Paradoxical effect of digital anaesthesia on force and corticospinal excitability.
The role played by sensory information in maintaining motor cortical representations is still incompletely understood. We investigated the effect of digital anaesthesia of the index finger and thumb on the amplitude of motor evoked potentials to transcranial magnetic stimulation (TMS) recorded from the first dorsal interosseus, F-wave response probability and maximal key pinch force. Whereas digital anaesthesia led to a 29% decrease in maximal force, both motor evoked potential amplitudes and F-wave probability remained unchanged. This dramatic decrease in maximal voluntary contraction following digital anaesthesia may result from a lack of proper sensory feedback during the task.
Duque
Julie
J
Laboratoire de Neurophysiologie, Université Catholique de Louvain, Bruxelles, Belgium. julie.duque@nefy.ucl.ac.be
Vandermeeren
Yves
Y
Lejeune
Thierry M
TM
Thonnard
Jean-Louis
JL
Smith
Allan M
AM
Olivier
Etienne
E
D000328:Adult; D000758:Anesthesia / Q000379:methods*; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology* / Q000528:radiation effects; D005385:Fingers / Q000294:innervation / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology / Q000528:radiation effects; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008280:Magnetics; D009044:Motor Cortex / Q000502:physiology* / Q000528:radiation effects; D009119:Muscle Contraction / Q000502:physiology / Q000528:radiation effects; D018482:Muscle, Skeletal / Q000502:physiology / Q000528:radiation effects; D011712:Pyramidal Tracts / Q000502:physiology* / Q000528:radiation effects; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects