Heterotopic CO2 laser stimulation inhibits tooth-related somatosensory evoked potentials.

Background: The diffuse noxious inhibitory control (DNIC) effect is the neurophysiological basis for the phenomenon that heterotopic "pain inhibits pain" in remote areas of the body. The effect of DNIC is mediated by spino-bulbo-spinal loops and a final postsynaptic inhibitory mechanism. The DNIC effect depends on intensity, duration, quality, and application site of conditioning stimulation and stimulated nerve fiber-type.

Diffuse noxious inhibitory controls triggered by heterotopic CO2 laser conditioning stimulation decreased the SEP amplitudes induced by electrical tooth stimulation with different intensity at an equally inhibitory rate.

The purpose of this study was to investigate (1) whether selective Adelta-fiber stimulation with CO(2) laser produces a diffuse noxious inhibitory controls (DNIC) effect in the trigeminal nerve territory; and (2) whether the DNIC effect differs depending on test stimulus intensities under constant conditioning stimuli. To examine whether the CO(2) laser radiation on the dorsum of the hand selectively stimulates Adelta-fibers, laser evoked potentials (LEP) were recorded. The mean peak latency of LEP was 381.

Heterotopic ischemic pain attenuates somatosensory evoked potentials induced by electrical tooth stimulation: diffuse noxious inhibitory controls in the trigeminal nerve territory.

The purpose of this study was to determine whether the late component of somatosensory evoked potentials (SEP) induced by electrical tooth stimulation and pain intensity are inhibited by heterotopic ischemic stimulation. The tourniquet pressure with 50 mmHg greater than the individual's systolic pressure was applied to the left upper arm for 10 min as ischemic conditioning stimulation. The late component of SEP and visual analogue scale (VAS) were recorded at 4 times and both were significantly decreased when ischemic conditioning stimulation was applied.

An experimental system for a heterotopic pain stimulation study in humans.

So far heterotopic pain stimulation study has been performed in humans. Many studies have examined changes in subjective pain threshold and nociceptive somatic reflex. However, there are few studies using somatosensory evoked potentials (SEPs) for heterotopic pain stimulation study.