PARKEOSub-thalamic Nucleus Stimulation in Parkinson Disease: Comparison of a Two-steps Electrophysiological Approach Under Local and General Anesthesia and a One-step Approach Under General Anesthesia

Deep brain stimulation (DBS) is an established procedure for the symptomatic treatment of Parkinson's disease. This procedure performed in two steps using electrophysiology (Limousin et al., 1995) to register the activity of the sub-thalamic nucleus and test the efficacy of stimulation while the patient is awake. A second procedure is needed a few days later to implant the stimulation device under general anaesthesia. The duration of the first procedure is long because of a necessary time of deep stimulation to control the target before definitive implantation. Firstly, the long time of procedure causes pain for the patient. Secondly, the time of procedure, and thus of electrophysiology, is correlated with a rate of device infection of 5 % - 6 % (Hamani et al., 2006; Kenney et al., 2007; Sillay et al., 2008; Doshi et al., 2011). Thirdly, the introduction of several microelectrodes increases the risk of operative and postoperative haemorrhages, estimated at 1 % (Kenney et al., 2007; Sansur et al., 2007; Voges et al., 2007; Bhatia et al., 2008). Moreover, Foltynie et al. (2011) described 12/79 patients treated under general anaesthesia alone with the same post operative results than those who were firstly treated under local anaesthesia. A better control of targeting and trajectory is necessary before not using electrophysiology, which is the reference procedure. A new definition of sub thalamic nuclei with new MRI stereotactic landmarks, the use of surgical robot (Neuromata Renishaw) and the use of operative imaging (O-arm) could allow the implantation of electrode in sub-thalamic nuclei without the need of electrophysiology. (Caire et al. 2012, In press). This study is a prospective, randomized and monocentric study. The randomization will be made according to a ratio 2:1 in favour of the technique without electrophysiology. Two groups of patients will be followed: a first group of patients with a procedure under general anesthesia alone without electrophysiological stimulation and a second smaller group of patients with a first step of electrode implantation under awake surgery with electrophysiological stimulation followed by a second step under general anesthesia. After a preoperative assessment, a end-point evaluation at 6 months after implantation will complete the follow-up. The stimulation efficacy (UPDRS-3) and the post operative adverse effects will be noticed. This study will also evaluate the occurrence of a post-traumatic stress disorder (PTSD) in Parkinson disease patients operated under deep brain stimulation.