PMID- 11387406
OWN - NLM
STAT- MEDLINE
DCOM- 20010726
LR  - 20171213
IS  - 0022-3077 (Print)
IS  - 0022-3077 (Linking)
VI  - 85
IP  - 6
DP  - 2001 Jun
TI  - Cerebral blood-flow changes induced by paired-pulse transcranial magnetic 
      stimulation of the primary motor cortex.
PG  - 2624-9
AB  - Positron emission tomography (PET) was used to assess changes in regional 
      cerebral blood flow (CBF) induced by paired-pulse transcranial magnetic 
      stimulation (TMS) of primary motor cortex (M1). The study was performed in eight 
      normal volunteers using two Magstim-200 stimulators linked with a Bistim module. 
      A circular TMS coil was held in the scanner by a mechanical arm and located over 
      the left M1. Surface electrodes were used to record motor evoked potentials 
      (MEPs) from the contralateral first dorsal interosseous muscle (FDI). Cortical 
      excitability was evaluated in the relaxed FDI using a paired conditioning-test 
      stimulus paradigm with two interstimulus intervals (ISIs): 3 and 12 ms. The 
      subjects were scanned three times during each of the following four conditions: 
      1) baseline with no TMS (BASE); 2) single-pulse TMS (TMSsing); 3) 3-ms 
      paired-pulse TMS (TMS3); and 4) 12-ms paired-pulse TMS (TMS12). CBF and 
      peak-to-peak MEP amplitudes were measured over each 60-s scanning period. To 
      assess TMS-induced changes in CBF, a t-statistic map was generated by first 
      subtracting the single-pulse TMS condition from the 3- and 12-ms paired-pulse TMS 
      conditions and then correlating the CBF differences, respectively, with the 
      amount of suppression and facilitation of the EMG responses. A significant 
      positive correlation was observed between the CBF difference (TMS3-TMSsing) and 
      the amount of suppression of EMG response, as well as between the CBF difference 
      (TMS12-TMSsing) and the amount of facilitation of EMG response. This positive 
      correlation was observed in the left M1, left lateral premotor cortex, and right 
      M1 in the case of 3-ms paired-pulse TMS, but only in the left M1 in the case of 
      12-ms paired-pulse TMS. The above pattern of CBF response to paired-pulse TMS 
      supports the possibility that suppression and facilitation of the EMG response 
      are mediated by different populations of cortical interneurons.
FAU - Strafella, A P
AU  - Strafella AP
AD  - Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, 
      Canada.
FAU - Paus, T
AU  - Paus T
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Neurophysiol
JT  - Journal of neurophysiology
JID - 0375404
SB  - IM
MH  - Adult
MH  - Cerebrovascular Circulation/*physiology
MH  - Female
MH  - Humans
MH  - Interneurons/physiology
MH  - Male
MH  - Motor Cortex/*blood supply/cytology/*physiology
MH  - Tomography, Emission-Computed
MH  - *Transcranial Magnetic Stimulation
EDAT- 2001/06/02 10:00
MHDA- 2001/07/28 10:01
CRDT- 2001/06/02 10:00
PHST- 2001/06/02 10:00 [pubmed]
PHST- 2001/07/28 10:01 [medline]
PHST- 2001/06/02 10:00 [entrez]
AID - 10.1152/jn.2001.85.6.2624 [doi]
PST - ppublish
SO  - J Neurophysiol. 2001 Jun;85(6):2624-9. doi: 10.1152/jn.2001.85.6.2624.