Fig. 1

Imaging and EEG data. (A): Sequential brain MRI: axial FLAIR images. From left to right: Cytotoxic edema of the right hippocampus and amygdala (arrow) at presentation (MTA right 0/1); Decreased edema of the right hippocampus and amygdala (arrow) 20 days later (MTA right 1); Atrophy of the right hippocampus (arrow) with increased T2/FLAIR signal consistent with hippocampal sclerosis two months later (MTA right 2); Stable atrophy of right hippocampus with hippocampal sclerosis (arrow) five months later (MTA right 2). (B): Axial and coronal images of ¹⁸F-FDG PET at presentation with hypermetabolism of the right hippocampus (arrow). (C): Axial and coronal image of ¹⁸F-MK6240 tau PET one month later shows increased SUVR in the hippocampus (R > L) (arrow) and typical Braak neocortical brain regions, a pattern consistent with AD. (D): Intracranial EEG (bottom panel) obtained from FO electrodes and spectrogram (top panel) on day 2. Subclinical electrographic mesial temporal lobe seizure on right FO electrode (under treatment with levetiracetam): LPDs on right FO electrode with evolution in frequency and morphology and abrupt end. Spectrogram reveals first increased delta activity (LPDs) with evolution to faster activity on the right FO electrode at the time of seizure onset (white arrow). Continuous EEG of 60 s. A referential montage is shown where the upper four channels represent the four contact points (from anterior to posterior) of the right FO electrode, and the lower four channels represent the left FO electrode. Filters at 0.53–15.0 Hz, 300µV/cm. The top panel represents a one hour spectrogram where the upper spectrogram corresponds to the third contact of the right FO electrode, and the lower spectrogram to the third contact of the left FO electrode