scholarly journals Long-term motor deficit in brain tumour surgery with preserved intra-operative motor-evoked potentials

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Davide Giampiccolo ◽  
Cristiano Parisi ◽  
Pietro Meneghelli ◽  
Vincenzo Tramontano ◽  
Federica Basaldella ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Brain Tumour ◽  
Evoked Potential ◽  
Corticospinal Tract ◽  
Motor Evoked Potentials ◽  
Motor Evoked Potential ◽  
Motor Deficit ◽  
Motor Deficits ◽  
Brain Tumour Surgery

Abstract Muscle motor-evoked potentials are commonly monitored during brain tumour surgery in motor areas, as these are assumed to reflect the integrity of descending motor pathways, including the corticospinal tract. However, while the loss of muscle motor-evoked potentials at the end of surgery is associated with long-term motor deficits (muscle motor-evoked potential-related deficits), there is increasing evidence that motor deficit can occur despite no change in muscle motor-evoked potentials (muscle motor-evoked potential-unrelated deficits), particularly after surgery of non-primary regions involved in motor control. In this study, we aimed to investigate the incidence of muscle motor-evoked potential-unrelated deficits and to identify the associated brain regions. We retrospectively reviewed 125 consecutive patients who underwent surgery for peri-Rolandic lesions using intra-operative neurophysiological monitoring. Intraoperative changes in muscle motor-evoked potentials were correlated with motor outcome, assessed by the Medical Research Council scale. We performed voxel–lesion–symptom mapping to identify which resected regions were associated with short- and long-term muscle motor-evoked potential-associated motor deficits. Muscle motor-evoked potentials reductions significantly predicted long-term motor deficits. However, in more than half of the patients who experienced long-term deficits (12/22 patients), no muscle motor-evoked potential reduction was reported during surgery. Lesion analysis showed that muscle motor-evoked potential-related long-term motor deficits were associated with direct or ischaemic damage to the corticospinal tract, whereas muscle motor-evoked potential-unrelated deficits occurred when supplementary motor areas were resected in conjunction with dorsal premotor regions and the anterior cingulate. Our results indicate that long-term motor deficits unrelated to the corticospinal tract can occur more often than currently reported. As these deficits cannot be predicted by muscle motor-evoked potentials, a combination of awake and/or novel asleep techniques other than muscle motor-evoked potentials monitoring should be implemented.

Neurophysiologic Mapping of Thalamocortical Tract in Asleep Craniotomies: Promising Results From an Early Experience

2020 ◽  
Author(s):  
Mirela V Simon ◽  
Daniel K Lee ◽  
Bryan D Choi ◽  
Pratik A Talati ◽  
Jimmy C Yang ◽  
...  
Keyword(s):  
General Anesthesia ◽  
Corticospinal Tract ◽  
Sensory Function ◽  
Motor Deficit ◽  
Motor Deficits ◽  
Central Sulcus ◽  
Postcentral Gyrus ◽  
Subcortical Stimulation ◽  
Subcortical Mapping

Abstract BACKGROUND Subcortical mapping of the corticospinal tract has been extensively used during craniotomies under general anesthesia to achieve maximal resection while avoiding postoperative motor deficits. To our knowledge, similar methods to map the thalamocortical tract (TCT) have not yet been developed. OBJECTIVE To describe a neurophysiologic technique for TCT identification in 2 patients who underwent resection of frontoparietal lesions. METHODS The central sulcus (CS) was identified using the somatosensory evoked potentials (SSEP) phase reversal technique. Furthermore, monitoring of the cortical postcentral N20 and precentral P22 potentials was performed during resection. Subcortical electrical stimulation in the resection cavity was done using the multipulse train (case #1) and Penfield (case #2) techniques. RESULTS Subcortical stimulation within the postcentral gyrus (case #1) and in depth of the CS (case #2), resulted in a sudden drop in amplitudes in N20 (case #1) and P22 (case #2), respectively. In both patients, the potentials promptly recovered once the stimulation was stopped. These results led to redirection of the surgical plane with avoidance of damage of thalamocortical input to the primary somatosensory (case #1) and motor regions (case #2). At the end of the resection, there were no significant changes in the median SSEP. Both patients had no new long-term postoperative sensory or motor deficit. CONCLUSION This method allows identification of TCT in craniotomies under general anesthesia. Such input is essential not only for preservation of sensory function but also for feedback modulation of motor activity.

Intraoperative Motor Evoked Potential Alteration in Intracranial Tumor Surgery and Its Relation to Signal Alteration in Postoperative Magnetic Resonance Imaging

Neurosurgery ◽  
2010 ◽  
Vol 67 (2) ◽  
pp. 302-313 ◽  
Author(s):  
Andrea Szelényi ◽  
Elke Hattingen ◽  
Stefan Weidauer ◽  
Volker Seifert ◽  
Ulf Ziemann
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Motor Cortex ◽  
Evoked Potential ◽  
Corticospinal Tract ◽  
Motor Evoked Potential ◽  
Motor Deficit ◽  
Warning Sign ◽  
Precentral Gyrus ◽  
Resonance Imaging

Abstract OBJECTIVE To determine the degree to which the pattern of intraoperative isolated, unilateral alteration of motor evoked potential (MEP) in intracranial surgery was related to motor outcome and location of new postoperative signal alterations on magnetic resonance imaging (MRI). METHODS In 29 patients (age, 42.8 ± 18.2 years; 15 female patients; 25 supratentorial, 4 infratentorial procedures), intraoperative MEP alterations in isolation (without significant alteration in other evoked potential modalities) were classified as deterioration (> 50% amplitude decrease and/or motor threshold increase) or loss, respectively, or reversible and irreversible. Postoperative MRI was described for the location and type of new signal alteration. RESULTS New motor deficit was present in all 5 patients with irreversible MEP loss, in 7 of 10 patients with irreversible MEP deterioration, in 1 of 6 patients with reversible MEP loss, and in 0 of 8 patients with reversible MEP deterioration. Irreversible compared with reversible MEP alteration was significantly more often correlated with postoperative motor deficit (P < .0001). In 20 patients, 22 new signal alterations affected 29 various locations (precentral gyrus, n = 5; corticospinal tract, n = 19). Irreversible MEP alteration was more often associated with postoperative new signal alteration in MRI compared with reversible MEP alteration (P = .02). MEP loss was significantly more often associated with subcortically located new signal alteration (P = .006). MEP deterioration was significantly more often followed by new signal alterations located in the precentral gyrus (P = .04). CONCLUSION MEP loss bears a higher risk than MEP deterioration for postoperative motor deficit resulting from subcortical postoperative MR changes in the corticospinal tract. In contrast, MEP deterioration points to motor cortex lesion. Thus, even MEP deterioration should be considered a warning sign if surgery close to the motor cortex is performed.

scholarly journals Feasibility of intraoperative motor evoked potential monitoring during tethered cord surgery in infants younger than 12 months

2021 ◽  
Author(s):  
Johannes Herta ◽  
Erdem Yildiz ◽  
Daniela Marhofer ◽  
Thomas Czech ◽  
Andrea Reinprecht ◽  
...  
Keyword(s):  
Motor Evoked Potentials ◽  
Motor Evoked Potential ◽  
Tethered Cord ◽  
Motor Deficit ◽  
Motor Deficits ◽  
Irreversible Loss ◽  
Intravenous Anesthesia ◽  
Evoked Potential Monitoring ◽  
Transcranial Motor Evoked Potentials ◽  
Clinical Records

Abstract Purpose Feasibility, reliability, and safety assessment of transcranial motor evoked potentials (MEPs) in infants less than 12 months of age. Methods A total of 22 patients with a mean age of 33 (range 13–49) weeks that underwent neurosurgery for tethered cord were investigated. Data from intraoperative MEPs, anesthesia protocols, and clinical records were reviewed. Anesthesia during surgery was maintained by total intravenous anesthesia (TIVA). Results MEPs were present in all patients for the upper extremities and in 21 out of 22 infants for the lower extremities. Mean baseline stimulation intensity was 101 ± 20 mA. If MEPs were present at the end of surgery, no new motor deficit occurred. In the only case of MEP loss, preoperative paresis was present, and high baseline intensity thresholds were needed. MEP monitoring did not lead to any complications. TIVA was maintained with an average propofol infusion rate of 123.5 ± 38.2 µg/kg/min and 0.46 ± 0.17 µg/kg/min for remifentanil. Conclusion In spinal cord release surgery, the use of intraoperative MEP monitoring is indicated regardless of the patient’s age. We could demonstrate the feasibility and safety of MEP monitoring in infants if an adequate anesthetic regimen is applied. More data is needed to verify whether an irreversible loss of robust MEPs leads to motor deficits in this young age group.

Motor Evoked Potentials from Transcranial Stimulation of the Motor Cortex in Humans

Neurosurgery ◽  
1984 ◽  
Vol 15 (3) ◽  
pp. 287-302 ◽  
Author(s):  
Walter J. Levy ◽  
Donald H. York ◽  
Michael McCaffrey ◽  
Fred Tanzer
Keyword(s):  
Spinal Cord ◽  
Motor Cortex ◽  
Evoked Potentials ◽  
Evoked Potential ◽  
Motor Evoked Potentials ◽  
Sensory Modality ◽  
Motor Evoked Potential ◽  
Transcranial Stimulation ◽  
Direct Stimulation ◽  
Stimulation Of

Abstract Electrical monitoring of the motor system offers the potential for the detection of injury, the diagnosis of disease, the evaluation of treatment, and the prediction of recovery from damage. Existing evoked potentials monitor one or another sensory modality, but no generally usable motor monitor exists. We have reported a motor evoked potential using direct stimulation of the spinal cord over the motor tracts in cats and in humans. To achieve a less invasive monitor, we used transcranial stimulation over the motor cortex in the cat, thus stimulating the motor cortex. We report here the initial application of this method to humans. A plate electrode over the motor cortex on the scalp and a second electrode on the palate direct a mild current through the motor cortex which will activate the motor pathways. This signal can be recorded over the spinal cord. It can elicit contralateral peripheral nerve and electromyographic signals in the limbs or movements when the appropriate stimulation parameters are used. In clinical use to date, this has been more reliable than the somatosensory evoked potential in predicting motor function in patients where the two tests differed. It offers a number of possibilities for the development of valuable brain and spinal cord monitoring techinques, but requires further animal studies and clinical experience. Studies to date have not demonstrated adverse effects, but evaluation is continuing.

scholarly journals Effect of Two Anesthetic Regimes with Dexmedetomidine as Adjuvant on Transcranial Electrical Motor Evoked Potentials during Spine Surgery

2020 ◽  
Vol 07 (02) ◽  
pp. 084-090
Author(s):  
Rajeeb K. Mishra ◽  
Hemanshu Prabhakar ◽  
Indu Kapoor ◽  
Dinu S. Chandran ◽  
Arvind Chaturvedi
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Spine Surgery ◽  
Evoked Potential ◽  
Motor Evoked Potentials ◽  
Spinal Column ◽  
Motor Evoked Potential ◽  
Standard Group ◽  
Time Points ◽  
Group D

Abstract Background Transcranial motor evoked potential (TcMEP) recording during spinal cord/spinal column surgery is a reliable and valid diagnostic adjunct to assess spinal cord integrity and is recommended if utilized for this purpose. Electrophysiologic monitoring in terms of TcMEP has been proven to be a useful tool in detecting spinal cord dysfunction at the earliest and allows corrective action to be taken before permanent neuronal dysfunction sets in. The quality of intraoperative neuromonitoring is influenced by various factors. Most anesthetics used in clinical practice suppress the evoked potentials. Thus, selecting an appropriate technique is always a challenging task. Materials and Methods Thirty ASA I and II patients scheduled for elective dorsolumbar spine surgery with TcMEP monitoring were recruited in the study. Patients were randomized into three groups: (1) Propofol (group P) 100 to 150 µg/kg/min with dexmedetomidine 0.6 µg/kg/hr and fentanyl 1 µg/kg/hr, (2) desflurane (group D) (<0.5 MAC) with dexmedetomidine 0.6 µg/kg/hr and fentanyl 1 µg/kg/hr, and (3)standard group (group S) patients received propofol 100 to 150 µg/kg/min, fentanyl 1 µg/kg/hr along with equal volume of saline (placebo). TcMEP amplitudes were recorded bilaterally from electrodes placed at least in one set of muscles with motor origin rostral and one set of muscle caudal to the spinal level of lesion at different time points. Results Three patients were excluded after allocation; 27 out of 30 patients were analyzed. The demographic and surgical characteristics of patients were comparable. The stimulation voltage needed to elicit the responses in all the three groups was comparable. No difference was observed in brachioradialis muscle amplitudes between the groups at different time points. However, in the right brachioradialis muscle, we found reduced amplitudes at baseline in group D and at 120 minutes in group P. We noticed reduced amplitudes of bilateral brachioradialis muscle in group P at 60 minutes and 90 minutes with respect to the baseline. For lower extremity, we measured amplitudes of TcMEP in tibialis anterior (TA) and did not find any difference in amplitudes between the groups at different time points. Conclusion We observed that the desflurane–dexmedetomidine combination did not hinder TcMEP as compared with both standard and propofol–dexmedetomidine groups. Thus, this combined regime could be used in surgeries requiring motor evoked potential monitoring.

scholarly journals Contraction intensity-dependent variations in the responses to brain and corticospinal tract stimulation after a single session of resistance training in men

2019 ◽  
Vol 127 (4) ◽  
pp. 1128-1139 ◽  
Author(s):  
David Colomer-Poveda ◽  
Salvador Romero-Arenas ◽  
Jesper Lundbye-Jensen ◽  
Tibor Hortobágyi ◽  
Gonzalo Márquez
Keyword(s):  
Electrical Stimulation ◽  
Resistance Training ◽  
Evoked Potentials ◽  
Muscle Contraction ◽  
Corticospinal Tract ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Motor Evoked Potential ◽  
Single Session ◽  
Compound Muscle Action Potentials

The aim of this study was to determine the effects of acute resistance training (RT) intensity on motor-evoked potentials (MEPs) generated by transcranial magnetic brain stimulation and on cervicomedullary motor-evoked potentials (CMEPs) produced by electrical stimulation of the corticospinal tract. In four experimental sessions, 14 healthy young men performed 12 sets of eight isometric contractions of the elbow flexors at 0 (Control session), 25, 50, and 75% of the maximal voluntary contraction (MVC). Before and after each session, MEPs, CMEPs, and the associated twitch forces were recorded at rest. MEPs increased by 39% ( P < 0.05 versus 25% in the control condition, Effect size (ES) = 1.04 and 1.76, respectively) after the 50% session and by 70% ( P < 0.05 vs. all other conditions, ES = 0.91–2.49) after the 75% session. In contrast, CMEPs increased similarly after the 25%, 50%, and 75% sessions with an overall increase of 27% ( P < 0.05 vs. control condition, ES = 1.34). The amplitude of maximal compound muscle action potentials (Mmax) was unchanged during the experiment. The MEP- and CMEP-associated twitch forces also increased after RT, but training intensity affected only the increases in MEP twitch forces. The data tentatively suggest that the intensity of muscle contraction used in acute bouts of RT affects cortical excitability. NEW & NOTEWORTHY Resistance training (RT) can acutely increase the efficacy of the corticospinal-motoneuronal synapse, motoneuron excitability and motor cortical excitability. We show that motor-evoked potential generated by transcranial magnetic stimulation but not cervicomedullary electrical stimulation increased in proportion to the intensity of training used during a single session of RT. The data suggest that the intensity of muscle contraction used in acute bouts of RT affects cortical excitability.

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.

Reliability of intraoperative neurophysiological monitoring using motor evoked potentials during resection of metastases in motor-eloquent brain regions

2013 ◽  
Vol 118 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
Sandro M. Krieg ◽  
Michael Schäffner ◽  
Ehab Shiban ◽  
Doris Droese ◽  
Thomas Obermüller ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Motor System ◽  
Motor Evoked Potentials ◽  
Motor Evoked Potential ◽  
Residual Tumor ◽  
Brain Regions ◽  
Cerebral Metastases ◽  
Significant Decline ◽  
Motor Deficit ◽  
Neurophysiological Monitoring

Object Resection of gliomas in or adjacent to the motor system is widely performed using intraoperative neuromonitoring (IOM). For resection of cerebral metastases in motor-eloquent regions, however, data are sparse and IOM in such cases is not yet widely described. Since recent studies have shown that cerebral metastases infiltrate surrounding brain tissue, this study was undertaken to assess the value and influence of IOM during resection of supratentorial metastases in motor-eloquent regions. Methods Between 2006 and 2011, the authors resected 206 consecutive supratentorial metastases, including 56 in eloquent motor areas with monitoring of monopolar direct cortically stimulated motor evoked potentials (MEPs). The authors evaluated the relationship between the monitoring data and the course of surgery, clinical data, and postoperative imaging. Results Motor evoked potential monitoring was successful in 53 cases (93%). Reduction of MEP amplitude correlated better with postoperative outcomes when the threshold for significant amplitude reduction was set at 80% (only > 80% reduction was considered significant decline) than when it was set at 50% (> 50% amplitude reduction was considered significant decline). Evidence of residual tumor was seen on MR images in 28% of the cases with significant MEP reduction. No residual tumor was seen in any case of stable MEP monitoring. Moreover, preoperative motor deficit, recursive partitioning analysis Class 3, and preoperative radiotherapy were independent risk factors for a new surgery-related motor weakness (occurring in 64% of patients with and 11% of patients without radiotherapy, p > 0.01). Conclusions Continuous MEP monitoring provides reliable monitoring of the motor system and also influences the course of operation in resection of cerebral metastases. However, in establishing warning criteria, only an amplitude decline > 80% of the baseline should be considered significant.

False Negative and Positive Motor Evoked Potentials in One Patient: Is Single Motor Evoked Potential Monitoring Reliable Method?

Spine ◽  
2010 ◽  
Vol 35 (18) ◽  
pp. E912-E916 ◽  
Author(s):  
Jae-Young Hong ◽  
Seung-Woo Suh ◽  
Hitesh N. Modi ◽  
Chang-Yong Hur ◽  
Hae-Ryong Song ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Reliable Method ◽  
Evoked Potential ◽  
Motor Evoked Potentials ◽  
False Negative ◽  
Motor Evoked Potential ◽  
Single Motor ◽  
Evoked Potential Monitoring ◽  
Potential Monitoring

scholarly journals Intraoperative subcortical motor evoked potential stimulation: how close is the corticospinal tract?

2015 ◽  
Vol 123 (3) ◽  
pp. 711-720 ◽  
Author(s):  
Ehab Shiban ◽  
Sandro M. Krieg ◽  
Bernhard Haller ◽  
Niels Buchmann ◽  
Thomas Obermueller ◽  
...  
Keyword(s):  
Evoked Potential ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Motor Evoked Potential ◽  
Motor Deficits ◽  
Subtotal Resection ◽  
Stimulation Intensity ◽  
Postoperative Mri ◽  
Subcortical Stimulation ◽  
Measured Distance

OBJECT Subcortical stimulation is a method used to evaluate the distance from the stimulation site to the corticospinal tract (CST) and to decide whether the resection of an adjacent lesion should be terminated to prevent damage to the CST. However, the correlation between stimulation intensity and distance to the CST has not yet been clearly assessed. The objective of this study was to investigate the appropriate correlation between the subcortical stimulation pattern and the distance to the CST. METHODS Monopolar subcortical motor evoked potential (MEP) mapping was performed in addition to continuous MEP monitoring in 37 consecutive patients with lesions located in motor-eloquent locations. The proximity of the resection cavity to the CST was identified by subcortical MEP mapping. At the end of resection, the point at which an MEP response was still measurable with minimal subcortical MEP intensity was marked with a titanium clip. At this location, different stimulation paradigms were executed with cathodal or anodal stimulation at 0.3-, 0.5-, and 0.7-msec pulse durations. Postoperatively, the distance between the CST as defined by postoperative diffusion tensor imaging fiber tracking and the titanium clip was measured. The correlation between this distance and the subcortical MEP electrical charge was calculated. RESULTS Subcortical MEP mapping was successful in all patients. There were no new permanent motor deficits. Transient new postoperative motor deficits were observed in 14% (5/36) of cases. Gross-total resection was achieved in 75% (27/36) and subtotal resection (> 80% of tumor mass) in 25% (9/36) of cases. Stimulation intensity with various pulse durations as well as current intensity was plotted against the measured distance between the CST and the titanium clip on postoperative MRI using diffusion-weighted imaging fiberitracking tractography. Correlational and regression analyses showed a nonlinear correlation between stimulation intensity and the distance to the CST. Cathodal stimulation appeared better suited for subcortical stimulation. CONCLUSIONS Subcortical MEP mapping is an excellent intraoperative method to determine the distance to the CST during resection of motor-eloquent lesions and is highly capable of further reducing the risk of a new neurological deficit.

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