Navarro V, Le Van Quyen M, Clemenceau S, Adam C, Petitmengin C, Dubeau F, Gotman J, Martinerie J, Baulac M
Unité d'épileptologie, service de neurologie-1, hôpital de la Pitié-Salpêtrière, AP-HP, and Centre de recherche de l'institut du cerveau et de la moelle épinière, Inserm, UMRS 795, CNRS UMR 7225, UMPC, université Pierre-et-Marie-Curie, 75651 Paris, France.
Rev Neurol (Paris). 2011 Mar;167(3):205-15. doi: 10.1016/j.neurol.2010.07.027. Epub 2010 Oct 8.
Clinical, metabolic and electrophysiologic studies suggest the existence of a preictal state, a transition between the interictal state and seizure.
Analysis of the intracranial EEG by mathematical methods shows changes of the brain dynamics several minutes before the occurrence of partial seizures. These modifications can be widespread and not restricted to the epileptogenic focus, which would explain why they can also be detected from scalp EEG. Several scenarios could underlie the preictal state: a progressive recruitment of neurons or a facilitating state with a high probability of seizure occurrence. Because of the high rate of false predictions, no satisfactory method for seizure prediction has been currently proposed.
A European multicenter study (Evolving platform for improving living expectation of patients suffering from IctAl events [EPILEPSIAE]) is currently evaluating a combination of 44 methods applied for EEG and ECG analysis on long-term recordings obtained from a large multicenter database (www.epilepsiae.eu).
Combining analyses of multi-level signals including intracranial EEG and microelectrodes, scalp EEG and in vitro electrophysiological studies of post-operative tissues should help clarify brain dynamics during the pre-ictal state.
