Sleep onset uncovers thalamic abnormalities in patients with idiopathic generalised epilepsy

Research output: Contribution to journalArticle

Authors

  • Brunno Campos
  • David Rollings
  • Rebecca Wilson
  • Marina Alvim
  • Ana Carolina Coan
  • Fernando Cendes

External organisations

  • Neuroimaging Laboratory, Department of Neurology, University of Campinas
  • Department of Neuroscience, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK

Abstract

The thalamus is crucial for sleep regulation and the pathophysiology of idiopathic generalised epilepsy (IGE), and may serve as the underlying basis for the links between the two. We investigated this using EEG-fMRI and a specific emphasis on the role and functional connectivity (FC) of the thalamus. We defined three types of thalamic FC: thalamocortical, inter-hemispheric thalamic, and intra-hemispheric thalamic. Patients and controls differed in all three measures, and during wakefulness and sleep, indicating disorder-dependent and state-dependent modification of thalamic FC. Inter-hemispheric thalamic FC differed between patients and controls in somatosensory regions during wakefulness, and occipital regions during sleep. Intra-hemispheric thalamic FC was significantly higher in patients than controls following sleep onset, and disorder-dependent alterations to FC were seen in several thalamic regions always involving somatomotor and occipital regions. As interactions between thalamic sub-regions are indirect and mediated by the inhibitory thalamic reticular nucleus (TRN), the results suggest abnormal TRN function in patients with IGE, with a regional distribution which could suggest a link with the thalamocortical networks involved in the generation of alpha rhythms. Intra-thalamic FC could be a more widely applicable marker beyond patients with IGE.

Details

Original languageEnglish
Pages (from-to)52-57
JournalNeuroImage: Clinical
Volume16
Early online date12 Jul 2017
Publication statusE-pub ahead of print - 12 Jul 2017

Keywords

  • Functional connectivity, Generalised epilepsy, Sleep, Thalamic reticular nucleus thalamus