Improvement of hand dexterity induced by stimulation of the peduncolopontine nucleus in a patient with advanced Parkinson's disease and previous long-lasting bilateral subthalamic DBS.

We report the case of a patient already submitted to bilateral deep-brain stimulation (DBS) of the subthalamic nucleus (STN) who started to develop gait impairment, postural imbalance and frequent falls in the course of the disease and who subsequently underwent DBS of the right pedunculopontine nucleus (PPN) at our institute. An immediate clinical benefit in hand dexterity was observed with acute external stimulation and maintained after the definitive implant of the internal pulse generator (IPG) at 6 months' follow-up. The benefit on hand dexterity seemed to be related to the interactions between the PPN low-frequency stimulation and the bilateral STN high-frequency stimulation.