Continuous Dynamic Mapping of the Corticospinal Tract in Motor Eloquent Tumor Surgery: Our Experience and Evaluation of the Method

Objective. The aim of this article is to present our experience with continuous dynamic mapping (CDM) of the corticospinal tract (CST) when removing tumors in motor eloquent regions.Methods. We studied 44 patients with a brain tumor adjacent to the CST where CDM was used. The mapping probe was integrated at the tip of the suction device. Thresholds for eliciting MEPs were recorded. In all patients, along with CDM, MEPs to direct cortical stimulation were also monitored throughout the operation. Motor function was assessed preoperatively, after the procedure and on discharge.Results. In the series, there were 37 patients with gliomas, six with brain metastasis, and one with cavernoma. The threshold to elicit MEPs in CDM was >20 mA in 17 cases, 16–20 mA in six cases, 11–15 mA in six cases, 6–10 mA in nine cases and 2–5 mA in six cases. MEPs to direct cortical stimulation were preserved in all patients. In three cases a new temporary motor deficit was noted. No new permanent motor deficit occurred. Gross total resection was reached in 57% of cases.Conclusions. From our experience, the combined use of CDM and MEPs to direct cortical stimulation improves the safety of surgery in the proximity of the CST, and at the same time offers the possibility of higher rates of gross total resection.

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Continuous Dynamic Mapping to Identify the Corticospinal Tract in Motor Eloquent Brain Tumors: An Update

Journal of Neurological Surgery Part A Central European Neurosurgery ◽

10.1055/s-0039-1698384 ◽

2020 ◽

Vol 81 (02) ◽

pp. 105-110

Author(s):

Kathleen Seidel ◽

Philippe Schucht ◽

Jürgen Beck ◽

Andreas Raabe

Keyword(s):

Corticospinal Tract ◽

Motor Evoked Potential ◽

Motor Deficit ◽

Mapping Technique ◽

Tumor Surgery ◽

Dynamic Mapping ◽

Spatial Coverage ◽

Eloquent Tumor ◽

Continuous Dynamic ◽

Subcortical Mapping

Abstract Objective We recently developed a new subcortical mapping technique based on the concept of stimulating the tissue at the site of and synchronously with resection. Our hypothesis was that instead of performing resection and mapping sequentially, a synchronized resection and mapping could potentially improve deficit rates. Methods We report our 5-year series of patients who prospectively underwent tumor surgery adjacent to the corticospinal tract (CST) (defined as < 1 cm using diffusion tension imaging and fiber tracking) with simultaneous subcortical short train cathodal monopolar mapping, equipped with a new acoustic motor evoked potential (MEP) alarm. Continuous (temporal coverage) and dynamic (spatial coverage) mapping was realized technically by integrating the mapping probe at the tip of a new suction device. Motor function was assessed using the Medical Research Council scale (from M1 to M5) 1 day after surgery, at discharge, and at 3 months. Results Technically, the method was successful in all 182 cases. The lowest individual motor thresholds reached during resection were > 10 mA, n = 56; 6–10 mA, n = 31; 4–5 mA, n = 37; and 1–3 mA, n = 58. At 3 months, six patients (3%) had a persisting postoperative motor deficit that was caused by direct mechanical injury in three of these patients (1.7%). Conclusions Continuous dynamic mapping was found to be a feasible and ergonomic technique for localizing the exact site of the CST and distance to the motor fibers. This new technique may improve the safety of motor eloquent tumor surgery.

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Continuous dynamic mapping of the corticospinal tract during surgery of motor eloquent brain tumors: evaluation of a new method

Journal of Neurosurgery ◽

10.3171/2014.1.jns13909 ◽

2014 ◽

Vol 120 (5) ◽

pp. 1015-1024 ◽

Cited By ~ 56

Author(s):

Andreas Raabe ◽

Jürgen Beck ◽

Philippe Schucht ◽

Kathleen Seidel

Keyword(s):

Corticospinal Tract ◽

Diffusion Tensor ◽

Motor Evoked Potential ◽

Motor Deficit ◽

Mapping Technique ◽

Tumor Surgery ◽

Motor Mapping ◽

Dynamic Mapping ◽

Spatial Coverage ◽

Continuous Dynamic

Object The authors developed a new mapping technique to overcome the temporal and spatial limitations of classic subcortical mapping of the corticospinal tract (CST). The feasibility and safety of continuous (0.4–2 Hz) and dynamic (at the site of and synchronized with tissue resection) subcortical motor mapping was evaluated. Methods The authors prospectively studied 69 patients who underwent tumor surgery adjacent to the CST (< 1 cm using diffusion tensor imaging and fiber tracking) with simultaneous subcortical monopolar motor mapping (short train, interstimulus interval 4 msec, pulse duration 500 μsec) and a new acoustic motor evoked potential alarm. Continuous (temporal coverage) and dynamic (spatial coverage) mapping was technically realized by integrating the mapping probe at the tip of a new suction device, with the concept that this device will be in contact with the tissue where the resection is performed. Motor function was assessed 1 day after surgery, at discharge, and at 3 months. Results All procedures were technically successful. There was a 1:1 correlation of motor thresholds for stimulation sites simultaneously mapped with the new suction mapping device and the classic fingerstick probe (24 patients, 74 stimulation points; r2 = 0.98, p < 0.001). The lowest individual motor thresholds were as follows: > 20 mA, 7 patients; 11–20 mA, 13 patients; 6–10 mA, 8 patients; 4–5 mA, 17 patients; and 1–3 mA, 24 patients. At 3 months, 2 patients (3%) had a persistent postoperative motor deficit, both of which were caused by a vascular injury. No patient had a permanent motor deficit caused by a mechanical injury of the CST. Conclusions Continuous dynamic mapping was found to be a feasible and ergonomic technique for localizing the exact site of the CST and distance to the motor fibers. The acoustic feedback and the ability to stimulate the tissue continuously and exactly at the site of tissue removal improves the accuracy of mapping, especially at low (< 5 mA) stimulation intensities. This new technique may increase the safety of motor eloquent tumor surgery.

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Surgical management of Rolandic area meningioma in the era of intraoperative neurophysiological monitoring

Romanian Neurosurgery ◽

10.33962/roneuro-2020-082 ◽

2020 ◽

pp. 488-494

Author(s):

Mihaela Coșman ◽

Ionuț Mihail Panțiru ◽

Andrei Ionuț Cucu ◽

Andreea Lenuța Atomei ◽

Gabriela Florența Dumitrecu ◽

...

Keyword(s):

Cortical Stimulation ◽

Motor Area ◽

Intraoperative Neurophysiological Monitoring ◽

Motor Deficit ◽

Cortical Mapping ◽

Neurophysiological Monitoring ◽

Direct Cortical Stimulation ◽

One Year ◽

The Impact

Introduction: The advantages and the necessity of intraoperative neurophysiological monitoring (IOM) in the surgery of motor area infiltrative tumours is well known. The use of this technique for Rolandic meningioma is still debatable. The absence or the loss of the cleavage plan and an infiltrative border make the dissection exceedingly difficult and increase the risk of new postoperative motor disfunction. Materials and methods: We evaluated the impact of IOM, especially direct cortical stimulation on the degree of resection, new postoperative deficits, symptom remission and clinical-imagistic aspects at one-year follow up of 19 cases of Rolandic meningioma admitted in Third Department of Neurosurgery,” Prof. Dr N. Oblu” Emergency Clinical Hospital, Yassi, Romania, between January 2014 and July 2018. Results: More than half of the cases (57,88%) had epileptic manifestations as the main clinical symptom with the Jacksonian seizures being on the first place (31,57%), followed by progressive paresis (26,31%) and other nonspecific symptoms. Intraparenchymal preoperative oedema was observed in 36,84% of patients. The intensity of direct cortical stimulation was between 6-13 mA (median = 9mA; mode = 12mA). Simpson degree of resection was dominated by S3– 47,36% and S4 was obtained in 15,78% of cases. Postoperative the outcome was favourable for 73,68% patients with 5,26% motor aggravation and 10,52% new deficits. At one-year follow up no imagistic recurrence was observed and the permanent motor deficit was maintained in one of the three cases (5,26%). Conclusion: Even though meningiomas are extranevraxial lesions and those located on the convexity have a low risk of complication, the absence of a clear dissection plan between the tumour and the adjacent motor cortex is associated with a high risk for new postoperative neurological deficits. Therefore, it is important to perform cortical mapping for Rolandic meningioma, to determine the location of the primary motor area and to protect it from mechanical and vascular trauma, during tumour resection.

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P166: Continuous dynamic mapping of the corticospinal tract during surgery of motor eloquent brain tumors

Clinical Neurophysiology ◽

10.1016/s1388-2457(14)50304-5 ◽

2014 ◽

Vol 125 ◽

pp. S90-S91

Author(s):

K. Seidel ◽

J. Beck ◽

P. Schucht ◽

A. Raabe

Keyword(s):

Brain Tumors ◽

Corticospinal Tract ◽

Dynamic Mapping ◽

Continuous Dynamic

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149 Continuous Dynamic Mapping of the Corticospinal Tract During Surgery of Motor Eloquent Brain Tumors

Neurosurgery ◽

10.1227/01.neu.0000432740.79451.f9 ◽

2013 ◽

Vol 60 ◽

pp. 169

Author(s):

Andreas Raabe ◽

Jürgen Beck ◽

Philippe Schucht ◽

Kathleen Seidel

Keyword(s):

Brain Tumors ◽

Corticospinal Tract ◽

Dynamic Mapping ◽

Continuous Dynamic

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Monitoring of muscle motor evoked potentials during cerebral aneurysm surgery: intraoperative changes and postoperative outcome

Journal of Neurosurgery ◽

10.3171/jns.2006.105.5.675 ◽

2006 ◽

Vol 105 (5) ◽

pp. 675-681 ◽

Cited By ~ 112

Author(s):

Andrea Szelényi ◽

David Langer ◽

Karl Kothbauer ◽

Adauri Bueno de Camargo ◽

Eugene S. Flamm ◽

...

Keyword(s):

Evoked Potentials ◽

Cerebral Aneurysm ◽

Motor Evoked Potentials ◽

Cortical Stimulation ◽

Constant Current ◽

Motor Deficit ◽

Neurophysiological Monitoring ◽

Transcranial Electrical Stimulation ◽

Aneurysm Surgery ◽

Direct Cortical Stimulation

Object The authors in this study evaluated muscle motor evoked potentials (MMEPs) elicited by transcranial electrical stimulation (TES) and direct cortical stimulation as a means of monitoring during cerebral aneurysm surgery. The analysis focused on the value and frequencies of any intraoperative changes and their correlation to the postoperative motor status. Methods One hundred nineteen patients undergoing surgery for 148 cerebral aneurysms were included in the study. Muscle motor evoked potentials were elicited by a train of five constant-current anodal stimuli with an individual pulse duration of 0.5 msec and a stimulation rate of 2 Hz. Stimulation intensity was up to 240 mA for TES and up to 33 mA for direct cortical stimulation. The MMEPs were continuously recorded from the abductor pollicis brevis and tibialis anterior muscles bilaterally and from the biceps brachii and extensor digitorum communis muscles contralateral to the surgical side. The motor status was evaluated immediately after surgery and 7 days later. In 97% of the patients MMEPs were recordable for continuous neurophysiological monitoring of the vascular territory of interest throughout the surgery. In 14 patients significant intraoperative MMEP changes occurred, resulting in a transient motor deficit in one patient and a permanent motor deficit in six. The permanent loss of MMEPs in three patients was followed by a permanent severe motor deficit in one patient and severe clinical deterioration in the other two. Conclusions Data in this study demonstrated that MMEPs are a useful means of intraoperative neurophysiological monitoring of motor pathway integrity and predicting postoperative motor status. The intraoperative loss of MMEPs reliably predicts both severe and permanent postoperative motor deficits.

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25. Continuous dynamic mapping of the corticospinal tract during surgery of motor eloquent brain tumours

Clinical Neurophysiology ◽

10.1016/j.clinph.2013.12.028 ◽

2014 ◽

Vol 125 (5) ◽

pp. e21

Author(s):

Kathleen Seidel ◽

Juergen Beck ◽

Philippe Schucht ◽

Andreas Raabe

Keyword(s):

Brain Tumours ◽

Corticospinal Tract ◽

Dynamic Mapping ◽

Continuous Dynamic

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Clinical presentation and surgical outcomes of intramedullary neurenteric cysts

Journal of Neurosurgery Spine ◽

10.3171/2014.11.spine14352 ◽

2015 ◽

Vol 23 (1) ◽

pp. 99-110 ◽

Cited By ~ 11

Author(s):

Tao Yang ◽

Liang Wu ◽

Jingyi Fang ◽

Chenlong Yang ◽

Xiaofeng Deng ◽

...

Keyword(s):

Case Reports ◽

Clinical Manifestations ◽

Gross Total Resection ◽

Neurological Deficits ◽

Motor Deficit ◽

Cervical Cord ◽

Subtotal Resection ◽

Total Resection ◽

Cyst Recurrence

OBJECT Intramedullary neurenteric cysts (NECs) are exceedingly rare lesions and have been previously reported in case reports. The aim of this study was to determine the clinical manifestations, radiological features, and long-term prognosis of patients with such lesions. METHODS The authors retrospectively reviewed the records of 13 patients with an intramedullary NEC. Each patient underwent MRI, laminotomy, and microsurgery. The accurate diagnosis was based on imaging and pathology findings. Each patient's follow-up status was determined through individual office visits and a structured telephone interview. RESULTS The series included 7 male and 6 female patients. Progressive or intermittent motor deficit was the main symptom associated with or without pain or sensory disturbance. Five cysts were located in the cervical cord, 1 in the cervicothoracic cord, 3 in the thoracic cord, and 4 in the conus medullaris. Concurrent malformations included scoliosis (3 cases), fusion of rib (1 case), enlarged spinal canal (1 case), tethered spinal cord (1 case), and ectocardia (1 case). Gross-total resection of the cyst was achieved in 8 cases, and subtotal resection (STR) was achieved in 5 cases. All patients were followed up, with a mean duration of 66.5 months. Cyst recurrence was observed in 4 cases after STR. In 2 cases the patients underwent reoperation; the other 2 patients remained clinically stable and did not undergo reoperation. At the last evaluation, neurological function was improved in 11 patients and remained stable in 2 patients. CONCLUSIONS Intramedullary NECs should be considered in the differential diagnosis of a middle-aged patient with intermittent neurological symptoms and concurrent malformations. Early surgery is advocated to prevent permanent neurological deficits. When gross-total resection cannot be achieved, maximally safe removal under the protection of intraoperative neuromonitoring is advised. Because of the high risk of cyst recurrence, routine follow-up MRI is needed. If a residual cyst shows obvious regrowth and results in neurological deficits, timely reoperation with a goal of STR should be performed.

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