Cavernous malformation of the hypoglossal nerve: case report and review of the literature

OBJECTIVE: To describe a patient who presented with a hypoglossal nerve palsy caused by a cavernous malformation, review the literature on cavernous malformations associated with cranial nerves and the differential diagnosis of hypoglossal palsy. RESULTS: Partial resection of the lesion was achieved and the diagnosis of cavernous malformation proven histologically. CONCLUSIONS: Involvement of a cranial nerve by a cavernous malformation is very uncommon and the facial nerve is the example most frequently reported. This case report adds another possible site for this rare occurrence.     

Cavernous malformation of the trigeminal nerve

A cavernous malformation involving the Gasserian ganglion, 2nd and 3rd divisions of the trigeminal nerve on the left side was resected via an extradural route in a 54 year old male. Cavernous malformations of the cranial nerves are rare. Specific origin from the trigeminal nerve has not been previously reported.     

Brainstem cavernous malformations: Natural history versus surgical management

While brainstem cavernous malformations were once considered inoperable, improvements in patient selection, surgical exposures, intraoperative MRI-guidance, MR tractography, and neurophysiologic monitoring have resulted in good outcomes in the majority of operated patients. In a consecutive series of 104 patients with brainstem cavernous malformations, only 14% of patients experienced cranial nerve or motor dysfunction that was worse at late follow-up, relative to their preoperative condition. Outcomes were predicted by several factors, including larger lesion size, lesions that crossed the midline, the presence of a developmental venous anomaly, older age, and greater time interval from lesion hemorrhage to surgery. The 14% of patients who experienced a persistent neurological deficit as a result of surgery, while substantial from any perspective, compares favorably with the risks of observation based on a recent meta-analysis. Curative resection is a safe and effective treatment for brainstem cavernous malformations that will prevent re-hemorrhage in symptomatic patients.     

颅脑手术中神经电生理功能监测661例效果评估

目的 总结术中神经电生理功能监测的经验,分析监测结果与患者预后的关系及影响因素。方法 使用美国Nicolet公司生产的Viking-IV型和Axon公司的EpochXP型监测仪,共对661例手术患者进行了术中神经电生理功能监测。其中听神经瘤220例,颈动脉狭窄237例（249侧）,颅内动脉瘤64例,脑干肿瘤21例,其他桥小脑病变47例,垂体瘤45例,颈静脉孔区肿瘤12例,侵犯海绵窦肿瘤15例。结果 通过诱发肌电图、EEG、SEP、ABR、F-VEP及MEP的监测,可以准确判断颅神经的位置或脑实质的功能状态,颅神经的监测可以最大程度避免颅神经的损伤,长束功能监测可以提供神经系统的整体功能状态,如脑供血的情况、功能区脑灌注状态。结论 术中神经功能的监测,对神经外科手术的安全性提供了一定的保障,减少了手术的风险。使用得当可降低手术的致残率,应该成为神经外科手术的常规工作。     

Monitoring of motor pathways during brain stem surgery: What we have achieved and what we still miss?

Intraoperative neurophysiological monitoring (IOM) has established itself as one of the paths by which modern neurosurgery can improve surgical results while minimizing morbidity. IOM consists of both monitoring (continuous "on-line" assessment of the functional integrity of neural pathways) and mapping (functional identification and preservation of anatomically ambiguous nervous tissue) techniques. In posterior-fossa and brainstem surgery, mapping techniques can be used to identify - and therefore preserve - cranial nerves, their motor nuclei and corticospinal or corticobulbar pathways. Similarly, free-running electromyography (EMG) and muscle motor-evoked potential (mMEP) monitoring can continuously assess the functional integrity of these pathways during surgery. Mapping of the corticospinal tract, at the level of the cerebral peduncle as well as mapping of the VII, IX-X and XII cranial nerve motor nuclei on the floor of the fourth ventricle, is of great value to identify "safe entry-zones" into the brainstem. Mapping techniques allow recognizing anatomical landmarks such as the facial colliculus, the hypoglosseal and glossopharyngeal triangles on the floor of the fourth ventricle, even when normal anatomy is distorted by a tumor. On the basis of neurophysiological mapping, specific patterns of motor cranial nuclei displacement can be recognized. However, brainstem mapping cannot detect injury to the supranuclear tracts originating in the motor cortex and ending on the cranial nerve motor nuclei. Therefore, monitoring techniques should be used. Standard techniques for continuously assessing the functional integrity of motor cranial nerves traditionally rely on the evaluation of spontaneous free-running EMG in muscles innervated by motor cranial nerves. Although several criteria have been proposed to identify those EMG activity patterns that are suspicious for nerve injury, the terminology remains somewhat confusing and convincing data regarding a clinical correlation between EMG activity and clinical outcome are still lacking. Transcranial mMEPs are also currently used during posterior-fossa surgery and principles of MEP monitoring to assess the functional integrity of motor pathways are similar to those used in brain and spinal-cord surgery. Recently, current concepts in muscle MEP monitoring have been extended to the monitoring of motor cranial nerves. So-called "corticobulbar mMEPs" can be used to monitor the functional integrity of corticobulbar tracts from the cortex through the cranial motor nuclei and to the muscle innervated by cranial nerves. Methodology for this purpose has appeared in the literature only recently and mostly with regards to the VII cranial nerve monitoring. Nevertheless, this technique has not yet been standardized and some limitations still exist. In particular, with regards to the preservation of the swallowing and coughing reflexes, available intraoperative techniques are insufficient to provide reliable prognostic data since only the efferent arc of the reflex can be tested.     

Cavernoma of the trochlear nerve

Here we present the case of a 53-year old man with progressive double vision due to isolated left trochlear nerve palsy. Cranial magnetic resonance imaging (MRI) showed a small tumor within the left quadrigeminal cistern that did not increase in size after several months. Explorative neurosurgical intervention revealed a left trochlear nerve cavernoma. The lesion was microsurgically excised followed by end-to-end anastomosis of the trochlear nerve. After a one-year follow up, double vision totally disappeared and cranial MRI showed no recurrence. Cerebral cavernous malformations usually become symptomatic in seizures or focal neurological deficits after intracerebral hemorrhage. Rarely, cavernomas arise from cranial nerves. To the authors' knowledge, this is the first report on a symptomatic cavernous malformation arising from the trochlear nerve and on its successful surgical management.     

脑干血管畸形的显微手术治疗(附19例报告)

目的 探讨脑干血管畸形的显微外科手术治疗方法和预后.方法 显微手术切除脑干血管畸形19例.6例经枕下正中第四脑室底入路切除;9例经枕下乙状窦后入路切除;3例经小脑延髓裂入路切除;1例经枕下正中入路上抬蚓垂后切除.结果 19例病灶均镜下全切,其中海绵状血管瘤15例,动静脉畸形4例.13例症状改善,5例出现并发症,1例因下呼吸道感染死亡.随访中GOS 5分15例,GOS 4分2例,GOS 3分1例.MRI复查无病灶残留.结论 在恰当选择手术适应证、手术时机和手术入路的基础上,运用娴熟的显微外科技术,脑干血管畸形的手术治疗结果是令人满意的.

Abstract：

Objective To investigate the microsurgical treatment of brainstem vascular malformation and evaluate the surgical outcome. Method Brain stem vascular malformations in 19 cases were resected by microsurgical techniques. Six cases of cavernous malformations ( CM ) in the dorsal of pons and medulla underwent operations via through the base of the forth ventrical approach. Another nine cases of CM in lateral and ventral lateral pons were treated via suboccipito - retrosigmoid approach. Three cases of arteriovenous malformation(AVM) in cerebellomedullary fissure were treated via telovelar approach. One case of AVM in the dosal medulla were resected via transvermian approach. Results All the lesions were totally resected. Pathologic diagnosis were CM( 15 cases) and AVM(4 cases). The diameter of all the CM were less than 1 centimeter. One AVM was 1.5 centimeter in diameter, the other two lesions was 2. 0 centimeter, the last one was 2. 5 centimeter. The functional disorders were improved after operation in 13 cases. Complications appeared in five patients, which improved between one week and three months. One patient died of sever pneumonia. During two months to six years after operation, the brainstem vascular malformation didn't recrudesce and re - bleed. No one patient appeared new syndromes. Conclusions The microsurgical management of brainstem vascular malformation can effectively prevent re - bleeding. Selecting different surgical approach basing on the locations can reduce the neurofunction damage. In order to accelerate the recovery of damaged brainstem, early surgery should be choosen for the patients with surgical indications. Basing on the correct choice of surgical indications, using the extensive knowledge of microanatomy,new concept of minimal invasive surgery and skillful microsurgical techniques, the surgical results of brainstem vascular malformation are satisfactory.     

Meningiomas of the cavernous sinus: the surgical resectability and complications

The optimal management for patients with cavernous sinus meningiomas is to evacuate tumor without causing mortality or morbidity. The records of 16 patients, including 11 women and 5 men ranging in age from 31 to 63 years, underwent surgical treatment for this condition were reviewed. Completeness of tumor resection, cranial nerve morbidity, complications, mortality, the internal carotid artery encasement and outcome were studied. Total removal was achieved in six patients. Of ten patients who underwent subtotal resection there was one death and four were sent to radiotherapy. Morbidity was 24% for cranial nerves controlling extraocular motor function; trigeminal nerve function did not improve after surgical treatment. Symptomatic recurrence occurred in two patients who underwent subtotal tumor resection and in one who underwent complete tumor resection. The average follow-up period was of 26 months. According to our findings, we conclude: 1) the resectability of meningiomas of cavernous sinus depends on the degree of internal carotid artery involvement; 2) total resection of meningiomas confined in cavernous sinus is rare; 3) morbidity of the cranial nerves is significant; 4) subtotal resection is an effective mean to obtain control of the disease.     

额颞颧入路海绵窦眶尖肿瘤切除及脑神经保护

目的探讨海绵窦眶尖肿瘤显微手术及脑神经保护的方法。方法回顾性分析8例海绵窦眶尖肿瘤临床资料,均采用额颞颧入路显微神经外科手术切除肿瘤及神经电生理检测保护脑神经,术后定期随访。结果肿瘤全切除4例,次全切2例,大部分切除1例,活检1例。脑神经继发损伤症状出现率22%,脑脊液漏1例,无脑内感染及死亡病例。结论掌握海绵窦眶尖区解剖及熟练的显微神经外科技术,再加上神经电生理检测保护脑神经,可提高肿瘤切除程度,减少脑神经继发损伤。     

非海绵窦区硬膜海绵状血管畸形2例报道并文献复习

目的 探讨非海绵窦区硬脑膜海绵状血管畸形的影像学特点、诊断及治疗。方法 回顾性分析2例经术后病理证实的非海绵窦区硬脑膜海绵状血管畸形的临床资料，结合相关文献进行分析。结果 1例术前考虑大脑镰旁脑膜瘤，另1例术前考虑左侧横窦及天幕脑膜瘤。2例病灶均全切除，术后病理均证实为硬脑膜海绵状血管畸形，术后均恢复良好，未出现手术并发症，无需放疗等后续治疗。术后随访1年以上无复发。结论 非海绵窦区硬膜海绵状血管畸形极少见，容易误诊为脑膜瘤。手术切除时，应先阻断肿瘤位于硬膜或静脉窦的肿瘤基底，并尽量整块切除，否则可能遭遇汹涌的出血。该类疾病手术往往可安全有效的全切除病变，预后良好。     

脑干海绵状血管瘤的显微外科治疗(附10例报告)

目的分析脑干海绵状血管瘤的显微外科治疗方法和预后。方法显微手术切除脑干海绵状血管瘤10例,病灶位于桥脑8例,延髓2例。6例桥脑、延髓背侧的海绵状血管瘤,采用枕下正中经四脑室底入路切除; 4例桥脑外侧和腹外侧的海绵状血管瘤,采用枕下乙状窦后入路切除。结果病灶均镜下全切除,病理证实为海绵状血管瘤。4例患者术后症状明显改善,5例患者出现不同程度并发症,在1周至3个月内恢复,1例患者术后因肺内感染死亡。患者术后随访3-58个月,复查MRI均未发现病灶复发,无其他并发症出现。结论在正确选择适应证的前提下,脑干海绵状血管瘤的显微外科治疗效果良好。     

Seizure outcome after resection of cavernous malformations is better when surrounding hemosiderin-stained brain also is removed

PURPOSE: Considering the epileptogenic effect of cavernoma-surrounding hemosiderin, assumptions are made that resection only of the cavernoma itself may not be sufficient as treatment of symptomatic epilepsy in patients with cavernous malformations. The purpose of this study was to test the hypothesis whether seizure outcome after removal of cavernous malformations may be related to the extent of resection of surrounding hemosiderin-stained brain tissue. METHODS: In this retrospective study, 31 consecutive patients with pharmacotherapy-refractory epilepsy due to a cavernous malformation were included. In all patients, cavernomas were resected, and all patients underwent pre- and postoperative magnetic resonance imaging (MRI). We grouped patients according to MRI findings (hemosiderin completely removed versus not/partially removed) and compared seizure outcome (as assessed by the Engel Outcome Classification score) between the two groups. RESULTS: Three years after resection of cavernomas, patients in whom hemosiderin-stained brain tissue had been removed completely had a better chance for a favorable long-term seizure outcome compared with those with detectable postoperative hemosiderin (p=0.037). CONCLUSIONS: Our study suggests that complete removal of cavernoma-surrounding hemosiderin-stained brain tissue may improve epileptic outcome after resection of cavernous malformations.     

两种不同入路手术治疗海绵窦区肿瘤

目的探讨海绵窦区肿瘤切除的手术入路,以提高手术全切率,降低残障率.方法对14例海绵窦内肿瘤行硬膜下入路切除5例,行硬膜外入路切除9例,比较两种入路的方法及疗效.结果行硬膜下入路者中全切除2例,大部切除3例;术后出现新的神经功能障碍4例.行硬膜外入路者中全切除5例,次全切除3例,大部切除1例;术后出现新的脑神经功能障碍3例,其中1例完全恢复.结论针对不同类型的肿瘤及生长特性,选择适当的手术入路和显微神经外科技术,可有效提高全切率,降低残障率.     

巨大海绵窦海绵状血管瘤的硬膜内入路显微外科治疗

目的探讨巨大海绵窦海绵状血管瘤(cavernous sinus cavernous hemangiomas,CSHs)的临床特征及显微外科治疗方法,为CSHs的治疗提供临床经验。方法回顾性分析2009年1月—2018年12月解放军东部战区总医院神经外科收治的15例CSHs患者的临床及随访资料;分析患者的临床表现、颅神经受累情况、手术方式、术后并发症及随访结果。结果15例CSHs患者占同期收治的颅内海绵状血管瘤(CHs)患者的5.6%。临床表现为头痛者11例、视神经损害者5例、动眼神经损害者6例、面部感觉异常者2例、肢体无力者1例。15例患者通过扩大翼点、翼点或颞前小切口入路经硬膜内切除血管瘤,均完整切除;无死亡病例。10例患者术后出现同侧Ⅲ、Ⅳ、Ⅴ及Ⅵ神经部分麻痹。术后获得随访的患者9例,随访时间5~117个月,平均48.9个月,均无肿瘤复发表现;其中4例患者遗留长期海绵窦颅神经功能障碍。结论CSHs多具备特征性影像学表现,术前多可明确诊断。经硬膜内入路手术切除是治疗巨大CSHs的有效方法,术中应尽量按界限整块切除,以减少出血。海绵窦内神经功能的保留仍是目前巨大CSHs手术治疗的难点。     

桥小脑角肿瘤术中面、听神经监护

目的研究术中监护下桥小脑角肿瘤显微镜下切除的临床疗效。方法在41例桥小脑角肿瘤切除手术中,均进行脑干听觉诱发电位和面神经肌电图监护。结果肿瘤全切除者33例,次全切除者7例,大部切除者1例。41例患者均达到了面神经解剖保留,27例(65.9%,27/41)患者保留听力,其中14例为听神经瘤,占听神经瘤的56.0%(14/25)。结论术中脑干听觉诱发电位和面神经肌电图监护对于桥小脑角肿瘤切除术有重要的临床价值。     

Malformation vasculaire cérébrale découverte dans le bilan pré-thrombolyse d’un infarctus cérébral. Impact sur la décision thérapeutique

Intravenous recombinant tissue plasminogen activator for acute ischemic stroke is contraindicated in patients harboring an asymptomatic intracranial vascular malformation, whether it is incidentally discovered at the time of the initial cerebral imaging or previously known. Because thrombolysis is associated with a risk of serious intracerebral hemorrhage, it is theoretically possible that this treatment increases the risk of bleeding or rupture of these malformations. However, this risk seems very low in clinical practice. We report two cases, one with a probable brainstem cavernous malformation treated with alteplase for a supratentorial ischemic stroke who developed just after treatment a fatal brainstem hemorrhage, and another one with asymptomatic dural arteriovenous fistula, treated by endovascular thrombectomy solely. This approach was safe and effective, and the patient had an endovascular embolization of the fistula one month later as it became symptomatic. Based on the literature, we discuss the bleeding risk of asymptomatic intracranial vascular malformations in acute ischemic stroke patients treated with alteplase, depending on the type of malformation (intracranial aneurysm, arteriovenous and cavernous malformation or fistula), and the alternative therapeutic options.     

脑干海绵状血管瘤手术入路选择

目的探讨脑干海绵状血管瘤手术适应证和手术入路的选择。方法回顾分析70例手术治疗的脑干海绵状血管瘤，其中位于：中脑15例、中脑-桥脑交界8例、桥脑34例、桥脑-延髓交界5例、延髓8例。我们共采用8种手术入路：经菱形窝27例、颞下或颞-枕入路14例、远外侧经髁7例、外侧小脑上幕下7例、中线小脑上幕下8例、枕经天幕4例、乳突后2例，以及眶颧1例。结果本组病例的年出血率为2．9％（77／2364），占同期颅内海绵状血管瘤的44％（70／159）；97％的病例手术选择在亚急性或慢性期、且所有患者均有颅神经症状和（或）运动功能障碍、感觉障碍、共济失调（包括失平衡）。中脑病变手术入路选择以中线小脑上（46．7％，7／15）、颞下或颞-枕（26．7％，4／15）为主；桥脑病变多选择菱形窝（58．8％，20／34）、颞下或颞-枕（23．5％，8／34）；而病变位于延髓者以远外侧经髁（62．5％，5／8）和菱形窝入路（37．5％，3／8）为主。结论脑干海绵状血管瘤表现为进行性神经功能缺失、具有占位效应、接近脑干表面者可考虑手术治疗；个体化地选择手术入路、术中神经电生理监测以及直接的电刺激是手术成功的关键。     

Radicular lesions in tuberculous meningitis. A clinicopathological study

In the present work, the involvement of cranial and spinal nerve roots in tuberculous meningitis was studied. Cranial nerves of 11 cases and the spinal roots of three patients were examined by means of serial sections of the base of the brain, brainstem and spinal cord. Although entrapment of the nerves by the tenacious inflammatory exudate was prominent, vasculitis lesions of the cranial nerves and spinal roots were also frequently observed. The latter could be an additional cause of nerve palsies in tuberculous meningitis.     

术中肌电监测在累及第四脑室底肿瘤手术中的应用

目的探讨术中肌电监测在累及第四脑室底面肿瘤切除术中的应用及影响因素。方法南方医科大学南方医院神经外科自2007年1月至2010年12月在后组颅神经肌电监测下完成累及第四脑室底面肿瘤切除术32例,其中髓母细胞瘤11例,第四脑室室管膜瘤9例,脑干海绵状血管瘤6例,脑干起源外生性胶质瘤4例,脑干背侧血管网状细胞瘤2例。分析术中肌电监测对手术效果的影响及其干扰因素。 结果 本组肿瘤全切除21例,次全切除9例,大部切除2例;无后组脑神经功能障碍9例,轻度后组颅神经损伤18例,中度后组颅神经损伤5例,无严重损伤者。肌电监测结果的干扰因素主要包括双极电凝产生的外泻电流、肌松药物的过多使用、麻醉深度的改变、以及患者体温、冲洗盐水温度、血压急剧变化等。 结论术中肌电监测可以为累及第四脑底面肿瘤切除术中颅神经核团的位置及功能保护提供客观依据。     

脑多发海绵状血管畸形的手术治疗

目的脑多发海绵状血管畸形手术治疗报道少见,探讨脑多发海绵状血管畸形患者的临床特征及手术治疗效果。方法回顾分析39例手术治疗脑多发海绵状血管畸形病例,采用改良MRS评分对患者神经功能状态进行评估。配对T检验对术前与随访时MRS评分进行比较,用Pearson相关分析对年龄、病变数量、术前MRS评分等对预后的影响因素进行相关性分析。结果 1例小脑脚海绵状血管畸形患者术后出现不全性面瘫,1例桥脑病变患者术后出现肢体偏瘫,经治疗后均逐渐好转。平均随访29.5月,无再次出血患者。随访时16例(41%)患者神经功能状态较术前明显改善,23例(59%)较前无变化,无病情加重患者。经统计学分析,术前与随访时MRS评分比较P=0.01,有统计学意义。性别、年龄、首发症状距手术时间、病变数量、出血次数、随访时间与预后不相关。手术病变部位(P=0.02)及术前MRS(P=0.01)与预后相关。结论脑多发海绵状血管畸形患者行致病病变切除多数患者效果良好,手术病变部位及术前MRS是影响预后的相关因素。