Effects of remote cutaneous pain on trigeminal laser-evoked potentials in migraine patients.
The present study aimed to evaluate heat pain thresholds and evoked potentials following CO(2) laser thermal stimulation (laser-evoked potentials, LEPs), during remote application of capsaicin, in migraine patients vs. non-migraine healthy controls. Twelve outpatients suffering from migraine without aura were compared with 10 healthy controls. The LEPs were recorded by 6 scalp electrodes, stimulating the dorsum of the right hand and the right supraorbital zone in basal condition, during the application of 3% capsaicin on the dorsum of the left hand and after capsaicin removal. In normal subjects, the laser pain and the N2-P2 vertex complex obtained by the hand and face stimulation were significantly reduced during remote capsaicin application, with respect to pre-and post-capsaicin conditions, while in migraine LEPs and laser pain were not significantly modified during remote painful stimulation. In migraine a defective brainstem inhibiting control may coexist with cognitive factors of focalised attention to facial pain, less sensitive to distraction by a second pain.
de Tommaso
Marina
M
Neurophysiopathology of Chronic Pain Unit, Neurological and Psychiatric Sciences Department, University of Bari, Clinica Neurologica, Policlinico, Piazza Giulio Cesare 11, I-70124 Bari, Italy. m.detommaso@neurol.uniba.it
Difruscolo
Olimpia
O
Sardaro
Michele
M
Libro
Giuseppe
G
Pecoraro
Carla
C
Serpino
Claudia
C
Lamberti
Paolo
P
Livrea
Paolo
P
D000328:Adult; D002211:Capsaicin; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005145:Face / Q000502:physiology; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D007834:Lasers; D008297:Male; D020326:Migraine without Aura / Q000503:physiopathology*; D010146:Pain / Q000139:chemically induced / Q000503:physiopathology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D010812:Physical Stimulation; D012867:Skin / Q000294:innervation; D013268:Stimulation, Chemical; D014276:Trigeminal Nerve / Q000503:physiopathology*
D002211:Capsaicin