TY - JOUR
T1 - Assessing the Influence of Nonischemic A-Fiber Conduction Blockade on Offset Analgesia
T2 - An Experimental Study
AU - Luebke, Luisa
AU - Lopes, Clara Gieseke
AU - Myka, Yasmin
AU - Lumma, Annika
AU - Adamczyk, Wacław M.
AU - Carvalho, Gabriela F.
AU - Scholten-Peeters, Gwendolyne G.M.
AU - Luedtke, Kerstin
AU - Szikszay, Tibor M.
N1 - Publisher Copyright:
© 2024 United States Association for the Study of Pain, Inc.
PY - 2024/10
Y1 - 2024/10
N2 - Offset analgesia (OA) is believed to reflect the efficiency of the endogenous pain modulatory system. However, the underlying mechanisms are still being debated. Previous research suggested both, central and peripheral mechanisms, with the latter involving the influence of specific A-delta-fibers. Therefore, this study aimed to investigate the influence of a nonischemic A-fiber conduction blockade on the OA response in healthy participants. A total of 52 participants were recruited for an A-fiber conduction blockade via compression of the superficial radial nerve. To monitor fiber-specific peripheral nerve conduction capacity, quantitative sensory testing was performed continuously. Before, during, and after the A-fiber block, an individualized OA paradigm was applied to the dorsum of both hands (blocked and control sides were randomized). The pain intensity of each heat stimulus was evaluated by an electronic visual analog scale. A successful A-fiber conduction blockade was achieved in thirty participants. OA has been verified within time (before, during, and after blockade) and condition (blocked and control side) (P < .01, d > .5). Repeated measurements analysis of variance showed no significant interaction effects between OA within condition and time (P = .24, η²p = .05). Hence, no significant effect of A-fiber blockade was detected on OA during noxious heat stimulation. The results suggest that peripheral A-fiber afferents may play a minor role in OA compared with alternative central mechanisms or other fibers. However, further studies are needed to substantiate a central rather than peripheral influence on OA. Perspective: This article presents the observation of OA before, during, and after a successful A-fiber conduction blockade in healthy volunteers. A better understanding of the mechanisms of OA and endogenous pain modulation, in general, may help to explain the underlying aspects of pain disorders.
AB - Offset analgesia (OA) is believed to reflect the efficiency of the endogenous pain modulatory system. However, the underlying mechanisms are still being debated. Previous research suggested both, central and peripheral mechanisms, with the latter involving the influence of specific A-delta-fibers. Therefore, this study aimed to investigate the influence of a nonischemic A-fiber conduction blockade on the OA response in healthy participants. A total of 52 participants were recruited for an A-fiber conduction blockade via compression of the superficial radial nerve. To monitor fiber-specific peripheral nerve conduction capacity, quantitative sensory testing was performed continuously. Before, during, and after the A-fiber block, an individualized OA paradigm was applied to the dorsum of both hands (blocked and control sides were randomized). The pain intensity of each heat stimulus was evaluated by an electronic visual analog scale. A successful A-fiber conduction blockade was achieved in thirty participants. OA has been verified within time (before, during, and after blockade) and condition (blocked and control side) (P < .01, d > .5). Repeated measurements analysis of variance showed no significant interaction effects between OA within condition and time (P = .24, η²p = .05). Hence, no significant effect of A-fiber blockade was detected on OA during noxious heat stimulation. The results suggest that peripheral A-fiber afferents may play a minor role in OA compared with alternative central mechanisms or other fibers. However, further studies are needed to substantiate a central rather than peripheral influence on OA. Perspective: This article presents the observation of OA before, during, and after a successful A-fiber conduction blockade in healthy volunteers. A better understanding of the mechanisms of OA and endogenous pain modulation, in general, may help to explain the underlying aspects of pain disorders.
UR - http://www.scopus.com/inward/record.url?scp=85199172683&partnerID=8YFLogxK
U2 - 10.1016/j.jpain.2024.104611
DO - 10.1016/j.jpain.2024.104611
M3 - Journal articles
C2 - 38908497
AN - SCOPUS:85199172683
SN - 1526-5900
VL - 25
JO - Journal of Pain
JF - Journal of Pain
IS - 10
M1 - 104611
ER -