title: Deep brain stimulation suppresses pallidal low frequency activity in patients with phasic dystonic movements.
abstract: Deep brain stimulation of the globus pallidus internus alleviates involuntary movements in patients with dystonia. However, the mechanism is still not entirely understood. One hypothesis is that deep brain stimulation suppresses abnormally enhanced synchronized oscillatory activity within the motor cortico-basal ganglia network. Here, we explore deep brain stimulation-induced modulation of pathological low frequency (4-12 Hz) pallidal activity that has been described in local field potential recordings in patients with dystonia. Therefore, local field potentials were recorded from 16 hemispheres in 12 patients undergoing deep brain stimulation for severe dystonia using a specially designed amplifier allowing simultaneous high frequency stimulation at therapeutic parameter settings and local field potential recordings. For coherence analysis electroencephalographic activity (EEG) over motor areas and electromyographic activity (EMG) from affected neck muscles were recorded before and immediately after cessation of high frequency stimulation. High frequency stimulation led to a significant reduction of mean power in the 4-12 Hz band by 24.8 ± 7.0% in patients with predominantly phasic dystonia. A significant decrease of coherence between cortical EEG and pallidal local field potential activity in the 4-12 Hz range was revealed for the time period of 30 s after switching off high frequency stimulation. Coherence between EMG activity and pallidal activity was mainly found in patients with phasic dystonic movements where it was suppressed after high frequency stimulation. Our findings suggest that high frequency stimulation may suppress pathologically enhanced low frequency activity in patients with phasic dystonia. These dystonic features are the quickest to respond to high frequency stimulation and may thus directly relate to modulation of pathological basal ganglia activity, whereas improvement in tonic features may depend on long-term plastic changes within the motor network.
authors.affiliation: Department of Neurology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Ewgenia
authors.initials: E
authors.lastname: Barow
authors.affiliation: Department of Neurology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Wolf-Julian
authors.initials: WJ
authors.lastname: Neumann
authors.affiliation: Department of Neurology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Brücke
authors.affiliation: Department of Neurology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Julius
authors.initials: J
authors.lastname: Huebl
authors.affiliation: Department of Neurology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Horn
authors.affiliation: Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Brown
authors.affiliation: Department of Neurosurgery, Medical University Hannover, MHH, Hannover, Germany.
authors.forename: Joachim K
authors.initials: JK
authors.lastname: Krauss
authors.affiliation: Department of Neurosurgery, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Gerd-Helge
authors.initials: GH
authors.lastname: Schneider
authors.affiliation: Department of Neurology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Kühn
mesh_terms: D000328:Adult; D046690:Deep Brain Stimulation / Q000295:instrumentation / Q000379:methods*; D020821:Dystonic Disorders / Q000503:physiopathology / Q000628:therapy*; D004569:Electroencephalography; D004576:Electromyography; D005260:Female; D005917:Globus Pallidus / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D016896:Treatment Outcome
keywords: basal ganglia; deep brain stimulation; dystonia; electrophysiology; oscillations