Details

Autor(en) / Beteiligte

• Conde, Virginia
• Vollmann, Henning
• Sehm, Bernhard
• Taubert, Marco
• Villringer, Arno
• Ragert, Patrick

Titel

Cortical thickness in primary sensorimotor cortex influences the effectiveness of paired associative stimulation

Ist Teil von

• NeuroImage (Orlando, Fla.), 2012-04, Vol.60 (2), p.864-870

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2012

Quelle

MEDLINE

Beschreibungen/Notizen

• Non-invasive brain stimulation protocols in general and paired associative stimulation (PAS) in particular seem to alter corticospinal excitability and thereby to influence behaviour with a high degree of inter-subject variability. The cause of this variability is multidimensional and to some extent still unknown. Here, we tested the hypothesis that individual variations in cortical thickness can explain some of the variability of PAS-induced excitability changes. Ten minutes of a facilitatory PAS protocol (PASLTP) rapidly increased corticospinal excitability in the majority of the subjects (14/19 subjects) while others showed no such effect (5/19 subjects). A whole brain correlation analysis based on high resolution T1-weighted images revealed a significant positive relationship of PASLTP-induced excitability changes with cortical thickness of the underlying left sensorimotor cortex (SM1) only. Cortical thickness alone, among other potential influencing factors, explained about half of the PASLTP variance, indicating that subjects with a strong after-effect were those with thicker gray matter in this region. Based on these findings, we provide novel evidence that local brain structure influences the individual amount of functional plasticity induced by PASLTP. While the underlying neurophysiological and/or anatomical reasons for this effect still remain elusive at this point, we conclude that cortical thickness should be considered as an important and until now not recognized modulating factor in studies employing non-invasive brain stimulation techniques. ► Facilitatory PAS rapidly increases corticospinal excitability in M1. ► PAS-induced excitability changes are highly variable across subjects. ► Cortical thickness in sensorimotor cortex (SM1) influences the variable PAS effects. ► Cortical thickness is an important determinant influencing the outcome of PAS.