Noninvasive central modulation of pain follwing TMS inhibition of the secondary somatosensory cortex in healthy subjects

• Applicant: Professor Dr. Jörn Lötsch
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology
• Term: from 2013 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 245507812

Pain is the most common reason for seeing a doctor. It can often be treated only inadequately, a fact which is reflected in the high direct and indirect costs associated with pain and its therapy. Therefore, new approaches at analgesic treatment are a medical need. One of the most innovative approaches consists of the non-invasive modulation of the activity of pain-processing brain regions. Therefore, the underlying hypothesis of this project is based on (i) findings that the secondary somatosensory cortex (S2) is a major brain area processing the perception of pain intensity, and (ii) on the technical possibility to modulate the neuronal activity in superficial brain regions by means of transcranial magnetic stimulation (TMS). The proposed project aims at assessing whether inactivation of S2 by means of TMS impedes the distinction of the intensity of pain stimuli that without TMS were perceived as clearly distinct. This would establish the key role of S2 plays in differentiating pain stimulus intensities. In a four-fold crossover study in 30 healthy volunteers, the effects of an inactivating stimulation (cTBS) of S2 on the perception of nociceptive stimuli will be compared with those of a cTBS of the primary motor cortex (M1) where pain modulatory effects have been shown (positive control), with those of a simultaneous cTBS of S2 and M1, and those of a sham cTBS of S2 and M1. Using functional magnet resonance tomography, the effects of cTBS stimulation on the connectivity within the pain matrix will be analyzed. The project aims at establishing the neuroscientific bases of a non-invasive central ("top-down") treatment of pain.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Ulf Ziemann