Open AccessNeural substrates of low‐frequency repetitive transcranial magnetic stimulation during movement in healthy subjects and acute stroke patients. A PET study
Author(s) -
Conchou Fabrice,
Loubinoux Isabelle,
CastelLacanal Evelyne,
Le Tinnier Anne,
GerdelatMas Angélique,
FaureMarie Nathalie,
Gros Helene,
Thalamas Claire,
Calvas Fabienne,
Berry Isabelle,
Chollet François,
Simonetta Moreau Marion
Publication year - 2009
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.20690
Subject(s) - transcranial magnetic stimulation , motor cortex , premotor cortex , stroke (engine) , psychology , stimulation , medicine , primary motor cortex , cerebral blood flow , physical medicine and rehabilitation , anesthesia , neuroscience , dorsum , anatomy , mechanical engineering , engineering
The aim of the study was to investigate, with an rTMS/PET protocol, the after‐effects induced by 1‐Hz repetitive transcranial magnetic stimulation (rTMS) in the regional cerebral blood flow (rCBF) of the primary motor cortex (M1) contralateral to that stimulated during a movement. Eighteen healthy subjects underwent a baseline PET scan followed, in randomized order, by a session of Real/Sham low‐frequency (1 Hz) subthreshold rTMS over the right M1 for 23 min. The site of stimulation was fMRI‐guided. After each rTMS session (real or sham), subjects underwent behavioral hand motor tests and four PET scans. During the first two scans, ten subjects (RH group) moved the right hand ipsilateral to the stimulated site and eight subjects (LH group) moved the left contralateral hand. All remained still during the last two scans (rest). Two stroke patients underwent the same protocol with rTMS applied on contralesional M1. Compared with Sham‐rTMS, Real‐rTMS over the right M1 was followed by a significant increase of rCBF during right hand movement in left S1M1, without any significant change in motor performance. The effect lasted less than 1 h. The same rTMS‐induced S1M1 overactivation was observed in the two stroke patients. Commissural connectivity between right dorsal premotor cortex and left M1 after real‐rTMS was observed with a psychophysiological interaction analysis in healthy subjects. No major changes were found for the left hand. These results give further arguments in favor of a plastic commissural connectivity between M1 both in healthy subjects and in stroke patients, and reinforce the potential for therapeutic benefit of low‐frequency rTMS in stroke rehabilitation. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.