Preservation Of Neural Function Research Articles

Intraoperative Neuromonitoring in Vestibular Schwannoma Surgery

Vestibular schwannoma surgery necessitates intraoperative neuromonitoring to secure long-term tumor control by sufficient tumor removal and preservation of neural function. Therein, facial nerve function can be assessed in real-time and quantitatively by intraoperative continuous facial nerve monitoring with repetitive direct stimulation. The ABR and, further, CNAP, are closely monitored for the continuous assessment of the hearing function. In addition, the evoked masseter and extraocular electromyograms, SEP, MEP, and neuromonitoring of the lower cranial nerves are implemented as needed. In this article, we introduce our neuromonitoring techniques during vestibular schwannoma surgery with an illustrative video.

Application of “key and lock” principle in the treatment of traumatic cervical Spondyloptosis of c6-7: Case report and literature review

Purpose: Traumatic cervical spondyloptosis is a rare clinical pathology that often causes complete paralysis. When a patient presents neurologically intact or incomplete paralysis, the management becomes more complicated. Preservation of neural function and restoration of anatomic alignment collectively remain the golden goals of therapy. There are still few reports on this issue, however, the existing literature did not clearly define severity of injuries and the treatment strategy in such cases. On the occasion of reporting one treated traumatic C6-7 spondyloptosis case, we reviewed existing literatures. Material and Methods: The patient was a 48-year-old man who had motorcycle accident and was presented with post-operation for right frontal epidural hematoma in 3 days before admitting to hospital. Neurological assessment showed motor strength grade 3/5 in the proximal upper and lower-extremity muscle groups on the right side, and 1/5 on the left side with incontinence of sphincters. X-rays and computed tomography (CT) scan revealed a three-column ligamentous injury with complete anterior displacement of C6 to C7 vertebral body. We applied the “Key - Lock” principle for better understanding of the biomechanics of the injury and found out the favorable strategy. The patient underwent posterior approach with decompression and anterior approach with reduction and anterior cervical discectomy fusion for C6-7. Results: After 8 months follow-up, the patient had recovered muscular strength in bilateral upper and lower-extremities muscle groups, sphincter function had fully recovered, and he was able to ambulate by himself. Plain radiograph and CT scan showed good aligment and progressive maturation of his fusion procedure. Conclusion: Traumatic cervical spondyloptosis of C6-7 is a high-energy unstable fracture and rare. This report develops a new principle called “Key and Lock” for more understand the biomechanics of the injury and treatment. Our patient was successfully treated with open reduction, decompression, and anterior cervical discectomy fusion.

Contemporary management of pediatric spinal tumors: a single institute's experience in Taiwan in the modern era

Pediatric spinal tumors are unique pathologies treated by pediatric neurosurgeons. Special attention is required for the preservation of neural function and bony alignment. We reported our experience in the management of these challenging lesions. A total of 75 pediatric patients with spinal tumors treated at the National Taiwan University Hospital from 1998 to 2018 were identified retrospectively. Clinical data, radiographic image, and pathological report were reviewed for analysis. There were 37 females and 38 males. The median age was 9years. Thirty-eight tumors (50.6%) were extradural, 20 (26.7%) intradural extramedullary, and 17 (22.6%) intramedullary. The most common pathologies were glioma, ependymoma, and neuroblastoma. The rate of total and subtotal resection was 45.3% and 21.3%. Thirty-four patients (45.3%) required post-operative adjuvant therapy. Eight patients (10.6%) with spinal deformity had simultaneous tumor excision and spinal fusion surgery. Additional six (8%) patients had subsequent spinal fixation and fusion for deformity after primary tumor operation. Eighty-four percent of patients were ambulatory 3years after operation. For patients with intradural extramedullary and intramedullary tumors, worse survival outcome was associated with tumor derived from CSF seeding and cranial involvement of spinal tumor, while poorer functional outcome was correlated with cranial involvement and adjuvant therapy with chemotherapy or radiotherapy. Pediatric spinal tumor surgery carries low surgical morbidity and mortality under current standard of neurosurgical practice. Post-operative adjuvant therapy is required for nearly half of the cases. Spinal deformity requires special attention and sometimes surgical correction. Contemporary management of pediatric spinal tumors enables effective ablation of the lesion and delivers favorable outcome for the majority of patients.

Lotus Root Extract Stimulates BDNF Gene Expression Through Potential Mechanism Depending on HO-1 Activity in C6 Glioma Cells

ABSTRACTPolyphenolic compounds have been suggested to be involved in the preservation of neural function via the production of neurotrophic factors in the brain. The nonedible joint part of lotus root (a rhizome of Nelumbo nucifera) has been reported to contain large amounts of polyphenolic compounds and, therefore, is expected to improve neural function by stimulating the production of brain-derived neurotrophic factor (BDNF) in glial cells. The effect of the aqueous extract prepared from the joint part of lotus root on BDNF gene expression was examined in C6 glioma cells as an in vitro model. This extract was shown to increase BDNF messenger ribonucleic acid (mRNA) levels to the elevation of HO-1 mRNA levels in the glioma cells, but failed to cause the elevation of BDNF mRNA levels in the cells pretreated with a HO-1 antisense oligodeoxynucleotide (ODN) or an HO-1 enzyme inhibitor zinc protoporphyrin (ZnPP). These findings strongly suggest that the aqueous extract prepared from the nonedible joint part of lotus root might be able to stimulate BDNF gene expression by enhancing HO-1 activity in the glioma cells, proposing the possibility that the joint part of lotus root might potentially improve neural function through the stimulation of BDNF production in glial cells.

52. Intraoperative neurophysiology monitoring in lumbar sacral conjoined twins separation

Objective Describe the intraoperative neurophysiological monitoring (IOM) used in the separation of two conjoined twins to lumbosacral level. Methods Case report. Six-month-old two twins joined at lumbosacral level, no relevant history or preoperative neurologic deficits. Preoperative magnetic resonance showed fusion of the lumbar-sacral roots. Separation surgery under anesthesia (propofol and fentanyl) was performed. It was recorded with a Cascade Elite, Cadwell, USA; Free run electromyography (EMG) and evoked EMG; transcranial electric motor evoked potentials (tMEP) of the muscles; vastus medialis (VM), tibialis anterior (TA), medial gastrocnemius (MG), extensor hallux (EHA) and anal sphincter bilaterally in both twins. Lower extremities somatosensory evoked potentials in twin 2. Results At baseline the tMEP were evoked: Twin 2 had responses in all muscle, except right TA and GM; twin-1, tMEP only the right GM. During separation, the remaining tMEP were evoked in the twin-1. No neuromiotonic discharges were seen and EMG evoked identified in the twin-1, left EHA and MG left. Postoperatively had no neurological deficit. Conclusions Multimodal MNIO is feasible in separating lumbo-sacral conjoined twins with preservation of neural function. Significance Multimodal MNIO in the separation of lumbo-sacral conjoined twins help to preserve neural function and improve neurological outcome.

欧州における聴神経腫瘍手術

欧州における聴神経腫瘍手術

Surgery and outcomes of six patients with intradural epidermoid cysts in the lumbar spine

Study designThis was a retrospective study.ObjectiveThe aim of this study was to analyze the clinical characteristics and discuss the treatment options for epidermoid cysts in the lumbar spine.Summary of background dataEpidermoid cysts are rare benign neoplasms, which account for less than 1% of all intraspinal tumors. Due to their rarity, there are only a few case reports in the literature. Complete excision is the recommended treatment for an epidermoid cyst, but this is difficult to achieve in the spine. In spite of their benign nature, local recurrence is not uncommon for spinal epidermoid cysts after incomplete excision.MethodsSix patients with an epidermoid cyst in the lumbar spine underwent surgical treatment in our center between 2004 and 2011. A total excision using microsurgical techniques and reconstruction was successfully undertaken in all patients. Clinical data and detailed pathologic results were retrospectively analyzed. All cases were followed up for a median time of more than 4 years. The clinical data and surgical efficacy were analyzed to suggest treatment options for epidermoid cysts in the lumbar spine on the basis of a literature review and our own experience.ResultsThe mean age of the patients in this study was 37.7 years and the mean duration of pre-operative symptoms was 29.7 months (2 to 120 months). All patients were disease-free during their follow-up period. Radicular pain nearly disappeared, and patients suffering from neurologic deficits and defecation disorders recovered well.ConclusionsAlthough an epidermoid cyst is a benign tumor, it is apt to recur locally following inadequate removal. Therefore, complete excision with preservation of neural function is an ideal protocol for intraspinal epidermoid cysts. Microsurgical techniques are very useful.

Use of supramaximal stimulation to predict facial nerve outcomes following vestibular schwannoma microsurgery: results from a decade of experience

The goal of vestibular schwannoma surgery is tumor removal and preservation of neural function. Intraoperative facial nerve (FN) monitoring has emerged as the standard of care, but its role in predicting long-term facial function remains a matter of debate. The present report seeks to describe and critically assess the value of applying current at supramaximal levels in an effort to identify patients destined for permanent facial paralysis. Over more than a decade, the protocol for stimulating and assessing the FN during vestibular schwannoma surgery at the authors' institution has consisted of applying pulsed constant-current stimulation at supramaximal levels proximally and distally following tumor resection to generate an amplitude ratio, which subtracted from 100% yields the degree to which the functional integrity of the FN "dropped off" intraoperatively. These data were prospectively collected and additional variables that might impact postoperative FN function were retrospectively reviewed from the medical record. Only patients with anatomically intact FNs and > 12 months of follow-up data were analyzed. There were 267 patients available for review. The average posterior fossa tumor diameter was 24 mm and the rate of long-term good (House-Brackmann Grade I-II) FN function was 84%. Univariate logistic regression analysis revealed that prior treatment, neurofibromatosis Type 2 status, tumor size, cerebellopontine angle extension, subjectively thinned FN at the time of operation, minimal stimulation threshold, percent dropoff by supramaximal stimulation (SMS), and postoperative FN function all correlated statistically (p < 0.05) with long-term FN function. When evaluating patients with significant FN weakness at the time of hospital discharge, only the percent dropoff by SMS remained a significant predictor of long-term FN function. However, the positive predictive value of SMS for long-term weakness is low, at 46%. In a large cohort of patients, the authors found that interrogating intraoperative FN function with SMS is safe and technically simple. It is useful for predicting which patients will ultimately have good facial function, but is very limited in identifying patients destined for long-term facial weakness. This test may prove helpful in the future in tailoring less than gross-total tumor removal to limit postoperative facial weakness.

Neural Fibrolipoma of the Digital Nerve: A Case Report

A 32-year-old woman underwent microsurgical resection of a neural fibrolipoma of the digital nerve of the ring finger. At the 6-month follow-up, the patient had good recovery, no recurrence, and preservation of neural function. Caution should be exercised while planning microsurgical dissection on soft-tissue masses of fingers and hands. Total resection of the lesion and nerve grafting should be avoided.

Complete recovery following atlantoaxial fracture-dislocation with bilateral carotid and vertebral artery injury

A patient sustained a flexion-distraction injury with atlantoaxial dislocation and traumatic dissection of the carotid and vertebral arteries bilaterally. Difficulties in management including fracture reduction and stabilization, avoidance of further vascular injury and preservation of neural function are discussed.

Cranial base approaches to inaccessible intracranial tumors

Craniotomy created through the base of the skull has improved exposure of many types of extraaxial tumors and thus enhanced both tumor control and preservation of neural function. The purpose of this article is to review recent advances in this emerging field. Use of microscopes and endoscopes has allowed these procedures to become progressively less invasive. Electrophysiological monitoring has enhanced neural identification and preservation. The increasingly documented efficacy of stereotactic radiation for certain tumor types (e.g. meningioma, schwannoma) has permitted nonoperative therapy for some individuals. In large tumors, selective use of less-than-complete microsurgical resection is establishing an increasing role, at times combined with focused radiotherapy of the surgical remnant. The role for transbasal craniotomy is well established in both benign tumors and vascular lesions, but has only limited applicability for high-grade malignant lesions. Today, the vast majority of procedures can be conducted in a single stage by a multidisciplinary team. Operative trajectories created through the cranial base, although technically demanding, have led to substantially improved outcomes for a wide variety of inaccessible intracranial lesions.

Decompression of cavernous sinus meningioma for preservation and improvement of cranial nerve function

Meningiomas are the most common tumors affecting the cavernous sinus (CS). Despite advances in microsurgery and radiosurgery, treatment of CS meningiomas remains difficult and controversial. As in cases of other meningiomas, the goal of treatment for CS meningioma is long-term growth control and preservation of neural function. Gross-total resection, the ideal treatment for meningioma, is not always possible to obtain in patients with CS meningiomas with an acceptable level of morbidity. Therefore, microsurgery and radiosurgery have recently been advocated as a combined therapy to achieve good control of tumor growth and favorable functional outcome. The authors describe a technique in which tumor volume can be reduced to a minimal residual amount, while preserving cranial nerve function. This enables the smallest field to be treated radiosurgically. The optic nerve is decompressed, and the tumor mass is reduced to provide at least a 5-mm interpositional distance between the optic nerve and the residual lesion. Direct decompression of the CS, with opening of the lateral and superior sinus walls, and piecemeal removal of the tumor in "safe" locations are performed to facilitate an improvement in cranial nerve function. The authors describe the use of this technique in a series of patients and demonstrate improvement of cranial nerve function in a subset of these patients.

頚動脈間隙の臨床

The carotid space, which is not necessarily identical to the carotid sheath that encircles the common carotid artery or internal carotid artery, internal jugular vein, and vagus nerve, extends from the skull base to the aortic arch. Constituents outside of the carotid sheath include the sympathetic chain and deep cervical lymph nodes. This space is bordered by the parotid, parapharyngeal, retropharyngeal, and prevertebral spaces in the suprahyoid neck. The visceral, retropharyngeal, posterior cervical, and prevertebral spaces bound the carotid space in the infrahyoid neck. The suprahyoid portion of this space is often referred to as the retrostyloid compartment of the parapharyngeal space.We discussed anatomical and diagnostic findings regarding this space. Common lesions of the space, diagnostic criteria of metastatic lymph nodes in CT or MRI, clinical manifestations of internal jugular vein thrombosis and carotid syncope, preservation of neural function during neurinoma surgery, and modern trends in paraganglioma surgery were also discussed.

Ischemic neuropraxia: Preservation of neural function by DFMO and blockade of preservation by exogenous putrescine

Ischemic neuropraxia: Preservation of neural function by DFMO and blockade of preservation by exogenous putrescine