Objective: To evaluate global changes in connectivity of large-scale structural brain networks in Parkinson’s disease (PD) patients, and to test the hypothesis that deep brain stimulation (DBS) might help normalize that impaired connectivity, as demonstrated by increases in the anisotropy fraction (AF) in specific brain areas after stimulation.

Background: DBS of the subthalamic nucleus (STN) is currently a cutting-edge, evidence-based therapeutic option for motor symptoms in patients with PD. However, the exact anatomical regions associated with patient improvement have not been accurately described; it has been suggested that DBS mechanism of action is not the simple stimulation of the nucleus, but a modulation of widespread brain networks. Therefore, it is necessary to use new methods to identify specific network changes after stimulation such as tractography.

Methods: 1.5 T brain DTI MRIs from 6 bilateral STN DBS patients (group A), 12 non-operated PD patients (group B), and 12 age and gender-matched healthy controls obtained from the global database Image & Data Archive (group C) were analyzed and compared to test for differences in AF. DICOM images were processed with the FSL5.0 software, and the statistical analysis was performed with the TBSS tool.

Results: In total, 22 men and 8 women were included in the study. No statistically significant differences in age, scores at the H&Y scale and mean follow-up between group A and B were found (4.2 +/-1-8 and 4.8+/- 1-11 years respectively (Figure 1A) Statistical analysis revealed: Group B versus group C- group C presents a greater FA in the left corticospinal tract, corona radiata, left fronto-occipital fascicle and both upper and lower longitudinal fascicles. Group A versus group B: group A showed a statistically significant higher AF, in the right thalamic radiations and in both corticospinal tracts (Figure 1B)

Conclusions: In our series, PD patients showed widespread areas of altered connectivity, probably related with the presence of motor and non-motor symptoms. When treated with bilateral STN-DBS, higher AF is found in different areas of cerebral white matter, inside and outside of motor regions, which could be related to its therapeutic and other effects observed with brain stimulation. This study shows that DBS should be understood as a stimulation of neural networks.

« Back to 2018 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/deep-brain-stimulation-in-parkinsons-disease-from-the-stimulation-of-a-nucleus-to-the-stimulation-of-neuronal-networks/