[The excitation site of MEP on facial nerve by transcranial magnetic stimulation].
A magnetic stimulator was used for direct transcutaneous stimulation of the intracranial portion of the facial nerve in 30 normal subjects. Compound muscle action potentials (CMAPs) thus elicited in the frontal muscle of controls were of similar amplitude but of longer latency (1.3 +/- 0.6ms) as compare with CMAPs produced by conventional electrical stimulation at the stylomastoid foramen. Because the measured distal facial nerve motor conduction velocity was 50-60 mm/ms, the locus of impulse generation induced by magnetic coil stimulation was estimated to be approximately 65mm proximal to the site of electrical stimulation at the stylomastoid foramen, i.e., closer to the exit of the facial nerve from the brain stem than to its entrance into the internal auditory meatus.
Gao
Z
Z
PUMC Hospital, Beijing.
Zhang
L
L
D000328:Adult; D004558:Electric Stimulation; D005071:Evoked Potentials; D005152:Facial Muscles / Q000502:physiology; D005154:Facial Nerve / Q000502:physiology*; D005260:Female; D006257:Head; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D050781:Transcranial Magnetic Stimulation