title: Lateralization of epileptic foci through causal analysis of scalp-EEG interictal spike activity.
abstract: OBJECTIVE
  The purpose of this work was to find an objective and quantitative method for epileptic foci lateralization that may aid and support the decision made by the usually chosen lateralizing criteria.
  
  
  METHODS
  A frequency-derived causal analysis method, full frequency adaptive directed transfer function, was applied to the interictal scalp EEG data collected from 2 groups of total 30 epileptic patients. Group A included 15 refractory epileptic patients who had undergone an epileptic surgery; group B consisted of 15 outpatient epileptic patients who had a seizure type of generalized tonic-clonic seizure. All patients had no abnormalities detected in their routine brain MRI examinations. The methodology that leads to the lateralization is based on several processing steps: interictal spikes selection, full frequency adaptive directed transfer function analysis, significant causal connections extraction, and then lateralization.
  
  
  RESULTS
  Ninety-six of 104 spikes' sources lateralized by full frequency adaptive directed transfer function were consistent with their corresponding surgery side in group A, with the accuracy of 92.31%. Ninety-seven of 101 spikes' sources were lateralized correctly in group B, according to technicians' judgments from ictal scalp video-EEG recordings, with the accuracy of 96.04%.
  
  
  CONCLUSIONS
  The results demonstrated the feasibility of correctly lateralizing the epileptic foci by using full frequency adaptive directed transfer function to scalp EEG interictal spike activity.
authors: *Bioengineering College, Chongqing University, Chongqing, China; and Departments of †Neurosurgery and ‡Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors: Weina
authors: W
authors: Li
authors: Nan
authors: N
authors: Wu
authors: Wensheng
authors: W
authors: Hou
authors: Jiuquan
authors: J
authors: Zhang
authors: Wenxin
authors: W
authors: Xu
authors: Guocai
authors: G
authors: Wu
authors: Xiaolin
authors: X
authors: Zheng
authors: Hua
authors: H
authors: Feng
mesh_terms: D000328:Adult; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D012535:Scalp; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult