scholarly journals Motor-evoked potential monitoring for intramedullary spinal cord tumor surgery: correlation of clinical and neurophysiological data in a series of 100 consecutive procedures

1998 ◽  
Vol 4 (5) ◽  
pp. E3 ◽  
Author(s):  
Karl F. Kothbauer ◽  
Vedran Deletis ◽  
Fred J. Epstein
Keyword(s):  
Spinal Cord ◽  
Evoked Potential ◽  
Spinal Cord Tumor ◽  
Motor Evoked Potential ◽  
Motor Deficit ◽  
Motor Deficits ◽  
Intramedullary Tumors ◽  
Intramedullary Spinal Cord ◽  
Motor Pathways ◽  
Evoked Potential Monitoring

Resection of intramedullary spinal cord tumors carries a high risk for surgical damage to the motor pathways. This surgery is therefore optimal for testing the performance of intraoperative motor evoked potential (MEP) monitoring. This report attempts to provide evidence for the accurate representation of patients' pre- and postoperative motor status by combined epidural and muscle MEP monitoring during intramedullary surgery. The authors used transcranial electrical motor cortex stimulation to elicit MEPs, which were recorded from the spinal cord (with an epidural electrode) and from limb target muscles (thenar, anterior tibial) with needle electrodes. The amplitude of the epidural MEPs and the presence or absence of muscle MEPs were the parameters for MEP interpretation. A retrospective analysis was performed on data from the resection of 100 consecutive intramedullary tumors and MEP data were compared with the pre- and postoperative motor status. Intraoperative monitoring was feasible in all patients without severe preoperative motor deficits. Preoperatively paraplegic patients had no recordable MEPs. The sensitivity of muscle MEPs to detect postoperative motor deficits was 100% and its specificity was 91%. There was no instance in which a patient with stable MEPs developed a motor deficit postoperatively. Intraoperative MEPs adequately represented the motor status of patients undergoing surgery for intramedullary tumors. Because deterioration of the motor status was transient in all cases, it can be considered that impairment of the functional integrity of the motor pathways was detected before permanent deficits occurred.

The value of intraoperative motor evoked potential monitoring during surgical intervention for thoracic idiopathic spinal cord herniation

2012 ◽  
Vol 16 (2) ◽  
pp. 114-126 ◽  
Author(s):  
Klaus Novak ◽  
Georg Widhalm ◽  
Adauri Bueno de Camargo ◽  
Noel Perin ◽  
George Jallo ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Evoked Potential ◽  
Surgical Repair ◽  
Motor Evoked Potential ◽  
Motor Deficit ◽  
Dural Defect ◽  
Spinal Cord Herniation ◽  
Dural Graft ◽  
Evoked Potential Monitoring ◽  
Idiopathic Spinal Cord Herniation

Object Thoracic idiopathic spinal cord herniation (TISCH) is a rare neurological disorder characterized by an incarceration of the spinal cord at the site of a ventral dural defect. The disorder is associated with clinical signs of progressive thoracic myelopathy. Surgery can withhold the natural clinical course, but surgical repair of the dural defect bears a significant risk of additional postoperative motor deficits, including permanent paraplegia. Intraoperative online information about the functional integrity of the spinal cord and warning signs about acute functional impairment of motor pathways could contribute to a lower risk of permanent postoperative motor deficit. Motor evoked potential (MEP) monitoring can instantly and reliably detect dysfunction of motor pathways in the spinal cord. The authors have applied MEPs during intraoperative neurophysiological monitoring (IOM) for surgical repair of TISCH and have correlated the results of IOM with its influence on the surgical procedure and with the functional postoperative outcome. Methods The authors retrospectively reviewed the intraoperative neurophysiological data and clinical records of 4 patients who underwent surgical treatment for TISCH in 3 institutions where IOM, including somatosensory evoked potentials and MEPs, is routinely used for spinal cord surgery. In all 4 patients the spinal cord was reduced from a posterior approach and the dural defect was repaired using a dural graft. Results Motor evoked potential monitoring was feasible in all patients. Significant intraoperative changes of MEPs were observed in 2 patients. The changes were detected within seconds after manipulation of the spinal cord. Monitoring of MEPs led to immediate revision of the placement of the dural graft in one case and to temporary cessation of the release of the incarcerated spinal cord in the other. Changes occurred selectively in MEPs and were reversible. In both patients, transient changes in intraoperative MEPs correlated with a reversible postoperative motor deficit. Patients without significant changes in somatosensory evoked potentials and MEPs demonstrated no additional neurological deficit postoperatively and showed improvement of motor function during follow-up. Conclusions Surgical repair of the dural defect is effected by release and reduction of the spinal cord and insertion of dural substitute over the dural defect. Careful monitoring of the functional integrity of spinal cord long tracts during surgical manipulation of the cord can detect surgically induced impairment. The authors' documentation of acute loss of MEPs that correlated with reversible postoperative motor deficit substantiates the necessity of IOM including continuous monitoring of MEPs for the surgical treatment of TISCH.

scholarly journals Efficacy of Transcranial Motor Evoked Potential Monitoring During Intra- and Extramedullary Spinal Cord Tumor Surgery: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research

2021 ◽  
pp. 219256822110114
Author(s):  
Hiroki Ushirozako ◽  
Go Yoshida ◽  
Shiro Imagama ◽  
Kazuyoshi Kobayashi ◽  
Kei Ando ◽  
...  
Keyword(s):  
Spinal Cord ◽  
False Positive ◽  
Evoked Potential ◽  
Spinal Cord Tumor ◽  
False Negative ◽  
Motor Evoked Potential ◽  
True Positive ◽  
True Negative ◽  
Intramedullary Spinal Cord ◽  
Transcranial Motor Evoked Potential

Study Design: Multicenter prospective study. Objectives: Although intramedullary spinal cord tumor (IMSCT) and extramedullary SCT (EMSCT) surgeries carry high risk of intraoperative motor deficits (MDs), the benefits of transcranial motor evoked potential (TcMEP) monitoring are well-accepted; however, comparisons have not yet been conducted. This study aimed to clarify the efficacy of TcMEP monitoring during IMSCT and EMSCT resection surgeries. Methods: We prospectively reviewed TcMEP monitoring data of 81 consecutive IMSCT and 347 EMSCT patients. We compared the efficacy of interventions based on TcMEP alerts in the IMSCT and EMSCT groups. We defined our alert point as a TcMEP amplitude reduction of ≥70% from baseline. Results: In the IMSCT group, TcMEP monitoring revealed 20 true-positive (25%), 8 rescue (10%; rescue rate 29%), 10 false-positive, a false-negative, and 41 true-negative patients, resulting in a sensitivity of 95% and a specificity of 80%. In the EMSCT group, TcMEP monitoring revealed 20 true-positive (6%), 24 rescue (7%; rescue rate 55%), 29 false-positive, 2 false-negative, and 263 true-negative patients, resulting in a sensitivity of 91% and specificity of 90%. The most common TcMEP alert timing was during tumor resection (96% vs. 91%), and suspension surgeries with or without intravenous steroid administration were performed as intervention techniques. Conclusions: Postoperative MD rates in IMSCT and EMSCT surgeries using TcMEP monitoring were 25% and 6%, and rescue rates were 29% and 55%. We believe that the usage of TcMEP monitoring and appropriate intervention techniques during SCT surgeries might have predicted and prevented the occurrence of intraoperative MDs.

scholarly journals Resection of Intramedullary Spinal Cord Tumor under Awake Anesthesia: A Novel Approach to Minimize Postoperative Motor Deficits

2017 ◽  
Vol 3 (1) ◽  
pp. 28-34
Author(s):  
Ahsan Ali Khan ◽  
Lukui Chen ◽  
Xiaoyuan Guo ◽  
Hong Wang ◽  
Guojian Wu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Evoked Potential ◽  
Spinal Cord Tumor ◽  
Tumor Resection ◽  
Motor Deficits ◽  
Spinal Cord Tumors ◽  
Intramedullary Spinal Cord ◽  
Intramedullary Spinal Cord Tumor ◽  
Advantages And Disadvantages ◽  
Sensory Evoked

Objective To observe advantages and disadvantages of the resection of intramedullary spinal cord tumor under awake anesthesia. Methods Two patients with intramedullary spinal cord tumor underwent resection under awake anesthesia and followed up post-operatibely for any motor deficits. Results Patients who underwent tumor resection under awake (AAA) anesthesia combined with intraoperative NPM had no motor deficits postoperatively. More accurate and nondelayed responses were observed in the awake cycle of anesthesia and helped guide surgery, thus avoiding injuries to the spinal cord. Conclusion Intramedullary spinal cord tumors are not common, but only gross total resection (GTR) can provide complete remission of symptoms and progression-free survival. However, GTR sometimes results in motor function deficits postoperatively, particularly when the cervical cord is involved, and especially if surgery is done under general anesthesia with intraoperative neurophysiological monitoring (NPM) alone, because of delayed sensory evoked potential and motor evoked potential responses. We present two cases that underwent GTR of cervical intramedullary spinal cord tumors under an asleep-awake-asleep (AAA) cycle of anesthesia, combined with intraoperative NPM in which no postoperative motor deficits were observed on 6-months follow up.

Motor Evoked Potential Monitoring Improves Outcome after Surgery for Intramedullary Spinal Cord Tumors: A Historical Control Study

Neurosurgery ◽  
2006 ◽  
Vol 58 (6) ◽  
pp. 1129-1143 ◽  
Author(s):  
Francesco Sala ◽  
Giorgio Palandri ◽  
Elisabetta Basso ◽  
Paola Lanteri ◽  
Vedran Deletis ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Evoked Potential ◽  
Spinal Cord Tumor ◽  
Motor Evoked Potential ◽  
Historical Control Group ◽  
Historical Control ◽  
Control Group ◽  
Intramedullary Spinal Cord ◽  
Control Study

Abstract OBJECTIVE: The value of intraoperative neurophysiological monitoring (INM) during intramedullary spinal cord tumor surgery remains debated. This historical control study tests the hypothesis that INM monitoring improves neurological outcome. METHODS: In 50 patients operated on after September 2000, we monitored somatosensory evoked potentials and transcranially elicited epidural (D-wave) and muscle motor evoked potentials (INM group). The historical control group consisted of 50 patients selected from among 301 patients who underwent intramedullary spinal cord tumor surgery, previously operated on by the same team without INM. Matching by preoperative neurological status (McCormick scale), histological findings, tumor location, and extent of removal were blind to outcome. A more than 50% somatosensory evoked potential amplitude decrement influenced only myelotomy. Muscle motor evoked potential disappearance modified surgery, but more than 50% D-wave amplitude decrement was the major indication to stop surgery. The postoperative to preoperative McCormick grade variation at discharge and at a follow-up of at least 3 months was compared between the two groups (Student's t tests). RESULTS: Follow-up McCormick grade variation in the INM group (mean, +0.28) was significantly better (P = 0.0016) than that of the historical control group (mean, –0.16). At discharge, there was a trend (P = 0.1224) toward better McCormick grade variation in the INM group (mean, –0.26) than in the historical control group (mean, –0.5). CONCLUSION: The applied motor evoked potential methods seem to improve long-term motor outcome significantly. Early motor outcome is similar because of transient motor deficits in the INM group, which can be predicted at the end of surgery by the neurophysiological profile of patients.

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