一种基于导航经颅磁刺激的功能性运动定位标准化协议

Overview

This article presents a standardized protocol for motor mapping and corticospinal tract (CST) assessment using navigated transcranial magnetic stimulation (nTMS) combined with diffusion tensor imaging (DTI). The protocol is designed for neurosurgical planning, functional mapping, and neuroplasticity research, enabling precise delineation of motor cortical regions and their subcortical projections. The method is clinically applicable, reproducible, and suitable for integration into routine workflows.

Key Study Components

Area of Science

• Neurosurgery
• Neurophysiology
• Neuroimaging

Background

• Intraoperative direct electrical stimulation is the gold standard for motor mapping, but preoperative methods are limited.
• Neuronavigation systems optimize coil positioning during repetitive TMS (rTMS) treatments.
• nTMS is increasingly used for functional mapping of motor and language areas, especially before tumor resection.
• Combining nTMS with DTI allows for detailed mapping of motor pathways and assessment of cortical plasticity.

Purpose of Study

• To provide a reproducible protocol for motor mapping using nTMS and DTI-based CST reconstruction.
• To improve preoperative motor mapping for neurosurgical planning and risk assessment.
• To enable detection of functional reorganization in patients with brain lesions.

Methods Used

• Import high-resolution anatomical brain images into neuronavigation software for 3D reconstruction.
• Coregister anatomical landmarks and scalp points for accurate subject-image alignment.
• Apply surface electrodes and perform electromyography (EMG) during nTMS stimulation.
• Map motor cortical areas by stimulating at defined intensities and coil orientations, recording motor evoked potentials (MEPs).
• Identify hotspots and determine resting motor thresholds for each muscle.
• Export positive stimulation points for DTI-based fiber tracking and CST reconstruction.
• Integrate motor maps and tractography data into neurosurgical planning software.

Main Results

• The protocol enables rapid and precise identification of motor eloquent cortical regions (in under 19 minutes in healthy subjects).
• Motor mapping reveals distinct cortical representations for different muscle groups.
• Combining nTMS with DTI allows for individualized CST reconstruction, even in patients with brain tumors or lesions.
• The method supports detection of functional reorganization and assessment of motor system integrity.

Conclusions

• The nTMS-DTI protocol is clinically applicable and reproducible for presurgical planning.
• It provides functional information that can guide individualized surgical strategies to maximize lesion resection while preserving motor function.
• The approach is valuable for neuroplasticity research and rehabilitation planning in neurological and psychiatric disorders.

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