Contribution of local field potential to subthalamic nucleus deep brain stimulation in Parkinson's disease

International audienceIntroduction: The subthalamic nucleus (STN) is the main target for deep brain stimulation (DBS) in Parkinson’s disease. We analyzed the relationships between magnetic resonance imaging (MRI) anatomy and electrophysiology (local field potential, LFP) done during surgery.Objectives: We hypothesized that the contribution of LFP to neuronal firing rate with detailed MRI anatomy should allow to explore finely anatomo-electrophysiological relationships and also to determine precisely functional surgical targets.Methods:Ten patients with Parkinson’s disease (5F; mean age: 62±4 years; 11±3 years disease duration) underwent bilateral STN DBS surgical procedure.Electrophysiology: 693 LFP recordings in MRI-outlined anatomical structures (Thalamus [Thal], Zona Incerta [ZI], Forel Field [Forel] and STN) were analyzed: Power spectral densities (PSD) from 0 to 100Hz; 1024 frequency values; Normalization: percent of total PSD; Calculation for delta (0-4 Hz), theta (4-7 Hz), alpha (7-13 Hz), beta (13-30 Hz), gamma (30-50 Hz, 50-100 Hz) frequency range. Non-parametric Kruskal-Wallis ANOVA tests were performed followed by pairwise comparisons with adjusted p-value.Results: Percentage of power spectral density for main physiological LFP frequency range was considered for thalamus, ZI, STN and Forel (Figure).Conclusions: This study suggests the interest of LFP to discriminate between structures in the subthalamic region using exploration electrode with patient at rest during DBS surgery. Another part of this study will consist in correlating extracellular neuronal activity and LFP, and analyzing modulations on LFP during voluntary movements of patients