a-standardized-protocol-for-functional-motor-mapping-using-navigated

A Standardized Protocol for Functional Motor Mapping Using Navigated Transcranial Magnetic Stimulation

Navigated transcranial magnetic stimulation (nTMS) is based on the integration of individual brain imaging data to determine the precise positioning of ...

Paris Est Créteil University

Henri Mondor University Hospital, APHP

Aarhus University Hospital

 Maximum safe resection of infiltrative brain tumors in eloquent area is the primary objective in surgical neuro-oncology. This goal can be achieved with direct electrical stimulation (DES) to perform a functional mapping of the brain in patients awake intraoperatively. When awake surgery is not possible, we propose a pipeline procedure that combines advanced techniques aiming at performing a dissection that respects the anatomo-functional connectivity of the peritumoral region. This procedure can benefit from intraoperative monitoring with computerized tomography scan (iCT-scan) and brain shift correction. Associated with this intraoperative monitoring, the additional value of preoperative investigation combining brain mapping by navigated transcranial magnetic stimulation (nTMS) with various neuroimaging modalities (tractography and resting state functional MRI) has not yet been reported.  A 42-year-old left-handed man had increased intracranial pressure (IICP), left hand muscle deficit, and dysarthria, related to an infiltrative tumor of the right frontal lobe with large mass effect and circumscribed contrast enhancement in motor and premotor cortical areas. Spectroscopy profile and intratumoral calcifications on CT-scan suggested an WHO grade III glioma, later confirmed by histology. The aforementioned surgical procedure was considered, since standard awake surgery was not appropriate for this patient. In preoperative time, nTMS mapping of motor function (deltoid, first interosseous, and tibialis anterior muscles) was performed, combined with magnetic resonance imaging (MRI)-based tractography reconstruction of 6 neural tracts (arcuate, corticospinal, inferior fronto-occipital, uncinate and superior and inferior longitudinal fasciculi) and resting-state functional MRI connectivity (rs-fMRI) of sensorimotor and language networks. In intraoperative time, DES mapping was performed with motor evoked response recording and tumor resection was optimized using non-rigid image transformation of the preoperative data (nTMS, tractography, and rs-fMRI) to iCT data. Image guidance was updated with correction for brain shift and tissue deformation using biomechanical modeling taking into account brain elastic properties. This correction was done at crucial surgical steps, i.e., when tumor bulged through the craniotomy after dura mater opening and when approaching the presumed eloquent brain regions. This procedure allowed a total resection of the tumor region with contrast enhancement as well as a complete regression of IICP and dysarthria. Hand paresis remained stable with no additional deficit. Postoperative nTMS mapping confirmed the good functional outcome.  This case report and technical note highlights the value of preoperative functional evaluation by nTMS updated intraoperatively with correction of brain deformation by iCT. This multimodal approach may become the optimized technique of reference for patients with brain tumors in eloquent areas that are unsuitable for awake brain surgery.

Case Report: Multimodal Functional and Structural Evaluation Combining Pre-operative nTMS Mapping and Neuroimaging With Intraoperative CT-Scan and Brain Shift Correction for Brain Tumor Surgical Resection.

A significant number of patients with a peripheral neuropathy have IgM monoclonal gammopathy (IgM-MG). In this work, we encompassed the spectrum and outcome of IgM-related neuropathies (IgM-NP) in a large monocentric cohort of patients with IgM-MG.

Revisiting the spectrum of IgM-related neuropathies in a large cohort of IgM monoclonal gammopathy.

Peripheral neuropathy is a frequent complication of brentuximab vedotin (BV), used in CD30+ lymphoma treatment. Classic BV-induced neuropathy (BV-CN) is a mild distal sensory axonal polyneuropathy. Severe BV-induced inflammatory neuropathies (BV-IN) have been described. BV-IN contribute to lymphoma-associated morbidity but might be immunotherapy-responsive. Our primary objective was to evaluate the rate of BV-IN. Our secondary objectives were to determine risk factors and warning signs.

Rate and characteristics of inflammatory neuropathies associated with brentuximab vedotin therapy.

Motor preparation and execution can be impaired in patients with multiple sclerosis (pwMS). These neural processes can be assessed using electroencephalography (EEG). During a self-paced movement, EEG signal amplitude decreases before movement (event-related desynchronization, ERD) and increases after movement (event-related synchronization, ERS).

Event-related desynchronization and synchronization in multiple sclerosis.

Impaired motor function is a major cause of disability in multiple sclerosis (MS), involving various neuroplasticity processes typically assessed by neuroimaging. This study aimed to determine whether navigated transcranial magnetic stimulation (nTMS) could also provide biomarkers of motor cortex plasticity in patients with MS (pwMS).

Motor function in multiple sclerosis assessed by navigated transcranial magnetic stimulation mapping.

To evaluate whether continuously tracking unconditioned thresholds for maintaining constant motor-evoked potential (MEP) amplitudes improves the variability of amplitude-based short-interval intracortical inhibition (SICI) measurements.

Short-interval intracortical inhibition (SICI): effect of target tracking on variability of responses for 1 mV and 200µV test-alone targets.

Electroencephalography (EEG)-guided neurofeedback (NFB) is a rarely evaluated neuromodulation technique for the treatment of chronic neuropathic pain.

Article	Year
Case Report: Multimodal Functional and Structural Evaluation Combining Pre-operative nTMS Mapping and Neuroimaging With Intraoperative CT-Scan and Brain Shift Correction for Brain Tumor Surg... Frontiers in human neuroscience\| PubMed ID: 33716700	2021
Revisiting the spectrum of IgM-related neuropathies in a large cohort of IgM monoclonal gammopathy. Journal of neurology\| PubMed ID: 35505107	2022
Rate and characteristics of inflammatory neuropathies associated with brentuximab vedotin therapy. European journal of neurology\| PubMed ID: 38511878	2024
Event-related desynchronization and synchronization in multiple sclerosis. Multiple sclerosis and related disorders\| PubMed ID: 38604003	2024
Motor function in multiple sclerosis assessed by navigated transcranial magnetic stimulation mapping. Journal of neurology\| PubMed ID: 38709305	2024
Short-interval intracortical inhibition (SICI): effect of target tracking on variability of responses for 1 mV and 200µV test-alone targets. Neurophysiologie clinique = Clinical neurophysiology\| PubMed ID: 40639034	2025
Relieving Chronic Neuropathic Pain With EEG-Neurofeedback. European journal of neurology\| PubMed ID: 40947911	2025

Benjamin Bardel

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