Model 3389

We investigated spectral states in the STN LFP before and after administration of levodopa in 32 patients (64 hemispheres) with advanced Parkinson’s disease undergoing DBS surgery targeting the STN. Patients had an average age of 58.5 years (range 34–79 years) and an average disease duration of 11.7 years (range 5–18 years). Twelve were female (Supplementary Table 1). All patients were diagnosed with Parkinson’s disease according to the Queen Square Brain Bank criteria.^{30 (link)}
The mean of the part III of the Unified Parkinson’s Disease Rating Scale (UPDRS) score OFF medication was 37.9 (range 15–72) while the mean score ON medication was 14.4 (range 3–30). The DBS electrodes were model 3389 (Medtronic) with four platinum–iridium cylindrical surfaces of 1.27 mm diameter, 1.5 mm length and 2 mm centre-to-centre separation. The contacts were numbered 0 (lowermost) to 3 (uppermost). Correct placement of the DBS electrodes was confirmed by intraoperative microelectrode recordings in 18 patients and by postoperative imaging in all patients. All experimental procedures had received prior approval from the local research ethics committee in accordance with the standards set by the Declaration of Helsinki, and patients gave their written informed consent.