title: Tremor-specific neuronal oscillation pattern in dorsal subthalamic nucleus of parkinsonian patients.
abstract: BACKGROUND
  Subthalamic nucleus (STN) deep brain stimulation effectively improves parkinsonian symptoms. It is hypothesized that distinct functional territories with different neurophysiologic activity within the STN relate to different symptoms.
  
  
  OBJECTIVE
  The aim of the study was to identify distinctive characteristics of STN neuronal activity related to tremor by directly comparing tremor sides with no-tremor sides. In addition, we studied the spatial pattern of frequency distributions within the STN in more detail.
  
  
  METHODS
  We analyzed intraoperative STN single/multiunit recordings from 33 tremor sides and 23 no-tremor sides. STN tracks were normalized to a length of 1 and subdivided into eight successive layers. The power spectral density was split into six frequency bands: theta (3-8 Hz), alpha (9-12 Hz), lower beta (13-20 Hz), upper beta (21-30 Hz), lower gamma (31-59 Hz), and upper gamma (60-100 Hz).
  
  
  RESULTS
  Tremor sides presented predominant theta frequency oscillations in the most dorsal layers of the STN, whereas in no-tremor sides beta frequencies predominated. Oscillatory activity was stronger in the dorsal STN than in the ventral, and this pattern was specific for frequencies in the theta, alpha, and beta bands, but not in the gamma bands.
  
  
  CONCLUSIONS
  Our study supports the hypothesis that the presence of tremor is associated with a distinctive neuronal oscillations pattern. In particular, we demonstrate the specificity of the association of theta frequencies in the dorsal STN with tremor. Identification of symptom-specific characteristics of intraoperative microrecordings in the STN may lead to refinement of targeting for each patient, tailored to the specific clinical presentation.
authors.affiliation: Department of Neurology/Clinical Neurophysiology, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: m.f.contarino@amc.uva.nl.
authors.forename: Maria Fiorella
authors.initials: MF
authors.lastname: Contarino
authors.affiliation: Department of Neurology/Clinical Neurophysiology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Lo J
authors.initials: LJ
authors.lastname: Bour
authors.affiliation: Department of Neurology/Clinical Neurophysiology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Bot
authors.affiliation: Department of Neurosurgery, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Pepijn
authors.initials: P
authors.lastname: van den Munckhof
authors.affiliation: Department of Neurology/Clinical Neurophysiology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Speelman
authors.affiliation: Department of Neurosurgery, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Peter Richard
authors.initials: PR
authors.lastname: Schuurman
authors.affiliation: Department of Neurology/Clinical Neurophysiology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Rob M
authors.initials: RM
authors.lastname: de Bie
mesh_terms: D001683:Biological Clocks; D046690:Deep Brain Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology* / Q000517:prevention & control*; D020531:Subthalamic Nucleus / Q000503:physiopathology*; D016896:Treatment Outcome; D014202:Tremor / Q000150:complications / Q000503:physiopathology* / Q000517:prevention & control*