Functional connectivity disturbances of ascending reticular activating system and posterior thalamus in juvenile myoclonic epilepsy in relation with photosensitivity: A resting-state fMRI study


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Ur Özçelik E., Kurt E., Şirin N. G., Eryürek K., Ulaşoglu Yıldız Ç., Harı E., ...More

EPILEPSY RESEARCH, vol.171, 2021 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 171
  • Publication Date: 2021
  • Doi Number: 10.1016/j.eplepsyres.2021.106569
  • Journal Name: EPILEPSY RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Abstracts in Social Gerontology, BIOSIS, CAB Abstracts, EMBASE, MEDLINE, Veterinary Science Database
  • Keywords: Juvenile myoclonic epilepsy, Ascending reticular activating system, rResting-state fMRI, Photosensitivity, Posterior thalamus, Locus coeruleus
  • Istanbul University Affiliated: Yes

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 (p(FWE- corr) < 0.001; p(FWE)-(corr) < 0.001; p(FWE)-(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 (p(FWE- 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 (p(FWE- 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 (p(FWE-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.