Nonspecific facilitation of responses to transcranial magnetic stimulation
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Nonspecific facilitation of responses to transcranial magnetic stimulation. / Andersen, Birgit; Rösler, Kai M.; Lauritzen, Martin.
In: Muscle and Nerve, Vol. 22, No. 7, 27.07.1999, p. 857-863.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Nonspecific facilitation of responses to transcranial magnetic stimulation
AU - Andersen, Birgit
AU - Rösler, Kai M.
AU - Lauritzen, Martin
PY - 1999/7/27
Y1 - 1999/7/27
N2 - We examined the effect of facial muscle contraction and eye movements on motor evoked potentials (MEPs) from the abductor pollicis brevis muscle (APB) evoked by transcranial magnetic stimulation (TMS). The hypothesis was that activity of large cortical regions (face) influences the excitability of spinal motoneurons via cortical or subcortical pathways. MEPs were recorded in 12 healthy subjects during the following conditions: (1) rest; (2) facial muscle contraction; (3) eye movements; (4) 10% precontraction of the target muscle; and (5) simultaneous target muscle precontraction and facial muscle contraction. In 9 subjects, spinal motoneuron excitability was assessed by measurements of F waves during the same facilitation maneuvers. Activation of eye and facial muscles clearly facilitated MEPs from the APB. The facilitation of MEP size during nonspecific maneuvers was almost similar to that obtained by target muscle precontraction, whereas shortening of latencies was significantly smaller. The occurrence and amplitude of F waves increased in parallel with MEP size during specific and nonspecific facilitation, pointing to spinal motoneuronal threshold changes as a potential facilitatory mechanism by facial and eye muscle activation. The different MEP latencies during specific and nonspecific facilitation were not explained by different spinal motoneuron excitability, but raise the possibility that supraspinal mechanisms contributed to nonspecific facilitation.
AB - We examined the effect of facial muscle contraction and eye movements on motor evoked potentials (MEPs) from the abductor pollicis brevis muscle (APB) evoked by transcranial magnetic stimulation (TMS). The hypothesis was that activity of large cortical regions (face) influences the excitability of spinal motoneurons via cortical or subcortical pathways. MEPs were recorded in 12 healthy subjects during the following conditions: (1) rest; (2) facial muscle contraction; (3) eye movements; (4) 10% precontraction of the target muscle; and (5) simultaneous target muscle precontraction and facial muscle contraction. In 9 subjects, spinal motoneuron excitability was assessed by measurements of F waves during the same facilitation maneuvers. Activation of eye and facial muscles clearly facilitated MEPs from the APB. The facilitation of MEP size during nonspecific maneuvers was almost similar to that obtained by target muscle precontraction, whereas shortening of latencies was significantly smaller. The occurrence and amplitude of F waves increased in parallel with MEP size during specific and nonspecific facilitation, pointing to spinal motoneuronal threshold changes as a potential facilitatory mechanism by facial and eye muscle activation. The different MEP latencies during specific and nonspecific facilitation were not explained by different spinal motoneuron excitability, but raise the possibility that supraspinal mechanisms contributed to nonspecific facilitation.
KW - F wave
KW - Facilitation
KW - Motor control
KW - Motor evoked potential
KW - Spinal excitability
KW - Transcranial magnetic stimulation
UR - http://www.scopus.com/inward/record.url?scp=0345643326&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1097-4598(199907)22:7<857::AID-MUS7>3.0.CO;2-B
DO - 10.1002/(SICI)1097-4598(199907)22:7<857::AID-MUS7>3.0.CO;2-B
M3 - Journal article
C2 - 10398202
AN - SCOPUS:0345643326
VL - 22
SP - 857
EP - 863
JO - Muscle & Nerve
JF - Muscle & Nerve
SN - 0148-639X
IS - 7
ER -
ID: 201453916