PMID- 15390002
OWN - NLM
STAT- MEDLINE
DCOM- 20050214
LR  - 20220316
IS  - 0885-3185 (Print)
IS  - 0885-3185 (Linking)
VI  - 19
IP  - 11
DP  - 2004 Nov
TI  - Elevated threshold for intracortical inhibition in focal hand dystonia.
PG  - 1312-7
AB  - Differences between control and focal hand dystonia (FHD) subject groups in short 
      interval intracortical inhibition (SICI) as determined by paired transcranial 
      magnetic stimulation (TMS) can be difficult to demonstrate, due to 
      interindividual differences. The purpose of this study was to compare two TMS 
      methods for assessing SICI in 8 control and 7 FHD subjects. Electromyographic 
      (EMG) data were recorded from the first dorsal interosseous (FDI) muscle of the 
      dominant hands of the control subjects and affected hands of the FHD subjects. 
      The first method used a conventional approach of setting conditioning stimulus 
      intensity to 80% of rest threshold (RTh) and test stimulus intensity to 120% RTh. 
      Three interstimulus intervals (ISIs) were used: 2 msec, 3 msec, and the ISI 
      between 2 and 3 msec that produced optimal SICI. The second method was novel in 
      that test stimulus intensity was set to 150% active threshold (ATh), and 
      conditioning stimulus intensity was varied between 50% and 100% ATh. The latter 
      was determined at the threshold for SICI and expressed as a ratio of ATh. There 
      was no difference between the subject groups in the degree of SICI produced using 
      the first method, at the three ISIs studied. However, using the second method, 
      the SICI threshold:ATh ratio was found to be significantly higher for FHD 
      subjects. This finding suggests that determining the SICI threshold:ATh ratio may 
      be a more sensitive measure of intracortical inhibitory function than more 
      conventional methods.
FAU - Stinear, Cathy M
AU  - Stinear CM
AD  - Human Motor Control Laboratory, University of Auckland, Auckland, New Zealand. 
      c.stinear@auckland.ac.nz
FAU - Byblow, Winston D
AU  - Byblow WD
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Mov Disord
JT  - Movement disorders : official journal of the Movement Disorder Society
JID - 8610688
SB  - IM
MH  - Adult
MH  - Cerebral Cortex/*physiopathology
MH  - Differential Threshold/physiology
MH  - Dominance, Cerebral/physiology
MH  - Dystonic Disorders/diagnosis/*physiopathology
MH  - Evoked Potentials, Motor/physiology
MH  - Female
MH  - Functional Laterality/physiology
MH  - Humans
MH  - *Magnetics
MH  - Male
MH  - Middle Aged
MH  - Neural Inhibition/*physiology
MH  - Reaction Time/physiology
MH  - Reference Values
EDAT- 2004/09/25 05:00
MHDA- 2005/02/16 09:00
CRDT- 2004/09/25 05:00
PHST- 2004/09/25 05:00 [pubmed]
PHST- 2005/02/16 09:00 [medline]
PHST- 2004/09/25 05:00 [entrez]
AID - 10.1002/mds.20160 [doi]
PST - ppublish
SO  - Mov Disord. 2004 Nov;19(11):1312-7. doi: 10.1002/mds.20160.