ABSTRACT
Objective@#This study aimed to measure the morphological parameters of the internal acoustic meatus(IAM) and its adjacent structures using temporal-bone thin-section CT(computed tomography).@*Methods@#CT images were obtained from 50 Chinese adult patients (25 males and 25 females, 100 sides) which had no visible lesion in the petrous part of the temporal bone and inner ear, the morphological parameters of all inner ear parts were sectionally measured on the specified plane using SPSS 22.0 software for statistical analysis.@*Results@#The integral morphological characteristics of the IAM were observed. These results revealed that anterior-posterior diameter of the internal acoustic poer(IAP)(CD) was (6.93±1.85)mm, the superior-inferior diameter of the IAP(EF) was (4.40±0.86)mm, the length of the IAM(AB) was (9.30±1.60)mm, the superior-inferior diameter of the IAM(the intersection of inner 1/3 section and middle 1/3 section) was (4.13±0.83)mm, the superior-inferior diameter of the IAM(the intersection of middle 1/3 section and outer 1/3 section) was (4.61±1.02)mm, the anterior-posterior diameter of the IAM(the intersection of inner 1/3 section and middle 1/3 section) was (6.62±1.92)mm, the anterior-posterior diameter of the IAM(the intersection of middle 1/3 section and outer 1/3 section) was (6.28±1.65)mm, the depth of transverse crest (superior wall) was (3.10±0.75)mm, the depth of transverse crest (interior wall)the was (1.46±0.59)mm, the distance from transverse crest vertex A to the superior wall of the IAM was (2.05±0.42)mm, the distance from transverse crest vertex A to the interior wall of the IAM was (2.93±0.41)mm, the thickness of the superior bone wall of the IAM (the intersection of inner 1/3 section and middle 1/3 section) was (4.45±1.34)mm, the thickness of the superior bone wall of the IAM (the intersection of middle 1/3 section and outer 1/3 section) was (4.32±1.12)mm, the thickness of the superior bone wall of the IAM (the intersection of outer 1/3 section and transverse crest vertex) was (4.37±1.28)mm, and the appearance ratio of the cells in the whole IAM superior wall was 32%.The whole IAM assumed the shape of short cylinder, inclining about 1 cm outward, with the upper-lower diameter and anterior-posterior diameter about 5 mm.@*Conclusion@#It is necessary for carrying out preoperative the temporal-bone thin-section CT to obtain the morphological parameters of the IAM, determine its basic morphology, and provide references to avoid damaging the other important structures during IAM surgeries.
ABSTRACT
OBJECTIVE: To explore and analyze the influencing factors of facial nerve function retainment after microsurgery resection of acoustic neurinoma. METHODS: Retrospective analysis of our hospital 105 acoustic neuroma cases from October, 2006 to January 2012, in the group all patients were treated with suboccipital sigmoid sinus approach to acoustic neuroma microsurgery resection. We adopted researching individual patient data, outpatient review and telephone followed up and the House-Brackmann grading system to evaluate and analyze the facial nerve function. RESULTS: Among 105 patients in this study group, complete surgical resection rate was 80.9% (85/105), subtotal resection rate was 14.3% (15/105), and partial resection rate 4.8% (5/105). The rate of facial nerve retainment on neuroanatomy was 95.3% (100/105) and the mortality rate was 2.1% (2/105). Facial nerve function when the patient is discharged from the hospital, also known as immediate facial nerve function which was graded in House-Brackmann: excellent facial nerve function (House-Brackmann I–II level) cases accounted for 75.2% (79/105), facial nerve function III–IV level cases accounted for 22.9% (24/105), and V–VI cases accounted for 1.9% (2/105). Patients were followed up for more than one year, with excellent facial nerve function retention rate (H-B I–II level) was 74.4% (58/78). CONCLUSION: Acoustic neuroma patients after surgery, the long-term (≥1 year) facial nerve function excellent retaining rate was closely related with surgical proficiency, post-operative immediate facial nerve function, diameter of tumor and whether to use electrophysiological monitoring techniques; while there was no significant correlation with the patient’s age, surgical approach, whether to stripping the internal auditory canal, whether there was cystic degeneration, tumor recurrence, whether to merge with obstructive hydrocephalus and the length of the duration of symptoms.
Subject(s)
Humans , Acoustics , Colon, Sigmoid , Facial Nerve , Hydrocephalus , Microsurgery , Mortality , Neuroanatomy , Neuroma, Acoustic , Outpatients , Recurrence , Retrospective Studies , TelephoneABSTRACT
Knowledge of the normal dimensions and local anatomy of the internal acoustic canal (IAM) is necessary during evaluation of temporal bone trauma, congenital anomalies, affecting the individual nerves, and some neuro-otologic surgeries. The purpose of this study was therefore to characterize the anthropometry of the IAM. We made the following measurements in 14 normal temporal bones of Iranian male skulls from individuals 35 to 60 years of age (average of 50): Height and width of the middle portion of the IAM (mean 4.04 and 3.69mm), Height and width of the fundus of the IAM (mean 2.86 and 2.43mm), inferior and superior length of the IAM (mean 8.39 and 10.75mm).This study provides baseline information that maybe used to evaluate the congenital anomalies of the IAM. These data may also be helpful in the presurgical evaluations of the patients undergoing surgeries involving the IAM.
El conocimiento de las dimensiones normales y de la anatomía local del meato acústico interno (MAI) es necesario durante la evaluación del trauma del hueso temporal, anomalías congénitas que afectan a nervios individuales y algunas cirugías neurootológicas. El objetivo del trabajo fue caracterizar la antropometría del MAL Las siguientes mediciones las realizamos en 14 huesos temporales normales de individuos iraníes masculinos, de 35 a 60 años de edad (promedio 50 años): altura y ancho de la porción media del MAI (4,04 y 3,69mm), altura y ancho del fondo del MAI (2,86 y 2,43mm), largo inferior y largo superior del MAI (promedio 8,39 y 10,75mm). Este estudio entrega información básica que puede ser usada para evaluar anomalías congénitas del MAL Estos datos también pueden ayudar en evaluaciones prequirúrgicas de pacientes que serán sometidos a cirugías que involucren el MAL.
Subject(s)
Humans , Male , Adult , Middle Aged , Anthropometry , Ear, Inner/anatomy & histologyABSTRACT
Schwannomas arising from the cranial nerves of the jugular foramen are rare, only 50 cases including 15 glossopharyngeal schwannomas have been reported. They may be confused with the far more common acoustic schwannoma because of the presenting symptom of hearing loss. With the symptoms and signs of the lower cranial nerve involvement, the characteristic radiographic findings of enlarged jugular foramen and normal internal acoustic meatus can make the diagnosis. The authors review the literature and present a unique case of glossopharyngeal schwannoma which had intra-and extracranial growth with intrapetrosal extension.