Reacción a "Researchers study the role of a new brain network in Parkinson's disease"

It is a robust study, both in terms of the volume of data analysed (863 participants) and the approach used: neuroimaging of brain connectivity at rest and in response to different treatments. It reinforces the idea that Parkinson's disease does not only affect the “movement centre”, but also a broader neural circuit that coordinates action, motivation and bodily functions and therefore has both a “physical and mental” component. This could help explain well-known clinical observations, such as the fact that slow movements or gait freezing can disappear when lines of light are projected onto the floor to guide the steps or when the patient listens to music with a marked rhythm. In Parkinson's disease, they show that this cortical region (the SCAN network) appears to be hyperconnected to deep areas of the brain that we know are involved in the disease. In other words, the “wiring” between this network and these subcortical regions is overactive, with excessive communication.

Interestingly, when treatments are effective—whether levodopa medication or various neuromodulation techniques such as deep brain stimulation (DBS), transcranial magnetic stimulation (TMS) or focused ultrasound—this “excessive connection” tends to normalise or decrease. This fits with previous observations, but what is truly disruptive is that the study proposes a “common piece” capable of integrating motor and non-motor symptoms within the same framework and better guiding the targets to be used in therapeutic neuromodulation. In fact, in a small trial with TMS, stimulating an area of the SCAN network improved symptoms more than stimulating classic motor areas.

In a way, the study suggests a possible paradigm shift in both diagnosis—using hyperconnectivity as a marker—and in the treatment of Parkinson's disease through neuromodulation. It suggests that personalising the stimulation “target” (in DBS, TMS or ultrasound) could significantly improve outcomes. Even so, it is important to be cautious: at this point, it does not imply a cure or an immediate change in clinical practice. The practical message today is that this approach can help refine where to stimulate and design better clinical trials, but it does not yet change standard care protocols.