Fig. 4

Spectral power of Parkinsonian tremor with DBS OFF and ON, when recorded by a force platform, from one patient standing with eyes open. Note how turning the DBS ON generally lowers also the spectral power within the 4–10 Hz range and slightly increase the spectral power in the 0.1–4 Hz range. Moreover, the DBS suppress both the primary Parkinsonian tremor at 5 Hz and the harmonics at 10 Hz and 15 Hz frequencies