Abstracts

Summary: Epileptic seizures are events during which intense neuronal activity takes place. This neuronal activity is accompanied by important changes in metabolism and blood flow, thought to be the necessary consequence of the energy demands made by neurons. Combined measurements of neuronal activity and metabolism inform us on the coupling between the two phenomena, whether it is normal or pathological and the role it may play in seizure genesis, maintenance or arrest. Neuronal activity may be measured from individual cells or at the cell aggregate level with EEG. Metabolism and blood flow may also be measured locally or at a more global level with fMRI, which has the unique advantage or evaluating simultaneously the whole brain. The workshop will review the fundamental mechanisms of neurovascular coupling in the normal brain, then evaluate expected and unexpected metabolic changes in experimental animal models of epilepsy, and finally see what can be learned from human measurements made before and during epileptic seizures. We will in particular try to interpret what could be the mechanisms of metabolism or blood flow changes that appear to occur a few seconds earlier than neuronal epileptic discharges.