MRI Differentiation Diagnosis of Occupying Lesions in Cerebellopontine Angle Area

Objective： To explore the value of magnetic resonance imaging （MRI） in diagnosis of occupying lesions in cerebellopontine angle area. Methods： MRI records of 78 patients with pathologically confirmed occupied lesions in cerebellopontine angle area were analyzed. Results： Of the 78 cases, 48 （61.5%） were unilateral acoustic neuroma, 5 （6.4%） were bilateral acoustic neuroma, 12 （15.4%） were meningioma, 4 （5.1%） were trigeminal neuroma, 3 （3.8%） were lipoma, 2 （2.6%） were melanoma, and 1 （1.3%） was medulloblastoma. According to the anatomic site, tumor lesion character, and MRI signal, the majority of cerebellopontine angle area tumors were diagnosed accurately. Conclusion： MRI plays an important role in diagnosis of occupying lesions in cerebellopontine angle area.

Clinical Application of Quantitative Nursing for Lower Cranial Nerves Injury after Cerebellopontine Angle Tumors

Objective: To retrospectively analyze the clinical utility of quantitative nursing measures of 10 cases of lower cranial nerves injury after cerebellopontine angle tumors surgery to provide the experience for improving the recovery rate and living quality of these patients. Methods: The clinical data of 10 cases of lower cranial nerves injury after cerebellopontine angle tumors surgery was analyzed. For problems such as dysphagia and dyspnea of these patients, the nursing care focused on strict monitoring, timely oxygen inhalation nursing, posture nursing, ventilator nursing, swallowing function training, etc. Results: After received quantitative care, 10 patients with lower cranial nerves injury after cerebellopontine angle tumors surgery were recovered well, and their symptoms such as dysphagia and dyspnea were gradually improved and safely discharged. Conclusion: Lower cranial nerves injury is one of the serious complications after removal of cerebellopontine angle tumors, which impacts the life and health of patients. Caregivers should accurately understand and analyze the symptoms, and quantitative and targeted nursing measures for posterior cranial nerves injury are helpful in the postoperative rehabilitation of patients and improve their living quality.

An adult case of medulloblastoma in the cerebellopontine angle extending to the supratentorial area

Medulloblastoma is an undifferentiated embryonic neuroepithelial tumor. It is a rare tumor in the central nervous system, with an even rarer occurrence during adulthood. It may develop at an atypical and uncommon site, such as the cerebellopontine angle （CPA）, and such tumors rarely present with supratentorial extension. The present study reports an adult case of medulloblastoma in the CPA extending to the supratentorial area. The patient presented with complaints of headache, vertigo, hearing difficulty in the left ear, nausea/vomiting, and unsteady gait. Disequilibrium began 4 weeks earlier. Examination revealed normal cranial nerves, and computed tomography showed a hyperdense lesion, with a heterogeneously enhancing mass, in the left CPA region. The patient underwent a nearly total excision of the lesion in the CPA region. Histopathological examination confirmed medulloblastoma, WHO grade IV. Postoperatively, the patient received radiotherapy and remained asymptomatic for 30 months. However, he received two more surgeries for relapse and progression of medulloblastoma and eventually died. A CPA medulloblastoma with supratentorial extension is relatively rare in the clinic.

Meningeal melanocytoma in the cerebellopontine angle:A rare case report and review of the literature

Primary meningeal melanocytoma(MM)in the cerebellopontine angle(CPA)region is an extremely rare neoplasm that originates from the melanocytes in the leptomeninges.These lesions are usually misdiagnosed as they mimic other common CPA lesions through their nonspecific presenting symptoms,signs,and radiological characteristics.Here,we report a 47-year-old Chinese female patient who presented with a 1-month history of the right-sided tongue numbness and 1-week history of the right-sided face numbness that had been worsening for 2 days.The tumor,in the right CPA region,showed a slight isointensity on T1-weighted image and mixed signal intensity on T2-weighted image.The clinical presentation,surgical treatment,and pathologic characteristics were determined.The tumor was microsurgically resected and gross-total resection was achieved.The tumor revealed a solid,capsulated,brown-black lesion.Immunohistochemistry showed that the tumor cells were positive for human melanoma black-45(HMB-45),melanoma antigen(MelanA),S100,SOX10,and BRAF,confirming the final diagnosis of meningeal melanocytoma.Ultimately,no signs of radiological local recurrence were observed during the two-year follow-up.Collectively,meningeal melanocytoma is difficult to distinguish from common tumors in the CPA region before operation due to the lack of specificity in imaging and symptoms.Complete surgical resection is the best therapeutic option for this tumor.Although the tumor is commonly considered as a benign lesion,recurrence and metastasis are common,and pathogenesis remains unclear.

Clinical Benefits of Facial Nerve Monitoring during Cerebellopontine Angle Surgery

Background: The surgery of cerebellopontine angle tumours has remarkably progressed over the last 2 decades due to improved microsurgical techniques. The primary operative goals are microscopic total removal of the tumour while securing the adjacent cranial nerves. Facial Nerve plays a critical role in facial muscles function and one’s cosmetic appearance, and its weakness can have profound implications on a patient’s quality of life. Aim of the Study: To assess the impact of monitoring techniques on the preservation of facial nerve function during cerebellopontine angle tumours surgery. Patients and Methods: This is a prospective study. This study was conducted on 30 cases (2 groups, each had 15 patients) with CPA lesions that had undergone surgical excision of these lesions performed by retrosigmoid approach (Group A: the patients were operated under continuous intraoperative facial nerve monitoring (IOFNM) and Group B: the patients were operated without IOFNM). They were operated upon in neurosurgery departments at Al-Azhar university hospitals between August 2019 and August 2021. Results: This study showed that excellent facial nerve function (HB Grade I and II) was higher in group A than group B, immediately and at 6-month post op (80% and 93% VS 53.3% and 66.7%). Intermediate (HB Grade III and VI) and Poor (HB Grade V and VI) facial nerve function was higher in group B than group A;both immediately and 6-month postop (46.7% and 33.3% VS 20% and 6.6%). However, no statistically significant P-Value between both groups. Conclusion: We concluded that IOFNM can help, but cannot guarantee, the preservation of facial nerve. Furthermore, it is merely a technical adjunct and does not replace surgical skills, knowledge of anatomy and experience.

Collision off-axis position dependence of relativistic nonlinear Thomson inverse scattering of an excited electron in a tightly focused circular polarized laser pulse

This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circularly polarized laser pulses of varying intensities. We examine the effects of the transverse ponderomotive force, specifically how the deviation angle and speed of electron motion are affected by the initial off-axis position of the electron and the peak amplitude of the laser pulse. When the laser pulse intensity is low, an increase in the electron's initial off-axis distance results in reduced spatial radiation power, improved collimation, super-continuum phenomena generation, red-shifting of the spectrum's harmonic peak, and significant symmetry in the radiation radial direction. However, in contradiction to conventional understandings,when the laser pulse intensity is relatively high, the properties of the relativistic nonlinear Thomson inverse scattering of the electron deviate from the central axis, changing direction in opposition to the aforementioned effects. After reaching a peak, these properties then shift again, aligning with the previous direction. The complex interplay of these effects suggests a greater nuance and intricacy in the relationship between laser pulse intensity, electron position, and scattering properties than previously thought.

Malignant meningioma of the cerebellopontine angle in a 2-year-old girl:a case report and literature review

Meningioma is a common intracranial tumor in adults.Pediatric cases account for approximately 1.5% of all intracranial meningiomas,and very few cases show malignant histological features.Primary pediatric malignant meningioma in the cerebellopontine angle is extremely uncommon.Herein,we report a 2-yearold girl with malignant meningioma in the cerebellopontine angle.The clinical features,diagnosis,and treatment protocol are discussed.

Cerebellopontine Angle Epidermoid Cyst: Case Report

Epidermoid cysts are rare congenital tumors of the central nervous system (CNS), histologically benign and slow- growing lesions. Their frequency among primitive intracranial tumors is about 1% and they account for 40% of all intracranial epidermoid of the cerebellopontine angle (CPA);there they constitute the third most frequent neoplasm (5%), after acoustic neuromas and meningiomas. We report the case of a patient with a paucisymptomatic epidermoid cyst of the CPA.

Influence of acceleration on relativistic nonlinear Thomson scattering in tightly focused linearly polarized laser pulses

The influence of acceleration of electrons on relativistic nonlinear Thomson scattering in tightly focused linearly polarized laser pulses is investigated for the first time. In the framework of classical electrodynamics, it is deduced and found that the more severe the change in the electron transverse acceleration, the stronger the asymmetry of the radiation angle distribution, and the greater the transverse acceleration, the greater the radiation energy. Tightly focused, ultrashort,and high-intensity lasers lead to violent electron acceleration processes, resulting in a bifurcated radiation structure with asymmetry and higher energy. Additionally, a change in the initial phase of the laser brings about periodic change of the acceleration, which in turn makes the radiation change periodically with the initial phase. In other cases, the radiation is in a symmetrical double-peak structure. These phenomena will help us to modulate radiation with more energy collimation.

Magnetic field induction and magnetic force distribution profiles in plasma focus discharge device

We report a simple-to-perform technique to investigate the distribution of the azimuthal magnetic field induction,Bθ,and the induced magnetic force acting on the plasma current sheath(PCS)in a plasma focus(PF)discharge.This in situ measurement technique can undoubtedly be beneficial when other fast-imaging techniques are not available.techniques are not available.Experimental work was conducted in the low-energy Mather-type EAEA-PF1 device operated in argon.The axial distribution(Bθ)z along the coaxial electrodes system was measured with a four magnetic-probe set technique at different radial distances(r=2.625×10^(−2) to 4.125×10^(−2) m)within the annular space between the coaxial electrodes during the 1st and 2nd half cycles of the discharge current waveform,where inner electrode of coaxial electrode system has a+ve polarity and−ve polarity,respectively.Axial,radial and total magnetic force distribution profiles were estimated from Bθdata.Investigation of PCS shape in terms of its inclination(curvature)angle,θ,along the axial rundown phase and the correlation between the magnetic forces per unit volume acting on the PCS,the inclination angleθof the PCS,and the formation of a powerful PF action during the 1st and 2nd half cycles is carried out.Dependence of inclination angle,θ,on total magnetic force per unit volume acting on PCS axial motion was studied,separately,during the 1st and 2nd half cycles.

阿特拉斯·科普柯推出Power Focus 6000系列拧紧系统

2017年6月12日,作为全球领先的工业生产解决方案供应商,阿特拉斯·科普柯推出了适用于多种手持式工具的Power Focus 6000拧紧系统,基于最新的平台打造,带来独一无二的用户操作体验和更好的质量管控,并具有极大的集成和扩展的灵活性,预见并满足未来“智慧工厂”对于装配的需求。

Anatomic structural study of cerebellopontine angle via endoscope

Background Minimally invasive surgery in skull base relying on searching for possible anatomic basis for endoscopic technology is controversial. The objective of this study was to observe the spatial relationships between main blood vessels and nerves in the cerebellopontine angle area and provide anatomic basis for lateral and posterior skull base minimally invasive surgery via endoscopic retrosigmoid keyhole approach.Methods This study was conducted on thirty dried adult skulls to measure the spatial relationships among the surface bony marks of posterior cranial fossa, and to locate the most appropriate drilling area for retrosigmoid keyhole approach. In addition, we used 10 formaldehyde-fixed adult cadaver specimens for simulating endoscopic retrosigmoid approach to determine the visible scope.Results The midpoint between the mastoid tip and the asterion was the best drilling point for retrosigmoid approach. A hole centered on this point with the 2.0 cm in diameter was suitable for exposing the related structures in the cerebellopontine angle. Retrosigmoid keyhole approach can decrease the pressure on the cerebellum and expose the related structures effectively which include facial nerve, vestibulocochlear nerve, trigeminal nerve, glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve, anterior inferior cerebellar artery, posterior inferior cerebellar artery and labyrinthine artery, etc.Conclusions Exact location on endoscope retrosigmoid approach can avoid dragging cerebellum during the minimally invasive surgery. The application of retrosigmoid keyhole approach will extend the application of endoscopic technology.

Cerebellopontine angle neoplasms in four cases: intra-axial or extra-axial?

Case 1:Hemangioblastoma.A 51-year-old woman was admitted to our hospital with a 6-month history of headache and vision impairment.Magnetic resonance imaging (MRI) revealed a lobulated and heterogeneous intense right CPA mass [Figure 1],and the neuroradiology reading indicated a meningioma.The pathological diagnosis showed hemangioblastoma which is World Health Organization (WHO) grade Ⅰ.

桥小脑角肿瘤继发性三叉神经痛的临床病理特征

目的:桥小脑角(cerebellopontine angle,CPA)肿瘤是继发性三叉神经痛(trigeminal neuralgia,TN)的常见病因,其位置隐蔽,进展缓慢,难以早期发现。本研究旨在探讨CPA肿瘤继发性TN患者的临床病理特征,提高对继发性TN诊治的认识。方法:回顾性分析中南大学湘雅医院2017年1月1日至2022年12月31日收治的116例CPA肿瘤继发TN患者的临床资料和病理结果,分析肿瘤病理类型与临床表现、肿瘤部位、手术方式及疗效的关系。结果:本组病例中95.7%(111/116)为良性肿瘤,3.4%(4/116)为恶性肿瘤,0.9%(1/116)为交界性肿瘤,良性肿瘤以胆脂瘤、脑膜瘤、神经鞘瘤多见。46.6%(54/116)的患者表现为单纯TN,53.4%(62/116)出现其他伴随症状,这取决于不同类型肿瘤的生长部位、生长速度等因素。本组病例手术全切率在90%以上,41.4%(48/116)的患者在切除肿瘤后同期行微血管减压,其中神经鞘瘤占比最高。手术治疗总体有效率达93.9%,神经鞘瘤的有效率高于胆脂瘤、脑膜瘤(均P<0.05);胆脂瘤的复发率显著高于脑膜瘤、神经鞘瘤(均P<0.05)。结论:CPA肿瘤是继发性TN的主要病因,以良性肿瘤多见,恶性肿瘤虽少但容易被漏诊,早期诊治对预后影响很大。不同类型肿瘤在临床症状、手术方式、疗效等方面有所不同,手术策略需兼顾肿瘤切除程度及神经功能保护,必要时行微血管减压术。

桥脑小脑角区脂肪瘤的诊治分析

目的探讨桥脑小脑角区脂肪瘤的临床特点、治疗方法及其疗效。方法回顾性分析2009年1月至2022年1月收治的6例桥脑小脑角区脂肪瘤的临床资料。结果6例均出现患侧听力减退,伴眩晕、面神经功能障碍及面部疼痛各1例;MRI呈特异性短T1、长T2信号,CT呈低密度。4例手术治疗,2例保守观察。术后除听力下降以外的症状均得到缓解。出院后随访10~151个月,未出现疾病进展。结论桥脑小脑角区脂肪瘤是先天性良性病变,影像表现较为特异;如出现明显临床症状,则可手术治疗,但手术难以保留残存听力,术中实现减压即可,不宜追求肿瘤切除程度。

桥小脑角脑膜瘤的显微外科治疗及疗效影响因素分析

目的探讨桥小脑角(CPA)脑膜瘤的显微外科治疗策略,并分析影响手术疗效的因素。方法回顾性分析南京医科大学第一附属医院神经外科2009年5月至2019年4月收治的137例CPA脑膜瘤患者的临床资料。采用Simpson分级评估肿瘤切除程度,以Karnofsky功能状态评分(KPS)评估预后,应用单因素分析探讨影响肿瘤切除程度的因素。结果137例患者中,132例行枕下乙状窦后入路,5例行颞下+乙状窦后入路。SimpsonⅠ~Ⅱ级切除122例(89.1%),Ⅲ级切除11例(8.0%),Ⅳ级切除4例(2.9%)。术后患者均获得随访,随访时间为(72.4±20.8)个月。随访期间,肿瘤复发2例(1.7%),进展1例(6.7%)。末次随访时KPS评分(92.3±13.1)分,高于出院时的(86.9±9.4)分和术前的(75.8±10.3)分(均P<0.001)。单因素分析结果表明,肿瘤的分型(P=0.013)、大小(P=0.023)、瘤周水肿(P=0.005)、瘤周蛛网膜不完整(P=0.030)为影响肿瘤全切的因素。结论经枕下乙状窦后入路可以切除大多数CPA区脑膜瘤。肿瘤体积较小、瘤周蛛网膜界面清晰、无瘤周水肿、非联合型脑膜瘤术中易获得全切。

双探头梯形矩阵聚焦成像方法

R角是曲面变壁厚结构,传统超声检测方法难以对其轮廓和缺陷进行完整成像显示。针对此问题,首先,提出双探头全聚焦成像方法,实现R角区域的完整成像显示;其次,为了改善双探头全聚焦成像效率较低的问题,采用梯形矩阵聚焦成像算法,实现高效实时成像;最后,对典型变壁厚R角试件开展聚焦成像实验,验证了双探头梯形矩阵聚焦成像方法的有效性。结果表明,与传统单探头全聚焦成像方法相比,双探头梯形矩阵聚焦成像方法能够显示R角结构的完整内轮廓,并清楚显示和定位内部缺陷。

改进的U-Net网络小断层识别技术在玛湖凹陷玛中地区三叠系白碱滩组的应用

利用改进的U-Net网络小断层识别技术,对准噶尔盆地玛湖凹陷玛中地区三叠系白碱滩组的小断层进行了识别。研究结果表明:(1)构造导向滤波预处理能有效改善地震资料的品质,提高断层识别的准确率。加入了跳跃连接和中继监督、正态标准化和聚焦均方损失函数的U-Net网络方法,对小断层的精细识别能力有所提升。(2)使用200组训练样本集和20组验证样本集,模型地震数据由反射系数与雷克子波褶积生成,断层由人工标注而成。选取最优的网络模型参数,并在合成的含噪地震数据上分别利用相干属性、常规U-Net网络方法及改进的U-Net网络方法进行测试,构造导向滤波有效突出了断层的边界,且增强了同相轴的横向连续性,改进后的U-Net网络方法对于7 m以上断距的断层可进行有效识别。(3)对于玛湖凹陷玛中地区三叠系白碱滩组高角度走滑断裂和伴生小断距次级断裂的识别,改进后的U-Net网络方法的识别精度明显高于相干属性和常规U-Net网络方法,研究区大侏罗沟断裂北翼的(3)号与(4)号砂体,是拓展MZ4井区三叠系白碱滩组高效勘探的有利区。

术中耳蜗电图监测在脑桥小脑角区胆脂瘤切除术中的应用

目的 分析术中耳蜗电图(ECochG)监测信息与术后美国耳鼻咽喉头颈外科学会(AAO-HNS)听力功能分级及听力残疾量表(HHI)之间的关系。方法 回顾性分析中日友好医院神经外科2019年3月—2022年3月收治的86例脑桥小脑角(CPA)区胆脂瘤患者的临床资料。所有患者均采用乙状窦后入路切除CPA区胆脂瘤,在术中ECochG的监测下完成肿瘤的完整切除。依据术中ECochG监测信息中动作电位(AP)波幅下降>30%与否分为两组,AP波幅下降>30%组和AP波幅下降≤30%组,分析两个组与术后听力功能障碍及听力残疾程度的关系。结果 AP波幅下降>30%组患者术后存在听力功能障碍,并且在随访3个月、1年和2年后,患者的听力功能障碍持续存在,且有统计学差异(P<0.001)。AP波幅下降>30%组患者术后存在不同程度的听力残疾,在随访3个月、1年和2年后,患者的HHI情绪相关(subtotal-E)及社会相关(subtotal-S)的听力残疾持续存在,有统计学差异(P<0.001);HHI subtotal-E及subtotal-S相关的残疾程度会逐渐加重,有统计学差异(P<0.05)。结论 术中AP波幅下降>30%的患者在CPA区胆脂瘤术后存在永久听力障碍,其术后subtotal-E及subtotal-S相关的听力残疾程度会逐渐加重。

11例表皮样囊肿继发面肌痉挛患者临床特征及预后分析

目的原发性面肌痉挛(HFS)是由面神经根出脑干区(REZ)处血管压迫引起的。而目前关于桥小脑角肿瘤尤其是表皮样囊肿引起的继发性HFS报道较少,且其具体机制尚不明确。本文研究旨在描述表皮样囊肿继发性HFS患者的临床和术中特点,提供治疗建议。方法回顾2010—2022年航空总医院收治的3950例HFS患者,对其中11例HFS合并表皮样囊肿患者进行了回顾性分析,重点分析其症状、肿瘤和血管之间的关系。结果所有患者均接受表皮样囊肿切除术,平均随访时间为45个月。11例患者中8例实现肿瘤全切除、3例实现次全切除,所有患者在随访期间均未出现复发情况。7例面神经REZ被动脉压迫,肿瘤切除后用聚四氟乙烯完全减压。9例患者术后症状立即缓解,2例无动脉压迫症状逐渐好转,2个月后痊愈。结论HFS可能是桥小脑角表皮样囊肿的最初症状,本组病例多为肿瘤和面神经REZ处的动脉共同压迫所致。为了彻底缓解症状,建议肿瘤切除后常规探查面神经根血管压迫情况。