Simultaneous EEG, fMRI, and behavior in typical childhood absence seizures.
OBJECTIVE
Absence seizures cause transient impairment of consciousness. Typical absence seizures occur in children, and are accompanied by 3-4-Hz spike-wave discharges (SWDs) on electroencephalography (EEG). Prior EEG-functional magnetic resonance imaging (fMRI) studies of SWDs have shown a network of cortical and subcortical changes during these electrical events. However, fMRI during typical childhood absence seizures with confirmed impaired consciousness has not been previously investigated.


METHODS
We performed EEG-fMRI with simultaneous behavioral testing in 37 children with typical childhood absence epilepsy (CAE). Attentional vigilance was evaluated by a continuous performance task (CPT), and simpler motor performance was evaluated by a repetitive tapping task (RTT).


RESULTS
SWD episodes were obtained during fMRI scanning from 9 patients among the 37 studied. fMRI signal increases during SWDs were observed in the thalamus, frontal cortex, primary visual, auditory, somatosensory, and motor cortex, and fMRI decreases were seen in the lateral and medial parietal cortex, cingulate gyrus, and basal ganglia. Omission error rate (missed targets) with SWDs during fMRI was 81% on CPT and 39% on RTT. For those seizure epochs during which CPT performance was impaired, fMRI changes were seen in cortical and subcortical structures typically involved in SWDs, whereas minimal changes were observed for the few epochs during which performance was spared.


CONCLUSIONS
These findings suggest that typical absence seizures involve a network of cortical-subcortical areas necessary for normal attention and primary information processing. Identification of this network may improve understanding of cognitive impairments in CAE, and may help guide development of new therapies for this disorder.
Berman
Rachel
R
Department of Neurology, Yale University School of Medicine, New Haven, Connecticut 06520-8018, USA.
Negishi
Michiro
M
Vestal
Matthew
M
Spann
Marisa
M
Chung
Mi Hae
MH
Bai
Xiaoxiao
X
Purcaro
Michael
M
Motelow
Joshua E
JE
Danielson
Nathan
N
Dix-Cooper
Linda
L
Enev
Miro
M
Novotny
Edward J
EJ
Constable
R T
RT
Blumenfeld
Hal
H
D000293:Adolescent; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology; D002648:Child; D003244:Consciousness Disorders / Q000175:diagnosis / Q000503:physiopathology; D004569:Electroencephalography / Q000379:methods / Q000706:statistics & numerical data*; D004832:Epilepsy, Absence / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D008297:Male; D009048:Motor Skills / Q000502:physiology; D009434:Neural Pathways / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D011597:Psychomotor Performance / Q000502:physiology; D013788:Thalamus / Q000503:physiopathology
D010100:Oxygen