Swiss researchers have developed a new technique for studying hallucinations using a robotic arm.
- There are about 200,0000 people with Parkinson’s disease in France, a figure that is constantly increasing.
- Today, Parkinson’s disease is the most common neurodegenerative pathology in the world after Alzheimer’s.
Tremors are the most well-known symptom of Parkinson’s disease. But this pathology can have other consequences: stiffness, motor difficulties, fatigue or even hallucinations. In the magazine Science Translational Medicine, Swiss researchers publish the results of a study carried out on this last symptom. “Hallucinations are a challenge because they can appear spontaneously, their occurrence cannot be predicted, many patients do not report them, perhaps because of fear, explains Fosco Bernasconi, one of the co-authors of the study. It is a real challenge for scientists to quantify their occurrence, their phenomenology and their intensity.” This lack of information leads to an often complicated diagnosis. The researchers believe that it is difficult for untrained or unequipped health professionals to detect hallucinations in their patients. However, they estimate that nearly half patients suffer from it.
How to trigger hallucinations?
In 2014, Olaf Blanke, a neuroscientist at the École polytechnique fédérale de Lausanne, found that it was possible to trigger hallucinations in healthy individuals using a robot and specific signals. In this new study, he took this discovery one step further, applying it to people with Parkinson’s disease.
This time, the researcher and his team recruited 26 individuals with this pathology. They were asked to punch in the air, while behind them, a robotic arm had been placed beforehand. He was programmed to do the same gesture but out of sync. In this way, the patients experienced hallucinations. “I felt a presencesays Joseph Rey, one of the participants, as if someone was behind me and touched my back.” Patients who had experienced hallucinations were more sensitive to the robot’s stimulation, compared to those who had never experienced them.
A new biomarker?
In the second part of the study, the researchers focused on the neural networks responsible for causing hallucinations. They were able to accurately predict the severity of symptoms using brain MRIs.
“Adapting the robotic tool and the procedure to the scanner allowed us to identify a brain network that is useful for detecting the presence of hallucinations in Parkinson’s patients, and that could serve as a biomarker for the most severe forms of the disease. , associated with hallucinations and cognitive deficits“, says Eva Blondiaux, one of the co-authors of the study. It is not a cure, nor even a treatment, but it provides a new diagnostic tool for health professionals.
A new brain test to assess the mental state of patients with #Parkinson involves waking up “ghosts” hidden in certain areas of the brain, to predict the onset of hallucinations. https://t.co/wDC57ReOKz
— EPFL (@EPFL) April 29, 2021
.
