Emel Ur Özçelik1, Elif Kurt2, Nermin Görkem Şirin3, Kardelen Eryürek4, Çiğdem Ulaşoglu Yıldız5, Emre Harı6, Ulaş Ay7, Nerses Bebek8, Tamer Demiralp9, Betül Baykan10. 1. Departments of Neurology and Clinical Neurophysiology, Istanbul University, Istanbul Faculty of Medicine, Millet Cad, 34093, Istanbul, Turkey; Department of Neurology, Istanbul Bakirkoy Prof. Dr. Mazhar Osman Research and Training Hospital for Psychiatry, Neurology, Neurosurgery, University of Health Sciences, Zuhuratbaba Mahallesi, Dr. Tevfik Sağlam Cad. 25/2, 34147, Bakırkoy, Istanbul, Turkey. Electronic address: emeluscas@gmail.com. 2. Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Millet Cad, 34093, Çapa, Istanbul, Turkey. Electronic address: elifkurt@istanbul.edu.tr. 3. Departments of Neurology and Clinical Neurophysiology, Istanbul University, Istanbul Faculty of Medicine, Millet Cad, 34093, Istanbul, Turkey. Electronic address: gorkemsirin@yahoo.com.tr. 4. Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Millet Cad, 34093, Çapa, Istanbul, Turkey; Hulusi Behçet Life Sciences Research Laboratory, Neuroimaging Unit, Istanbul University, Millet Cad, 34093, Capa, Istanbul, Turkey. Electronic address: eryurekkardelen@gmail.com. 5. Hulusi Behçet Life Sciences Research Laboratory, Neuroimaging Unit, Istanbul University, Millet Cad, 34093, Capa, Istanbul, Turkey. Electronic address: cigdemulasoglu@gmail.com. 6. Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Millet Cad, 34093, Çapa, Istanbul, Turkey; Hulusi Behçet Life Sciences Research Laboratory, Neuroimaging Unit, Istanbul University, Millet Cad, 34093, Capa, Istanbul, Turkey. Electronic address: emrehr@hotmail.com. 7. Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Millet Cad, 34093, Çapa, Istanbul, Turkey; Hulusi Behçet Life Sciences Research Laboratory, Neuroimaging Unit, Istanbul University, Millet Cad, 34093, Capa, Istanbul, Turkey. Electronic address: psk.ulasay@gmail.com. 8. Departments of Neurology and Clinical Neurophysiology, Istanbul University, Istanbul Faculty of Medicine, Millet Cad, 34093, Istanbul, Turkey. Electronic address: nersesb@yahoo.com. 9. Hulusi Behçet Life Sciences Research Laboratory, Neuroimaging Unit, Istanbul University, Millet Cad, 34093, Capa, Istanbul, Turkey; Department of Physiology, Istanbul University, Istanbul Faculty of Medicine, Millet Cad, 34093, Capa, Istanbul, Turkey. Electronic address: demiralp.tamer@gmail.com. 10. Departments of Neurology and Clinical Neurophysiology, Istanbul University, Istanbul Faculty of Medicine, Millet Cad, 34093, Istanbul, Turkey. Electronic address: baykanb@istanbul.edu.tr.
Abstract
OBJECTIVE: Juvenile myoclonic epilepsy (JME) is typified by the occurrence of myoclonic seizures after awakening, though another common trait is myoclonic seizures triggered by photic stimulation. We aimed to investigate the functional connectivity (FC) of nuclei in the ascending reticular activating system (ARAS), thalamus and visual cortex in JME with and without photosensitivity. METHODS: We examined 29 patients with JME (16 photosensitive (PS), 13 non- photosensitive-(NPS)) and 28 healthy controls (HCs) using resting-state functional magnetic resonance imaging (rs-fMRI). Seed-to-voxel FC analyses were performed using 25 seeds, including the thalamus, visual cortex, and ARAS nuclei. RESULTS: Mesencephalic reticular formation seed revealed significant hyperconnectivity between the bilateral paracingulate gyrus and anterior cingulate cortex in JME group, and in both JME-PS and JME-NPS subgroups compared to HCs (pFWE-corr < 0.001; pFWE-corr < 0.001; pFWE-corr = 0.002, respectively). Locus coeruleus seed displayed significant hyperconnectivity with the bilateral lingual gyri, intracalcarine cortices, occipital poles and left occipital fusiform gyrus in JME-PS group compared to HCs (pFWE-corr <0.001). Additionally, locus coeruleus seed showed significant hyperconnectivity in JME-PS group compared to JME-NPS group with a cluster corresponding to the bilateral lingual gyri and right intracalcarine cortex (pFWE-corr < 0.001). Lastly, the right posterior nuclei of thalamus revealed significant hyperconnectivity with the right superior lateral occipital cortex in JME-PS group compared to HCs (pFWE-corr < 0.002). CONCLUSIONS: In JME, altered functional connectivity of the arousal networks might contribute to the understanding of myoclonia after awakening, whereas increased connectivity of posterior thalamus might explain photosensitivity.
OBJECTIVE: Juvenile myoclonic epilepsy (JME) is typified by the occurrence of myoclonic seizures after awakening, though another common trait is myoclonic seizures triggered by photic stimulation. We aimed to investigate the functional connectivity (FC) of nuclei in the ascending reticular activating system (ARAS), thalamus and visual cortex in JME with and without photosensitivity. METHODS: We examined 29 patients with JME (16 photosensitive (PS), 13 non- photosensitive-(NPS)) and 28 healthy controls (HCs) using resting-state functional magnetic resonance imaging (rs-fMRI). Seed-to-voxel FC analyses were performed using 25 seeds, including the thalamus, visual cortex, and ARAS nuclei. RESULTS: Mesencephalic reticular formation seed revealed significant hyperconnectivity between the bilateral paracingulate gyrus and anterior cingulate cortex in JME group, and in both JME-PS and JME-NPS subgroups compared to HCs (pFWE-corr < 0.001; pFWE-corr < 0.001; pFWE-corr = 0.002, respectively). Locus coeruleus seed displayed significant hyperconnectivity with the bilateral lingual gyri, intracalcarine cortices, occipital poles and left occipital fusiform gyrus in JME-PS group compared to HCs (pFWE-corr <0.001). Additionally, locus coeruleus seed showed significant hyperconnectivity in JME-PS group compared to JME-NPS group with a cluster corresponding to the bilateral lingual gyri and right intracalcarine cortex (pFWE-corr < 0.001). Lastly, the right posterior nuclei of thalamus revealed significant hyperconnectivity with the right superior lateral occipital cortex in JME-PS group compared to HCs (pFWE-corr < 0.002). CONCLUSIONS: In JME, altered functional connectivity of the arousal networks might contribute to the understanding of myoclonia after awakening, whereas increased connectivity of posterior thalamus might explain photosensitivity.