title: A novel human surrogate model of noninjurious sharp mechanical pain.
abstract: We propose a blade as a noninjurious nociceptive stimulus modeling sharp mechanical pain and yielding acute pain and hyperalgesia responses with closer proximity to incision-induced pain/hyperalgesia than punctate or blunt pressure mechanical pain models. Twenty-six healthy men and women were investigated to compare a small incision in the left forearm with noninvasive stimuli of different shapes and modalities to the right forearm. The magnitude and time course of incisional and blade-induced pain were assessed by numerical rating scales. Affective vs sensory components of pain experience were differentiated using a pain sensation questionnaire. The magnitude and time course of the axon reflex vasodilator response and of secondary hyperalgesia following a 7-second blade application were assessed. The maximum blade or incisional pain was similar (visual analogue scale [mean ± SD]: 32.9 ± 22.5 [blade] vs. 33.6 ± 29.8 [incision]), and both time courses matched closely in the first 10 seconds (paired t test; P = 0.5-1.0), whereas incision but not blade was followed by a second phase of pain, probably related to the tissue injury (decrease to half maximum pain 8 ± 2 vs. 33 ± 35 seconds; P < 0.01). Affective pain scores were significantly lower than sensory scores for all stimuli (P < 0.001). Comparing blade and incision, patterns of affective and sensory pain descriptors exhibited a remarkably similar pattern. Hence, we suggest the blade as novel model of sharp mechanical pain, which will be useful in investigating postoperative/mechanical pain and the role of self-injurious behavior in, eg, patients with borderline personality disorder.
authors.affiliation: Department of Neurophysiology, Centre of Biomedicine and Medical Technology Mannheim, Medical Faculty Mannheim, Ruprecht Karls-University Heidelberg, Mannheim, Germany Department of Psychosomatic Medicine and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany.
authors.forename: Polina
authors.initials: P
authors.lastname: Shabes
authors.forename: Natalie
authors.initials: N
authors.lastname: Schloss
authors.forename: Walter
authors.initials: W
authors.lastname: Magerl
authors.forename: Christian
authors.initials: C
authors.lastname: Schmahl
authors.forename: Rolf-Detlef
authors.initials: RD
authors.lastname: Treede
authors.forename: Ulf
authors.initials: U
authors.lastname: Baumgärtner
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods; D055815:Young Adult