Modulation of pain perception by transcranial magnetic stimulation of left prefrontal cortex

Abstract

Evidence by functional imaging studies suggests the role of left dorsolateral prefrontal cortex (DLPFC) in the inhibitory control of nociceptive transmission system. Repetitive transcranial magnetic stimulation (rTMS) is able to modulate pain response to capsaicin. In the present study, we evaluated the effect of DLPFC activation (through rTMS) on nociceptive control in a model of capsaicin-induced pain. The study was performed on healthy subjects that underwent capsaicin application on right or left hand. Subjects judged the pain induced by capsaicin through a 0–100 VAS scale before and after 5 Hz rTMS over left and right DLPFC at 10 or 20 min after capsaicin application in two separate groups (8 subjects each). Left DLPFC-rTMS delivered either at 10 and 20 min after capsaicin application significantly decreased spontaneous pain in both hands. Right DLPFC rTMS showed no significant effect on pain measures. According to these results, stimulation of left DLPFC seems able to exert a bilateral control on pain system, supporting the critical antinociceptive role of such area. This could open new perspectives to non-invasive brain stimulation protocols of alternative target area for pain treatment.

Transcranial Direct Current Stimulation Targeting Primary Motor Versus Dorsolateral Prefrontal Cortices: Proof-of-Concept Study Investigating Functional Connectivity of Thalamocortical Networks Specific to Sensory-Affective Information Processing

“…Instead, active DLPFC tDCS increased FC between VPL and M1. Our findings, in part, challenge a classical notion that suggests that DLPFC is a region primarily involved in processing emotional-affective information (Brighina et al, 2011;Garcia-Larrea et al, 2003;Lorenz et al, 2003). Here instead, we highlight that stimulation of DLPFC can modulate FC between VPL and M1.…”

“…While subjects rested their hands, we used visual confirmation of contraction of the left first dorsal interosseous muscle to finalize our motor hotspot in right M1. Similarly, for DLPFC tDCS, center of the anodal electrode was placed over the right DLPFC, localized to a point 5 cm anterior to the coordinates of the motor hotspot in right M1, as outlined in previous studies (Brighina et al, 2011;Graff-Guerrero et al, 2005;Pascual-Leone et al, 1996) (Fig. 2A).…”

“…Although M1 is commonly targeted, benefits of M1 stimulation remain modest and variable (Lefaucheur et al, 2014), suggesting that networks other than the known sensory-discriminative components may be involved (Machado et al, 2013). Indeed, recent studies have suggested that targeting structures, such as the DLPFC, associated with emotional-affective information processing may be more effective in modulating the overall experience of pain (Brighina et al, 2011;Graff-Guerrero et al, 2005;Plow et al, 2012). The DLPFC is believed to specifically modulate activity within the midbrain-medial thalamic pathway (Apkarian et al, 2009;Lorenz et al, 2003;Stagg et al, 2013;Zubieta et al, 2001).…”

Significance of Non-phase Locked Oscillatory Brain Activity in Response to Noxious Stimuli

“…Interestingly, a few recent pain studies have used rTMS technology to identify the role played by the DLPFC. [23][24][25][26][27] For example, Nahmias et al 27 showed that unilateral, high frequency rTMS pulses applied to the right DLPFC produced diffuse analgesic effects in healthy human participants exposed to experimental heat and cold pain. This initial result suggests that the DLPFC may, indeed, play a causal role in reducing painful sensations.…”

Interhemispheric Dorsolateral Prefrontal Cortex Connectivity is Associated with Individual Differences in Pain Sensitivity in Healthy Controls

“…Investigations utilizing transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) provided initial evidence that DLPFC stimulation may have a role in decreasing pain reports (Boggio et al, 2009;Borckardt et al, 2006;Brighina et al, 2011) and increasing pain tolerance (Borckardt et al, 2007;Lefaucheur et al, 2008;Mylius et al, 2012). A potential mechanism for some of these findings is the modulation of DLPFC interhemispheric connectivity (interactions among the left DLPFC (lDLPFC) and right DLPFC (rDLPFC) across the corpus callosum).…”