Effects of rTMS and tDCS on neuropathic pain after brachial plexus injury: A randomized placebo-controlled pilot study

Abstract

Neuropathic pain (NP) after brachial plexus injury (NPBPI) is a highly disabling clinical condition and is increasingly prevalent due to increased motorcycle accidents. Currently, no randomized controlled trials have evaluated the effectiveness of non-invasive brain stimulation techniques such as Repetitive Transcranial Magnetic Stimulation (rTMS) and Transcranial Direct-Current Stimulation (tDCS) in patients suffering from NPBPI. In this study, we directly compare the efficacy of 10-Hz rTMS and anodal 2 mA tDCS techniques applied over the motor cortex (5 daily consecutive sessions) in 21 patients with NPBPI, allocated into 2 parallel groups (active or sham). The order of the sessions was randomised for each of these treatment groups according to a crossover design and separated by a 30-day interval. Scores for “continuous” and “paroxysmal” pain (primary outcome) were tabulated after the last stimulation day and 30 days after. Secondary outcomes included the improvement in multidimensional aspects of pain, anxiety state and quality of life. Active rTMS and tDCS were both superior to sham in reducing continuous (p < 0,001) and paroxysmal pain (p = 0.04) as well as in multidimensional aspects of pain and anxiety state. Repetitive TMS was superior to tDCS in reducing continuous (p = 0.01) and paroxysmal pain (p = 0.03), and in improving multidimensional aspects of pain (p = 0.01). Our results suggest rTMS and tDCS are able to treat NPBPI with little distinction in pain and anxiety state, which may promote the use of tDCS in brachial plexus injury pain management, as it constitutes an easier and more available technique.

PSD-95 in the anterior cingulate cortex contributes to neuropathic pain by interdependent activation with NR2B

“…These results demonstrated that PSD-95 in the ACC contributes to NP by interdependent activation of NR2B.Neuropathic pain (NP), resulting from lesions or diseases of the somatosensory system, is characterized by aberrant spontaneous pain, allodynia, and hyperalgesia 1,2 . Because of the obscure mechanisms underlying NP, current therapeutic measures are often ineffective 3,4 . Studies have suggested that central and peripheral sensitization are the fundamental factors involved in NP [5][6][7] .…”