Contact Heat and Cold Evoked Potentials
De Keyser R., van den Broeke E., Courtin A., Dufour A., Mouraux A. (2018). Event-related brain potentials elicited by high-speed cooling of the skin: A robust and non-painful method to assess the spinothalamic system in humans. Clinical Neurophysiology. 129(5), 1011-1019.
"We show in healthy participants that brisk non-painful cooling of the skin using a very steep cooling ramp can be used to elicit event-related potentials having a high signal-to-noise ratio. Because these responses are related to the selective activation of cool-sensitive Aδ-fiber free nerve endings whose inputs are conveyed by the spinothalamic tract, these responses could be used as a robust tool to test the function of the spinothalamic system in humans.”
Lenoir C., Algoet M. & Mouraux A. (2018). Deep continuous theta burst stimulation of the opercula-insular cortex selectively affects Adelta fibre heat pain. The Journal of Physiology. 596(19), 4767-4787.
Facial Neuropathic Pain
Vertex complex (N2-P2 recorded at Cz-A1) of cold evoked potentials (CEP, blue traces) and laser evoked potentials (LEP, red traces) after stimulation of the healthy and the affected side. Each trace represents the average of 20-30 trials. Dotted lines indicate the stimulus onset. Whereas the laser stimulation of the affected side yielded dampened, though still present, scalp potentials, cold stimulation failed to evoke reproducible scalp potentials.
Leone C., Dufour A., Di Stefano G., Fasolino A., Di Lionardo A., La Cesa S., Galosi E., Valeriani M.,
Nolano M., Cruccu G. Truini A. (2019). Cooling the skin for assessing small-fibre function. Pain. 160(9), 1967-1975
High sensitivity QST with the adaptive staircase method
Thanks to very brief stimulations (50 ms), an adaptative staircase method is now possible. Experiments using this method show that the cold threshold can be as small as 0.2°C.
Lithfous S., Després O, Pebayle T. & Dufour A. (2019). Modification of descending analgesia in aging: critical role of the prefrontal cortex.Clinical Journal of Pain. 35(1), 23-30.
Després O, Lithfous S, Pebayle T. Casadio C. & Dufour A. (2019). Effects of thermosensory aging well demonstrated by cold stimulation with high temporal resolution.Muscle Nerve. 60(2)., 141-146.