Chondromyxoid fibroma of the mastoid facial nerve canal mimicking a facial nerve schwannoma

Chondromyxoid fibroma of the skull base is a rare entity. Involvement of the temporal bone is particularly rare. We present an unusual case of progressive facial nerve paralysis with imaging and clinical findings most suggestive of a facial nerve schwannoma. The lesion was tubular in appearance, expanded the mastoid facial nerve canal, protruded out of the stylomastoid foramen, and enhanced homogeneously. The only unusual imaging feature was minor calcification within the tumor. Surgery revealed an irregular, cystic lesion. Pathology diagnosed a chondromyxoid fibroma involving the mastoid portion of the facial nerve canal, destroying the facial nerve. Laryngoscope, 2009     

面神经鼓乳段定位及术中面瘫预防

目的:根据颞骨解剖结合中耳手术体会,探讨面神经走行定位,避免中耳手术中面神经损伤.方法:用30侧颞骨标本,模拟面神经减压术的手术步骤暴露面神经鼓乳段,确定面神经走行,用易见且恒定的标志进行面神经定位.结果:面神经水平段位于水平半规管与镫骨之间达匙突前上;垂直段位于鼓室后壁,垂直段后缘延长线与水平半规管后1/3相交,夹角为(117.04±2.42)°,其深度位于水平半规管及鼓环平面以下;外膝位于水平半规管前下方.水平半规管中点至面神经最短距离为(1.97±0.53)mm,砧骨短脚至面神经最短距离为(1.03±0.29)mm,匙突至面神经最短距离为(0.93±0.25)mm,镫骨头至面神经最短距离为(1.18±0.42)mm,前庭窗平面鼓沟至面神经的距离为(3.08±0.28)mm,圆窗平面鼓沟与面神经的距离为(2.13±0.34)mm.结论:水平半规管凸、砧骨短脚、镫骨、鼓环及匙突,是面神经鼓乳段理想的定位标志.熟悉面神经走行,可提高中耳手术安全性.     

耳大神经移植修复面神经缺损的临床研究

目的:探讨采用耳大神经移植修复面神经缺损的可行性。方法:采用耳大神经移植修复面神经缺损14例,手术方式为经乳突进路面神经移植术。以House-Brackmann(HB)分级法评估手术前和手术后面神经功能。结果:在8例颞骨骨折所致面神经麻痹的患者中,颞骨骨折的类型均为纵形骨折,面神经受累及的部位主要在第2膝及其附近,术前面神经功能均为Ⅵ级。3例面神经肿瘤中面神经呈多节段受累,病理结果均为神经鞘膜瘤,术前面神经功能Ⅲ级1例、Ⅴ级2例。医源性损伤2例患者原发病均为胆脂瘤中耳炎,损伤部位分别为面神经乳突段和第2膝。1例钢水烧伤面神经损伤部位在面神经鼓室段,术前面神经功能Ⅵ级。除3例患者失访外,其余患者术后面神经功能恢复Ⅲ级4例、Ⅳ级3例、Ⅴ级2例、Ⅵ级2例。结论:颞骨骨折是导致面神经离断的最常见原因,以耳大神经移植修复面神经缺损是一种实用有效的方法,面神经移植后神经功能恢复最佳可达HBⅢ级。     

Actinomycosis of the temporal bone with labyrinthine and facial nerve involvement

OBJECTIVES: To demonstrate the clinical, radiologic, and pathologic findings of actinomycosis of the temporal bone. STUDY DESIGN: Case report and literature review. METHODS: Analysis of a case through medical records and literature review. RESULTS: Actinomycosis is a rare cause of subacute-chronic suppurative infection of the temporal bone. We present an 11-year-old male with a history of ciliary dyskinesia presenting with a 6-week history of right-sided otorrhea, otalgia, and a 1-week history of progressive facial weakness. Final histopathology revealed a diagnosis of actinomycosis. A review of the literature showed 25 cases of temporal bone actinomycosis. This is the first reported case of actinomycosis causing facial nerve palsy and labyrinthine invasion. Effective treatment includes aggressive surgical debridement followed by long-term administration of appropriate antibiotic. CONCLUSIONS: Actinomycosis can be a cause for bone erosive lesions of the temporal bone and can result in significant morbidities. Prompt tissue diagnosis with suspicion for nonmalignant causes of bone erosive disease can help in implementing appropriate treatment.     

不同病因的周围性面神经麻痹外科治疗分析

目的:探讨不同病因的周围性面神经麻痹患者外科治疗的相关问题。方法:面神经麻痹患者37例,病因包括:贝尔面瘫5例,颞骨骨折20例,中耳乳突炎4例,内耳道面神经肿瘤3例,颅脑颌面手术损伤5例,针对不同病因采取相应外科治疗方式。结果:H-B分级Ⅰ～Ⅱ级恢复率:贝尔面瘫80%,颞骨骨折80%,中耳乳突炎100%;内耳道面神经肿瘤术后1例由Ⅳ级改善至Ⅲ级,2例术后无明显变化;颅脑颌面手术损伤行面-舌吻合者4例由Ⅴ级改善至Ⅲ级3例,Ⅳ级1例,行瘢痕切除+面神经探查减压术者1例由Ⅴ级改善至Ⅳ级。结论:针对不同病因导致的面神经麻痹,选择合适的手术治疗方法,可以取得良好效果。     

Vascular Malformation (so-called Hemangioma) of Scarpa's Ganglion

Vascular malformations of the cerebello-pontine angle (CPA) arising from the capillary plexus surrounding Scarpa's ganglion are rare tumors. We report a case of so-called “hemangioma” of the CPA which was operated on via a trans-labyrinthine approach based on a preoperative diagnosis of vestibular schwannoma. Although there are some differences between these tumors in terms of the clinical, biological and especially MRI findings, surgery is usually performed based on an assumption of vestibular schwannoma. Surgery is the treatment of choice for these lesions as early intervention ensures better postoperative facial function. It is important to make the differential diagnosis if conservative management of vestibular schwannoma is adopted.     

On the duality of the facial nerve ganglion

Objectives: Describe quantitatively the number of ganglion cells in the geniculate (G) and meatal (M) segments of the human facial nerve. Study Design: One hundred human temporal bone specimens that were sectioned horizontally and stained with hematoxylin and eosin were selected from a temporal bone collection on the basis of minimal artifact and absence of pathology involving the facial nerve. Methods: Cells with a nucleolus in all sections through the facial nerve were projected on tracing paper with a camera lucida and counted manually. A modified Abercrombie technique was employed to compute total cells in the G and M segments. Results: Ages of patients ranged from 1 month to 92 years; the male-to-female ratio was 56:44. The total number of cells in individual temporal bones ranged from 589 to 4183 (mean, 2162 cells). The range of cells in the G ganglion was from 66 to 4017 (mean, 1713 cells); in the M ganglion the number ranged from 0 to 2764 (mean, 448 cells). There was no correlation of total ganglion cell number to age or sex. The majority of cells were found in the G ganglion in 88% of temporal bones. In 8% temporal bones the majority of cells were in the M ganglion and in 4% the M and G ganglions contained an equal number of cells. Conclusions: The facial nerve sensory ganglion consists of two components: G and M. The G ganglion outnumbers the M component in the majority of temporal bones (88%). The M ganglion was equal to or greater in number than the G ganglion in 12% of temporal bones.     

Experiments on herpes simplex viral infections of the facial nerve in the tympanic cavity

Summary An experimental protocol was developed to study viral infection of the facial nerve. Facial palsy was induced in a guinea pig model by inoculating type 1 herpes simplex virus (HSV-1) directly onto the facial nerve in the temporal bone. Partial removal of the bony wall of the fallopian canal was effected, and virus was placed on the nerve after incising its sheath on the right side and without incision of the sheath on the left side. All animals exhibited subsequent bilateral facial palsies, but with severe changes occurring on the right side. The animals were then sacrificed sequentially following infection. Immunofluorescence and histopathological studies revealed the presence of HSV antigen, infiltration of inflammatory cells, hemorrhage, and degeneration of the right facial nerve. In the left nerves, a slight hemorrhage was recognized without cellular infiltration or HSV antigens. These results suggest that the intact facial nerve is rather resistant to HSV infection, but this defense mechanism is easily destroyed by damage to the facial nerve sheath.     

Surgical anatomy of tympano-mastoid segment of facial nerve

Objective  Facial nerve is known to have a considerable variations more so in the temporal bone. An otologist with inadequate familiarity with facial nerve usually have a tendency to do incomplete surgery in chronic suppurative otitis media. The present study was conducted to explore the microanatomy of tympanic and mastoid segments of facial nerve. Setting  Temporal bone lab. Materials and Methods  This study was conducted at PGIMS Rohtak in 25 wet temporal bones which were dissected under the microscope. Various parameters studied included the length of tympanic and mastoid segments of facial nerve, various anomalies, depth from the cortex and relation to various important structures. Results  The mean length of tympanic segment was 11.1 mm±0.88 and mastoid segment was 15.4 mm±2.4. The angle at second genu was 95–125° and the facial canal was dehiscent in 12% cases. Conclusions  The tympanomastoid segment of facial nerve has variations in length and in its relation with various middle ear structures. Further the nerve, in Indians is also at variance as compared to Japanese and Americans probably because of different racial configuration of the skull.     

Use of a novel ultrasonic surgical system for decompression of the facial nerve

OBJECTIVE: The middle cranial fossa approach has been used to explore and decompress the facial nerve in patients with Bell's palsy and facial nerve tumors. Unfortunately, this approach is technically challenging and has a significant risk of injury to the facial nerve and to the cochleovestibular organs. One way to minimize the risk may be with the use of the Sonopet Omni ultrasonic aspirator (Synergetics Inc., St Charles, MO) instead of an otologic drill. METHODS: In this prospective study using cadaveric temporal bones, a total of 17 temporal bone specimens were used. Seven cadaveric temporal bones were used (4-left, 3-right) for the initial feasibility study. At a second session, an additional 10 temporal bones (5-left, 5-right) underwent decompression of the facial nerve from the fundus of the internal auditory canal (IAC) to the geniculate ganglion (ie, labyrinthine segment). The average time to decompress the labyrinthine segment was measured. The temporal bones were then examined for evidence of any injury. RESULTS: None of the 17 temporal bones showed any sign of injury to the superior semicircular canal or the cochlea. However, one specimen did have penetration of the IAC dura; another specimen did have penetration of the epineurium of the facial nerve. However, in neither case was there any evidence of injury to the facial nerve itself. At the first session, the average time for decompression of the labyrinthine segment was 10 minutes and 12 seconds. At the second session, the average time for decompression was 5 minutes and 0 seconds. CONCLUSION: The ultrasonic surgical system may be used as an alternative to the surgical drill for decompression of the facial nerve. Although a learning curve does exist, as with any new surgical tool or device, our results indicate that the device can be used safely and in a reasonable amount of time. However, before proceeding with intraoperative use of this device for otologic and neurotologic procedures, familiarization is first recommended on cadaveric temporal bone specimens.     

高分辨率CT对颞骨外伤性面瘫的诊断价值

目的：探讨高分辨率CT（HRCT）对颞骨外伤性面瘫的诊断价值及对手术的指导意义。方法：据临床资料和颞骨HRCT表现,对29例拟行手术治疗的颞骨外伤性面瘫患者提出预测性诊断,并与术中所见进行对比。结果：CT显示骨折线走行情况与术中所见基本符合,不同类型的骨折引起的神经损伤具有各自的特点。面神经损伤的直接征象包括骨折线贯穿骨管、骨管断裂或断离;间接征象包括面神经局部增粗、骨管壁密度降低、膝状神经窝扩大、面神经受压等。各种征象与术中所见的符合率均在90％以上。结论：HRCT可明确显示颞骨骨折线的位置及走行,有助于判断面神经损伤范围、程度以及邻近结构破坏情况,为临床诊断及治疗提供可靠依据。     

Postparotidectomy facial nerve paralysis: possible etiologic factors and results with routine facial nerve monitoring.

OBJECTIVE: Analyze the incidence and factors responsible for postparotidectomy facial nerve paralysis when the surgery is performed with the routine use of facial nerve monitoring. STUDY DESIGN: A prospective, nonrandomized study. METHODS: Seventy consecutive patients underwent parotidectomy with intraoperative facial nerve monitoring. Two devices were used: a custom mechanical transducer and a commercial electromyograph-based apparatus. All patients were analyzed, including those with cancer and those with deliberate or accidental sectioning of facial nerve branches. The outcome variables were the motor facial nerve function according to the House-Brackmann grading scale (HB) at 1 week (temporary paralysis) and 6 to 12 months (definitive paralysis). Facial nerve grading was performed blindly from reviewing videotapes. RESULTS: The overall incidence of facial paralysis (HB>1) was 27% for temporary and 4% for permanent deficits. Most of the deficits were partial, most often concerning the marginal mandibular branch. Temporary deficits with HB scores of greater than 2 were only present in patients with parotid cancer or infection. Permanent deficits were present in three patients, including one patient with facial nerve sacrifice. Factors significantly associated with an increased incidence of temporary facial paralysis include the extent of parotidectomy, the intraoperative sectioning of facial nerve branches, the histopathology and the size of the lesion, and the duration of the operation. CONCLUSIONS: Despite a stringent accounting of postoperative facial nerve deficits, these data compare favorably to the literature with or without the use of monitoring. An overall incidence of 27% for temporary facial paralysis and 4% for permanent facial paralysis was found. Although the lack of a control group precludes definitive conclusions on the role of electromyograph-based facial nerve monitoring in routine parotidectomy, the authors found its use very helpful.     

外耳道皮下组织压片行鼓膜穿孔修补术

目的探讨应用外耳道上壁中、外段皮下组织压片修补鼓膜穿孔的临床疗效。方法对65例（69耳）由中耳炎或外伤引起的鼓膜穿孔直径大于3 mm伴外耳道狭窄、弯曲患者,用此法行耳内切口、扩大外耳道,用外耳道上壁中、外段皮下组织压片行鼓膜修补术。结果67耳鼓膜穿孔修补术后愈合,穿孔愈合率97.1%。修补鼓膜愈合时间平均15.2 d。术后外耳道宽畅。随访0.5-3.5年,无鼓膜再穿孔。术后纯音测听（取0.5,1,2,4 kHz）气导听力提高10-30 dB（平均18.6 dB）者66耳,气骨导差距在10-20 dB,较术前平均缩小16.8 dB,听力改善率95.7%。另3耳听力无改善。结论用耳道上壁中、外段皮下结缔组织压片修补鼓膜穿孔是一种取材简便、术野显露好、愈合时间短、穿孔愈合率高的新术式,更适合鼓膜穿孔大、外耳道狭窄和弯曲者。     

The use of the rat facial nerve model to assess the effect of differing nerve anastomotic agents on the facial nerve

There are relatively few papers which prove that one nerve anastomotic agent for the facial nerve is superior to any other. Previous experiments on the division and anastomosis of the facial nerve have failed to consider the indeterminate variables involved, i.e. operator variability, controls and the reaction of the materials on normal nerve tissue. In this experiment, a variety of anastomotic agents were tested to see if the anastomotic agents themselves affected the extra-temporal facial nerve function. The absorbable suture, non-absorbable suture, glue and tube wrap used had no effect on normal nerve tissue or on the anastomosis of the sectioned facial nerve of the rat compared with simple laying together of the divided ends of the divided nerve.     

Functional assessments of the rodent facial nerve: a synkinesis model

Objectives/Hypothesis: Rodent whisker movement has been used as a tool, after facial nerve manipulation, to quantify functional recovery. We have recently established a method to study functional correlates of aberrant regeneration of the facial nerve. Our objective was to establish normative parameters for both spontaneous and induced whisking and blinking behavior in a large group of normal rats. Study Design: Prospective animal study. Methods: Eighty animals underwent quantitative facial movement testing to measure simultaneous vibrissal movement and ocular closure for each side independently. Right and left C‐1 whisker positions were continuously recorded for 5‐minute sessions, and changes in infrared detection corresponding to eye closure were continuously recorded. Whisking and blinking were elicited by delivery of olfactory stimuli (10 s scented airflows) and corneal air puffs. Whisks were counted and analyzed, and eye closures were counted. Results: Whisking amplitude, velocity, and acceleration were consistent with literature values. Air puff delivery elicited an ipsilateral blink 99% of the time, a contralateral blink 18% of the time, and changes in or initiation of bilateral whisking 70% of the time. Olfactory stimulus delivery prompted a change in whisking behavior 83% of the time, and eye closure 20% of the time. Conclusions: This study establishes normative data for assessing cranial nerve VII‐controlled facial movement in four separate facial regions. We demonstrate the capability and tendency of animals to move their orbicularis oculi muscles independently of and simultaneously with their midfacial muscles. This model provides an excellent tool for the study of aberrant regeneration after facial nerve injury in the rodent.