Relief of chronic pain associated with increase in midline frontal theta power

Abstract

Introduction: There is a need to identify objective cortical electrophysiological correlates for pain relief that could potentially contribute to a better pain management. However, the field of developing brain biomarkers for pain relief is still largely underexplored. Objectives: The objective of this study was to investigate cortical electrophysiological correlates associated with relief from chronic pain. Those features of pain relief could serve as potential targets for novel therapeutic interventions to treat pain. Methods: In 12 patients with chronic pain in the upper or lower extremity undergoing a clinically indicated nerve block procedure, brain activity was recorded by means of electroencephalogram before and 30 minutes after the nerve block procedure. To determine the specific cortical electrophysiological correlates of relief from chronic pain, 12 healthy participants undergoing cold-pressor test to induce experimental acute pain were used as a control group. The data were analyzed to characterize power spectral density patterns of pain relief and identify their source generators at cortical level. Results: Chronic pain relief was associated with significant delta, theta, and alpha power increase at the frontal area. However, only midfrontal theta power increase showed significant positive correlation with magnitude of reduction in pain intensity. The sources of theta power rebound were located in the left dorsolateral prefrontal cortex (DLPFC) and midline frontal cortex. Furthermore, theta power increase in the midline frontal cortex was significantly higher with chronic vs acute pain relief. Conclusion: These findings may provide basis for targeting chronic pain relief via modulation of the midline frontal theta oscillations.

Modulations in high-density EEG during the suppression of phantom-limb pain with neurostimulation in upper-limb amputees

“…The observed pain-related reduction of aperiodic theta activity in frontal cortex is in line with previously reported reduction in excitatory inputs from the thalamus to the medial prefrontal cortex (mPFC) in chronic pain models, which affects both pyramidal neurons and inhibitory interneurons (Jefferson et al, 2021). Furthermore, this finding is consistent with the increase in frontal theta band activity observed following chronic pain relief, as reported by (Rustamov et al, 2022).…”

“…On the other hand, it should be noted that the standard theta-component observed in eyes-open condition in patient P02, was increased when the stimulation was turned off and suppressed irrespective of the type of stimulation (effective TENS and ineffective PNS). The observation of this pronounced pain-related theta peak is not in conflict with our previous observations of pain-related decreased aperiodic theta activity in patients P01 and P02, since not all the patients with chronic pain develop abnormal periodic theta oscillations (Jensen et al, 2013; Schmidt et al, 2012; Rustamov et al, 2022). Therefore, the suppression of a pronounced theta peak induced by stimulation and the increase in aperiodic theta activity should be viewed as distinct processes.…”

A novel theta-controlled vibrotactile brain–computer interface to treat chronic pain: a pilot study

“…Further, the variation in brain regions previously reported in pain processing justifies targeted reinforcement of physiology consistently observed in multiple contexts 26 . The current work builds on the previous demonstrations that relief of both chronic pain and experimental acute pain is associated with increased frontal theta (θ) rhythms (4–7 Hz) 27 , 28 .…”

“…These regions have previously been shown to play a major role in the top-down modulation of pain and are perturbed during chronic pain 7 , 52 – 55 . More recently, the electrophysiology of pain relief in acute and chronic settings has demonstrated that EEG frontal θ power increases are associated with the remittance of pain 27 , 28 . Source localization of these brain signals converges with previously identified anatomic sites from TMS, tDCS, and functional imaging studies 27 , 28 , 44 , 46 – 51 , 56 – 58 .…”

Evaluating the effectiveness of neurofeedback in chronic pain management: a narrative review

“…Recent literature has begun to reveal how specific brain oscillations are related to chronic pain. For example, studies have shown that neurofeedback aimed at modulating activity in the theta (4–8 Hz) and alpha bands (8–12 Hz) can lead to a reduction in pain perception in individuals with chronic pain ( Maddison et al, 2022 ; Rustamov et al, 2022 ). These findings suggest that training in the modulation of specific brain oscillations via neurofeedback may alter pain-processing mechanisms in the brain, offering a potential therapeutic pathway for the treatment of chronic pain.…”