Session Time: 1:15pm-2:45pm
Location: Les Muses Terrace, Level 3
Objective: To investigate changes in connectivity of the nigrostriatal and striatonigral pathways in PD and association with clinical symptoms.
Background: Loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc), which projects to the dorsal striatum, is the main pathological feature of Parkinson’s disease (PD). Probabilistic tractography, that analyses in vivo white matter trajectories can be employed to study the connectivity between brain regions.
Method: Probabilistic tractography was performed in 24 PD patients and 16 healthy controls (HCs) to measure the nigrostriatal connectivity using as a seed the SNpc manually delineated on neuromelanin sensitive MRI and the striatonigral connectivity using as a seed the dorsal striatum manually delineated on T1 MRI. Neuromelanin-sensitive MRI allows the identification of dopaminergic neurons within the SNpc to differentiate the SNpc from SN reticulata.
Results: Mean nigrostriatal (P<0.001; -79%) and striatonigral (P<0.01; -52%) streamline number was lower in PD compared to HCs. Moreover, in PD the number of streamlines of the nigrostriatal tract correlated positively with the neuromelanin area (r=0.435; P<0.05) and negatively with UPDRS-III scores (r=-0.431; P=<0.05).
Conclusion: Abnormal tractography characteristics in both the nigrostriatal and striatonigral pathways suggest loss of integrity of the motor control circuitry in PD. Degradation of the nigrostriatal tract in PD is associated with the severity of motor symptoms. The loss of pigmented neurons inside the SNpc is correlated with the loss of microstructural integrity inside the motor circuitry. Our results suggest that probabilistic tractography and neuromelanin-sensitive MRI are a potential diagnostic marker of the disease. This abstract was also submitted for presentation at the 2019 European Academy of Neurology conference.
To cite this abstract in AMA style:S. Tagliente, H. Wilson, Z. Chappell, T. Yousaf, E. de Natale, G. Pagano. Probabilistic tractography study of the nigrostriatal pathway in Parkinson’s disease [abstract]. Mov Disord. 2019; 34 (suppl 2). https://www.mdsabstracts.org/abstract/probabilistic-tractography-study-of-the-nigrostriatal-pathway-in-parkinsons-disease/. Accessed December 5, 2023.
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MDS Abstracts - https://www.mdsabstracts.org/abstract/probabilistic-tractography-study-of-the-nigrostriatal-pathway-in-parkinsons-disease/