PMID- 17963336
OWN - NLM
STAT- MEDLINE
DCOM- 20080117
LR  - 20211020
IS  - 0513-5796 (Print)
IS  - 1976-2437 (Electronic)
IS  - 0513-5796 (Linking)
VI  - 48
IP  - 5
DP  - 2007 Oct 31
TI  - Different modulation of the cortical silent period by two phases of short 
      interval intracortical inhibition.
PG  - 795-801
AB  - PURPOSE: To investigate the influence of 2 phases of short interval intracortical 
      inhibition (SICI) on the cortical silent period (SP). MATERIALS AND METHODS: 
      Single- and paired-pulse transcranial magnetic stimulations (TMSs) at 1 and 2.5ms 
      interstimulus intervals (ISIs) were applied to the left motor cortex in 12 
      healthy subjects while their right hand muscles were moderately activated. 
      Conditioning stimulation intensity was 90% of the active motor threshold (AMT). 
      Test stimulation intensities were 120, 140, 160, 180, 200, 220, 240, 260% of the 
      AMT and at 100% of the maximal stimulator output, the order of which was arranged 
      randomly. The rectified electromyography area of motor evoked potential (MEP) and 
      duration of the SP were measured off-line using a computerized program. RESULTS: 
      At high-test stimulation intensities, MEP areas were saturated in both single- 
      and paired-pulse stimulations, except that saturated MEPs were smaller for the 
      paired-pulse TMS at 1ms ISI than for the other conditions. As the test 
      stimulation intensity increased, SP was progressively prolonged in both single- 
      and paired-pulse stimulations but was shorter in paired-pulse than single-pulse 
      TMS. Overall, the ratio of SP duration/MEP area was comparable between single- 
      and paired-pulse TMS except for the paired-pulse TMS at 1 ms ISI with a test 
      stimulation intensity at 140-180% of the AMT, in which the ratio was 
      significantly higher than in the single pulse TMS. CONCLUSION: These results 
      suggest that 2 phases of SICI modulate MEP saturation and SP duration differently 
      and provide additional evidence supporting the view that 2 phases of SICI are 
      mediated by different inhibitory mechanisms.
FAU - Kang, Suk Yun
AU  - Kang SY
AD  - Department of Neurology, Yonsei University College of Medicine, 250 Seongsanno, 
      Seodaemun-gu, Seoul, Korea.
FAU - Shin, Hae-Won
AU  - Shin HW
FAU - Sohn, Young Ho
AU  - Sohn YH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Korea (South)
TA  - Yonsei Med J
JT  - Yonsei medical journal
JID - 0414003
SB  - IM
MH  - Adult
MH  - Evoked Potentials, Motor/*physiology
MH  - Female
MH  - Humans
MH  - Male
MH  - Motor Cortex/*physiology
MH  - Transcranial Magnetic Stimulation
PMC - PMC2628145
EDAT- 2007/10/30 09:00
MHDA- 2008/01/18 09:00
PMCR- 2007/10/31
CRDT- 2007/10/30 09:00
PHST- 2007/10/30 09:00 [pubmed]
PHST- 2008/01/18 09:00 [medline]
PHST- 2007/10/30 09:00 [entrez]
PHST- 2007/10/31 00:00 [pmc-release]
AID - 200710795 [pii]
AID - 10.3349/ymj.2007.48.5.795 [doi]
PST - ppublish
SO  - Yonsei Med J. 2007 Oct 31;48(5):795-801. doi: 10.3349/ymj.2007.48.5.795.