To describe the use of local field potentials (LFP) as an objective measure to guide initial deep brain stimulation (DBS) programming in Parkinson disease (PD).
Fluctuations in beta frequency LFP power (13-30Hz) are a biomarker of motor symptom control in PD, suppressible by levodopa and stimulation in correlation with symptom improvement. The localization of the highest beta signal often correlates with the location of the most effective stimulating contact. There is opportunity to use beta LFPs in DBS programming optimization.
We conducted a retrospective chart review of PD patients who underwent initial OFF-medication programming using the Medtronic Percept™ platform. The strongest beta LFP peak was identified using the Brainsense™ survey along with the frequency band of interest for chronic sensing. LFP suppression and clinical response were observed while titrating the stimulation at the contact with the highest beta power. Stimulation and sensing parameters were observed over a 6-month period. Stimulation efficacy was measured using the MDS-UPDRS3 score and the levodopa equivalent daily dose (LEDD).
Amongst eight patients with 15 leads (9-STN, 4-GPi), n=12 leads had measurable beta peaks with mean frequency=17.50Hz (range 7.81-27.34) and mean power=2.89uVp (range 1.15-6.64). With chronic sensing at mean frequency=18.31Hz +/-2.5Hz (range 11.72-28.32), n=12 leads showed beta suppression with stimulation titration and symptom improvement. Stimulation-limiting side effects were seen in n=7 and all resolved by the second session. Traditional monopolar review was required in one lead. The stimulating contact was changed in n=10 (seven to double monopolar), and the sensed band in n=12, due to a shifting beta peak, all by the third visit. Mean MDS-UPDRS3 improvement at 6mos was 51% (range 22%-82%), and LEDD reduction was 30% (range -13%-100%).
LFP-guided initial programming facilitates effective contact selection and troubleshooting during stimulation optimization. Long term outcomes and comparison to other programming techniques are needed.