Insular and anterior cingulate cortex deep stimulation for central neuropathic pain

Abstract

OBJECTIVE: To compare the analgesic effects of stimulation of the anterior cingulate cortex (ACC) or the posterior superior insula (PSI) against sham deep (d) repetitive (r) transcranial magnetic stimulation (TMS) in patients with central neuropathic pain (CNP) after stroke or spinal cord injury in a randomized, double-blinded, sham-controlled, 3-arm parallel study. METHODS: Participants were randomly allocated into the active PSI-rTMS, ACC-rTMS, sham-PSI-rTMS, or sham-ACC-rTMS arms. Stimulations were performed for 12 weeks, and a comprehensive clinical and pain assessment, psychophysics, and cortical excitability measurements were performed at baseline and during treatment. The main outcome of the study was pain intensity (numeric rating scale [NRS]) after the last stimulation session. RESULTS: = 0.018). CONCLUSIONS: ACC- and PSI-dTMS were not different from sham-dTMS for pain relief in CNP despite a significant antinociceptive effect after insular stimulation and anxiolytic effects of ACC-dTMS. These results showed that the different dimensions of pain can be modulated in humans noninvasively by directly stimulating deeper SNC cortical structures without necessarily affecting clinical pain per se. CLINICALTRIALSGOV IDENTIFIER: NCT01932905.