fMRI group analysis of the tapping test performed by PD patients (N = 12) before and after implantation of the electrodes bilaterally to the STN in absence of DBS.

a) Contrast showing decrease of the BOLD signal after implantation (OFF state) as compared to situation before implantation (OFF state) with the UPDRS-III or the oedema score as covariates; x, y, z – local maxima of clusters in MNI coordinates derived from the contrast before vs. after implantation with the UPDRS-III covariate; k – size of the cluster in voxels;‡- regions belonging to the same cluster; T – T-score; p – uncorrected level of significance;*(p**(p***(p†– values derived from the contrast before vs. after implantation with the UPDRS-III covariate;#– values derived from the contrast before vs. after implantation with the oedema covariate.b), c), d), e) – Impact of the UPDRS-III sub-scores on size of the BOLD response expressed as inverse effects of rigidity and axial covariates.