el síndrome de Ramsay Hunt se diagnóstica, fundamentalmente, mediante hallazgos clínicos. El tratamiento empírico y adecuado, acompañado de una buena terapia posterior, anticipa un pronóstico favorable sin secuelas neurológicas...(AU)