On the calculation of transcallosal conduction time using transcranial magnetic stimulation.
Transcallosal conduction time (TCT), based on the results of transcranial magnetic stimulation studies, is currently calculated as a function of the ipsilateral silent period (iSP) and of the motor evoked potential (MEP) obtained from a target muscle (TCTcurrent = iSP latency - MEP latency). We argue that this measure overestimates TCT and may lead to a bias in statistical group comparisons. We propose an alternative measure, TCTproposed, which we defined as TCTproposed = iSP latency - cSP latency, where cSP is the contralateral silent period. We report our results on the comparison of the two measures in twenty healthy individuals and provide a theoretical basis for TCTproposed.
Deftereos
Spyros N
SN
Department of Neurology, G. Gennimatas Athens General Hospital, Athens, Greece. deftereo@gmail.com
Panagopoulos
Gregory
G
Georgonikou
Dimitra
D
Karageorgiou
Elissaios
E
Andriopoulos
Panagiotis
P
Karageorgiou
Clementine E
CE
D000328:Adult; D055592:Biophysical Phenomena / Q000502:physiology*; D003337:Corpus Callosum / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology*; D012189:Retrospective Studies; D050781:Transcranial Magnetic Stimulation / Q000379:methods*