Real-World Local Field Potential Recordings in Patients with Parkinson’s Disease: Peak Detection and Influence of Patient Related Factors
Nathan Morelli1, Alexa Singer1, Claudia Sannelli1, Hideo Mure2, Kenneth Martinez3, Genko Oyama4, Steven Falowski5, Sarah Bick6, Mya Schiess7, Farrokh Farrokhi8, Thomas Witt9
1Neuromodulation, Medtronic, 2Center for Neuromodulation, Department of Neurosurgery, Kurashiki Heisei Hospital, 3Neurology & Pain Specialty Center, 4Department of Neurology, Juntendo University School of Medicine, 5Neurosurgical Associates of Lancaster, 6Department of Neurosurgery, Vanderbilt University Medical Center, 7Department of Neurology, Movement Disorders and Neurodegenerative Disease Program, McGovern Medical School, University of Texas, 8Neuroscience Institute, Department of Neurosurgery, Virginia Mason Franciscan Health, 9Department of Neurosurgery, Indiana University Medical Center
Objective:
To determine the association of real-world local field potential (LFP) recordings in patients with Parkinson’s disease (PD) with mobility quality of life (m-QoL), patient demographics, interhemispheric recordings, and stimulation parameters.
Background:
LFPs are associated with various symptoms in PD and are considered a biomarker of interest for deep brain stimulation (DBS). However, real-world LFP data is limited. 
Design/Methods:
Twenty-seven patients (age: 63.7±9.4-years, Sex: 18-male, Disease Duration: 12.9±7.3-years) with PD and bilateral subthalamic nucleus DBS (STN-DBS) were included. Recordings occurred during routine clinic visits, OFF stimulation. Raw LFP data was processed to identify spectral peaks and frequency band power in the alpha, beta, and gamma ranges. M-QoL was assessed using the EuroQol-5 Dimensions (EQ-5D) question 1. Due to non-normally distributed data, non-parametric tests were used for all analyses with significance set at p<0.05.
Results:
Peaks were detected in 42(77.8%) of 54 STNs with 18(66.7%) patients demonstrating bilateral peaks and 6(22%) demonstrating unilateral peaks. No significant differences were found in LFP characteristics between hemispheres (p>0.05). Interhemispheric peak frequency (rho=0.46, p=0.06) and amplitude (rho=0.34, p=0.162) demonstrated non-significant interhemispheric correlations. Interhemispheric band power demonstrated a significant correlation in the low-beta (rho=0.43, p=0.027) and high-beta (rho=0.42, p=0.031) ranges. Those with worse m-QoL demonstrated increased low- (Z=-2.47, p=0.012, eta squared=0.23) and high-beta (Z=-2.26, p=0.023, eta squared=0.20) band power. No sex differences were noted across peak characteristics and beta band power averages (p>0.05). Peak characteristics and beta band power primarily demonstrated non-significant correlations with age, disease duration, and stimulation amplitude (p>0.05).
Conclusions:

LFP peaks were readily detected in real-world, clinical settings. Elevated STN low- and high-beta band power of patients with PD may be linked to worse m-QoL. This information, along with other significant findings related to STN LFPs, may guide further treatment of patients with PD and improve our understanding of PD pathophysiology.

10.1212/WNL.0000000000201799