Cortico-cortical networks in patients with ideomotor apraxia as revealed by EEG coherence analysis.
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.
Wheaton
Lewis A
LA
Human Motor Control Section, NINDS, NIH, Bethesda, MD 20892-1428, United States.
Bohlhalter
Stephan
S
Nolte
Guido
G
Shibasaki
Hiroshi
H
Hattori
Noriaki
N
Fridman
Esteban
E
Vorbach
Sherry
S
Grafman
Jordan
J
Hallett
Mark
M
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