11 th Congress of the European Pain Federation, Valencia, Spain, 4 - 07 September 2019, pp.10-11
Background and aims: Functional near-infrared spectroscopy (fNIRS) is a novel, noninvasive neuroimaging
modality for monitoring cortical activation. The aim of this study was to quantify the efficacy of an exercise program
tailored for knee osteoarthritis patients with chronic pain via fNIRS. To this aim, cortical hemodynamic correlates
of painful stimuli were obtained before and after a 6-week intervention. The second aim was to investigate the
relationship between changes in pain level and hemodynamic parameters pre and post-intervention.
Methods: Eleven patients with knee osteoarthritis participated in the study. They attended 18 sessions in 6 weeks.
Pain severity during activity was determined using the Visual Analog Scale, and brain hemodynamic responses were
assessed with a 48 channel fNIRS device at the onset and end of the exercise program. The fNIRS experimental
protocol consisted of 15 trials of painful and nonpainful stimuli applied for 5 seconds in a randomized order,
separated by interstimulus intervals of 30 seconds.
Results: Preliminary results yielded a significant main effect of channel location and intervention at the group level
for painful stimuli in terms of parameters related to oxyhemoglobin (HbO) consumption calculated by repeated
measures ANOVA (p< 0.05). Post-hoc paired t-tests revealed a significant difference in HbO parameters pre- and post-exercise pointing out an increase in dorsolateral prefrontal and frontopolar cortex activation.
Conclusions: Our preliminary results demonstrate the potential of fNIRS as an objective biomarker of pain
assessment and therapy monitoring. fNIRS is a promising tool for exploring the neuroplastic effects of exercise
programme in chronic pain conditions.