Fig. 2: High-frequency oscillations (HFO) and resonant evoked compound activity (ECA) are observed during high-frequency DBS only in the STN.

a Representative TFM and PSD plots of out- and in-STN stimulation from a sample patient shows HFO was induced only within the STN. The vertical red lines on TFMs are the transition artifacts associated with turning the stimulator on and off. The large artifacts caused by harmonics of the stimulation frequency are interpolated. The color scale of the TFMs is the same as the limits of the y-axis of their respective PSD plots. b The evoked response waveform at the end of 22 s stimulation was only seen in-STN. The thick lines illustrate the mean waveform for all subjects. The first 1 ms after the stimulation pulse is blanked out due to large artifact amplitude. c Comparison of the HFO power change between out- and in-STN stimulations show a significant difference (n = 10). d Similarly, the difference between ECA amplitude of out- and in-STN stimulations was significant (n = 10). e The grand average TFM from all 16 hemispheres with 130 Hz in-STN stimulation shows a stark enhancement in the HFO range, similar to the representative subject. The transition artifacts on TFM are masked with blue boxes. f The grand average PSD plots for baseline, stimulation, and recovery periods from all 16 hemispheres with high-frequency stimulation in-STN. There was a significant suppression in the beta and significant enhancement in the HFO ranges (n = 16). g In the STN, the ECA amplitude and induced HFO power correlated (n = 16). On each box in the boxplots, the central mark indicates the median, and the bottom and top edges of the box indicate the 25th and 75th percentiles, respectively. The whiskers extend to the most extreme data points not considered outliers, and the outliers are plotted individually using the “+” symbol. The individual data points are also plotted as red circles. ** denotes significance <0.01, *** denotes significance <0.001.