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Diffuse noxious inhibitory controls (DNIC) attenuate temporal summation of second pain in normal males but not in normal females or fibromyalgia patients
- Source :
- Pain. 101:167-174
- Publication Year :
- 2003
- Publisher :
- Ovid Technologies (Wolters Kluwer Health), 2003.
-
Abstract
- Diffuse noxious inhibitory control (DNIC) is part of a central pain modulatory system that relies on spinal and supraspinal mechanisms. Previous studies have shown that fibromyalgia (FMS) patients are lacking DNIC effects on experimental pain, compared to normal control (NC) subjects. Because DNIC has a greater effect on second pain than on first pain, we hypothesized that wind-up (WU) of second pain should be attenuated by a strong conditioning stimulus. Thus, we compared DNIC's effect on WU in three groups of subjects: 11 NC males, 22 NC females, and 11 FMS females. To separately assess the contributions of distraction related mechanisms to inhibition of second pain, we designed the experiment in such a way that directed the subjects' attention to either the test or conditioning stimulus. Repeated heat taps to the thenar surface of the right hand were used as test stimuli to generate WU of second pain. Immersion of the left hand into a hot water bath was the conditioning stimulus. As previous experiments have shown, DNIC requires a strong conditioning stimulus for pain attenuation, which may be at least partly dependent on a distraction effect. DNIC significantly inhibited thermal WU pain in normal male subjects, but adding distraction to the DNIC effect did not increase the extent of this inhibition. In contrast, neither DNIC nor DNIC plus distraction attenuated thermal WU pain in female NCs. DNIC plus distraction but not DNIC alone produced significant inhibition of thermal WU pain in female FMS patients. Our results indicate that DNIC effects on experimental WU of second pain are gender specific, with women generally lacking this pain-inhibitory mechanism.
- Subjects :
- Adult
Male
Fibromyalgia
Hot Temperature
media_common.quotation_subject
Pain
Stimulus (physiology)
Inhibitory postsynaptic potential
Summation
Distraction
Conditioning, Psychological
Noxious stimulus
medicine
Humans
media_common
Sex Characteristics
Diffuse noxious inhibitory control
Water
Neural Inhibition
Middle Aged
medicine.disease
Anesthesiology and Pain Medicine
Neurology
Anesthesia
Female
Neurology (clinical)
Psychology
Vigilance (psychology)
Subjects
Details
- ISSN :
- 03043959
- Volume :
- 101
- Database :
- OpenAIRE
- Journal :
- Pain
- Accession number :
- edsair.doi.dedup.....a0210e68f3c6b695545d1a75371c9078