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

This study presents an ambitious analysis based on a large amount of neuroimaging data and different therapeutic approaches to Parkinson's disease. The authors propose that a recently described brain network in the primary motor cortex, related to the integration between cognition and action, could be significantly involved in the pathophysiology of the disease. The work is part of a growing line of research that attempts to understand Parkinson's disease as a disorder of brain networks and not just as an alteration of specific motor circuits.

However, it is important to interpret the results with caution, also from the point of view of the scientific narrative constructed by the article. The study follows a structure that is very common in this type of research: first, it reinterprets the disease from a conceptual construct that guides the reading of the results; then it identifies a “signature” in magnetic resonance imaging that is consistent with the construct; next, it shows that this signature changes with different treatments; and finally, it interprets these changes as a central mechanism of the disease. This type of narrative can be suggestive, but it does not always clearly distinguish between statistical correlation and biological causality. First, the “signature” in this case is based on correlations obtained using functional magnetic resonance imaging at rest, which are mathematical measures that do not allow direct inference of changes in the actual connectivity of the brain. Secondly, the experiment with transcranial magnetic stimulation, which provides the most direct causal and therapeutic evidence, is limited in size and presents possible technical confounding factors.

Therefore, although the study is undoubtedly very interesting and opens up new lines of research, it does not yet justify claiming that Parkinson's disease is a “somato-cognitive action network disorder”, as the title suggests, nor that this concept will “double” the effectiveness of treatments in clinical practice. Studies using other techniques will be necessary to confirm or refute the proposed hypothesis, as well as larger, independent trials with more rigorous designs before these ideas can be transferred to routine clinical practice.