The functional organization of human epileptic hippocampus

Petr Klimes, Juliano J. Duque, Benjamin Brinkmann, Jamie Van Gompel, Squire Matthew Stead, Erik K St Louis, Josef Halamek, Pavel Jurak, Gregory Alan Worrell

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The function and connectivity of human brain is disrupted in epilepsy. We previously reported that the region of epileptic brain generating focal seizures, i.e., the seizure onset zone (SOZ), is functionally isolated from surrounding brain regions in focal neocortical epilepsy. The modulatory effect of behavioral state on the spatial and spectral scales over which the reduced functional connectivity occurs, however, is unclear. Here we use simultaneous sleep staging from scalp EEG with intracranial EEG recordings from medial temporal lobe to investigate how behavioral state modulates the spatial and spectral scales of local field potential synchrony in focal epileptic hippocampus. The local field spectral power and linear correlation between adjacent electrodes provide measures of neuronal population synchrony at different spatial scales, ~1 and 10 mm, respectively. Our results show increased connectivity inside the SOZ and low connectivity between electrodes in SOZ and outside the SOZ. During slow-wave sleep, we observed decreased connectivity for ripple and fast ripple frequency bands within the SOZ at the 10 mm spatial scale, while the local synchrony remained high at the 1 mm spatial scale. Further study of these phenomena may prove useful for SOZ localization and help understand seizure generation, and the functional deficits seen in epileptic eloquent cortex.

Original languageEnglish (US)
Pages (from-to)3140-3145
Number of pages6
JournalJournal of Neurophysiology
Volume115
Issue number6
DOIs
StatePublished - Jun 1 2016

Fingerprint

Hippocampus
Seizures
Sleep
Electrodes
Brain
Partial Epilepsy
Temporal Lobe
Scalp
Electroencephalography
Epilepsy
Population

Keywords

  • Behavioral state
  • Connectivity
  • Epilepsy
  • Intracranial EEG
  • Seizure onset zone

ASJC Scopus subject areas

  • Neuroscience(all)
  • Physiology
  • Medicine(all)

Cite this

The functional organization of human epileptic hippocampus. / Klimes, Petr; Duque, Juliano J.; Brinkmann, Benjamin; Van Gompel, Jamie; Stead, Squire Matthew; St Louis, Erik K; Halamek, Josef; Jurak, Pavel; Worrell, Gregory Alan.

In: Journal of Neurophysiology, Vol. 115, No. 6, 01.06.2016, p. 3140-3145.

Research output: Contribution to journalArticle

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