Psychophysiological interaction analysis for the detection of stimulus‐specific networks in reflex epilepsy

Autor: Felix Zahnert, Marcus Belke, Jens Sommer, Julia Oesterle, Vincent Möschl, Christopher Nimsky, Susanne Knake, Katja Menzler
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Epilepsia Open, Vol 7, Iss 3, Pp 518-524 (2022)
Druh dokumentu: article
ISSN: 2470-9239
DOI: 10.1002/epi4.12622
Popis: Abstract We report detailed functional MRI (fMRI) analyses in a patient with reflex seizures elicited by driving along a specific rural crossroad or by watching a video thereof. Semiology consisted of epigastric aura, followed by a sensory seizure of the left hand and sporadic automotor seizures. The right amygdala‐region (rh‐amygdala) was surgically and electroclinically confirmed as the epileptogenic zone. Presurgical task‐fMRI was performed, during which videos of the driving along that specific crossroad (IC), of another crossroad (NC) or noise were presented. Independent component analysis was conducted, and one component was used to aid in selection of a seed region within the rh‐amygdala for subsequent psychophysiological interaction analysis (PPI). Here, the following regions showed stronger connectivity with the rh‐amygdala seed during the IC condition compared to NC: right > left visual cortex, bilateral insulae, and right secondary somatosensory cortex (S2), potentially explaining epigastric aura and left somatosensory seizure semiology. Contralateral analyses did not reproduce these results. Overall, the ictogenic stimulus elicited enhanced connectivity of the epileptogenic rh‐amygdala with visual cortex and further regions of potential seizure spread (S2, insula) as a putative mechanism of ictogenesis. Our results highlight the potential of PPI in the analysis of stimulus‐dependent networks in patients with reflex epilepsies to gain insight into seizure generation.
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