Spatio-temporal characterizations of non-linear changes in intracranial activities prior to human temporal lobe seizures.
Recent studies have shown that non-linear analysis of intracranial activities can detect a 'pre-ictal phase' preceding the epileptic seizure. Nevertheless, the dynamical nature of the underlying neuronal process and the spatial extension of this pre-ictal phase still remain unknown. In this paper, we address these aspects using a new non-linear measure of dynamic similarity between different parts of intracranial recordings of nine patients with medial temporal lobe epilepsy recorded during transitions to seizure. Our results confirm that non-linear changes in neuronal dynamics allow, in most cases (16 out of 17), a seizure anticipation several minutes in advance. Furthermore, we show that the spatial distribution of pre-ictal changes often involves an extended network projecting beyond the limits of the epileptogenic region. Finally, the pre-ictal phase could frequently (13 out of 17) be characterized with a marked shift toward slower frequencies in upper delta or theta frequency range.
Le Van Quyen
M
M
Laboratoire de Neurosciences Cognitives et Imagerie Cérébrale, CNRS UPR 640, University of Paris VI,Hôpital de la Salpêtrière, 47 Blvd. de l'Hôpital, 75651 Paris cedex 13, France. lenalm@ext.jussieu.fr
Adam
C
C
Martinerie
J
J
Baulac
M
M
Clémenceau
S
S
Varela
F
F
D002540:Cerebral Cortex / Q000503:physiopathology; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology*; D006801:Humans; D008959:Models, Neurological; D017711:Nonlinear Dynamics; D012640:Seizures / Q000503:physiopathology