Changes in alpha, theta, and gamma oscillations in distinct cortical areas are associated with altered acute pain responses in chronic low back pain patients

Abstract

IntroductionChronic pain negatively impacts a range of sensory and affective behaviors. Previous studies have shown that the presence of chronic pain not only causes hypersensitivity at the site of injury but may also be associated with pain-aversive experiences at anatomically unrelated sites. While animal studies have indicated that the cingulate and prefrontal cortices are involved in this generalized hyperalgesia, the mechanisms distinguishing increased sensitivity at the site of injury from a generalized site-nonspecific enhancement in the aversive response to nociceptive inputs are not well known.MethodsWe compared measured pain responses to peripheral mechanical stimuli applied to a site of chronic pain and at a pain-free site in participants suffering from chronic lower back pain (n = 15) versus pain-free control participants (n = 15) by analyzing behavioral and electroencephalographic (EEG) data.ResultsAs expected, participants with chronic pain endorsed enhanced pain with mechanical stimuli in both back and hand. We further analyzed electroencephalographic (EEG) recordings during these evoked pain episodes. Brain oscillations in theta and alpha bands in the medial orbitofrontal cortex (mOFC) were associated with localized hypersensitivity, while increased gamma oscillations in the anterior cingulate cortex (ACC) and increased theta oscillations in the dorsolateral prefrontal cortex (dlPFC) were associated with generalized hyperalgesia.DiscussionThese findings indicate that chronic pain may disrupt multiple cortical circuits to impact nociceptive processing.

The psychophysiology of music-based interventions and the experience of pain

“…Pain-induced changes in gamma oscillations in somatosensory cortex have been described (Gross et al, 2007), while noxious heat stimulation in healthy subjects was shown to increase gamma wave activity in bilateral mPFC but decrease alpha and beta wave activity in somatosensory cortex (Nickel et al, 2017). Specific patterns of altered brainwave activity involving theta, alpha and gamma oscillations have been recorded in prefrontal areas and anterior cingulate in people with chronic pain (Kenefati et al, 2023). Supporting a link between gamma oscillations and pain perception, variability in amplitude of these oscillations was found to predict inter-individual pain sensitivity (Hu and Iannetti, 2019) and others have reported links between reduced pain perception and modulated delta, beta or gamma band oscillations (Hauck et al, 2013).…”

“…These rhythmic patterns of synchronized neural activity flowing within and across, and linking, neighboring regions of the brain have different repetitive frequencies (delta,(1)(2)(3)(4)theta,(4)(5)(6)(7)(8)alpha,(8)(9)(10)(11)(12)(13)beta,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)gamma,, each associated with different brain states. Interestingly, there is evidence that oscillatory brain activity is linked to pain perception (Ploner and Gross, 2019;Kenefati et al, 2023;Li et al, 2023b). Pain-induced changes in gamma oscillations in somatosensory cortex have been described (Gross et al, 2007), while noxious heat stimulation in healthy subjects was shown to increase gamma wave activity in bilateral mPFC but decrease alpha and beta wave activity in somatosensory cortex (Nickel et al, 2017).…”