Accessory nerve electroneurography by magnetic stimulation in normal subjects.
An electroneurographic study was made of the accessory nerve in 15 healthy subjects by conventional peripheral electrical stimulation and transcranial magnetic stimulation at three different levels: cortical contralateral (frontoparietal), homolateral occipital and at the base of the skull. The motor evoked potential (MEP) obtained by magnetic stimulation at the skull base exhibited greater latency and amplitude than that recorded by conventional peripheral electrical stimulation. The MEP obtained by stimulating at occipital level again exhibited a greater latency than that corresponding to skull base stimulation, but the amplitude was smaller. Finally, the MEP resulting from cortical stimulation failed to appear uniformly in all of the individuals studied. Its amplitude was smaller than in the previous cases, with a mean latency of 11.76 ms and a central conduction time of 7.5 ms. The magnetic stimulation technique allowed the efficient, painless, non-invasive and easily reproducible study of the motor pathway of the spinal nerve over its entire trajectory (motor cortex-motor neuron-muscle).
Barona
R
R
Department of Otolaryngology, Valencia University General Hospital, Spain.
Montalt
J
J
Escudero
J
J
Campos
A
A
Escudero
M
M
D000055:Accessory Nerve / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D004568:Electrodiagnosis / Q000379:methods*; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D010812:Physical Stimulation / Q000379:methods*