title: Exaggerated phase-amplitude coupling in the primary motor cortex in Parkinson disease.
abstract: An important mechanism for large-scale interactions between cortical areas involves coupling between the phase and the amplitude of different brain rhythms. Could basal ganglia disease disrupt this mechanism? We answered this question by analysis of local field potentials recorded from the primary motor cortex (M1) arm area in patients undergoing neurosurgery. In Parkinson disease, coupling between β-phase (13-30 Hz) and γ-amplitude (50-200 Hz) in M1 is exaggerated compared with patients with craniocervical dystonia and humans without a movement disorder. Excessive coupling may be reduced by therapeutic subthalamic nucleus stimulation. Peaks in M1 γ-amplitude are coupled to, and precede, the subthalamic nucleus β-trough. The results prompt a model of the basal ganglia-cortical circuit in Parkinson disease incorporating phase-amplitude interactions and abnormal corticosubthalamic feedback and suggest that M1 local field potentials could be used as a control signal for automated programming of basal ganglia stimulators.
authors.affiliation: Departments of Neurological Surgery and Neurology, University of California, San Francisco, CA 94143-94115, USA. coralie.dehemptinne@ucsf.edu
authors.forename: Coralie
authors.initials: C
authors.lastname: de Hemptinne
authors.forename: Elena S
authors.initials: ES
authors.lastname: Ryapolova-Webb
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Air
authors.forename: Paul A
authors.initials: PA
authors.lastname: Garcia
authors.forename: Kai J
authors.initials: KJ
authors.lastname: Miller
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Ojemann
authors.forename: Jill L
authors.initials: JL
authors.lastname: Ostrem
authors.forename: Nicholas B
authors.initials: NB
authors.lastname: Galifianakis
authors.forename: Philip A
authors.initials: PA
authors.lastname: Starr
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009044:Motor Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D011859:Radiography; D020531:Subthalamic Nucleus / Q000000981:diagnostic imaging / Q000503:physiopathology*