Topographic effects of tonic cutaneous nociceptive stimulation on human electroencephalograph.
To examine the specific effects of cutaneous pain on electroencephalographic (EEG) activities, tonic painful and non-painful sensations in left forearm were induced by intradermal injection of capsaicin 100 microg/20microl and the same volume of vehicle, respectively, in 15 healthy males. The EEG data acquired in five experimental conditions: (i) baseline A; (ii) non-painful vehicle injection; (iii) baseline B; (iv) painful capsaicin injection and (v) waning pain, were analyzed and compared with analysis of variance. Only the painful capsaicin injection evoked significant decreases of theta, alpha-1 and alpha-2 powers over the centro-parieto-occipital regions compared with baseline B. No significant difference in EEG activation between the non-painful vehicle injection and painful capsaicin injection was found. This implicates that the observed topographic EEG activation is not specific for pain but probably related to the cutaneous stimulation.
Chang
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PF
Human Brain Mapping and Cortical Imaging Laboratory, Center for Sensory-Motor Interaction, Aalborg University, Fredrik Bajers Vej 7 D-3 DK-9220, Aalborg, Denmark.
Arendt-Nielsen
L
L
Graven-Nielsen
T
T
Svensson
P
P
Chen
A C
AC
D000328:Adult; D000513:Alpha Rhythm; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods*; D002211:Capsaicin / Q000494:pharmacology; D004569:Electroencephalography; D006801:Humans; D007271:Injections, Intradermal; D008297:Male; D009619:Nociceptors / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology; D012016:Reference Values; D012867:Skin / Q000503:physiopathology*
D002211:Capsaicin