French researchers have reported promising early results from a groundbreaking clinical trial that uses light to stimulate damaged nerve cells in the brains of Parkinson’s disease patients. The experimental technique has shown potential to slow neurological decline and partially restore brain function, according to scientists at Grenoble University Hospital.
The clinical trial, still in its early stages, has been conducted on seven patients diagnosed with early-stage Parkinson’s. In three of those cases, researchers observed a notable slowdown in the progression of symptoms and signs of restored brain function following continued light-based stimulation.
Speaking to Radio France, Dr. Stephan Chabardès, a neurosurgeon leading the project, explained that the approach targets dopamine-producing neurons—cells that are progressively destroyed as Parkinson’s advances. “Our aim is to slow down the degeneration of these neurons, which are critical for motor function,” he said.
Parkinson’s disease currently affects an estimated 10 million people globally, a figure projected to double by 2050, according to Parkinson’s Europe. The disease is marked by symptoms such as tremors, muscle stiffness, and reduced mobility, all of which result from a steady loss of dopamine receptors. By the time these symptoms become evident, roughly half of the affected neurons may already be damaged.
The technique developed by Chabardès and his team uses beams of light to stimulate the mitochondria—the energy-producing structures inside cells—within dopamine neurons. By energising these mitochondria, the researchers hope to revive and sustain the function of compromised nerve cells.
To reach the affected areas deep within the brain, the team engineered a miniaturised device that combines cutting-edge electronics, nanotechnology, and photonics. “It is the synergy between neurosurgical expertise and innovation in micro- and nanotechnologies that allows us to achieve these feats,” Chabardès said.
The compact system delivers the light directly to the targeted brain regions without invasive surgery, offering a potentially safer and more sustainable treatment than traditional methods such as deep brain stimulation or medication.
Although the results so far are limited, Chabardès remains cautiously optimistic. “It’s very preliminary, but what we are seeing is quite promising,” he said. A larger clinical trial will only proceed if these early findings are confirmed as stable and reproducible over time.
If further validated, the approach could mark a significant step toward more effective, non-invasive treatments for Parkinson’s—a disease that currently has no cure.
