In this section
@article{Murphy:2026:10.1016/j.jpain.2026.106405,
author = {Murphy, J and Strutton, PH and Morgan, C and Bannister, K and Hughes, SW},
doi = {10.1016/j.jpain.2026.106405},
journal = {J Pain},
title = {Bidirectional modulation of the R2 blink reflex using a lower limb cuff-pressure heterotopic conditioning stimulus across repeated sessions.},
url = {http://dx.doi.org/10.1016/j.jpain.2026.106405},
volume = {49},
year = {2026}
}
TY - JOUR
AB - The R2 blink reflex (R2BR) provides a neurophysiological marker of trigeminofacial somatosensory processing in the human brainstem. In the current study, we paired the R2BR with a heterotopic noxious conditioning stimulus (HNCS) applied via semi-automated cuff pressure algometry to the lower limb across repeated test sessions. Twenty-four healthy participants completed two identical sessions in which the R2BR stimulus-response function was assessed across 11 intensities (0.9-1.9x threshold) at baseline, during tonic cuff-pressure conditioning applied to the contralateral lower limb, and during post-conditioning recovery periods. Overall R2BR excitability was also quantified using an excitability index derived from the stimulus-response function. The HNCS produced bidirectional effects on R2BR excitability, causing both inhibition and facilitation of the reflex across repeated sessions. Post-conditioning R2BR responses returned to baseline levels. The baseline R2BR excitability index demonstrated fair-to-good test-retest reliability (ICC = 0.73), whereas reliability during conditioning was reduced to poor-to-fair (ICC = 0.57). These findings demonstrate that a HNCS can modulate R2BR responses in a bidirectional manner, which was observed across repeated test sessions. These results indicate that the combined use of a semi-automated lower limb cuff pressure HNCS with the R2BR may provide a complementary neurophysiological approach for assessing descending inhibitory and facilitatory influences over brainstem reflex pathways. PERSPECTIVE: The R2 blink reflex (R2BR) paired with a semi-automated cuff-pressure HNCS provides a neurophysiological approach for assessing bidirectional endogenous modulatory influences on brainstem reflex excitability.
AU - Murphy,J
AU - Strutton,PH
AU - Morgan,C
AU - Bannister,K
AU - Hughes,SW
DO - 10.1016/j.jpain.2026.106405
PY - 2026///
TI - Bidirectional modulation of the R2 blink reflex using a lower limb cuff-pressure heterotopic conditioning stimulus across repeated sessions.
T2 - J Pain
UR - http://dx.doi.org/10.1016/j.jpain.2026.106405
UR - https://www.ncbi.nlm.nih.gov/pubmed/42567240
VL - 49
ER -