Cortical/subcortical BOLD changes associated with epileptic discharges: an EEG-fMRI study at 3 T.
BACKGROUND
Malformations of cortical development have characteristic interictal discharges, yet the mechanisms of generation of these discharges are not known in humans. Interictal discharges in malformations of cortical development were studied with EEG-fMRI.


METHODS
Six subjects with malformations of cortical development and seizures were studied using spike-triggered fMRI at 3 T. The blood oxygen level-dependent (BOLD) signal changes associated with interictal discharges were measured.


RESULTS
All subjects showed spike-related BOLD signal changes. In four subjects, the signal increases were seen in the lesion, and in four subjects, decreases were seen surrounding the lesion. Five subjects had BOLD signal changes at distant cortical sites and three had subcortical changes (basal ganglia, reticular formation, or thalamic).


CONCLUSIONS
BOLD signal changes may be directly correlated with overall synaptic activity. Changes were found in and around the lesion of malformations of cortical development and in distant cortical and subcortical structures. The results suggest that EEG-fMRI studies might help elucidate the mechanisms of epileptic discharges in humans.
Federico
Paolo
P
Brain Research Institute, Heidelberg West, Victoria, Australia.
Archer
John S
JS
Abbott
David F
DF
Jackson
Graeme D
GD
D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D001479:Basal Ganglia / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000002:abnormalities* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008280:Magnetics; D008297:Male; D009415:Nerve Net / Q000002:abnormalities / Q000503:physiopathology; D009421:Nervous System Malformations / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D009474:Neurons / Q000502:physiology; D011237:Predictive Value of Tests; D012154:Reticular Formation / Q000503:physiopathology; D013788:Thalamus / Q000503:physiopathology