Brain mechanisms of pain relief by transcutaneous electrical nerve stimulation: A functional magnetic resonance imaging study

Abstract

TENS led to pain reduction, probably due to activation of the descending pain-inhibitory pathway, indicating that this TENS method may be applied in clinical practice.

Transcutaneous electrical acupoint stimulation as an adjunct therapy for obsessive-compulsive disorder: A randomized controlled study

“…Transcutaneous electrical nerve stimulation (TENS) on the median nerve induced SEPs, resulting in delayed gating effects on cortical response (Torquati et al, 2007). TENS also broadly modulated sensorimotor brain network activity, including the somatosensory cortex, basal ganglia, and thalamus (Choi et al, 2016;Dhond et al, 2008;Fang et al, 2009;Kara et al, 2010), and cortical neuronal excitability (Veldman et al, 2014). It appears that TENS, in particular TEAS, is capable of repairing filtering' dysfunction of the sensorimotor gating via enhancing 5-HT and neuropeptide functions in related brain regions.…”

Testosterone effects on pain and brain activation patterns

“…In our previous study with humans, testosterone levels were significantly negatively correlated with average pain rating. Across both men and women participants, as testosterone level increased, functional connectivity between the periaqueductal gray (PAG) area and lateral prefrontal cortex (PFC) significantly increased for the pain+TENS compared to the pain‐only condition.…”

“…In our previous study, pain and unpleasantness ratings were significantly higher in women than in men . Pain perception has been found to increase with decreased testosterone levels, and brain activation has been shown to correlate with testosterone levels . These findings indicate that testosterone levels influence an individual's susceptibility to noxious stimulation, and suggest that low testosterone level may increase nociceptive input and pain ratings by affecting pain‐related regions in the central nervous system.…”

Contralateral segmental transcutaneous electrical nerve stimulation inhibits nociceptive flexion reflex in healthy participants

“…It is also possible that contralateral analgesic effects of TENS are involved in the supra‐spinal structure. TENS administration activated muscarine (Radhakrishnan & Sluka, ), opioid (Kalra et al., ; Sluka et al., ) and serotonin spinal receptors (Radhakrishnan et al., ), which are all also involved in analgesia mediated by descending pain inhibition from the periaqueductal grey and rostral ventromedial medulla (RVM) of the brain (Choi et al., ; Jensen & Yaksh, ). Electrical or chemical stimulation of nuclei of the RVM changed the nociceptive thresholds bilaterally in the hindpaws of rats (Hurley & Hammond, ; Terayama, Dubner, & Ren, ).…”

“…In general, extra-segmental analgesia is strongly involved in supra-spinal modulation (van Wijk, & Veldhuijzen, 2010). For TENS administration, higher pulse intensities activate thin nerve fibres from deep tissue, and this activation generates descending pain modulation from the supra-spinal structure and produces diffuse analgesic effects (Choi et al, 2015;Duranti, Pantaleo, & Bellini, 1988;Radhakrishnan & Sluka, 2005). Large diameter nerve fibres were activated by sensory intensity, whereas thin nerve fibres were activated by intensities at 2× the motor threshold in an animal study (Radhakrishnan & Sluka, 2005).…”