Correlation of functional magnetic source imaging with intraoperative cortical stimulation in neurosurgical patients

Roberts, T.P.L.; Zusman, Edie E.; McDermott, Michael; Barbaro, Nicholas M.; Rowley, Howard A.

doi:10.1002/(sici)1522-712x(1995)1:6<339::aid-igs5>3.0.co;2-b

Cited by 54 publications

(26 citation statements)

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“…The introduction in 1993 of functional imaging of the brain combined with intraoperative neuronavigation represented a big advance in the safety of neurosurgery [14]. Since then, the accuracy of the different functional imaging techniques for functional neuronavigation was not always confirmed by an independent standard such as the phase reversal technique, but all authors have reported acceptable clinical results in their series [15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30].…”

Section: Discussionmentioning

confidence: 99%

Practicability of magnetoencephalography-guided neuronavigation

et al. 2002

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Magnetoencephalography (MEG) is a noninvasive option for localizing electroneurophysiological activity on the human cortex. The purpose of this study was to evaluate the practicability and reliability of MEG imaging integrated into a neuronavigation system to identify the sensorimotor cortex intraoperatively in patients with brain tumors in or near the central motor strip. It was performed prior to surgery in 30 patients with space-occupying lesions in or around the central region to localize the primary somatosensory cortex. These functional brain maps were superimposed on MR images obtained prior to surgery and transferred in the operating room for intraoperative functional neuronavigation. During surgery, the phase reversal technique identified a generator which coincided with the somatosensory cortex as displayed by the MEG-based functional neuronavigation system. Following surgery, the motor deficit improved in seven patients, was unchanged in five, and showed a slight transient deterioration in five. One patient suffered a deterioration of motor function with incomplete recovery. The MEG-based functional neuronavigation was found to be practicable and useful in finding a safe approach to tumors in or adjacent to the central region. The accuracy of MEG was concluded to be reliable as verified by the phase reversal technique.

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Section: Discussionmentioning

confidence: 99%

Practicability of magnetoencephalography-guided neuronavigation

et al. 2002

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“…Peaks in evoked neuromagnetic field data are used to localize dipoles with the aid of source modeling algorithms. Utilizing MS imaging, relevant somatosensory, speech, and motor cortices can be mapped preoperatively to aid surgical navigation and avoid 4,6,7,9,16,20,22 With the increasing use of MS imaging at clinical centers worldwide, the accuracy of functional localization has become paramount.The utility of neuromagnetic somatosensory, auditory, and speech mapping for preoperative tumor localization has been validated previously. 5,8,21,[24][25][26] More recently, neuromagnetic MEFs have been shown to be useful in mapping motor cortex by using a single-equivalent current dipole model.…”

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confidence: 99%

“…In previous MEG-based studies of preoperative localization, investigators have used similar magnetometers with sensor arrays containing from 37 to 204 channels. 1,[3][4][5][6]19,22,24,25,27 Newer models such as whole-head MEG systems combined with advanced analysis methods provide a higher spatial sampling density, which may improve the accuracy of source localization beyond dipole fitting. Nonetheless, the motor cortex in the present study was adequately covered with a high density of sensors.…”

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confidence: 99%

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Motor field sensitivity for preoperative localization of motor cortex

Lin

Berger²,

Nagarajan³

2006

JNS

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Object-In this study the role of magnetic source imaging for preoperative motor mapping was evaluated by using a single-dipole localization method to analyze motor field data in 41 patients.Methods-Data from affected and unaffected hemispheres were collected in patients performing voluntary finger flexion movements. Somatosensory evoked field (SSEF) data were also obtained using tactile stimulation. Dipole localization using motor field (MF) data was successful in only 49% of patients, whereas localization with movement evoked field (MEF) data was successful in 66% of patients. When the spatial distribution of MF and MEF dipoles in relation to SSEF dipoles was analyzed, the motor dipoles were not spatially distinct from somatosensory dipoles.Conclusions-The findings in this study suggest that single-dipole localization for the analysis of motor data is not sufficiently sensitive and is nonspecific, and thus not clinically useful. Keywordsmagnetoencephalography; brain mapping; motor field; movement-evoked field; functional localizationThe preoperative localization of functionally viable brain tissue helps to guide neurosurgical planning in optimizing the region of resection while allowing for improved postsurgical neurological function. Various neuroimaging techniques, including MS and fMR imaging, are now available to preoperatively map functional brain organization. Coregistering structural MR imaging data to functional data acquired via MS or fMR imaging allows for the intraoperative creation of a neuronavigation system. 9,15,17 Magnetic source imaging has been shown to be increasingly important in preoperative planning and complements intraoperative mapping by delineating retained areas of function noninvasively and in advance, and thus reducing the time needed for intraoperative procedures. Peaks in evoked neuromagnetic field data are used to localize dipoles with the aid of source modeling algorithms. Utilizing MS imaging, relevant somatosensory, speech, and motor cortices can be mapped preoperatively to aid surgical navigation and avoid 4,6,7,9,16,20,22 With the increasing use of MS imaging at clinical centers worldwide, the accuracy of functional localization has become paramount.The utility of neuromagnetic somatosensory, auditory, and speech mapping for preoperative tumor localization has been validated previously. 5,8,21,[24][25][26] More recently, neuromagnetic MEFs have been shown to be useful in mapping motor cortex by using a single-equivalent current dipole model. 19 Here, we examine the role of single-equivalent current dipole modeling of pre-and postmovement evoked responses. 3,11,13,28,29 The premovement evoked response typically peaks before the onset of movement, presumably arising from motor cortex, and this peak is referred to as the "MF." Postmovement onset, the earliest peak activation, is referred to as the "MEF" and is presumed to reflect the sum of activity arising from motor and somatosensory cortices given the presence of both efferent activity and sensory feedback during mo...

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“…The method and its application for a frame-and pointer-based navigation system have already been described. [7,20,21]. In this report we address the question of whether the use of neuronavigation combined with functional imaging may contribute to a better clinical outcome in patients who undergo surgery that involves areas around the sensorimotor cortex.…”

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confidence: 99%

Functional neuronavigation with magnetoencephalography: outcome in 50 patients with lesions around the motor cortex

Ganslandt

Fahlbusch²,

Nimsky³

et al. 1999

FOC

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The authors conducted a study to evaluate the clinical outcome in 50 patients with lesions around the motor cortex who underwent surgery in which functional neuronavigation was performed. The sensorimotor cortex was identified in all patients with the use of magnetoencephalography (MEG). The MEG-source localizations were superimposed onto a three-dimensional magnetic resonance image, and the image data set was then implemented into a neuronavigation system. Based on this setup, the surgeon chose the best surgical strategy. During surgery, the pre- and postcentral gyrus were identified by neuronavigation, and in addition, the central sulcus was localized using intraoperative recording of somatosensory evoked potentials. In all cases MEG localizations of the sensory or motor cortex were correct. In 30% of the patients preoperative paresis improved, in 66% no additional deficits occurred, and in only 4% (two patients) deterioration of neurological function occurred. In one of these patients the deterioration was not related to the method. The method of incorporating functional data into neuronavigation systems is a promising tool that can be used in more radical surgery to cause less morbidity around eloquent brain areas.

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Correlation of functional magnetic source imaging with intraoperative cortical stimulation in neurosurgical patients

Cited by 54 publications

References 0 publications

Practicability of magnetoencephalography-guided neuronavigation

Practicability of magnetoencephalography-guided neuronavigation

Motor field sensitivity for preoperative localization of motor cortex

Functional neuronavigation with magnetoencephalography: outcome in 50 patients with lesions around the motor cortex

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