**5. Conclusions**

When administering sedation during DBS electrode implantation, the aim is always to achieve an optimal balance between patient comfort and good quality MER, to allow optimal placement of the probe. Our results showed that PSA influenced neuronal properties in the STN and that the DEX e ffect was dose-dependent. Moreover, patient dependent characteristics influenced MER. Whether these effects are large enough to be clinically relevant was not addressed in this study.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0383/9/4/1229/s1, Table S1: random e ffects modeling with patient as a random variable, Table S2: random e ffects modeling with sorter as a random variable.

**Author Contributions:** Conceptualization, M.J.R. and M.L.F.J.; Formal analysis, M.J.R., A.M.A.S., R.B., M.J.R. and M.L.F.J.; Investigation, M.J.B., A.M.A.S., M.J.R. and M.L.F.J; Methodology, A.M.A.S., B.T.A.d.G., M.J.R. and M.L.F.J.; Software, M.J.R.; Supervision, Y.T. and M.L.F.J.; Writing – original draft, M.J.B., A.M.A.S. and M.J.R.; Writing – review & editing, M.J.B., R.B., Y.T., B.T.A.d.G., A.R.A., E.D.G., V.H.J.M.v.K.-M., W.F.B., M.J.R. and M.L.F.J. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by a gran<sup>t</sup> from de Stichting Weijerhorst.

**Conflicts of Interest:** The authors declare no conflict of interest.
