gms | German Medical Science

62nd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Polish Society of Neurosurgeons (PNCH)

German Society of Neurosurgery (DGNC)

7 - 11 May 2011, Hamburg

Analysis of the bidirectional information flow between the STN and cortex using microelectrode recordings and EEG

Meeting Abstract

  • G. Naros - Eberhard-Karls-Universität Tübingen, Universitätskliniken für Neurochirugie
  • D. Weiß - Eberhard-Karls-Universität Tübingen, Universitätskliniken für Neurologie
  • F. Grimm - Eberhard-Karls-Universität Tübingen, Universitätskliniken für Neurochirugie
  • S. Breit - Eberhard-Karls-Universität Tübingen, Universitätskliniken für Neurologie
  • R. Krüger - Eberhard-Karls-Universität Tübingen, Universitätskliniken für Neurologie
  • A. Gharabaghi - Eberhard-Karls-Universität Tübingen, Universitätskliniken für Neurochirugie

Deutsche Gesellschaft für Neurochirurgie. Polnische Gesellschaft für Neurochirurgen. 62. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgen (PNCH). Hamburg, 07.-11.05.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. DocP 020

doi: 10.3205/11dgnc241, urn:nbn:de:0183-11dgnc2419

Published: April 28, 2011

© 2011 Naros et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: Coherent activity between basal ganglia (BG) local field potentials (LFPs) and cortical electroencephalographic (EEG) signals over several cortical areas including the sensorimotor cortex (MC) has been demonstrated for patients suffering from Parkinson’s disease (PD). Several studies show prominent and synchronized neuronal oscillations at beta band frequencies (13–35 Hz) which seem to be related to bradykinesia and rigidity, whereas coherent activity in lower frequencies seem to be associated with tremor. Recently, the bidirectionality of cortico-basal ganglia communication across different frequency bands has been confirmed. Nevertheless, the question whether clinical presentation is correlated with a specific frequency or origin of BG/Cortex network oscillations remains unclear. Here, we used the intraoperative setting to evaluate the processing in different functional subloops between MC and STN.

Methods: Nine patients with Parkinson's disease who were selected for bilateral implantation of deep-brain electrodes in the STN participated in the study. After STN spike identification, intraoperative LFPs and a concurrent multi-channel EEG over the bilateral sensorimotor cortex was recorded. Patients performed externally cued sequences of finger and wrist extension movements of the contralateral limb. Using a Fast Fourrier Transformation (FFT)-based approach, a time-frequency analysis was performed and the magnitude squared coherence (MSC) was calculated for the rest, movement and post-movement periods. In order to determine asymmetry in coherent activity between STN and MC, we calculated the Partial Directed Coherence (PDC) using a multivariate autoregressive model (MVAR).

Results: Finger and wrist extension led to event-related desynchronization (ERD) of oscillatory activity of the STN and the MC and was accompanied by a decrease in cortico-nuclear coherence. ERD and coherence peaks were distributed in two distinct frequency bands [sub-beta (3–13 Hz) and beta (13–35 Hz)]. PDC analysis revealed that beta band activity is driven by MC whereas sub-beta oscillations are mainly driven by the STN, in particular in patients with a tremor dominant phenotype.

Conclusions: The results confirm a bidirectional information flow between STN and motor cortex and support the hypothesis of different functional subloops between these two sites. Further studies are needed to understand the relationship between different oscillatory patterns, their sources and the according clinical phenotypes.