title: Cortico-cortical networks in patients with ideomotor apraxia as revealed by EEG coherence analysis.
abstract: We sought to determine whether coherent networks which circumvent lesioned cortex are seen in patients with ideomotor apraxia (IMA) while performing tool-use pantomimes. Five normal subjects and five patients with IMA (three patients with corticobasal degeneration and two with left hemisphere stroke) underwent 64-channel EEG recording while performing three tool-use pantomimes with their left hand in a self-paced manner. Beta band (20-22 Hz) coherence indicates that normal subjects have a dominant left hemisphere network responsible for praxis preparation, which was absent in patients. Corticobasal degeneration patients showed significant coherence increase between left parietal-right premotor areas. Left hemisphere stroke patients showed significant coherence increases in a right parietofrontal network. The right hemisphere appears to store useable praxis representations in IMA patients with left hemisphere damage.
authors.affiliation: Human Motor Control Section, NINDS, NIH, Bethesda, MD 20892-1428, United States.
authors.forename: Lewis A
authors.initials: LA
authors.lastname: Wheaton
authors.forename: Stephan
authors.initials: S
authors.lastname: Bohlhalter
authors.forename: Guido
authors.initials: G
authors.lastname: Nolte
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shibasaki
authors.forename: Noriaki
authors.initials: N
authors.lastname: Hattori
authors.forename: Esteban
authors.initials: E
authors.lastname: Fridman
authors.forename: Sherry
authors.initials: S
authors.lastname: Vorbach
authors.forename: Jordan
authors.initials: J
authors.lastname: Grafman
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
mesh_terms: D000328:Adult; D000368:Aged; D020240:Apraxia, Ideomotor / Q000473:pathology* / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D019636:Neurodegenerative Diseases / Q000473:pathology / Q000503:physiopathology; D020521:Stroke / Q000473:pathology / Q000503:physiopathology