Parkinson's disease (PD) is a neurodegenerative disorder with an association of akinesia, rigidity and tremor, but also so-called "axial" motor signs (disturbance of posture, gait and balance) that usually appear after several years of disease evolution. These axial signs, generally resistant to drug treatment and deep brain stimulation (DBS) of subthalamic nucleus (STN), can generate a loss of autonomy and traumatic complications due to frequent falls. An improvement of axial signs by DBS of the pedunculo-pontin nucleus (PPN) has been described for a small number of patients. Nevertheless, this effect needs to be confirmed in more patients and there is need for complementary knowledge, including optimal stimulation modalities.