Initial Experience with Pseudomonopolar Local Field Potentials in Deep Brain Stimulation for Parkinson's Disease

BACKGROUND: Local field potentials (LFPs) can assist DBS contact selection in Parkinson's disease (PD). To overcome the spatial uncertainty of bipolar recordings, pseudomonopolar recordings with an onboard algorithm have recently been introduced. OBJECTIVE: To report initial experience with pseudomonopolar recordings. METHODS: Pseudomonopolar recordings obtained during routine clinical care were retrospectively analyzed by a blinded rater. Potential reference-related electrical contamination was evaluated. The degree of agreement with the clinically optimized contact configuration was compared between visual power spectral density (PSD) and algorithm-based contact selection. RESULTS: Among 97 hemispheres of 49 PD patients, 49.5% demonstrated clinically useful PSDs. PSDs were less often clinically useful when the contralateral reference contact had the highest beta activity. Agreement with clinically optimized contacts may be lower for the algorithm than for visual assessment. CONCLUSIONS: Pseudomonopolar recordings may facilitate PSD interpretation, but their referenced nature sometimes reduces reliability. Further evaluation of the onboard algorithm's performance is needed.