Acute administration of methylphenidate modulates functional connectivity during irrelevant stimuli processing in Parkinson's disease

Objective Methylphenidate (MPD) may have therapeutic benefits in Parkinson's disease (PD) patients. However, the effects of MPD on attentional functional connectivity (FC) networks, in PD, have not been investigated to date. Our objective was to examine the effects of a single dose of MPD, on event-related FC, in PD. The study was a randomized, double-blind, placebo-controlled, single-dose, cross-over clinical trial. Methods We recorded electroencephalogram (EEG) in PD patients during the performance of an extended version of a visual oddball task. We evaluated FC during the processing of task-relevant (targets, predictive sequence) and task-irrelevant (randomized standards) stimuli, using the weighted phase-locking index and graph theory. Two recording sessions (20 mg MPD or placebo) were performed in each patient. Results MPD, in comparison with placebo, modulated FC during the processing of standards, within the theta band, in PD patients. MPD induced decreases in the FC and global efficiency within fronto-parietal networks, during the processing of task-irrelevant stimuli. Conclusions In PD patients, the administration of a single dose of MPD, compared with placebo, attenuated FC within fronto-parietal networks, during the processing of non-informative standards. Significance MPD may have cognitive therapeutic effects in PD, by modulating attention during the processing of task-irrelevant stimuli.