@article{93fb4fd73c9b482b83da45251134d129,
title = "Subthalamic nucleus phase-amplitude coupling correlates with motor impairment in Parkinson's disease",
abstract = "Objective: High-amplitude beta band oscillations within the subthalamic nucleus are frequently associated with Parkinson's disease but it is unclear how they might lead to motor impairments. Here we investigate a likely pathological coupling between the phase of beta band oscillations and the amplitude of high-frequency oscillations around 300 Hz. Methods: We analysed an extensive data set comprising resting-state recordings obtained from deep brain stimulation electrodes in 33 patients before and/or after taking dopaminergic medication. We correlated mean values of spectral power and phase-amplitude coupling with severity of hemibody bradykinesia/rigidity. In addition, we used simultaneously recorded magnetoencephalography to look at functional interactions between the subthalamic nucleus and ipsilateral motor cortex. Results: Beta band power and phase-amplitude coupling within the subthalamic nucleus correlated positively with severity of motor impairment. This effect was more pronounced within the low-beta range, whilst coherence between subthalamic nucleus and motor cortex was dominant in the high-beta range. Conclusions: We speculate that the beta band might impede pro-kinetic high-frequency activity patterns when phase-amplitude coupling is prominent. Furthermore, results provide evidence for a functional subdivision of the beta band into low and high frequencies. Significance: Our findings contribute to the interpretation of oscillatory activity within the cortico-basal ganglia circuit.",
keywords = "Beta oscillations, Cross-frequency coupling, Local field potentials, Motor system, Parkinson's disease, Subthalamic nucleus",
author = "{van Wijk}, {Bernadette C.M.} and Martijn Beudel and Ashwani Jha and Ashwini Oswal and Tom Foltynie and Hariz, {Marwan I.} and Patricia Limousin and Ludvic Zrinzo and Aziz, {Tipu Z.} and Green, {Alexander L.} and Peter Brown and Vladimir Litvak",
note = "Funding Information: This research was supported by the National Institute for Health Research University College London Hospitals Biomedical Research Centre . PB is supported by the Medical Research Council ( MC_UU_12024 ) and the National Institute for Health Research Oxford Biomedical Research Centre . VL is supported by the MRC/EPSRC UK MEG Partnership award. The Wellcome Trust Centre for Neuroimaging is supported by core funding from the Wellcome Trust 091593/Z/10/Z. The Unit of Functional Neurosurgery is supported by the Parkinson Appeal UK, and the Monument Trust. The authors declare no competing financial interests. Funding Information: This research was supported by the National Institute for Health Research University College London Hospitals Biomedical Research Centre. PB is supported by the Medical Research Council (MC_UU_12024) and the National Institute for Health Research Oxford Biomedical Research Centre. VL is supported by the MRC/EPSRC UK MEG Partnership award. The Wellcome Trust Centre for Neuroimaging is supported by core funding from the Wellcome Trust 091593/Z/10/Z. The Unit of Functional Neurosurgery is supported by the Parkinson Appeal UK, and the Monument Trust. The authors declare no competing financial interests.Conflict of interest: None of the authors have potential conflicts of interest to be disclosed. Publisher Copyright: {\textcopyright} 2016 International Federation of Clinical Neurophysiology.",
year = "2016",
month = apr,
day = "1",
doi = "https://doi.org/10.1016/j.clinph.2016.01.015",
language = "English",
volume = "127",
pages = "2010--2019",
journal = "Clinical neurophysiology",
issn = "1388-2457",
publisher = "Elsevier Ireland Ltd",
number = "4",
}