Malignant schwannoma of the intrathoracic vagus nerve: Report of a case

We report herein the case of a 48-year-old man with malignant schwannoma of the intrathoracic vagus nerve associated with von Recklinghausen's disease. Malignant intrathoracic vagal tumors are extremely rare and to our knowledge, only four other cases have been documented in the literature, none of which were associated with von Recklinghausen's disease.     

Malignant schwannoma in the posterior tibial nerve

Our group have studied a patient affected by a malignant schwannoma in the posterior tibial nerve. Schwannomas are uncommon neoplasms that originate from the Schwann cells of the peripheral nerves: the most common forms are benign. Malignant transformation is rarer. The therapy is surgical and the operation undertaken, if possible, should be the amputation. Alternatively, where amputation is not possible due to the specific localisation or due to patient refusal, the alternative must be the largest and most radical excision possible.     

Plexiform schwannoma of the ulnar nerve

Plexiform schwannoma is a rare benign neurogenic tumour; we report a case that arose in the ulnar nerve of a 59-year-old woman. Exploration showed a continuous multinodular tumour that involved the ulnar nerve from the hand to the upper arm; the length of the tumour was 35 cm.     

Greater superficial petrosal nerve schwannoma

Summary Greater superficial petrosal nerve (GSPN) schwannoma is a very rare type of facial nerve schwannoma. Including our case, only 6 schwannomas have been reported to originate from the GSPN. Clinical features, imaging, diagnosis, differential diagnosis and treatment are discussed reviewing other cases in the pertinent literature.     

A case of schwannoma of the intrathoracic vagus nerve]

A 42-year-old female was noted to have a mediastinal mass on routine chest roentgenogram. She was asymptomatic and physical examination was unremarkable. Computed tomography of the chest confirmed the presence of a 3.5 cm well circumscribed mass in the middle mediastinum adjacent to the aortic arch. Operation was performed. A solitary middle mediastinal tumor was readily apparent at the aortic arch to the left subclavian artery, originating from the vagus nerve superior to the take-off of the recurrent laryngeal nerve. Excision was possible by enucleation of the mass. The postoperative period was uneventful, although there was paralysis of the left vocal cord as evidenced by hoarseness. Histologically the diagnosis of a schwannoma of the vagus nerve was made.     

Management of vagus nerve stimulation therapy in the peri-operative period

Vagus nerve stimulation is a well-established treatment option for patients with drug-resistant epilepsy and has an expanding range of other clinical indications. Side effects of vagus nerve stimulation therapy include: cough; voice changes; vocal cord adduction; rarely, obstructive sleep apnoea; and arrhythmia. Patients with implanted vagus nerve stimulation devices may present for unrelated surgery and critical care to clinicians who are unfamiliar with their function and safe management. These guidelines have been formulated by multidisciplinary consensus based on case reports, case series and expert opinion to support clinicians in the management of patients with these devices. The aim is to provide specific guidance on the management of vagus nerve stimulation devices in the following scenarios: the peri-operative period; peripartum period; during critical illness; and in the MRI suite. Patients should be aware of the importance of carrying their personal vagus nerve stimulation device magnet with them at all times to facilitate urgent device deactivation if necessary. We advise that it is generally safer to formally deactivate vagus nerve stimulation devices before general and spinal anaesthesia. During periods of critical illness associated with haemodynamic instability, we also advise cessation of vagus nerve stimulation and early consultation with neurology services.     

Hardware failure in vagus nerve stimulation therapy

Summary A 20 year old male patient who had been successfully treated for epilepsy with vagus nerve stimulation (VNS) for 7 years (50% seizure frequency reduction), had experienced multiple episodes of severe hoarseness, throat pain and impaired breathing during physical exercise. As malfunctioning of the pulse generator was suspected, it was decided to replace the device. During surgery, the pulse generator was found to have broken in two, due to an unstable connection between the battery subunit and the connector subunit. With a new pulse generator seizure frequency reduction was restored. No side effects occurred. Correspondence: Kim Rijkers, M.D., Department of Neurosurgery, Maastricht University Hospital, PO BOX 5800, 6202 AZ Maastricht, The Netherlands.     

无创迷走神经刺激的临床应用进展

迷走神经活性的调节影响大脑和身体之间的信息传递过程及生理状态。无创迷走神经刺激（nVNS）通过刺激耳迷走神经或颈部迷走神经对多个器官和系统产生保护作用,远程调节机体功能。近年来nVNS在预防及治疗神经系统疾病、自身免疫相关性疾病及心血管系统疾病中取得重大进展。本文对nVNS及相关技术的应用研究进展进行综述,为进一步探索nVNS在围术期的应用提供参考。     

Revision and removal of stimulating electrodes following long-term therapy with the vagus nerve stimulator

BACKGROUND

A significant concern about vagus nerve stimulation therapy has been the disposition of the spiral stimulating electrodes once treatment is considered ineffective or is no longer desired. Because the electrodes are wrapped around the vagus nerve, there is the potential for nerve injury during their removal.

METHODS

We attempted removal of the spiral stimulating electrodes from 10 patients who received long-term vagus nerve stimulation therapy for drug-resistant epilepsy. In some patients, replacement with electrodes was also performed for poorly functioning leads.

RESULTS

The mean duration of electrode implantation was 3.7 ± 2.2 years (range 1.1–7.3 years). In seven patients, the old electrodes were removed completely from the nerve. No adverse events occurred intraoperatively or postoperatively.

CONCLUSIONS

Our results indicate that the spiral electrodes may be safely removed from the vagus nerve, even after the electrodes have been implanted for several years. The reversibility of lead implantation may enhance the attractiveness of vagus nerve stimulation therapy for patients with medically-intractable epilepsy.     

以低强度聚焦超声刺激大鼠迷走神经的安全性

目的 观察以低强度聚焦超声（LIFU）刺激大鼠迷走神经的安全性。方法 将12只雄性SD大鼠随机均分为刺激A、B、C组和假刺激组（D组）,每组3只。以装配适宜准直器的超声刺激系统,分别以1.05、3.87及4.25 MPa声压对A、B、C组大鼠左侧迷走神经行LIFU刺激,脉冲重复频率、占空比及刺激方式均相同;对D组大鼠将超声换能器定位于左侧颈部但不予刺激。记录LIFU刺激前、中、后4组大鼠心率及颈部局部温度变化。结束刺激后对C、D组采集MR T2WI,取迷走神经,观察有无病理改变。结果 LIFU刺激前5 min、刺激中及刺激后5 min,4组间心率差异均无统计学意义（P 均＞0.05）。A、B、C、D组换能器下方局部区域温度分别为28.1～30.1 ℃、28.3～30.3 ℃、27.9～30.4 ℃及27.8～30.2 ℃,温度波动均小于2.5 ℃。T2WI显示C、D组大鼠颈部软组织无明显异常;2组大鼠迷走神经均未见明显病理改变。结论 以特定参数LIFU刺激大鼠迷走神经的安全性较好。     

完整迷走神经刺激对大鼠全身炎性反应的影响

目的 了解完整迷走神经刺激(IVNS)对大鼠全身炎性反应的影响. 方法以内毒素血症为全身炎性反应模型.将100只SD大鼠随机分为A组[静脉注射内毒素/脂多糖(LPS)]、B组(切断迷走神经、注射LPS后对其远端行电刺激)、C组(注射LPS后行迷走神经干电刺激)、D组(除注射等量等渗盐水外,同C组处理)、E组(仅注射等量等渗盐水).于注射前及注射后2、4、6 h,观察血清肿瘤坏死因子α(TNF-α)、白细胞介素10(IL-10)水平变化.每组取5只大鼠测定平均动脉压(MAP). 结果注射后10 min,前3组大鼠MAP值显著升高(P<0.05),以A组最明显[(134.4±7.3)mm Hg,1 mm Hg=0.133 kPa,P<0.05];注射后30 min,前3组MAP值明显下降(P<0.05);注射后10 min～6 h,A组MAP值均明显低于B、c组(P<0.05).注射后2、4、6 h,B、C组血清TNF-α水平均明显低于A组(P<0.05).注射后4、6 h,C组大鼠IL-10水平显著高于A、B组(P<0.05).结论 IVNS能稳定全身炎性反应时的血流动力学指征,并具有抗炎效应.     

Ancient schwannoma of the hand

Ancient schwannoma is a schwannoma subtype, characterized by extensive degeneration and diffuse hypocellular areas. These changes are believed to occur because it takes a long time for ancient schwannomas to develop. Schwannomas with these degenerative changes can be misdiagnosed as sarcomas or other soft-tissue neoplasms. We present a case of a slowly enlarging ancient schwannoma of the thenar area in a 67-year-old woman. The differential diagnosis included atypical soft tissue sarcomas and tumors of neural origin. The combination of ultrasound and magnetic resonance imaging findings provided features that narrowed the differential diagnosis, and histology confirmed the presence of an encapsulated schwannoma with extensive myxomatous degeneration and multiple vessel thrombosis. The clinical, radiological, and histological features and the diagnostic approach of this rare entity are described.     

Facial nerve function and hearing preservation after retrosigmoid excision of vestibular schwannoma: Christchurch Hospital experience with 97 patients

BACKGROUND: Between January 1988 and December 2002, 97 patients underwent surgery for excision of vestibular schwannoma via the retrosigmoid approach at Christchurch Hospital. METHODS: A retrospective review was undertaken of the clinical notes with emphasis on facial nerve function and hearing preservation postoperatively. RESULTS: Of patients with small and medium-sized tumours, 81% had good facial nerve function at 1 year (House-Brackmann grade 1 and grade 2), 16% had moderate function (grade 3 and grade 4) and 3% had poor function (grade 5). Of patients with large tumours, 22% had good facial function (grade 1 and grade 2), 37% had moderate function (grade 3 and grade 4) and 41% had poor function (grade 5 and grade 6). Useful postoperative hearing was preserved in 21% of the 47 patients with tumours <3 cm and useful preoperative hearing. In the last 5 years the authors have been operating in conjunction with an ear, nose and throat surgeon (PAB) trained in base-of-skull surgery. Over this period, useful hearing was preserved in 32% of patients with small and medium-sized tumours and useful preoperative hearing. CONCLUSIONS: Tumour size was an important predictor of the postoperative facial and cochlear nerve function. The multidisciplinary approach to these tumours offers better results. These results compare well with other published series.     

Papillary Carcinoma in A Huge Intrathoracic Goiter with Tracheal Stenosis and Invasion

A rare case in tracheal invasion by a papillary carcinoma in an intrathoracic goiter is reported. Subtotal thyroidectomy and tracheoplasty were performed. Surgery should be considered as first-line treatment of intrathoracic goiter in order to avoid future compression of the respiratory tract and to remove possible concomitant malignant lesion.