Hippocampal spreading depolarization as a key epilepsy disease factor
Michael Wenzel MD PhD
Dept. of Epileptology
University Hospital Bonn

Résumé
Confusion, aphasia, and unaware wandering are prominent post-ictal symptoms, most often observed in temporal lobe epilepsy (TLE). Despite their potentially life-threatening nature, their neurobiological underpinnings remain understudied. We employ chronic cellular scale calcium imaging (CA1, CTX), electrophysiology and locomotor assessment in an encephalitis mouse model or optogenetic hippocampal spreading depolarization (SD) with/without preceding epileptic Sz. We find a complete association of hippocampal Sz with SD (‘sSD’), a wave characterized by non-synaptic spreading depolarization of neurons above inactivation threshold followed by transient depression of activity. We study sSD trajectories, and show that temporo-mesial SD causes post-ictal wandering, while importantly, Sz-like episodes do not. Finally, we revisit the murine findings in Behnke-Fried (BF) depth-electrode recordings in human epilepsy, and provide initial evidence for putative focal sSD with a similar temporo-mesial propensity as in mice. These cross-species results point towards sSD as a pathoclinical key factor in epilepsy, and challenge the current clinical EEG-standard bandwidth that has rendered sSD invisible in clinical recordings.

Invité par Roustem Khazipov
Vendredi 10 avril à 15h, salle de conférence de l’Inmed