Orthostatic hypotension after cervicomedullary junction surgery: illustrative case

BACKGROUND Surgery at the cervicomedullary junction carries a risk of damaging vital brainstem functions. Because the nucleus of the solitary tract (NS) is involved in the baroreceptor reflex, damage to its integrity may lead to orthostatic hypotension. OBSERVATIONS A 56-year-old man with a medical history of hypertension, von Hippel-Lindau disease, and previous bilateral adrenalectomy due to pheochromocytoma was referred with symptoms of dysphagia and paralysis of the left vocal cord. Paralysis of the left vagus nerve was suspected. Magnetic resonance imaging revealed a contrast-enhancing cystic process in the cervicomedullary junction. Twenty-three years earlier, the patient had undergone surgical treatment for a hemangioblastoma in the same region. After repeated surgery, the patient temporarily developed orthostatic hypotension. At discharge, the patient no longer needed antihypertensive medication. LESSONS Surgery near the cervicomedullary junction can affect the NS, leading to disruption of the baroreceptor response that regulates blood pressure.

An Extremely Rare Case of Primary Anterior Mediastinal Tumor

Background: There were very few reports of atypical carcinoid in anterior mediastinum. Atypical carcinoids originating in the mediastinum belong to a neuroendocrine tumor (NET), which is also a very rare clinically aggressive mediastinal tumor. Case presentation: We herein reported a rare case of NET of mediastinal origin and a review of several cases concerning the clinical and pathological features of this disease, which is often misdiagnosed as atypical carcinoid tumor in mediastinum. The tumor was removed by mid-sternal thoracotomy with superior vena cava formation, left common carotid artery resection and artificial blood vessel replacement, left upper lobe wedge resection, left phrenic nerve resection, left vagus nerve resection and partial pericardectomy.Conclusions: To the best of our knowledge, this is the sixth atypical carcinoid occurring in mediastinum with proof via histology and IHC. Our findings suggest the difficulty of making a diagnosis before surgery and more cases will need to be reported in order to facilitate the preoperative diagnosis of such a rare tumor.

Unilateral vocal cord adductor weakness: an atypical manifestation of motor neurone disease

BackgroundBulbar involvement is a recognised feature of motor neuron disease/amyotrophic lateral sclerosis (MND/ALS), both as a presenting complaint and as a consequence of advancing disease. Hoarseness and dysphonia have been associated with vocal cord abductor weakness. This is usually bilateral and has also been reported as the presenting clinical feature in a handful of patients with superoxide dismutase 1 (SOD1) gene mutations. Presentation with an isolated, unilateral vocal cord adductor weakness, however, is atypical and rare.CaseIn this report, we detail the case of a 38-year-old woman with dysphonia and a family history of an SOD1 mutation. Neurological features remained confined to the territory of the left vagus nerve for the next 12 months, before a more rapid rate of disease dissemination and progression.ConclusionsThis case highlights the importance of recognition of vocal cord palsy as an early manifestation of MND/ALS and the critical need for monitoring to recognise potential disease progression.

Complete section of the left vagus nerve does not preclude the efficacy of vagus nerve stimulation: illustrative case

BACKGROUND Vagus nerve stimulation (VNS) represents a valid therapeutic option for patients with medically intractable seizures who are not candidates for epilepsy surgery. Even when complete section of the nerve occurs, stimulation applied cranially to the involved nerve segment does not preclude the efficacy of VNS. Complete vagus nerve section with neuroma causing definitive left vocal cord palsy has never been previously reported in the literature. OBSERVATIONS Eight years after VNS implant, the patient experienced worsening of seizures; the interrogation of the generator revealed high impedance requiring surgical revision. On surgical exploration, complete left vagus nerve section and a neuroma were found. Vocal cord atrophy was found at immediate postoperative laryngeal inspection as a confirmation of a longstanding lesion. Both of these events might have been caused by direct nerve injury during VNS surgery, and they presented in a delayed fashion. LESSONS VNS surgery may be complicated by direct damage to the left vagus nerve, resulting in permanent neurological deficits. A complete section of the nerve also enables an efficacious stimulation if applied cranially to the involved segment. Laryngeal examination should be routinely performed before each VNS surgery to rule out preexisting vocal cord dysfunction.

Vagus Nerve Cross-Sectional Area in Patients With Parkinson's Disease—An Ultrasound Case-Control Study

Background: Vagal parasympathetic neurons are prone to degeneration in Parkinson's disease (PD). High-resolution ultrasound can precisely estimate the cross-sectional (CSA) area of peripheral nerves. Here, we tested the hypothesis that vagus CSA is reduced in PD.Methods: We included 56 healthy controls (HCs) and 63 patients with PD. Using a high-end ultrasound system equipped with a high-frequency transducer, five images were obtained of each nerve. The hypoechoic neuronal tissue was delineated offline with dedicated software and the CSA extracted.Results: In the initial PD vs. HC comparison, no statistically significant differences were observed in mean left vagus CSA (HC: 1.97 mm2, PD: 1.89 mm2, P = 0.36) nor in mean right vagus CSA (HC: 2.37 mm2, PD: 2.23 mm2, P = 0.17). The right vagus CSA was significantly larger than the left vagus CSA in both groups (P < 0.0001). Females were overrepresented in the HC group and presented with generally smaller vagus CSAs. Consequently, sex-adjusted CSA was significantly smaller for the right vagus nerve of the PD group (P = 0.041), but not for the left.Conclusion: A small but significant reduction in sex-adjusted right vagus CSA was observed in patients with PD. The left vagus CSA was not significantly reduced in patients with PD. Ultrasound may not be a suitable method to detecting vagal axonal loss in individual patients.

REFRACTORY EPILEPSY AND VAGUS NERVE STIMULATION: THE WAY FORWARD

Vagus Nerve Stimulation (VNS) an efficacious neurophysiological modality of treatment for both medically & surgically refractory epilepsy was first implanted in 1988 & later approved by US FDA in 1997. In clinical practice, trains of current are applied intermittently to the left vagus using a pacemaker or AICD like device 'the VNS device'. The device has four components pulse generator, lead, spiral electrodes & a magnet. The pulse generator is implanted beneath left clavicle by a simple surgical method & attached to left vagus nerve via lead & spiral electrodes.[1] The magnet provides an extra edge to control the aura or impending seizure by providing 'On Demand' stimulations. The poor cardiac innervation by left vagus helps to minimize the unwanted or at time dangerous side effects like severe bradycardia, brady arrythmia, or even cardiac asystole.[2]

Vagus nerve cross-sectional area in patients with Parkinson’s Disease – an ultrasound case-control study

BackgroundVagal parasympathetic neurons are prone to degeneration in Parkinson’s disease (PD). High-resolution ultrasound can precisely estimate the cross-sectional area (CSA) of peripheral nerves. Here, we tested the hypothesis that vagus CSA is reduced in PD.MethodsWe included 56 healthy controls (HCs) and 63 patients with PD. Using a high-end ultrasound system equipped with a high-frequency transducer, five images were obtained of each nerve. The hypoechoic neuronal tissue was delineated offline with dedicated software and the CSA extracted.ResultsIn the initial PD vs. HC comparison, no statistically significant differences were observed in mean left vagus CSA (HC: 1.97mm2, PD: 1.89mm2, P=0.36) or in mean right vagus CSA (HC: 2.37mm2, PD: 2.23mm2, P=0.17). The right vagus CSA was significantly larger than the left vagus CSA in both groups (P<0.0001). Females were overrepresented in the HC group and presented with generally smaller vagus CSAs. Consequently, sex-adjusted CSA was significantly smaller for the right vagus nerve of the PD group (P=0.041), but not for the left.ConclusionA small but significant reduction in sex-adjusted right vagus CSA was observed in patients with PD. The left vagus CSA was not significantly reduced in patients with PD. Ultrasound may not be a suitable method to detecting vagal axonal loss in individual patients.

Surgical Excision of Dumbbell-shaped Vagus Nerve Schwannoma: A Case Report

Schwannoma is a benign peripheral nerve sheath tumour that arises from the uncontrolled proliferation of Schwann cells. Intracranial and extracranial vagus nerve schwannoma is an extremely rare entity that poses a surgical challenge due to its delicate location in the cerebrum and parapharyngeal space adjacent to major neck vessels. This report describes a unique case of a 42 years old female with left dumbbell vagus nerve schwannoma, involving both the intracranial and extracranial portion of the left vagus nerve, extending into the parapharyngeal space. She underwent a two-stage surgery in which intracranial vagus schwanomma was debulked initially, and excision of the extracranial schwanomma in the parapharyngeal space was performed in a later setting via a transcervical approach.