Thalamocortical relationship in epileptic patients with generalized spike and wave discharges - A multimodal neuroimaging study

Clara Huishi Zhang, Zhiyi Sha, John Mundahl, Sa Liu, Yunfeng Lu, Thomas R. Henry, Bin He

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

Unlike focal or partial epilepsy, which has a confined range of influence, idiopathic generalized epilepsy (IGE) often affects the whole or a larger portion of the brain without obvious, known cause. It is important to understand the underlying network which generates epileptic activity and through which epileptic activity propagates. The aim of the present study was to investigate the thalamocortical relationship using non-invasive imaging modalities in a group of IGE patients. We specifically investigated the roles of the mediodorsal nuclei in the thalami and the medial frontal cortex in generating and spreading IGE activities. We hypothesized that the connectivity between these two structures is key in understanding the generation and propagation of epileptic activity in brains affected by IGE. Using three imaging techniques of EEG, fMRI and EEG-informed fMRI, we identified important players in generation and propagation of generalized spike-and-wave discharges (GSWDs). EEG-informed fMRI suggested multiple regions including the medial frontal area near to the anterior cingulate cortex, mediodorsal nuclei of the thalamus, caudate nucleus among others that related to the GSWDs. The subsequent seed-based fMRI analysis revealed a reciprocal cortical and bi-thalamic functional connection. Through EEG-based Granger Causality analysis using (DTF) and adaptive DTF, within the reciprocal thalamocortical circuitry, thalamus seems to serve as a stronger source in driving cortical activity from initiation to the propagation of a GSWD. Such connectivity change starts before the GSWDs and continues till the end of the slow wave discharge. Thalamus, especially the mediodorsal nuclei, may serve as potential targets for deep brain stimulation to provide more effective treatment options for patients with drug-resistant generalized epilepsy.

Original languageEnglish (US)
Article number548
Pages (from-to)117-127
Number of pages11
JournalNeuroImage: Clinical
Volume9
DOIs
StatePublished - Aug 4 2015

Keywords

  • Adaptive directed transfer function (ADTF)
  • Directed transfer function (DTF)
  • EEG
  • Functional connectivity
  • Generalized spike-wave discharge
  • Granger Causality
  • Idiopathic generalized epilepsy
  • Independent component analysis
  • fMRI

Fingerprint Dive into the research topics of 'Thalamocortical relationship in epileptic patients with generalized spike and wave discharges - A multimodal neuroimaging study'. Together they form a unique fingerprint.

  • Cite this