Ipsilateral Motor Innervation Discovered Incidentally on Intraoperative Monitoring: A Case Report

Neurosurgery ◽  
2017 ◽  
Vol 80 (3) ◽  
pp. E194-E200
Author(s):  
Jerry Ku ◽  
Daniel Mendelsohn ◽  
Jason Chew ◽  
Jason Shewchuk ◽  
Charles Dong ◽  
...  
Keyword(s):  
Intraoperative Monitoring ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Motor Evoked Potentials ◽  
Motor Deficits ◽  
Motor Innervation ◽  
First Case ◽  
Technical Issues ◽  
Cautious Interpretation ◽  
Rare Anatomic Variant

Abstract BACKGROUND AND IMPORTANCE: Lesions in the corticospinal tract above the decussation at the medullary pyramids almost universally produce contralateral deficits. Rare cases of supratentorial lesions causing ipsilateral motor deficits have been reported previously, but only ever found secondary to stroke or congenital pyramidal tract malformations. CLINICAL PRESENTATION: Herein, we report a case of ipsilateral corticospinal tract innervation discovered incidentally with intraoperative monitoring during a microsurgical resection of a vestibular schwannoma. Intraoperative monitoring with electrical transcranial stimulation of the frontal scalp triggered motor-evoked potentials in the ipsilateral arms. The uncrossed pathways were later confirmed with MRI tractography using diffusion tensor imaging. CONCLUSION: To the best of our knowledge, this is the first case of isolated ipsilateral motor innervation of the corticospinal tract discovered incidentally during a neurosurgical procedure. Given the increasing use of intraoperative monitoring, this case underscores the importance of cautious interpretation of seemingly discordant neurophysiological findings. Once technical issues have been ruled out, ipsilateral motor innervation may be considered as a possible explanation and neurosurgeons should be aware of the existence of this rare anatomic variant.

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.

Intraoperative Monitoring of Central Neurophysiology

2017 ◽  
Author(s):  
Alan D. Legatt ◽  
Marc R. Nuwer ◽  
Ronald G. Emerson
Keyword(s):  
Intraoperative Monitoring ◽  
Corticospinal Tract ◽  
Motor Evoked Potentials ◽  
Anesthetic Management ◽  
Depth Of Anesthesia ◽  
Central Nervous System Function ◽  
Anatomy And Physiology ◽  
Anesthetic Agents ◽  
Nervous System Function ◽  
Signal Changes

This chapter covers neurophysiological intraoperative monitoring (NIOM). It describes the relevant neurophysiological signals, their anatomical sources, the techniques used to record them, the manner in which they are assessed, and possible causes of intraoperative signal changes. Techniques used include electroencephalography (EEG), electromyography, and auditory, somatosensory, and motor evoked potentials. Some of these techniques can be used to localize and identify areas of cerebral cortex or the corticospinal tract. Recording of the electromyogram generated by reflex activity can be used to evaluate central nervous system function in some circumstances. EEG can be used to assess depth of anesthesia. Signals can be affected by anesthesia, and the chapter discusses various anesthetic agents, their effects on signals, and considerations for anesthetic management during NIOM. Personnel performing NIOM must be knowledgeable about the anatomy and physiology underlying the signals, the technology used to record them, and the factors (including anesthesia) that can affect them.

scholarly journals Acute changes in diffusion tensor-derived metrics and its correlation with the motor outcome in gliomas adjacent to the corticospinal tract

2021 ◽  
Vol 12 ◽  
pp. 51
Author(s):  
Santiago Cepeda ◽  
Sergio García-García ◽  
Ignacio Arrese ◽  
María Velasco-Casares ◽  
Rosario Sarabia
Keyword(s):  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Premotor Cortex ◽  
Motor Impairment ◽  
Mean Diffusivity ◽  
Motor Deficits ◽  
Low Grade ◽  
Contralateral Hemisphere ◽  
Motor Outcome ◽  
Acute Changes

Background: This study involves analysis of the relationship between variables obtained using diffusion tensor imaging (DTI) and motor outcome in gliomas adjacent to the corticospinal tract (CST). Methods: Histologically confirmed glioma patients who were to undergo surgery between January 2018 and December 2019 were prospectively enrolled. All patients had a preoperative magnetic resonance imaging (MRI) study that included DTI, a tumor 2 cm or less from the CST, and postsurgical control within 48 h. Patients with MRI that was performed at other center, tumors with primary and premotor cortex invasion, postsurgical complications directly affecting motor outcome and tumor progression <6 months were excluded in the study. In pre- and post-surgical MRI, we measured the following DTI-derived metrics: fractional anisotropy (FA), mean diffusivity, axial diffusivity, and radial diffusivity of the entire CST and peritumoral CST regions and in the contralateral hemisphere. The motor outcome was assessed at 1, 3, and 6 months using the Medical Research Council scale. Results: Eleven patients were analyzed, and six corresponded to high-grade gliomas and five to low-grade gliomas. Four patients had previous motor impairment and seven patients had postsurgical motor deficits (four transient and three permanent). An FA ratio of 0.8 between peritumoral CST regions and the contralateral hemisphere was found to be the cutoff, and lower values were obtained in patients with permanent motor deficits. Conclusion: Quantitative analysis of DTI that was performed in the immediate postsurgery period can provide valuable information about the motor prognosis after surgery for gliomas near the CST.

scholarly journals Corticospinal Tract Change during Motor Recovery in Patients with Medulla Infarct: A Diffusion Tensor Imaging Study

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Dongdong Rong ◽  
Miao Zhang ◽  
Qingfeng Ma ◽  
Jie Lu ◽  
Kuncheng Li
Keyword(s):  
Diffusion Tensor Imaging ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Three Dimensional ◽  
Imaging Study ◽  
Internal Capsule ◽  
Motor Recovery ◽  
Motor Deficits ◽  
Cerebral Peduncle ◽  
The Right

Diffusion tensor imaging (DTI) and tractography (DTT) provide a powerful vehicle for investigating motor recovery mechanisms. However, little is known about these mechanisms in patients with medullary lesions. We used DTI and DTT to evaluate three patients presenting with motor deficits following unilateral medulla infarct. Patients were scanned three times during 1 month (within 7, 14, and 30 days after stroke onset). Fractional anisotropy (FA) values were measured in the medulla, cerebral peduncle, and internal capsule. The three-dimensional corticospinal tract (CST) was reconstructed using DTT. Patients 1 and 2 showed good motor recovery after 14 days, and the FA values of their affected CST were slightly decreased. DTTs demonstrated that the affected CST passed along periinfarct areas and that tract integrity was preserved in the medulla. Patient 3 had the most obvious decrease in FA values along the affected CST, with motor deficits of the right upper extremity after 30 days. The affected CST passed through the infarct and was disrupted in the medulla. In conclusion, DTI can detect the involvement and changes of the CST in patients with medulla infarct during motor recovery. The degree of degeneration and spared periinfarct CST compensation may be an important motor recovery mechanism.

Is Intraoperative Diffusion Tensor Imaging at 3.0T Comparable to Subcortical Corticospinal Tract Mapping?

Neurosurgery ◽  
2013 ◽  
Vol 73 (5) ◽  
pp. 797-807 ◽  
Author(s):  
Svatopluk Ostrý ◽  
Tomáš Belšan ◽  
Jakub Otáhal ◽  
Vladimír Beneš ◽  
David Netuka
Keyword(s):  
Correlation Coefficient ◽  
Primary Motor Cortex ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Tumor Resection ◽  
Motor Evoked Potential ◽  
Radical Resection ◽  
Threshold Current ◽  
Motor Deficits ◽  
Intracerebral Lesion

Abstract BACKGROUND: Primary brain tumors in motor eloquent areas are associated with high-risk surgical procedures because of potentially permanent and often disabling motor deficits. Intraoperative primary motor cortex mapping and corticospinal tract (CST) monitoring are well-developed and reliable techniques. Imaging of the CST by diffusion tensor tractography (DTT) is also feasible. OBJECTIVE: To evaluate the practical value of 3.0T intraoperative MRI (iMRI) with intraoperative DTT (iDTT) in surgery close to the CST, and to compare high-field iDTT with intraoperative neurophysiological CST mapping during glioma and metastasis resection in a routine setting. METHODS: Twenty-five patients (13 males, 12 females, median 47 years) were enrolled prospectively from June 2010 to June 2012. Patients were included if they had a solitary supratentorial intracerebral lesion compressing or infiltrating the CST according to preoperative MRI. Subcortical CST mapping was performed by monopolar (cathodal) stimulation (500 Hz, 400 μs, 5 pulses). CST DTT was made both at preoperative and intraoperative 3.0T MRI. Subcortical motor-evoked potential threshold current and probe-CST distance were recorded at 155 points before and at 103 points after iMRI. Current-distance correlations were performed both for pre-iMRI and for post-iMRI data. RESULTS: The correlation coefficient pre-iMRI was R = 0.470 (P &lt; .001); post-iMRI, the correlation coefficient was R = 0.338 (P &lt; .001). MRI radical resection was achieved in 17 patients (68%), subtotal in 5 (24%), and partial in 3 (12%). Postoperative paresis developed in 8 patients (32%); the paresis was permanent in 1 case (4%). CONCLUSION: The linear current-distance correlation was found both in pre-iMRI and in post-iMRI data. Intraoperative image distortion appeared in 36%. Neurophysiological subcortical mapping remains superior to DTT. Combining these 2 methods in selected cases can help increase the safety of tumor resection close to the CST.

The refractory period of fast conducting corticospinal tract axons in man and its implications for intraoperative monitoring of motor evoked potentials

2004 ◽  
Vol 115 (8) ◽  
pp. 1931-1941 ◽  
Author(s):  
Klaus Novak ◽  
Adauri Bueno de Camargo ◽  
Michael Neuwirth ◽  
Karl Kothbauer ◽  
Vahe E. Amassian ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Refractory Period ◽  
Intraoperative Monitoring ◽  
Corticospinal Tract ◽  
Motor Evoked Potentials

scholarly journals Intraoperative MRI–based elastic fusion for anatomically accurate tractography of the corticospinal tract: correlation with intraoperative neuromonitoring and clinical status

2021 ◽  
Vol 50 (1) ◽  
pp. E9
Author(s):  
Sebastian Ille ◽  
Axel Schroeder ◽  
Arthur Wagner ◽  
Chiara Negwer ◽  
Kornelia Kreiser ◽  
...  
Keyword(s):  
Corticospinal Tract ◽  
Motor Evoked Potentials ◽  
Clinical Status ◽  
Intraoperative Neuromonitoring ◽  
Intraoperative Mri ◽  
Preoperative Imaging ◽  
Motor Deficits ◽  
Study Cohort ◽  
Brain Shift ◽  
Subcortical Lesion

OBJECTIVETractography is a useful technique that is standardly applied to visualize subcortical pathways. However, brain shift hampers tractography use during the course of surgery. While intraoperative MRI (ioMRI) has been shown to be beneficial for use in oncology, intraoperative tractography can rarely be performed due to scanner, protocol, or head clamp limitations. Elastic fusion (EF), however, enables adjustment for brain shift of preoperative imaging and even tractography based on intraoperative images. The authors tested the hypothesis that adjustment of tractography by ioMRI-based EF (IBEF) correlates with the results of intraoperative neuromonitoring (IONM) and clinical outcome and is therefore a reliable method.METHODSIn 304 consecutive patients treated between June 2018 and March 2020, 8 patients, who made up the basic study cohort, showed an intraoperative loss of motor evoked potentials (MEPs) during motor-eloquent glioma resection for a subcortical lesion within the corticospinal tract (CST) as shown by ioMRI. The authors preoperatively visualized the CST using tractography. Also, IBEFs of pre- and intraoperative images were obtained and the location of the CST was compared in relation to a subcortical lesion. In 11 patients (8 patients with intraoperative loss of MEPs, one of whom also showed loss of MEPs on IBEF evaluation, plus 3 additional patients with loss of MEPs on IBEF evaluation), the authors examined the location of the CST by direct subcortical stimulation (DSCS). The authors defined the IONM results and the functional outcome data as ground truth for analysis.RESULTSThe maximum mean ± SD correction was 8.8 ± 2.9 (range 3.8–12.0) mm for the whole brain and 5.3 ± 2.4 (range 1.2–8.7) mm for the CST. The CST was located within the lesion before IBEF in 3 cases and after IBEF in all cases (p = 0.0256). All patients with intraoperative loss of MEPs suffered from surgery-related permanent motor deficits. By approximation, the location of the CST after IBEF could be verified by DSCS in 4 cases.CONCLUSIONSThe present study shows that tractography after IBEF accurately correlates with IONM and patient outcomes and thus demonstrates reliability in this initial study.

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.

Management of an Uncommon Complication: Anterior Choroidal Artery Occlusion by Posterior Clinoid Process Detected Through Intraoperative Monitoring After Clipping of Paraclinoid Aneurysm: 2-Dimensional Operative Video

2021 ◽  
Author(s):  
Walter Marani ◽  
Francisco Mannará ◽  
Kosumo Noda ◽  
Tomomasa Kondo ◽  
Nakao Ota ◽  
...  
Keyword(s):  
Intraoperative Monitoring ◽  
Motor Evoked Potential ◽  
Japanese Woman ◽  
Motor Deficits ◽  
Anterior Choroidal Artery ◽  
Diffusion Weighted Images ◽  
Ct Angiogram ◽  
Paraclinoid Aneurysms ◽  
Anterior Choroidal ◽  
Choroidal Artery

Abstract Despite technological advances in endovascular therapy, surgical clipping of paraclinoid aneurysms remains an indispensable treatment option and has an acceptable profile risk. Intraoperative monitoring of motor and somatosensory evoked potentials has proven to be an effective tool in predicting and preventing postoperative motor deficits during aneurysm clipping.1,2 We describe the case of a 61-yr-old Japanese woman with a history of hypertension and smoking. During follow-up for bilateral aneurysms of ophthalmic segment of the internal carotid artery (ICA), left-sided aneurysm growth was detected. A standard pterional approach with extradural clinoidectomy was used to approach the aneurysm. After clipping, a significant intraprocedural change in motor evoked potential (MEP) amplitude was observed despite native vessel patency was confirmed through micro-Doppler and indocyanine green video angiography.3-5 After extensive dissection of the sylvian fissure and exposure of the communicating segment of ICA, the anterior choroidal artery was found to be compressed and occluded by the posterior clinoid because of an inadvertent shift of the ICA after clip application and removal of brain retractors. Posterior clinoidectomy was performed intradurally with microrongeur and MEP amplitude returned readily to baseline values. Computed tomography (CT) angiogram demonstrated complete exclusion of the aneurysm, and magnetic resonance imaging (MRI) was negative for postoperative ischemic lesions on diffusion weighted images. The patient tolerated the procedure well and was discharged home on postoperative day 3 with modified Rankin Scale (mRS) 0. The patient signed the Institutional Consent Form to undergo the surgical procedure and to allow the use of her images and videos for any type of medical publications.

Sign in / Sign up

Export Citation Format

Share Document