Desynchronizing weak cortical fields during deep brain stimulation

Informations projet

DECODE

N° de convention de subvention: 101116047

DOI

10.3030/101116047

Date de signature de la CE 23 Novembre 2023

Date de début 1 Janvier 2024

Date de fin 31 Decembre 2028

Financé au titre de

• European Research Council (ERC)

Coût total

€ 1 498 914,00

Contribution de l’UE

€ 1 498 914,00

Coordonné par

UNIVERSITEIT TWENTE
Netherlands

Periodic Reporting for period 1 - DECODE (Desynchronizing weak cortical fields during deep brain stimulation)

Période du rapport: 2024-01-01 au 2026-06-30

Résumé du contexte et des objectifs généraux du projet

Deep brain stimulation (DBS) is a type of brain surgery used to treat Parkinson’s disease and other neurological conditions. It works by sending small, controlled electrical pulses to specific areas deep inside the brain. These pulses change how brain cells communicate with each other across large networks. For many patients, DBS can greatly improve movement problems. However, some people experience serious side effects, or the treatment does not help enough.
A lot of research is trying to improve DBS, but progress has been limited because we still do not fully understand how it works. Several explanations have been proposed, while so far, none can completely explain the complex effects of DBS. Current theories focus on the strong electrical fields close to the stimulation electrodes, which directly activate nearby brain cells. These theories suggest that DBS may reduce symptoms by changing how brain networks are organized, how brain cells send signals to each other, or in which patterns they are active.
DECODE explores a new possible working mechanism of DBS, based on recent findings from noninvasive brain stimulation research. It suggests that not only strong electrical signals, but also very weak electrical fields—too weak to directly activate brain cells—can still influence brain activity. According to this idea, the combination of strong electrical stimulation deep in the brain and weaker electrical effects in the outer layers of the brain may help reduce abnormal, overly synchronized brain activity. By calming this abnormal activity across the motor system, DBS may help restore normal movement control.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

We developed a new framework that can simulate the electric fields generated by deep brain stimulation across the entire head. This framework combines freely available tools used for both non-invasive and invasive brain stimulation. Using this approach, we simulated electric fields in 23 patients (covering 45 brain hemispheres) and mapped how strong these fields are in different parts of the brain. Our results show that the electric fields reaching the outer layers of the brain during DBS are stronger than those typically produced by transcranial alternating current stimulation, a non-invasive technique known to influence the timing of brain cell activity.
We then studied how these weak DBS-related electric fields affect individual brain cells using detailed computer models. These models represent neurons as collections of small connected sections and capture how their shape and structure influence their dynamics. Because neurons differ in shape as well as intrinsic dynamics, their responses to electric fields also vary. We found that some types of neurons were clearly affected by the weak DBS electric fields, with their activity becoming synchronized to the DBS pulses. Other neurons showed little or no such effect.
Ongoing work is expanding these simulations and testing the model’s predictions in clinical studies.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

All project results are novel, as weak electric fields of DBS have not been investigated yet. These results, including the described modeling results, can lead to important insights into the working mechanism of deep brain stimulation, or mechanisms of side effects. A critical factor will be the more detailed simulations as well as the planned clinical validation.