A team of researchers from the École Polytechnique Fédérale de Lausanne (EPFL) has developed an innovative method to deeply stimulate the human brain without resorting to invasive procedures.
This discovery could transform the treatment of various neurological and psychiatric disorders such as addictions, depression, and obsessive-compulsive disorder (OCD). The significance of this advancement lies in its ability to precisely target the deep regions of the brain, often involved in these disorders, without the risks associated with traditional invasive methods.
Brain stimulation is not new and has already proven effective in treating several neurological disorders. However, techniques used so far, such as deep brain stimulation (DBS), involve invasive surgical interventions. The EPFL team, led by Professor Friedhelm Hummel and Dr. Pierre Vassiliadis, aimed to overcome these limitations by developing transcranial temporal interference stimulation (tTIS). This approach, detailed in the journal Nature Human Behaviour, aims to provide a non-invasive alternative.
tTIS is based on the principle of temporal interference, using two pairs of electrodes placed on the scalp. These electrodes generate low-intensity electric fields that, when they intersect inside the brain, allow specifically targeting deep regions. Until now, non-invasive methods could not reach these areas selectively, rendering treatments ineffective. tTIS overcomes this obstacle by using high frequencies that do not directly stimulate intermediate neural activity, thus concentrating the effect on the targeted region.
The experiments conducted by the EPFL team focused on the human striatum, a brain region involved in decision-making and reward mechanisms. The researchers set one pair of electrodes at a frequency of 2,000 Hz and the other at 2,080 Hz. The 80 Hz frequency difference becomes the effective stimulation frequency in the target area, thus disrupting its normal functioning. This approach has shown that reinforcement learning, essential to how we learn through rewards, can be influenced by targeting specific brain frequencies.
The potential clinical applications of this technique are vast. In treating addictions, where patients tend to overvalue rewards, tTIS could help modulate these pathological behaviors. Similarly, for conditions such as depression and OCD, where reward and decision-making mechanisms are often altered, this method offers a promising new therapeutic avenue. The team is also exploring how different stimulation patterns could enhance brain functions instead of merely disrupting them.
The future of research on tTIS looks promising, with ongoing trials to test its effectiveness on other neurological disorders. Preliminary studies also suggest potential benefits for improving motor and cognitive abilities, particularly in the elderly. By expanding clinical trials, EPFL hopes to confirm these results and pave the way for new therapeutic applications for this revolutionary technique. This innovation could thus mark a significant advancement in the treatment of neuropsychiatric disorders.
Article Author: Cédric DEPOND