Brain Networks as Targets of Neurodegeneration in Parkinson’s and Alzheimer’s Diseases

Study Rationale:                   
The study is based on two recent discoveries in neuroscience: (1) the brain is organized in large scale neuronal networks; (2) the misfolded proteins implicated in Parkinson’s and Alzheimer’s diseases (synuclein, amyloid and tau) can spread from nerve cell to nerve cell, like infectious particles.

Hypothesis:
Different intrinsic brain networks are targeted by Parkinson’s and Alzheimer’s diseases, and over the time the disease process will progress through these networks.

Study Design:
We will use the MRI scans from two public databases — the Parkinson’s Progression Markers Initiative and the Alzheimer’s Disease Neuroimaging Initiative — to measure the amount and distribution of brain atrophy in both diseases, related to clinical severity. We will then use other MRI data from control subjects to map out the intrinsic brain networks in healthy brain. We will test the theory that Parkinson’s and Alzheimer’s diseases spread via these networks.

Impact on Diagnosis/Treatment of Parkinson’s Disease:             
Proving that the misfolded protein alpha synuclein spreads through networks of neurons would be a major advance in our understanding of the disease. The hope is that preventing the spread of abnormal protein from cell to cell could halt disease progression.

Next Steps for Development:
This study may contribute to the development of MRI methods to assess the success of future therapies in stopping the spread of neurodegeneration. It may also provide predictive power for the development of complications in Parkinson’s disease.