title: Movement-related changes in local and long-range synchronization in Parkinson's disease revealed by simultaneous magnetoencephalography and intracranial recordings.
abstract: Functional neurosurgery has afforded the opportunity to assess interactions between populations of neurons in the human cerebral cortex and basal ganglia in patients with Parkinson's disease (PD). Interactions occur over a wide range of frequencies, and the functional significance of those >30 Hz is particularly unclear. Do they improve movement, and, if so, in what way? We acquired simultaneously magnetoencephalography and direct recordings from the subthalamic nucleus (STN) in 17 PD patients. We examined the effect of synchronous and sequential finger movements and of the dopamine prodrug levodopa on induced power in the contralateral primary motor cortex (M1) and STN and on the coherence between the two structures. We observed discrete peaks in M1 and STN power at 60-90 Hz and at 300-400 Hz. All these power peaks increased with movement and levodopa treatment. Only STN activity at 60-90 Hz was coherent with activity in M1. Directionality analysis showed that STN gamma activity at 60-90 Hz tended to drive gamma activity in M1. The effects of levodopa on both local and distant synchronization at 60-90 Hz correlated with the degree of improvement in bradykinesia-rigidity as did local STN activity at 300-400 Hz. Despite this, there were no effects of movement type, nor interactions between movement type and levodopa in the STN, nor in the coherence between STN and M1. We conclude that synchronization at 60-90 Hz in the basal ganglia cortical network is prokinetic but likely through a modulatory effect rather than any involvement in explicit motor processing.
authors.affiliation: Sobell Department of Motor Neuroscience, UCL Institute of Neurology, London, WC1N 3BG, United Kingdom, Department of Clinical Neurology, University of Oxford, Oxford, OX3 9DU, United Kingdom. v.litvak@ucl.ac.uk
authors.forename: Vladimir
authors.initials: V
authors.lastname: Litvak
authors.forename: Alexandre
authors.initials: A
authors.lastname: Eusebio
authors.forename: Ashwani
authors.initials: A
authors.lastname: Jha
authors.forename: Robert
authors.initials: R
authors.lastname: Oostenveld
authors.forename: Gareth
authors.initials: G
authors.lastname: Barnes
authors.forename: Tom
authors.initials: T
authors.lastname: Foltynie
authors.forename: Patricia
authors.initials: P
authors.lastname: Limousin
authors.forename: Ludvic
authors.initials: L
authors.lastname: Zrinzo
authors.forename: Marwan I
authors.initials: MI
authors.lastname: Hariz
authors.forename: Karl
authors.initials: K
authors.lastname: Friston
authors.forename: Peter
authors.initials: P
authors.lastname: Brown
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000978:Antiparkinson Agents / Q000494:pharmacology / Q000627:therapeutic use; D003344:Cortical Synchronization / Q000187:drug effects / Q000502:physiology*; D046690:Deep Brain Stimulation; D004569:Electroencephalography; D005260:Female; D005385:Fingers / Q000503:physiopathology; D007839:Functional Laterality; D006801:Humans; D007980:Levodopa / Q000494:pharmacology / Q000627:therapeutic use; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000187:drug effects / Q000503:physiopathology; D009068:Movement / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010300:Parkinson Disease / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology*; D011597:Psychomotor Performance; D013057:Spectrum Analysis; D013223:Statistics as Topic; D020531:Subthalamic Nucleus / Q000187:drug effects / Q000473:pathology*; D013997:Time Factors
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa