Altered physiological brain variation in drug-resistant epilepsy

Abstract: Introduction
Functional magnetic resonance imaging (fMRI) combined with simultaneous electroencephalography (EEG-fMRI) has become a major tool in mapping epilepsy sources. In the absence of detectable epileptiform activity, the resting state fMRI may still detect changes in the blood oxygen level-dependent signal, suggesting intrinsic alterations in the underlying brain physiology.

Methods
In this study, we used coefficient of variation (CV) of critically sampled 10 Hz ultra-fast fMRI (magnetoencephalography, MREG) signal to compare physiological variance between healthy controls (n = 10) and patients (n = 10) with drug-resistant epilepsy (DRE).

Results
We showed highly significant voxel-level (p < 0.01, TFCE-corrected) increase in the physiological variance in DRE patients. At individual level, the elevations range over three standard deviations (σ) above the control mean (μ) CVMREG values solely in DRE patients, enabling patient-specific mapping of elevated physiological variance. The most apparent differences in group-level analysis are found on white matter, brainstem, and cerebellum. Respiratory (0.12–0.4 Hz) and very-low-frequency (VLF = 0.009–0.1 Hz) signal variances were most affected.

Conclusions
The CVMREG increase was not explained by head motion or physiological cardiorespiratory activity, that is, it seems to be linked to intrinsic physiological pulsations. We suggest that intrinsic brain pulsations play a role in DRE and that critically sampled fMRI may provide a powerful tool for their identification

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: Brain and behavior. - 8, 9 (2018) , e01090, ISSN: 2162-3279

Classification and Topics

• Classification: Medizin, Gesundheit

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2019
• Creator: Kananen, Janne ; Tuovinen, Timo ; Ansakorpi, Hanna ; Rytky, Seppo ; Helakari, Heta ; Huotari, Niko ; Raitamaa, Lauri ; Raatikainen, Ville ; Rasila, Aleksi ; Borchardt, Viola ; Korhonen, Vesa ; LeVan, Pierre ; Nedergaard, Maiken ; Kiviniemi, Vesa
• Contributor: Klinik für Radiologie

Further information

• DOI: 10.1002/brb3.1090
• URN: urn:nbn:de:bsz:25-freidok-1474135
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 25.03.2025, 1:41 PM CET