title: Cordance: a new method for assessment of cerebral perfusion and metabolism using quantitative electroencephalography.
abstract: Increased slow-wave and decreased fast-wave activity on the electroencephalogram is common in brain dysfunction and may be caused by partial cortical deafferentation. No measure that is specific or sensitive for this deafferentation, however, has yet been reported. We studied a series of subjects with white-matter lesions undercutting the cortex and developed a method for analyzing electrical activity called "cordance" that has face validity as a measure of cortical deafferentation. Cordance is measured along a continuum of values: positive values denote "concordance," an indicator associated with normally functioning brain tissue; negative values denote "discordance," an indicator associated with undercutting lesions, low perfusion, and low metabolism. We present a series of subjects studied with magnetic resonance imaging, positron emission tomography, and single-photon emission computed tomography that demonstrate strong associations between cordance and other measures of brain structure and function.
authors.affiliation: Quantitative EEG Laboratory, UCLA Neuropsychiatric Institute and Hospital, USA.
authors.forename: A F
authors.initials: AF
authors.lastname: Leuchter
authors.forename: I A
authors.initials: IA
authors.lastname: Cook
authors.forename: R B
authors.initials: RB
authors.lastname: Lufkin
authors.forename: J
authors.initials: J
authors.lastname: Dunkin
authors.forename: T F
authors.initials: TF
authors.lastname: Newton
authors.forename: J L
authors.initials: JL
authors.lastname: Cummings
authors.forename: J K
authors.initials: JK
authors.lastname: Mackey
authors.forename: D O
authors.initials: DO
authors.lastname: Walter
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000098:blood supply; D000368:Aged; D000369:Aged, 80 and over; D001927:Brain Diseases / Q000175:diagnosis / Q000503:physiopathology; D001931:Brain Mapping / Q000295:instrumentation*; D002540:Cerebral Cortex / Q000098:blood supply*; D003199:Computer Systems; D004569:Electroencephalography / Q000295:instrumentation*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D014055:Tomography, Emission-Computed / Q000295:instrumentation; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation