## 5 Conclusions  
Our study, despite the reduced number of subjects included, has been able to differentiate PD patients off medications from healthy control subjects, which, to our knowledge, has not been shown with time series analysis methods so far.  
Changes in connectivity may be a dynamic process that varies with behavior and cognition alongside the disease progression; thus, it might be also a disease progression marker. We do not know whether higher dopamine doses will mean normalization of assortativity values or whether earlier stages mean less hyper-connectivity.  
Up to date, most connectivity studies have used mainly invasive recordings of cortical and subcortical activity. The EEG connectivity approach used in our study could potentially be used to measure objectively dopamine effects and adjust the dosing when clinical clues are not enough, or non-motor symptoms are predominant. It could be also used for integrating closed loop systems for DBS stimulation parameters regulation.  
In closing, the differences found in network assortativity suggest that the different cortex areas within a healthy brain can perform tasks independently. On the contrary, PD brains exhibit a greater connectivity, which grows during motor activation. Although the administration of levodopa appears to mitigate this behavior, it does not seem to produce a sufficiently strong modification so that the assortativity values match those of the controls in any situation.  
Our findings should be considered only as a preliminary result, more for exploratory purposes than for a solid conclusion. Further additional studies with larger samples are required. The potential for EEG analysis in PD diagnosis and treatment regulation is yet to be fully explored.  
Conceptualization, J.P.R., D.H.-A., and R.P.; methodology. J.P.R., D.H.-A., and R.P.; software, J.I.S., M.D.D.C., A.M.M.; validation, J.I.S., M.D.D.C., and J.P.R.; formal analysis, A.M.M., D.H.-A., and R.P.; investigation, A.M.M.; resources, J.P.R.; data curation, A.A., J.A.; writing--original draft preparation, J.P.R., D.H.-A., R.P., and A.M.M.; writing--review and editing, J.P.R., D.H.-A., and R.P.; visualization, A.M.M.; supervision, J.P.R.; project administration, J.P.R.; funding acquisition, J.P.R. All authors have read and agreed to the published version of the manuscript.  
This research was supported mainly by FEDER funds. Dr. [PERSON] is supported by the Ministry of Economy and Competitiveness (grant DPI2015-68664-C4-3-R (MINECO/FEDER), NeuroMOD Therapy development and evaluation of motor and cognitive impact for Parkinson's disease rehabilitation). [PERSON], [PERSON] are supported by the Ministry of Economy and Competitiveness (grant DPI2015-68664-C4-1-R (MINECO/FEDER), NeuroMOD.  
The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Institutional Ethics Committee of Hospital de Fuenlabrada, Spain. (protocol code 16/37 on 16 December 2016).  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
The data presented in this study are available on request from the corresponding author.  
We would like to thank [PERSON] for her assistance with the EEG recordings.  
The authors declare no conflict of interest.