PMID- 10363781
OWN - NLM
STAT- MEDLINE
DCOM- 19990624
LR  - 20190921
IS  - 1388-2457 (Print)
IS  - 1388-2457 (Linking)
VI  - 110
IP  - 3
DP  - 1999 Mar
TI  - Modulation of intracortical excitability for different muscles in the upper 
      extremity: paired magnetic stimulation study with focal versus non-focal coils.
PG  - 575-81
AB  - OBJECTIVE: Intracortical excitability was studied for 4 muscles in the upper 
      extremity by paired transcranial magnetic stimulation on the motor cortex, using 
      focal and non-focal coils. METHODS: Surface EMG responses of two hand and two 
      forearm muscles were simultaneously recorded in 13 healthy subjects, after 
      delivering paired stimuli at interstimulus intervals (ISIs) of 1-50 ms using 
      circular and figure-of-8 (focal) coils. The intensities of conditioning and test 
      stimuli were submotor and supramotor thresholds, respectively. RESULTS: Paired 
      stimulation using a circular coil showed constant inhibition at 2 ms ISI for all 
      muscles, but not at 5 ms ISI, and induced facilitation at 10 ms ISI. The results 
      using a focal coil were similar to those with a circular coil at all ISIs except 
      at 5 ms ISI, where the former showed inhibition. At 20 and 30 ms ISIs, there was 
      interindividual variability for both coils, some subjects showing inhibition and 
      others facilitation. CONCLUSIONS: The difference of the inhibition at 5 ms ISI 
      between using circular and focal coils could be attributed to the cortical 
      mechanism. The inhibitory effect at 2 ms ISI, consistently observed for the 4 
      muscles with both types of coil, could be easily applied to assess the inhibitory 
      intracortical function in patients with neurological diseases.
FAU - Shimizu, T
AU  - Shimizu T
AD  - I.R.C.C.S. Ospedale di Riabilitazione S. Lucia, Rome, Italy.
FAU - Filippi, M M
AU  - Filippi MM
FAU - Palmieri, M G
AU  - Palmieri MG
FAU - Oliveri, M
AU  - Oliveri M
FAU - Vernieri, F
AU  - Vernieri F
FAU - Pasqualetti, P
AU  - Pasqualetti P
FAU - Rossini, P M
AU  - Rossini PM
LA  - eng
PT  - Journal Article
PL  - Netherlands
TA  - Clin Neurophysiol
JT  - Clinical neurophysiology : official journal of the International Federation of 
      Clinical Neurophysiology
JID - 100883319
SB  - IM
MH  - Adult
MH  - Arm/*physiology
MH  - Brain/*physiology
MH  - Female
MH  - H-Reflex/physiology
MH  - Humans
MH  - *Magnetics
MH  - Male
MH  - Middle Aged
MH  - Muscles/*physiology
MH  - Time Factors
EDAT- 1999/06/11 00:00
MHDA- 1999/06/11 00:01
CRDT- 1999/06/11 00:00
PHST- 1999/06/11 00:00 [pubmed]
PHST- 1999/06/11 00:01 [medline]
PHST- 1999/06/11 00:00 [entrez]
AID - S1388-2457(98)00081-9 [pii]
AID - 10.1016/s1388-2457(98)00081-9 [doi]
PST - ppublish
SO  - Clin Neurophysiol. 1999 Mar;110(3):575-81. doi: 10.1016/s1388-2457(98)00081-9.