Open Access

S. Paschen, R. Anwar, P. Kuravi, D. Falk, G. Deuschl, Muthuraman Muthuraman, J. Raethjen

• Objective: For electrode implantation into the STN in Parkin-son’s disease most DBS centers use microelectrode recording (MER)with multiple trajectories. The aim of the study is to identify MERpatterns to predict optimal electrode position and to keep clinicaltesting as short as possible in order to reduce operation time andadverse events. Background: There is an ongoing debate whether MER is associ-ated with higher operation risks and time-consuming or leading to asignificant better clinical outcome. Here, we focus on correlationsbetween background activity and firing rate to predict optimal elec-trode placement. Methods: 10 patients with advanced PD underwent bilateral STNDBS operation. Recording was done simultaneously for 3–5 micro-electrodes using a ben-gun for multiple trajectories. MER data wererecorded and analyzed postoperatively using spike2VRand wave_clusVRfor segmentation and spikeObjective: For electrode implantation into the STN in Parkin-son’s disease most DBS centers use microelectrode recording (MER)with multiple trajectories. The aim of the study is to identify MERpatterns to predict optimal electrode position and to keep clinicaltesting as short as possible in order to reduce operation time andadverse events. Background: There is an ongoing debate whether MER is associ-ated with higher operation risks and time-consuming or leading to asignificant better clinical outcome. Here, we focus on correlationsbetween background activity and firing rate to predict optimal elec-trode placement. Methods: 10 patients with advanced PD underwent bilateral STNDBS operation. Recording was done simultaneously for 3–5 micro-electrodes using a ben-gun for multiple trajectories. MER data wererecorded and analyzed postoperatively using spike2VRand wave_clusVRfor segmentation and spike sorting. The overall mean amplitude wasdetermined for each patient separately for firing rate and backgroundactivity to define an individual threshold and the needles with the fir-ing rate and background activity above this threshold was selected. Results: In 8 out of 10 patients the permanent electrode wasimplanted in the trajectory of the microelectrode with the highestbackground activity compared to all other microelectrodes, in the other 2 patients a neighbouring trajectory was chosen because of lowthresholds for side effects. The postoperatively chosen active contactof the permanent electrode was in 70% in the place of the highestfiring rate. Conclusions: MER in implantation of electrodes into the STN isvery helpful to predict the optimum stimulation place analysingbackground activity and firing rate. Finding a good ratio of effectand threshold for side effects at that place further clinical testingmight be useless and the permanent electrode could be implanteddirectly. This helps to save operation time and might reduce adverseevents, e.g. haemorrhage und infections.…