The application of intraoperative neurophysiological monitoring in selective dorsal neurotomy for primary premature ejaculation: a prospective single-center study / 亚洲男科学杂志(英文版)

Selective dorsal neurotomy (SDN) is a surgical treatment for primary premature ejaculation (PE), but there is still no standard surgical procedure for selecting the branches of the dorsal penile nerves to be removed. We performed this study to explore the value of intraoperative neurophysiological monitoring (IONM) of the penile sensory-evoked potential (PSEP) for standard surgical procedures in SDN. One hundred and twenty primary PE patients undergoing SDN were selected as the PE group and 120 non-PE patients were selected as the normal group. The PSEP was monitored and compared between the two groups under both natural and general anesthesia (GA) states. In addition, patients in the PE group were randomly divided into the IONM group and the non-IONM group. During SDN surgery, PSEP parameters of the IONM group were recorded and analyzed. The differences in PE-related outcome measurements between the perioperative period and 3 months' postoperation were compared for the PE patients, and the differences in effectiveness and complications between the IONM group and the non-IONM group were compared. The results showed that the average latency of the PSEP in the PE group was shorter than that in the normal group under both natural and GA states (P < 0.001). Three months after surgery, the significant effective rates in the IONM and non-IONM groups were 63.6% and 34.0%, respectively (P < 0.01), and the difference in complications between the two groups was significant (P < 0.05). IONM might be useful in improving the short-term therapeutic effectiveness and reducing the complications of SDN.

Manejo quirúrgico de ependimomas en médula cervical: A propósito de un caso clínico / Surgical management of ependymomas in the cervical spine: Apropos of a clinical case

Introducción: los ependimomas son tumores cerebrales que surgen de células ependimarias, células de soporte en el cerebro y la médula espinal. Representan entre el 2 y el 3% de todos los tumores cerebrales primarios. Son el cuarto tumor cerebral más común en los niños, donde el 90% de los mismos se localizan en la fosa posterior. En adultos, el 60% de estos tumores se encuentran en la médula espinal pudiendo presentarse a cualquier nivel de ésta; el caso a continuación reporta un ependimoma cervical. Objetivo: reportar un caso de ependimoma medular de ubicación poco frecuente, con resección total, sin recidiva porterior a 2 años de seguimiento.Descripción del caso: se reporta el caso de un paciente adulto, 44 años, masculino, con un síndrome medular cervical completo, progresivo, provocado por un ependimoma cervical. Intervención: se realizó laminectomía de dos espacios [C7 a T1], apertura dural, mielotomía posterior logrando exéresis total de la lesión con durorrafia a sello de agua y posterior cierre por planos sin complicaciones, con seguimiento de 2 años de sobrevida. Conclusiones: la resección total macroscópica de este tipo de tumores es muy importante para poder evitar residiva. El ependimoma cervical puede recidivar, sobre todo cuando existen residuales de la lesión. El manejo oportuno depende de gran manera de que los pacientes acudan tempranamente a valoración especializada; la resección guiada con monitorización neurofisiológica transoperatoria provee mayor oportunidad a los pacientes a no presentar secuelas permanentes y permite asimismo, mejores resultados de la rehabilitación neurológica postoperatoria

Introduction: ependymomas are brain tumors that arise from ependymal cells, supporting cells in the brain and spinal cord. They represent between 2 and 3% of all primary brain tumors. They are the fourth most common brain tumor in children, where 90% of them are located in the posterior fossa. In adults, 60% of these tumors are found in the spinal cord and can occur at any level of the spinal cord; the case below reports a cervical ependymoma. Objective: to report a case of medullary ependymoma of rare location, with total resection, without recurrence after 2 years of follow-up. Case description: a 44-year-old male adult patient with a progressive, complete cervical spinal cord syndrome, caused by a cervical ependymoma, is reported.Intervention: two-space laminectomy [C7 to T1], dural opening and posterior myelotomy were performed, achieving total excision of the lesion with water-seal durorrhaphy and subsequent closure by planes without complications, with a 2-year survival follow-up. Conclusions: macroscopic total resection of this type of tumor is very important to avoid residual. Cervical ependymoma can recur, especially when there is residual lesion. Timely management depends to a great extent on the patients attending early for a specialized evaluation; guided resection with intraoperative neurophysiological monitoring provides a greater opportunity for patients to not present permanent sequelae and also allows better results of postoperative neurological rehabilitation.

The Role of Neurophysiological Monitoring during Complex Aneurysm Surgery: Report of Two Cases and Review of the Literature

The surgical treatment of intracranial aneurysms is a routine operation in the neurosurgeon practice. Complex aneurysms are those with morphological irregularities, usually large or giant; thrombosed, partially thrombosed or calcified; with aberrant fundus/neck ratio and near eloquent neurological structures. These cases demand special skills by the surgical team. The present article is a report of two cases of complex aneurysms successfully treated, with a discussion on the role of neurophysiological monitoring. In these two cases of supra- and infratentorial complex giant aneurysms, intraoperative monitoring was extremely relevant. Thus, we believe that treating complex and giant aneurysms carries several pitfalls, and the use of multimodal intraoperative monitoring is mandatory to mitigate risks and deliver the best result to the patient.

A dedicated stitch to allow early safe mobilization avoiding drain-induced heart injury

Abstract Placement of a mediastinal drain is a routine procedure following heart surgery. Postoperative bed rest is often imposed due to the fear of potential risk of drain displacement and cardiac injury. We developed an encapsulating stitch as a feasible, effective and low-cost technique, which does not require advanced surgical skills for placement. This simple, novel approach compartmentalizes the drain allowing for safe early mobilization following cardiac surgery.

Neuromonitorización intraoperatoria del nervio facial: a propósito de un caso / Intraoperative neuromonitoring of the facial nerve: a case report

Introdução: A preservação do nervo facial (NF) é uma das principais preocupações do cirurgião durante o tratamento aberto das fraturas mandibulares, uma vez que uma lesão nessa estrutura anatômica pode causar sequelas estéticas e funcionais permanentes. A existência de variações anatômicas (anastomoses e ramificações incomuns) aumenta o risco de danos no NF, mesmo nas mãos de cirurgiões experientes. O neuromonitoramento intraoperatório tem-se mostrado um grande aliado para evitar lesões nos ramos nervosos que podem estar envolvidos na área cirúrgica. Considerando a escassez desse assunto na literatura referente à cirurgia maxilo-facial, objetivamos demonstrar o uso da técnica de neuromonitoração do NF durante o acesso submandibular para o tratamento da fratura bilateral do ângulo mandibular. Relato de caso: No presente relato de caso, as abordagens cirúrgicas de ambos os lados não apresentaram danos permanentes ao NF. Esse resultado assim como a literatura sugerem que o neuromonitoramento intraoperatório proporciona maior segurança durante a realização de abordagens cirúrgicas, nas quais os ramos do nervo facial estão envolvidos, reduzindo, assim, o risco de sequelas nervosas. Considerações Finais: Esse recurso pode ser de grande auxílio no treinamento hospitalar ao longo do processo de formação de cirurgiões bucomaxilofaciais... (AU)

Introduction: Facial nerve (FN) preservation is one of the surgeon's major concerns during the open treatment of mandibular fractures since an injury to this anatomical structure can cause permanent aesthetic and functional sequelae. The existence of anatomical variations (anastomosis and unusual branching) increases the risk of FN damage even in the hands of experienced surgeons. Intraoperative neuromonitoring has proven to be a great ally to avoid injury to the nerve branches that may be involved in the surgical area. Considering the scarcity of this subject in the maxillofacial surgery literature, we aimed to demonstrate the use of the FN neuromonitoring technique during the submandibular approach for the treatment of bilateral mandibular angle fracture. Case report: In the present case report, the surgical approaches of both sides presented no permanent damage to the FN. Results: This result, as well as previous literature, suggests that intraoperative neuromonitoring provides greater safety during the performance of surgical approaches in which the facial nerve branches are involved and thus, reduces the risk of nerve sequelae. Final considerations: This resource can be of special assistance in teaching hospitals throughout the training process of maxillofacial surgeons... (AU)

Intraoperative Neurophysiological Monitoring during Microvascular Decompression Surgery for Hemifacial Spasm

Hemifacial spasm (HFS) is due to the vascular compression of the facial nerve at its root exit zone (REZ). Microvascular decompression (MVD) of the facial nerve near the REZ is an effective treatment for HFS. In MVD for HFS, intraoperative neurophysiological monitoring (INM) has two purposes. The first purpose is to prevent injury to neural structures such as the vestibulocochlear nerve and facial nerve during MVD surgery, which is possible through INM of brainstem auditory evoked potential and facial nerve electromyography (EMG). The second purpose is the unique feature of MVD for HFS, which is to assess and optimize the effectiveness of the vascular decompression. The purpose is achieved mainly through monitoring of abnormal facial nerve EMG that is called as lateral spread response (LSR) and is also partially possible through Z-L response, facial F-wave, and facial motor evoked potentials. Based on the information regarding INM mentioned above, MVD for HFS can be considered as a more safe and effective treatment.

Clinical Usefulness of Intraoperative Motor-Evoked Potential Monitoring during Temporal Lobe Epilepsy Surgery

BACKGROUND AND PURPOSE: We aimed to determine the effectiveness of intraoperative neurophysiological monitoring focused on the transcranial motor-evoked potential (MEP) in patients with medically refractory temporal lobe epilepsy (TLE). METHODS: We compared postoperative neurological deficits in patients who underwent TLE surgery with or without transcranial MEPs combined with somatosensory evoked potential (SSEP) monitoring between January 1995 and June 2018. Transcranial motor stimulation was performed using subdermal electrodes, and MEP responses were recorded in the four extremity muscles. A decrease of more than 50% in the MEP or the SSEP amplitudes compared with baseline was used as a warning criterion. RESULTS: In the TLE surgery group without MEP monitoring, postoperative permanent motor deficits newly developed in 7 of 613 patients. In contrast, no permanent motor deficit occurred in 279 patients who received transcranial MEP and SSEP monitoring. Ten patients who exhibited decreases of more than 50% in the MEP amplitude recovered completely, although two cases showed transient motor deficits that recovered within 3 months postoperatively. CONCLUSIONS: Intraoperative transcranial MEP monitoring during TLE surgery allowed the prompt detection and appropriate correction of injuries to the motor nervous system or ischemic stroke. Intraoperative transcranial MEP monitoring is a reliable modality for minimizing motor deficits in TLE surgery.

Development of a Novel Intraoperative Neuromonitoring System Using a Surface Pressure Sensor to Detect Muscle Movement: A Rabbit Model Study

OBJECTIVES: False-negative or false-positive responses in intraoperative neuromonitoring (IONM) using electromyography (EMG) in thyroid surgery pose a challenge. Therefore, we developed a novel IONM system that uses a surface pressure sensor instead of EMG to detect muscle twitching. This study aimed to investigate the feasibility and safety of a new IONM system using a piezo-electric surface pressure sensor in an experimental animal model. METHODS: We developed the surface pressure sensor by modifying a commercial piezo-electric sensor. We evaluated the stimulus thresholds to detect muscle movement, as well as the amplitude and latency of the EMG and surface pressure sensor in six sciatic nerves of three rabbits, according to the stimulus intensity. RESULTS: The surface pressure sensor detected the muscle movements in response to a 0.1 mA stimulation of all six sciatic nerves. There were no differences in the thresholds of stimulus intensity between the surface pressure sensor and EMG recordings to detect muscle movements. CONCLUSION: It is possible to measure the change in surface pressure by using a piezo-electric surface pressure sensor instead of EMG to detect muscle movement induced by nerve stimulation. The application of IONM using a piezo-electric surface pressure sensor during surgery is noninvasive, safe, and feasible. Measuring muscle twitching to identify the state of the nerves using the novel IONM system can be an alternative to recording of EMG responses.

Comparison of multi-mode and single-mode intraoperative neurophysiological monitoring in the treatment of severe ossification of the cervical posterior longitudinal ligament with anterior cervical corpectomy with fusion / 中国骨伤

OBJECTIVE@#To compare the application of multi-mode and single-mode intraoperative neurophysiological monitoring in the treatment of severe ossification of posterior longitudinal ligament of cervical spine with anterior cervical corpectomy with fusion.@*METHODS@#From April 2015 to June 2018, 32 patients with severe ossification of the posterior longitudinal ligament were treated in the Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. There were 21 males and 11 females, aged 45 to 73 years old, with a mean age of 59 years old. The duration of the disease ranged from 6 to 72 months, with a mean of 39 months. The main manifestations were numbness, numbness and weakness of limbs, cotton feeling of foot stepping on lower limbs, instability of standing and walking. With the gradual aggravation of symptoms, quadriplegia, dysfunction of urine and defecation may occur. Patients with ossification of posterior longitudinal ligament of cervical spine were monitored by somatosensory evoked potentials, motor evoked potentials and electromyogram patterns.@*RESULTS@#During the operation, 8 patients had abnormal amplitude of somatosensory evoked potential(SEP); 5 of them had bleeding during anterior cervical decompression procedure and were placed with too much hemostatic cotton, which caused compression of spinal cord and resulted in abnormal SEP waveform. After removal of the hemostatic cotton, SEP waveform returned ot normal; 3 patients had abnormal SEP waveform due to decreased systolic pressure, which was corrected by increased systolic pressure. Twelve patients had abnormal amplitude of motor evoked potential during monitoring, 9 of which were caused by intraoperative mis-contact with nerve root, and turned to normal after timely adjustment of position, 3 of which were caused by intraoperative inhalation of muscle relaxant during surgery. Among 11 patients with abnormal EMG waveform, 9 patients recovered to normal waveform after adjusting operation, 2 patients recovered to normal waveform after short observation, and all patients recovered to normal waveform of motor evoked potential after operation(<0.05). There were 2 cases of cerebrospinal fluid leakage after operation, which healed spontaneously 7 days after operation, and no complications of spinal cord and nerve occurred in all patients after operation.@*CONCLUSIONS@#In anterior cervical corpectomy with fusion operation for the treatment of severe cervical ossification of posterior longitudinal ligament, various modes of intraoperative neurophysiological monitoring can real-time understand spinal cord and nerve function status, significantly reduce the incidence of spinal cord and nerve injury during operation, and effectively improve the safety of operation.

Visual and electrophysiological identification of the external branch of superior laryngeal nerve in redo thyroid surgery compared with primary thyroid surgery

PURPOSE: Thyroid reoperations are surgically challenging because of significant anatomical variance. Visual and functional identification of the external branch of the superior laryngeal nerve (EBSLN) were studied in 2 groups of patients who underwent primary and redo thyroid surgery. METHODS: This study was conducted on 200 patients: 100 patients with redo and 100 patients with primary thyroid surgery. In addition to visual identification, nerve branches were functionally identified by intraoperative nerve monitoring (IONM). Visual, functional, and total identification rates of the EBSLN in both primary and redo surgery were determined and compared between the 2 groups. RESULTS: We attempted to identify 138 and 170 EBSLNs at risk in redo and primary surgery, respectively. Visual identification rates were 65.3% and 30.4% (P < 0.001) in primary and redo surgery groups, respectively. In total, 164 (96.5%) and 97 EBSLNs (70.3%) were identified in primary and redo surgery, respectively (P < 0.001), including the use of IONM. In primary surgery group, 53 nonvisualized EBSLNs of 164 identified nerves (32.3%) were determined by IONM alone. In redo surgery group, 55 of 97 identified nerves (56.7%) were determined by IONM alone (P < 0.001). CONCLUSION: Both visual and total identification rates of the EBSLN are significantly decreased in reoperative thyroidectomy. IONM increases the total identification rate of the EBSLN in primary and redo thyroid surgery. Electrophysiological monitoring makes a substantial contribution to the identification of the EBSLN both in primary and especially in redo thyroid surgery.

Intraoperative Neurophysiological Monitoring during Microvascular Decompression Surgery for Hemifacial Spasm

Hemifacial spasm (HFS) is due to the vascular compression of the facial nerve at its root exit zone (REZ). Microvascular decompression (MVD) of the facial nerve near the REZ is an effective treatment for HFS. In MVD for HFS, intraoperative neurophysiological monitoring (INM) has two purposes. The first purpose is to prevent injury to neural structures such as the vestibulocochlear nerve and facial nerve during MVD surgery, which is possible through INM of brainstem auditory evoked potential and facial nerve electromyography (EMG). The second purpose is the unique feature of MVD for HFS, which is to assess and optimize the effectiveness of the vascular decompression. The purpose is achieved mainly through monitoring of abnormal facial nerve EMG that is called as lateral spread response (LSR) and is also partially possible through Z-L response, facial F-wave, and facial motor evoked potentials. Based on the information regarding INM mentioned above, MVD for HFS can be considered as a more safe and effective treatment.

Intraoperative Neurophysiologic Testing of the Perigastric Vagus Nerve Branches to Evaluate Viability and Signals along Nerve Pathways during Gastrectomy

PURPOSE: The perigastric vagus nerve may play an important role in preserving function after gastrectomy, and intraoperative neurophysiologic tests might represent a feasible method of evaluating the vagus nerve. The purpose of this study is to assess the feasibility of neurophysiologic evaluations of the function and viability of perigastric vagus nerve branches during gastrectomy. MATERIALS AND METHODS: Thirteen patients (1 open total gastrectomy, 1 laparoscopic total gastrectomy, and 11 laparoscopic distal gastrectomy) were prospectively enrolled. The hepatic and celiac branches of the vagus nerve were exposed, and grabbing type stimulation electrodes were applied as follows: 10–30 mA intensity, 4 trains, 1,000 µs/train, and 5× frequency. Visible myocontractile movement and electrical signals were monitored via needle probes before and after gastrectomy. Gastrointestinal symptoms were evaluated preoperatively and postoperatively at 3 weeks and 3 months, respectively. RESULTS: Responses were observed after stimulating the celiac branch in 10, 9, 10, and 6 patients in the antrum, pylorus, duodenum, and proximal jejunum, respectively. Ten patients responded to hepatic branch stimulation at the duodenum. After vagus-preserving distal gastrectomy, 2 patients lost responses to the celiac branch at the duodenum and jejunum (1 each), and 1 patient lost response to the hepatic branch at the duodenum. Significant procedure-related complications and meaningful postoperative diarrhea were not observed. CONCLUSIONS: Intraoperative neurophysiologic testing seems to be a feasible methodology for monitoring the perigastric vagus nerves. Innervation of the duodenum via the celiac branch and postoperative preservation of the function of the vagus nerves were confirmed in most patients. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0000823

Sequential method for determining the maximum dose of mivacurium continuously infused for intraoperative neuromonitoring in thyroid surgery / 南方医科大学学报

OBJECTIVE@#To determine the maximum dose of continuously infused mivacurium for intraoperative neuromonitoring and observe its adverse effects in thyroid surgery.@*METHODS@#Twenty-eight patients undergoing thyroid surgery with intraoperative neuromonitoring received continuous infusion of mivacurium at the initial rate of 5.43 μg?kg?min, and the infusion rate for the next patient was adjusted based on the response of the previous patient according to the results of neurological monitoring. The depth of anesthesia was maintained with sevoflurane and remifentanil during the surgery. The LD50 and 95% of mivacurium were calculated using Brownlee's up-and-down sequential method.@*RESULTS@#The LD50 of continuously infused mivacurium was 8.94 μg?kg?min (95% : 8.89- 8.99 μg?kg?min) during thyroid surgery, which did not affect neurological function monitoring. Transient chest skin redness occurred after induction in 9 patients (32.1%). None of the patients experienced intubation difficulties or showed intraoperative body motions during the surgery.@*CONCLUSIONS@#In patients undergoing thyroid surgery under anesthesia maintained by inhalation and intravenous infusion, the LD50 of mivacurium was 8.94 μg?kg?min (95% : 8.89-8.99 μg?kg?min) for continuous infusion, which does not cause serious adverse effects during the operation.

Total Deformity Angular Ratio as a Risk Factor for Complications after Posterior Vertebral Column Resection Surgery

OBJECTIVE: The aim of the present study was to identify whether the deformity angular ratio (DAR) influences the occurrence of complications after posterior vertebral column resection (PVCR) and to establish the DAR cut-off value. METHODS: Thirty-six consecutive patients undergoing PVCR from December 2010 to October 2016 were reviewed. The relationships between the total, sagittal, and coronal DAR and complications were assessed using receiver operator characteristics curves. The patients were divided into two groups according to a reference value based on the cut-off value of DAR. Demographic, surgical, radiological, and clinical outcomes were compared between the groups. RESULTS: There were no significant differences in the patient demographic and surgical data between the groups. The cut-off values for the total DAR (T-DAR) and the sagittal DAR (S-DAR) were 20.2 and 16.4, respectively (p=0.018 and 0.010). Both values were significantly associated with complications (p=0.016 and 0.005). In the higher T-DAR group, total complications (12 vs. 21, p=0.042) and late-onset complications (3 vs. 9, p=0.036) were significantly correlated with the T-DAR. The number of patients experiencing complications (9 vs. 11, p=0.029) and the total number of complications (13 vs. 20, p=0.015) were significantly correlated with the S-DAR. Worsening intraoperative neurophysiologic monitoring was more frequent in the higher T-DAR group (2 vs. 4) than in the higher S-DAR group (3 vs. 3). There was no difference in neurological deterioration between the groups after surgery. CONCLUSION: Both the T-DAR and the S-DAR are risk factors for complications after PVCR. Those who had a T-DAR >20.2 or S-DAR >16.4 experienced a higher rate of complications after PVCR.

Analysis According to Characteristics of 18 Cases of Brachial Plexus Tumors : A Review of Surgical Treatment Experience

OBJECTIVE: Because the anatomical structure of the brachial plexus is very complex, surgical treatment of tumors in this region is challenging. Therefore, a lot of clinical and surgical experience is required for successful treatment; however, many neurosurgeons have difficulty accumulating this experience owing to the rarity of brachial plexus tumors. The purpose of this report is to share our surgical experience with brachial plexus tumor with other neurosurgeons. METHODS: The records of 18 consecutive patients with brachial plexus tumors who underwent surgical treatment between January 2010 and December 2017 in a single institution were retrospectively reviewed. The surgical approach was determined according to the tumor location and size, and intraoperative neurophysiological monitoring (IONM) was used in most of cases to prevent iatrogenic nerve injury during surgery. In addition, to evaluate the differences in tumor characteristics according to pathologic diagnosis, the tumors were divided twice into two groups, based on two separate classifications, and statistical analysis was performed. RESULTS: The 18 brachial plexus tumors comprised 15 (83.3%) benign peripheral nerve sheath tumors including schwannoma and neurofibroma, one (5.6%) malignant peripheral nerve sheath tumor, one (5.6%) benign tumor of non-neural sheath origin (neurogenic cyst), and one (5.6%) metastatic tumor (papillary carcinoma). The authors analyzed relationship between tumor size/location and tumor characteristic parameters such as age, size, right-left, and pathology. There were no statistically significant differences except a tendency of bigger tumor size in young age. CONCLUSION: For a successful surgical outcome, an appropriate surgical approach is essential, and the appropriate surgical approach is determined by the location and size of the tumor. Furthermore, applying IONM may prevent postoperative complications and it is favorable option for brachial plexus tumors surgery.

Intraoperative Neurophysiological Monitoring : A Review of Techniques Used for Brain Tumor Surgery in Children

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal ageadjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.

Total Deformity Angular Ratio as a Risk Factor for Complications after Posterior Vertebral Column Resection Surgery

OBJECTIVE: The aim of the present study was to identify whether the deformity angular ratio (DAR) influences the occurrence of complications after posterior vertebral column resection (PVCR) and to establish the DAR cut-off value.METHODS: Thirty-six consecutive patients undergoing PVCR from December 2010 to October 2016 were reviewed. The relationships between the total, sagittal, and coronal DAR and complications were assessed using receiver operator characteristics curves. The patients were divided into two groups according to a reference value based on the cut-off value of DAR. Demographic, surgical, radiological, and clinical outcomes were compared between the groups.RESULTS: There were no significant differences in the patient demographic and surgical data between the groups. The cut-off values for the total DAR (T-DAR) and the sagittal DAR (S-DAR) were 20.2 and 16.4, respectively (p=0.018 and 0.010). Both values were significantly associated with complications (p=0.016 and 0.005). In the higher T-DAR group, total complications (12 vs. 21, p=0.042) and late-onset complications (3 vs. 9, p=0.036) were significantly correlated with the T-DAR. The number of patients experiencing complications (9 vs. 11, p=0.029) and the total number of complications (13 vs. 20, p=0.015) were significantly correlated with the S-DAR. Worsening intraoperative neurophysiologic monitoring was more frequent in the higher T-DAR group (2 vs. 4) than in the higher S-DAR group (3 vs. 3). There was no difference in neurological deterioration between the groups after surgery.CONCLUSION: Both the T-DAR and the S-DAR are risk factors for complications after PVCR. Those who had a T-DAR >20.2 or S-DAR >16.4 experienced a higher rate of complications after PVCR.

Analysis According to Characteristics of 18 Cases of Brachial Plexus Tumors : A Review of Surgical Treatment Experience

OBJECTIVE: Because the anatomical structure of the brachial plexus is very complex, surgical treatment of tumors in this region is challenging. Therefore, a lot of clinical and surgical experience is required for successful treatment; however, many neurosurgeons have difficulty accumulating this experience owing to the rarity of brachial plexus tumors. The purpose of this report is to share our surgical experience with brachial plexus tumor with other neurosurgeons.METHODS: The records of 18 consecutive patients with brachial plexus tumors who underwent surgical treatment between January 2010 and December 2017 in a single institution were retrospectively reviewed. The surgical approach was determined according to the tumor location and size, and intraoperative neurophysiological monitoring (IONM) was used in most of cases to prevent iatrogenic nerve injury during surgery. In addition, to evaluate the differences in tumor characteristics according to pathologic diagnosis, the tumors were divided twice into two groups, based on two separate classifications, and statistical analysis was performed.RESULTS: The 18 brachial plexus tumors comprised 15 (83.3%) benign peripheral nerve sheath tumors including schwannoma and neurofibroma, one (5.6%) malignant peripheral nerve sheath tumor, one (5.6%) benign tumor of non-neural sheath origin (neurogenic cyst), and one (5.6%) metastatic tumor (papillary carcinoma). The authors analyzed relationship between tumor size/location and tumor characteristic parameters such as age, size, right-left, and pathology. There were no statistically significant differences except a tendency of bigger tumor size in young age.CONCLUSION: For a successful surgical outcome, an appropriate surgical approach is essential, and the appropriate surgical approach is determined by the location and size of the tumor. Furthermore, applying IONM may prevent postoperative complications and it is favorable option for brachial plexus tumors surgery.

Intraoperative Neurophysiological Monitoring : A Review of Techniques Used for Brain Tumor Surgery in Children

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal ageadjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.