PMID- 24075915
OWN - NLM
STAT- MEDLINE
DCOM- 20140825
LR  - 20160518
IS  - 1876-4754 (Electronic)
IS  - 1876-4754 (Linking)
VI  - 7
IP  - 1
DP  - 2014 Jan-Feb
TI  - Influence of waveform and current direction on short-interval intracortical 
      facilitation: a paired-pulse TMS study.
PG  - 49-58
LID - S1935-861X(13)00231-3 [pii]
LID - 10.1016/j.brs.2013.08.002 [doi]
AB  - BACKGROUND: Transcranial magnetic stimulation (TMS) of the human primary motor 
      hand area (M1-HAND) can produce multiple descending volleys in fast-conducting 
      corticospinal neurons, especially so-called indirect waves (I-waves) resulting 
      from trans-synaptic excitation. Facilitatory interaction between these I-waves 
      can be studied non-invasively using a paired-pulse paradigm referred to as 
      short-interval intracortical facilitation (SICF). OBJECTIVE/HYPOTHESIS: We 
      examined whether SICF depends on waveform and current direction of the TMS 
      pulses. METHODS: In young healthy volunteers, we applied single- and paired-pulse 
      TMS to M1-HAND. We probed SICF by pairs of monophasic or half-sine pulses at 
      suprathreshold stimulation intensity and inter-stimulus intervals (ISIs) between 
      1.0 and 5.0 ms. For monophasic paired-pulse stimulation, both pulses had either a 
      posterior-anterior (PA) or anterior-posterior (AP) current direction (AP-AP or 
      PA-PA), whereas current direction was reversed between first and second pulse for 
      half-sine paired-pulse stimulation (PA-AP and AP-PA). RESULTS: Monophasic AP-AP 
      stimulation resulted in stronger early SICF at 1.4 ms relative to late SICF at 
      2.8 and 4.4 ms, whereas monophasic PA-PA stimulation produced SICF of comparable 
      size at all three peaks. With half-sine stimulation the third SICF peak was 
      reduced for PA-AP current orientation compared with AP-PA. CONCLUSION: SICF 
      elicited using monophasic as well as half-sine pulses is affected by current 
      direction at clearly suprathreshold intensities. The impact of current 
      orientation is stronger for monophasic compared with half-sine pulses. The 
      direction-specific effect of paired-pulse TMS on the strength of early versus 
      late SICF shows that different cortical circuits mediate early and late SICF.
CI  - Copyright (c) 2014 Elsevier Inc. All rights reserved.
FAU - Delvendahl, Igor
AU  - Delvendahl I
AD  - Carl-Ludwig-Institute for Physiology, Medical Faculty, Leipzig University, 
      Leipzig, Germany; European Neuroscience Institute Gottingen, Gottingen, Germany.
FAU - Lindemann, Hannes
AU  - Lindemann H
AD  - Department of Pediatrics and Adolescent Medicine, University Medical Center, 
      Freiburg, Germany.
FAU - Jung, Nikolai H
AU  - Jung NH
AD  - Department of Pediatrics, Technische Universitat Munchen, Munich, Germany.
FAU - Pechmann, Astrid
AU  - Pechmann A
AD  - Department of Pediatrics and Adolescent Medicine, University Medical Center, 
      Freiburg, Germany.
FAU - Siebner, Hartwig R
AU  - Siebner HR
AD  - Danish Research Center for Magnetic Resonance, Copenhagen University Hospital 
      Hvidovre, Denmark.
FAU - Mall, Volker
AU  - Mall V
AD  - Department of Pediatrics, Technische Universitat Munchen, Munich, Germany. 
      Electronic address: volker.mall@tum.de.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130910
PL  - United States
TA  - Brain Stimul
JT  - Brain stimulation
JID - 101465726
SB  - IM
MH  - Adult
MH  - Evoked Potentials, Motor/physiology
MH  - Female
MH  - Humans
MH  - Male
MH  - Motor Cortex/*physiology
MH  - Transcranial Magnetic Stimulation/*methods
MH  - Young Adult
OTO - NOTNLM
OT  - I-waves
OT  - Motor cortex
OT  - Paired-pulse transcranial magnetic stimulation
OT  - Short-interval intracortical facilitation
EDAT- 2013/10/01 06:00
MHDA- 2014/08/26 06:00
CRDT- 2013/10/01 06:00
PHST- 2013/03/23 00:00 [received]
PHST- 2013/07/14 00:00 [revised]
PHST- 2013/08/07 00:00 [accepted]
PHST- 2013/10/01 06:00 [entrez]
PHST- 2013/10/01 06:00 [pubmed]
PHST- 2014/08/26 06:00 [medline]
AID - S1935-861X(13)00231-3 [pii]
AID - 10.1016/j.brs.2013.08.002 [doi]
PST - ppublish
SO  - Brain Stimul. 2014 Jan-Feb;7(1):49-58. doi: 10.1016/j.brs.2013.08.002. Epub 2013 
      Sep 10.