title: Advanced target identification in STN-DBS with beta power of combined local field potentials and spiking activity.
abstract: BACKGROUND
  In deep brain stimulation of the subthalamic nucleus (STN-DBS) for Parkinson's Disease (PD), often microelectrode recordings (MER) are used for STN identification. However, for advanced target identification of the sensorimotor STN, it may be relevant to use local field potential (LFP) recordings. Then, it is important to assure that the measured oscillations are coming from the close proximity of the electrode.
  
  
  METHODS
  Through multiple simultaneous recordings of LFP and neuronal spiking, we investigated the temporal relationship between local neuronal spiking and more global LFP. We analyzed the local oscillations in the LFP by calculating power only over specific frequencies that show a significant coherence between LFP and neuronal spiking. Using this 'coherence method', we investigated how well measurements in the sensorimotor STN could be discriminated from measurements elsewhere in the STN.
  The 'sensorimotor power index' (SMPI) of beta frequencies, representing the ability to discriminate sensorimotor STN measurements based on the beta power, was significantly larger using the 'coherence method' for LFP spectral analysis compared to other methods where either the complete LFP beta spectrum or only the prominent peaks in the LFP beta spectrum were used to calculate beta power.
  
  
  CONCLUSIONS
  The results suggest that due to volume conduction of beta frequency oscillations, proper localization of the sensorimotor STN with only LFP recordings is difficult. However, combining recordings of LFP and neuronal spiking and calculating beta power over the coherent parts of the LFP spectrum can be beneficial in discriminating the sensorimotor STN.
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Academic Medical Center, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands. Electronic address: r.verhagen@amc.uva.nl.
authors.forename: Rens
authors.initials: R
authors.lastname: Verhagen
authors.affiliation: MIRA Institute for Biomedical Engineering and Technical Medicine, Biomedical Signals & Systems, University of Twente, Drienerlolaan 5, Enschede 7522 NB, The Netherlands.
authors.forename: Daphne G M
authors.initials: DG
authors.lastname: Zwartjes
authors.affiliation: MIRA Institute for Biomedical Engineering and Technical Medicine, Biomedical Signals & Systems, University of Twente, Drienerlolaan 5, Enschede 7522 NB, The Netherlands.
authors.forename: Tjitske
authors.initials: T
authors.lastname: Heida
authors.affiliation: MIRA Institute for Biomedical Engineering and Technical Medicine, Biomedical Signals & Systems, University of Twente, Drienerlolaan 5, Enschede 7522 NB, The Netherlands.
authors.forename: Evita C
authors.initials: EC
authors.lastname: Wiegers
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Academic Medical Center, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands; Department of Neurology, Haga Teaching Hospital, Leyweg 275, Den Haag 2545 CH, The Netherlands.
authors.forename: M Fiorella
authors.initials: MF
authors.lastname: Contarino
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Academic Medical Center, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands.
authors.forename: Rob M A
authors.initials: RM
authors.lastname: de Bie
authors.affiliation: Department of Neurosurgery, Academic Medical Center, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands.
authors.forename: Pepijn
authors.initials: P
authors.lastname: van den Munckhof
authors.affiliation: Department of Neurosurgery, Academic Medical Center, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands.
authors.forename: P Richard
authors.initials: PR
authors.lastname: Schuurman
authors.affiliation: MIRA Institute for Biomedical Engineering and Technical Medicine, Biomedical Signals & Systems, University of Twente, Drienerlolaan 5, Enschede 7522 NB, The Netherlands.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Veltink
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Academic Medical Center, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands.
authors.forename: Lo J
authors.initials: LJ
authors.lastname: Bour
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000328:Adult; D000368:Aged; D001611:Beta Rhythm / Q000502:physiology*; D001931:Brain Mapping; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000502:physiology*
keywords: Coherence; Deep brain stimulation; Local field potential; Neuronal spiking activity; Parkinson's disease; Subthalamic nucleus