Not sure if this study would apply to PD since the problem plaques are alpha synuclein but I would guess it would. Unfortunately, it's not even a clinical trial. So it's up to some risk adverse, clever person to build a led simulator and try it at home.



Brain wave stimulation may improve Alzheimer’s symptoms | MIT News


Unique visual stimulation may be new treatment for Alzheimer’s | MIT News


By exposing mice to a unique combination of light and sound, MIT neuroscientists have shown that they can improve cognitive and memory impairments similar to those seen in Alzheimer’s patients.
This noninvasive treatment, which works by inducing brain waves known as gamma oscillations, also greatly reduced the number of amyloid plaques found in the brains of these mice. Plaques were cleared in large swaths of the brain, including areas critical for cognitive functions such as learning and memory.
“When we combine visual and auditory stimulation for a week, we see the engagement of the prefrontal cortex and a very dramatic reduction of amyloid,” says Li-Huei Tsai, director of MIT’s Picower Institute for Learning and Memory and the senior author of the study.


What is alpha-synuclein? Alpha-synuclein (also α-synuclein) is a protein whose function in the healthy brain is currently unknown.It is of great interest to Parkinson's researchers because it is a major constituent of Lewy bodies, protein clumps that are the pathological hallmark of Parkinson's disease.