Cortico-conus motor conduction time (CCCT) for leg muscles.
OBJECTIVE
To measure the conduction time from the motor cortex to the conus medullaris (cortico-conus motor conduction time, CCCT) for leg muscles using magnetic stimulation.


METHODS
Motor evoked potentials (MEPs) were recorded from tibialis anterior muscles in 51 healthy volunteers. To activate spinal nerves at the most proximal cauda equina level or at the conus medullaris level, magnetic stimulation was performed using a MATS coil. Transcranial magnetic stimulation of the motor cortex was also conducted to measure the cortical latency for the target muscle. To obtain the CCCT, the latency of MEPs to conus stimulation (conus latency) was subtracted from the cortical latency.


RESULTS
MATS coil stimulation evoked reproducible MEPs in all subjects, yielding CCCT data for all studied tibialis anterior muscles.


CONCLUSIONS
MATS coil stimulation provides CCCT data for healthy subjects.


CONCLUSIONS
This novel method is useful for evaluation of corticospinal tract function for leg muscles because no peripheral component affects the CCCT.
Matsumoto
Hideyuki
H
Department of Neurology, Division of Neuroscience, Graduate School of Medicine, The University of Tokyo, Japan. hideyukimatsumoto@mail.goo.ne.jp
Hanajima
Ritsuko
R
Shirota
Yuichiro
Y
Hamada
Masashi
M
Terao
Yasuo
Y
Ohminami
Shinya
S
Furubayashi
Toshiaki
T
Nakatani-Enomoto
Setsu
S
Ugawa
Yoshikazu
Y
D000328:Adult; D000368:Aged; D002420:Cauda Equina / Q000502:physiology; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D007866:Leg / Q000294:innervation / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult