Use a grid placed over the motor region to
simply move the TMS coil from one grid
location to the other. In addition to TMS
pulse location and coil direction, additional
information such as motor output
percentage, amplitude,latency, etc. are
saved for further analysis.
Explore how TMS Motor Mapping Works
Single pulse TMS combined with neuronavigation allows to ‘map’, i.e. to locate and outline, functional areas of the
cortex. This feature is used for applications ranging from basic neurophysiology / plasticity assessment, brain surgery
planning or to understand motor recovery after stroke. It is known that cortical locations corresponding to neurologic
functions can vary significantly among individuals. In addition, lesions and tumors may distort underlying anatomical
features, thereby further hindering localization of key functions. TMS Motor Mapping therefore presents a rational way to
assess and locate the exact cortical area responsible for a specific function.
Motor mapping with TMS begins with acquiring high-resolution structural MRI data sufficient to provide necessary
anatomical detail. The MRI is imported into the Neural Navigator system and a 3D model of the patient showing the skin
is constructed immediately. A patient-specific file is created by marking facial landmarks on the scalp like the tip of the
nose, tragus of the ears, etc. and then using the in-built brain segmentation routine to visualize the brain. This file is
created offline and prior to the procedure. In the patient room, surface electrodes are attached to the patient’s muscles
for EMG recording. The exact location is determined by the muscles that the physician wants to study. This could range
from the face,hand, arm, leg to the foot muscles. To initiate navigated TMS, the patient-specific file created prior, is
opened. The hand-held pointer is then moved close to the chosen facial landmarks on the patient’s skin one-by-one
and the tip coordinates of the pointer captured. These tip coordinates are then aligned with the coordinates of the
patients 3D model to begin navigation. Resting motor threshold (RMT) of the patient is then determined by delivering
magnetic pulses from a TMS coil. It is typically defined as the minimum TMS stimulation intensity capable of generating
an Motor Evoked Potential (MEP) in 50% of the cases. Motor mapping is then performed at 110% of the RMT.
The location of the TMS pulses as well as the TMS coil direction are depicted as flags and additional information such
as motor output percentage, amplitude, latency, etc. are saved. After motor mapping is complete, the physician
processes the saved MEP data (for instance less than or equal to a certain threshold, range, etc.) and determines the
The Neural Navigator is the only FDA cleared Neuronavigation System that is not affected by line-of-sight occlusion.
The clearance was based on clinical evidence showing tracking and navigation system accuracy better than the
The Neural Navigator offers additional benefits such has highly intuitive software workflow, light weight, and having the
smallest footprint in its class that allows fitting the system into tight spaces.
The fully integrated solution from Soterix Medical combines Neural Navigator, MEGA-TMS (Single Pulse TMS device)
with an EMG system. This combined offering reflects the only system that is built to accommodate the latest advance
in TMS Motor Mapping.