Since the 1990’s, doctors worldwide have used deep brain stimulation to treat movement disorders like Parkinson's disease and conditions such as obsessive-compulsive disorder and epilepsy. During the procedure, surgeons drill holes in the skull and place electrodes deep in the brain. Through a wire under the skin, these electrodes are then connected to a neurostimulator, a device in the patient’s chest which applies electric pulses to modulate brain activity.
Puzzle
It's an invasive treatment and nobody knows how and why exactly it works. The piece of this complex puzzle that Bettina Schwab tries to figure out, lies in the outer part of the brain. ‘The electrodes implanted into the patient’s brain apply electric currents that lead to different electric fields’, she explains. ‘Near the stimulation site, the field is very strong, and we can see that neurons directly react to it. However, there are also weaker fields remote from this site, to which the neurons don’t react so clearly. Because of this, they have not been considered important in the outcome of the treatment. I suggest that the weaker electric fields have a characteristically different effect on neural activity, which is harder to capture but might be critical to the success of the treatment.’
Mystery
This is the mystery Schwab tries to unravel with her ERC project called DECODE, which stands for ‘Desynchronizing weak cortical fields during deep brain stimulation’. ‘If the weak electric fields are indeed a critical factor, it could open doors to better treatments. We could use it to achieve better results and less severe side effects.’
Clinical data
Schwab officially started the project in January. She and her team first focus on computational modelling, to see how the weak electric fields are distributed and how they could potentially be changed. ‘So we can find out how they are related to the suppression of different symptoms. These models require clinical data, for example on individual head morphology and about the symptoms. Furthermore, we want to see how we can adjust the weaker electric fields. The next part is to investigate how these fields affect neural activity in dynamic models. Finally, we will clinically test these predictions.’
Specific expertise
Although Schwab uses the facilities of the Biomedical Signals & Systems group, and the main experiments of DECODE will take place at the University Medical Center Hamburg-Eppendorf, she does benefit from the TechMed Centre infrastructure. ‘For my project, it’s not necessarily what’s under the roofs, but who is under the roofs. I can profit from the collaboration with researchers with a certain specific expertise that I don’t fully possess. There are also benefits career development-wise: getting feedback from peers, supervising PhD candidates together with others, and building up my own team. So it’s more the network rather than the infrastructure where the TechMed Centre adds value to this project.’
