Full-Length Original Research
Reduced default mode network connectivity in treatment-resistant idiopathic generalized epilepsy
Article first published online: 7 JAN 2013
Wiley Periodicals, Inc. © 2013 International League Against Epilepsy
Volume 54, Issue 3, pages 461–470, March 2013
How to Cite
Kay, B. P., DiFrancesco, M. W., Privitera, M. D., Gotman, J., Holland, S. K. and Szaflarski, J. P. (2013), Reduced default mode network connectivity in treatment-resistant idiopathic generalized epilepsy. Epilepsia, 54: 461–470. doi: 10.1111/epi.12057
- Issue published online: 4 MAR 2013
- Article first published online: 7 JAN 2013
- Manuscript Accepted: 24 OCT 2012
- National Institute of Neurological Disorders and Stroke. Grant Number: K23 NS052468
- University of Cincinnati Academic Health Center
- Medical Scientist Training Program (MSTP). Grant Number: T32 GM063483
- Independent component analysis;
- Seed-based voxel correlation;
- Primary generalized epilepsy;
- Dual regression;
- Resting-state functional connectivity;
- Valproic acid
Idiopathic generalized epilepsy (IGE) resistant to treatment is common, but its neuronal correlates are not entirely understood. Therefore, the aim of this study was to examine resting-state default mode network (DMN) functional connectivity in patients with treatment-resistant IGE.
Treatment resistance was defined as continuing seizures despite an adequate dose of valproic acid (valproate, VPA). Data from 60 epilepsy patients and 38 healthy controls who underwent simultaneous electroencephalography (EEG) and resting-state functional magnetic resonance imaging (fMRI) were included (EEG/fMRI). Independent component analysis (ICA) and dual regression were used to quantify DMN connectivity. Confirmatory analysis using seed-based voxel correlation was performed.
There was a significant reduction of DMN connectivity in patients with treatment-resistant epilepsy when compared to patients who were treatment responsive and healthy controls. Connectivity was negatively correlated with duration of epilepsy.
Our findings in this large sample of patients with IGE indicate the presence of reduced DMN connectivity in IGE and show that connectivity is further reduced in treatment-resistant epilepsy. DMN connectivity may be useful as a biomarker for treatment resistance.