TMS Brain Mapping in Less Than Two Minutes

Abstract

To account for inter-participant variability, outliers, coil positioning errors and, most importantly, participant comfort during data acquisition, we recommend creating a map with 80 stimuli and a 1.5 s ISI. This makes it possible to acquire TMS maps in 2 min, making mapping a more feasible tool to study short- and long-term changes in cortical organization.

Neuromuscular Plasticity: Disentangling Stable and Variable Motor Maps in the Human Sensorimotor Cortex

“…During the mapping, about 100 stimuli were applied, with some subject-to-subject variability due to the individual cortical representation of the EDC [31]. Recent findings indicate that reliable motor maps could be created with around 60 stimuli [42]. During this study, the respective map could also be captured with less than 100 stimuli in subjects who had a small cortical representation of the EDC, while in others, more stimuli were required.…”

Interindividual Variability in Use-Dependent Plasticity Following Visuomotor Learning: The Effect of Handedness and Muscle Trained

“…The x-and y-coordinate of the COG was calculated from the MEP pp amplitude and its position on the map, thus creating an amplitude weighted mean of the map. Full details of this process are described in van de Ruit, Perenboom, and Grey (2015).…”

“…CSE was assessed using TMS maps acquired with a novel rapid mapping procedure that takes advantage of frameless stereotaxy together with a reduced interstimulus interval (van de Ruit, Perenboom, & Grey, 2015). After finding the motor hotspot and motor threshold of the muscle studied, a square 6 £ 6 cm grid was positioned over the hemisphere studied.…”

“…We aimed to quantify the number of responders and nonresponders with regard to changes in CSE across all trained muscles. Changes in CSE are assessed using a novel TMS mapping technique (van de Ruit, Perenboom, & Grey, 2015), rather than averaging a set of single MEPs to quantify CSE by mean MEP amplitude. TMS maps allow one to draw the same conclusions as the more commonly used stimulus-response curve (Ridding & Rothwell, 1997), while providing the additional ability to expose uneven expansions of the cortical map or changes in the distribution of excitability which can otherwise not be detected.…”

Mapping dynamical properties of cortical microcircuits using robotized TMS and EEG: Towards functional cytoarchitectonics

“…The sham condition consisted of stimulating 3 to 5 cm above one of the cortical targets (randomly distributed between subjects) at the highest intensity used within each subject (see below), in order to produce a click sound of maximum intensity. Each cortical target was stimulated during 2 min 30 s at instantaneous frequency around 0.5-0.7 Hz in a random manner, so that no phase effect could build up as demonstrated by others on corticospinal excitability (van de Ruit et al, 2015). This led to an average number of 90 trials per stimulation point.…”