Lalit Gupta1, Rick Janssens2, Mariëlle C G Vlooswijk2,3, Rob P W Rouhl2,3,4, Anton de Louw3,5, Albert P Aldenkamp2,3,4,5,6, Shrutin Ulman7, René M H Besseling1,5,6, Paul A M Hofman1,3,4, Vivianne H van Kranen-Mastenbroek8, Danny M Hilkman8, Jacobus F A Jansen1,4, Walter H Backes1,4. 1. Departments of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands. 2. Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands. 3. Academic Center for Epileptology Kempenhaeghe/Maastricht University Medical Center, Heeze and Maastricht, The Netherlands. 4. School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands. 5. Epilepsy Center Kempenhaeghe, Heeze, The Netherlands. 6. Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands. 7. Philips India Ltd., Bangalore, Karnataka, India. 8. Department of Clinical Neurophysiology, Maastricht University Medical Center, Maastricht, The Netherlands.
Abstract
OBJECTIVE: The diagnosis of epilepsy cannot be reliably made prior to a patient's second seizure in most cases. Therefore, adequate diagnostic tools are needed to differentiate subjects with a first seizure from those with a seizure preceding the onset of epilepsy. The objective was to explore spontaneous blood oxygen level-dependent (BOLD) fluctuations in subjects with a first-ever seizure and patients with new-onset epilepsy (NOE), and to find characteristic biomarkers for seizure recurrence after the first seizure. METHODS: We examined 17 first-seizure subjects, 19 patients with new-onset epilepsy (NOE), and 18 healthy controls. All subjects underwent clinical investigation and received electroencephalography and resting-state functional magnetic resonance imaging (MRI). The BOLD time series were analyzed in terms of regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuations (fALFFs). RESULTS: We found significantly stronger amplitudes (higher fALFFs) in patients with NOE relative to first-seizure subjects and healthy controls. The frequency range of 73-198 mHz (slow-3 subband) appeared most useful for discriminating patients with NOE from first-seizure subjects. The ReHo measure did not show any significant differences. SIGNIFICANCE: The fALFF appears to be a noninvasive measure that characterizes spontaneous BOLD fluctuations and shows stronger amplitudes in the slow-3 subband of patients with NOE relative first-seizure subjects and healthy controls. A larger study population with follow-up is required to determine whether fALFF holds promise as a potential biomarker for identifying subjects at increased risk to develop epilepsy. Wiley Periodicals, Inc.
OBJECTIVE: The diagnosis of epilepsy cannot be reliably made prior to a patient's second seizure in most cases. Therefore, adequate diagnostic tools are needed to differentiate subjects with a first seizure from those with a seizure preceding the onset of epilepsy. The objective was to explore spontaneous blood oxygen level-dependent (BOLD) fluctuations in subjects with a first-ever seizure and patients with new-onset epilepsy (NOE), and to find characteristic biomarkers for seizure recurrence after the first seizure. METHODS: We examined 17 first-seizure subjects, 19 patients with new-onset epilepsy (NOE), and 18 healthy controls. All subjects underwent clinical investigation and received electroencephalography and resting-state functional magnetic resonance imaging (MRI). The BOLD time series were analyzed in terms of regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuations (fALFFs). RESULTS: We found significantly stronger amplitudes (higher fALFFs) in patients with NOE relative to first-seizure subjects and healthy controls. The frequency range of 73-198 mHz (slow-3 subband) appeared most useful for discriminating patients with NOE from first-seizure subjects. The ReHo measure did not show any significant differences. SIGNIFICANCE: The fALFF appears to be a noninvasive measure that characterizes spontaneous BOLD fluctuations and shows stronger amplitudes in the slow-3 subband of patients with NOE relative first-seizure subjects and healthy controls. A larger study population with follow-up is required to determine whether fALFF holds promise as a potential biomarker for identifying subjects at increased risk to develop epilepsy. Wiley Periodicals, Inc.