title: Vagus nerve stimulation balanced disrupted default-mode network and salience network in a postsurgical epileptic patient.
abstract: BACKGROUND
  In recent years, treatment of intractable epilepsy has become more challenging, due to an increase in resistance to antiepileptic drugs, as well as diminished success following resection surgery. Here, we present the case of a 19-year old epileptic patient who received vagus nerve stimulation (VNS) following unsuccessful left parietal-occipital lesion-resection surgery, with results indicating an approximate 50% reduction in seizure frequency and a much longer seizure-free interictal phase.
  
  
  METHODS
  Using resting-state functional magnetic resonance imaging, we measured the changes in resting-state brain networks between pre-VNS treatment and 6 months post-VNS, from the perspective of regional and global variations, using regional homogeneity and large-scale functional connectives (seeding posterior cingulate cortex and anterior cingulate cortex), respectively.
  
  
  RESULTS
  After 6 months of VNS therapy, the resting-state brain networks were slightly reorganized in regional homogeneity, mainly in large-scale functional connectivity, where excessive activation of the salience network was suppressed, while at the same time the suppressed default-mode network was activated.
  
  
  CONCLUSIONS
  With regard to resting-state brain networks, we propose a hypothesis based on this single case study that VNS acts on intractable epilepsy by modulating the balance between salience and default-mode networks through the integral hub of the anterior cingulate cortex.
authors: Beijing Neurosurgical Institute, Capital Medical University; Beijing Key Laboratory of Neurostimulation.
authors: Kailiang
authors: K
authors: Wang
authors: Beijing Neurosurgical Institute, Capital Medical University.
authors: Qi
authors: Q
authors: Chai
authors: Beijing Neurosurgical Institute, Capital Medical University.
authors: Hui
authors: H
authors: Qiao
authors: Beijing Key Laboratory of Neurostimulation; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China.
authors: Jianguo
authors: J
authors: Zhang
authors: Beijing Neurosurgical Institute, Capital Medical University; Beijing Key Laboratory of Neurostimulation.
authors: Tinghong
authors: T
authors: Liu
authors: Beijing Neurosurgical Institute, Capital Medical University; Beijing Key Laboratory of Neurostimulation.
authors: Fangang
authors: F
authors: Meng
keywords: brain-network balance; epilepsy monitoring; epilepsy surgery; functional neuroimaging; vagus nerve stimulation