G. Cruccu et al., Conduction velocity of the human spinothalamic tract as assessed by laser evoked potentials, NEUROREPORT, 11(13), 2000, pp. 3029-3032
To study the conduction velocity of the spinothalamic tract (STT) we delive
red CO2 laser pulses, evoking pinprick sensations, to the skin overlying th
e vertebral spinous processes at different spinal levels from C5 to T10 and
recorded evoked potentials (LEPs) in 15 healthy human subjects. These stim
uli yielded large-amplitude vertex potentials consisting of a negative wave
at a peak latency of about 200 ms followed by a positive wave at a peak la
tency of about 300 ms. The mean conduction velocity of the STT was 21 m/s,
i.e. higher than the reported velocity of the corresponding primary sensory
neurons (type II AMH). Because dorsal stimulation readily yields reproduci
ble brain LEPs, we expect this technique to be useful as a diagnostic tool
for assessing the level of spinal cord lesions. NeuroReport 11:3029-3032 (C
) 2000 Lippincott Williams & Wilkins.