title: Functional connectivity between right and left mesial temporal structures.
abstract: The aim of this study is to investigate functional connectivity between right and left mesial temporal structures using cerebrocerebral evoked potentials. We studied seven patients with drug-resistant focal epilepsy who were explored with stereotactically implanted depth electrodes in bilateral hippocampi. In all patients cerebrocerebral evoked potentials evoked by stimulation of the fornix were evaluated as part of a research project assessing fornix stimulation for control of hippocampal seizures. Stimulation of the fornix elicited responses in the ipsilateral hippocampus in all patients with a mean latency of 4.6 ms (range 2-7 ms). Two patients (29 %) also had contralateral hippocampus responses with a mean latency of 7.5 ms (range 5-12 ms) and without involvement of the contralateral temporal neocortex or amygdala. This study confirms the existence of connections between bilateral mesial temporal structures in some patients and explains seizure discharge spreading between homotopic mesial temporal structures without neocortical involvement.
authors.affiliation: Epilepsy Center, UH Case Medical Center, 11100 Euclid Avenue, Cleveland, OH, 44106, USA, nuria.lacuey@uhhospitals.org.
authors.forename: Nuria
authors.initials: N
authors.lastname: Lacuey
authors.forename: Bilal
authors.initials: B
authors.lastname: Zonjy
authors.forename: Emine S
authors.initials: ES
authors.lastname: Kahriman
authors.forename: Farhad
authors.initials: F
authors.lastname: Kaffashi
authors.forename: Jonathan
authors.initials: J
authors.lastname: Miller
authors.forename: Hans O
authors.initials: HO
authors.lastname: Lüders
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology*; D004567:Electrodes, Implanted; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology*; D013702:Temporal Lobe / Q000503:physiopathology; D055815:Young Adult