Mapping shows how the brain shrinks in Parkinson's disease
2022
Research Centre Jülich, Juelich, Germany
The neuropathological features of idiopathic Parkinson's disease (PD) are the degeneration of dopaminergic neurons in the striatum and the spread of aggregates of misfolded α-synuclein in the brain according to a specific pattern. However, the relationship between this pattern and motor and cognitive symptoms has not been clearly established. Therefore, this study investigated the spatiotemporal pattern of atrophy propagation in PD, its interindividual variability, and its relationship with clinical symptoms. Magnetic resonance (MR) images of 37 PD patients and 27 control subjects were acquired at up to 15 time points per subject and over an observation period of up to 8.8 years (mean: 3.7 years). MR images were analyzed using deformation-based morphometry (DBM) to measure region volumes and their longitudinal changes. Differences in these regional volume data between patients and control subjects and their associations with clinical symptoms were calculated.
At the beginning of the study, the researchers found that the volumes of several brain regions were smaller in the PD patients than in the control group, while some regions were enlarged in the patients' brains, presumably due to compensatory effects. Over time, the difference between the groups became larger and more pronounced: the brain volumes of the Parkinson's patients decreased almost twice as fast as those of the control group, especially in the grey matter. The temporal and occipital lobes, adjacent parts of the inferior parietal lobe and ventral parts of the frontal lobe were most affected by this volume decrease.
Detailed analysis of which parts of the brain changed over time was performed using neuroanatomical atlases, most notably the Julich Brain Atlas, which is freely available through the EBRAINS infrastructure. This detailed anatomical analysis revealed a very specific regional pattern of volume changes in Parkinson's patients that differed from that of healthy ageing. The researchers found that volume reductions in cortical areas, amygdala, and basal forebrain correlated with worsening clinical symptoms in PD patients.
Thus, longitudinal DBM appears to already map the progression of neuropathological changes in vivo, providing a tool to further explore PD.
Regional changes of brain structure during progression of idiopathic Parkinson's disease – A longitudinal study using deformation based morphometry
Peter Pieperhoff
Added on: 07-06-2022
[1] https://www.sciencedirect.com/science/article/pii/S0010945222000855?via%3Dihub[2] https://www.technologynetworks.com/neuroscience/news/mapping-shows-how-the-brain-shrinks-in-parkinsons-disease-361706
