Higher Pain Expression Tied to Pro-Nociceptive State
With sensory over-responsiveness, daily non-painful stimuli felt more intensely
FRIDAY, Aug. 11, 2017 (HealthDay News) -- Sensory over-responsiveness (SOR) in otherwise healthy subjects is associated with a pro-nociceptive state, according to a study published online Aug. 7 in PAIN Practice.
Irit Weissman-Fogel, Ph.D., from the University of Haifa in Israel, and colleagues conducted psychophysical testing in 30 healthy subjects (14 SOR and 16 non-SOR participants, based on the Sensory Responsiveness Questionnaire). Testing evaluated (1) hyperalgesic responses; (2) adaptation and sensitization to 14 phasic heat stimuli; (3) habituation; (4) six minutes after-sensation; and (5) conditioned pain modulation (i.e., phasic heat stimuli applied with and without hand immersion in hot water).
The researchers found that, compared to non-SOR individuals, the SOR group had a steeper escalation in numerical pain scale ratings to temperature increase (P = 0.003) indicating hyperalgesia, increased sensitization (P ≤ 0.001), habituation responses (P < 0.001), and enhanced pain ratings during the after-sensation (P = 0.006). There were no group differences in conditioned pain modulation.
"This is the first study to report a coupling between the general SOR to daily innocuous stimuli and enhanced pain facilitation rather than deficient inhibition," the authors write.