We next explored how STN-DBS may act on M1 PAC and freezing severity. Given that we did not observe significant differences between HFS and LFS conditions in any of the trial-PAC, episode-PAC and freezing severity (although a trend favouring LFS manifested as lower trial PAC and less freezing were observed, Supplementary Fig. 5A–C), HFS and LFS were collectively referred to as STIM in further analysis. We found that stimulation significantly reduced the three types of PAC and simultaneously alleviated freezing severity measured through the three aforementioned indices (Fig. 5A and B). When we further correlated the STIM-induced PAC reduction to the STIM-induced percentage improvement of freezing severity, only PACstable remained significant in all three indices of freezing measurements (Bonferroni corrected P < 0.05, Fig. 5C–E). These results suggested that STN-DBS improved FOG by reducing PAC during stable walking.
