Brain Imaging and Behavior

, Volume 10, Issue 2, pp 373–386

Altered brain rhythms and functional network disruptions involved in patients with generalized fixation-off epilepsy

  • Ana Beatriz Solana
  • Kenia Martínez
  • Juan Antonio Hernández-Tamames
  • Victoria San Antonio-Arce
  • Rafael Toledano
  • Irene García-Morales
  • Juan Alvárez-Linera
  • Antonio Gil-Nágel
  • Francisco del Pozo
Original Research

DOI: 10.1007/s11682-015-9404-6

Cite this article as:
Solana, A.B., Martínez, K., Hernández-Tamames, J.A. et al. Brain Imaging and Behavior (2016) 10: 373. doi:10.1007/s11682-015-9404-6

Abstract

Generalized Fixation-off Sensitivity (CGE-FoS) patients present abnormal EEG patterns when losing fixation. In the present work, we studied two CGE-FoS epileptic patients with simultaneous EEG-fMRI. We aim to identify brain areas that are specifically related to the pathology by identifying the brain networks that are related to the EEG brain altered rhythms. Three main analyses were performed: EEG standalone, where the voltage fluctuations in delta, alpha, and beta EEG bands were obtained; fMRI standalone, where resting-state fMRI ICA analyses for opened and closed eyes conditions were computed per subject; and, EEG-informed fMRI, where EEG delta, alpha and beta oscillations were used to analyze fMRI. Patient 1 showed EEG abnormalities for lower beta band EEG brain rhythm. Fluctuations of this rhythm were correlated with a brain network mainly composed by temporo-frontal areas only found in the closed eyes condition. Patient 2 presented alterations in all the EEG brain rhythms (delta, alpha, beta) under study when closing eyes. Several biologically relevant brain networks highly correlated (r > 0.7) to each other in the closed eyes condition were found. EEG-informed fMRI results in patient 2 showed hypersynchronized patterns in the fMRI correlation spatial maps. The obtained findings allow a differential diagnosis for each patient and different profiles with respect to healthy volunteers. The results suggest a different disruption in the functional brain networks of these patients that depends on their altered brain rhythms. This knowledge could be used to treat these patients by novel brain stimulation approaches targeting specific altered brain networks in each patient.

Keywords

Fixation-off Simultaneous EEG-fMRI Resting-state networks EEG-informed fMRI ICA 

Supplementary material

11682_2015_9404_MOESM1_ESM.docx (694 kb)
ESM 1(DOCX 694 kb)

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Ana Beatriz Solana
    • 1
    • 7
  • Kenia Martínez
    • 2
  • Juan Antonio Hernández-Tamames
    • 3
  • Victoria San Antonio-Arce
    • 4
  • Rafael Toledano
    • 5
  • Irene García-Morales
    • 5
  • Juan Alvárez-Linera
    • 6
  • Antonio Gil-Nágel
    • 5
  • Francisco del Pozo
    • 1
  1. 1.Department of Neuroimaging, Center for Biomedical TechnologyUniversidad Politécnica de MadridPozuelo de AlarcónSpain
  2. 2.Research Unit, Instituto de Investigación Sanitaria del Hospital Gregorio Marañón (IISGM)MadridSpain
  3. 3.Department of Electronical TechnologyUniversidad Rey Juan CarlosMóstolesSpain
  4. 4.Epilepsy CenterUniversity Hospital FreiburgFreiburgGermany
  5. 5.Department of NeurologyHospital Ruber InternacionalMadridSpain
  6. 6.Department of NeuroradiologyHospital Ruber InternacionalMadridSpain
  7. 7.GE Global ResearchGarching bei MunichGermany

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