RT Journal Article
SR Electronic
T1 Functional connectivity alterations in Parkinson’s disease during the stop-signal task
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 304584
DO 10.1101/304584
A1 Chris Vriend
A1 Douglas T. Leffa
A1 James P. Trujillo
A1 Niels J.H.M. Gerrits
A1 Femke E. de Boer
A1 Henk W. Berendse
A1 Ysbrand D. van der Werf
A1 Odile A. van den Heuvel
YR 2018
UL http://biorxiv.org/content/early/2018/04/19/304584.abstract
AB Although deficits in response inhibition are common in Parkinson’s disease (PD), studies on their neural correlates are relatively scarce. In our previous study, medication-naïve PD patients showed, among others, lower activation of the inhibition-related bilateral inferior frontal gyrus (IFG) compared with healthy controls while performing the stop-signal task. Here we report on a follow-up study in the same cohort.Fourteen medicated PD patients and 16 healthy controls performed the same stop-signal task during MRI; 3.1±1.0 years after our previous study. During that time, all PD patients had started to use dopaminergic medication. We analyzed task-related functional activity and connectivity in the bilateral IFG and anterior insula, brain regions that are important response inhibition. Task-related functional connectivity was analyzed with generalized psychophysiological interaction.PD patients were significantly slower on response initiation (GO reaction time) and response inhibition (stop-signal reaction time) than healthy controls. There were no between-group differences in functional activity. On the other hand, functional connectivity of the IFG and anterior insula was significantly lower in PD compared with healthy controls. Mainly the inferior parietal lobule and dorsolateral prefrontal cortex were less connected with these seed regions.These results show that early-stage medicated PD patients show lower task-related functional connectivity but not activity of brain regions that are important for response inhibition; the IFG and anterior insula. We tentatively speculate that the use of dopaminergic medication upheld task-related activity but not connectivity.