title: Electroencephalography and Brain MRI Patterns in Encephalopathy.
abstract: BACKGROUND
  Using electroencephalography (EEG) and histology in patients with diffuse encephalopathy, Gloor et al reported that paroxysmal synchronous discharges (PSDs) on EEG required combined cortical gray (CG) and "subcortical" gray (SCG) matter pathology, while polymorphic delta activity (PDA) occurred in patients with white matter pathology. In patients with encephalopathy, we compared EEG findings and magnetic resonance imaging (MRI) to determine if MRI reflected similar pathological EEG correlations.
  
  
  METHODS
  Retrospective case control study of 52 cases with EEG evidence of encephalopathy and 50 controls without evidence of encephalopathy. Review of clinical, EEG and MRI data acquired within 4 days of each other.
  
  
  RESULTS
  The most common EEG finding in encephalopathy was background slowing, in 96.1%. We found PSDs in 0% of cases with the combination of CG and SCG abnormalities. Although 13.5% (n=7) had PSDs on EEG; 3 of these had CG and 4 had SCG abnormalities. A total of 73.1% (38/52) had white matter abnormalities-of these 28.9% (11/38) had PDA.
  
  
  CONCLUSIONS
  PSDs were found with either CG or "SCG" MRI abnormalities and did not require a combination of the two. In agreement with Gloor et al, PDA occurred with white matter MRI abnormalities in the absence of gray matter abnormalities.
authors.affiliation: Department of Neurology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA wabulya@neurology.unc.edu.
authors.forename: Angela
authors.initials: A
authors.lastname: Wabulya
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Lesser
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Rafael
authors.initials: R
authors.lastname: Llinas
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Kaplan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001927:Brain Diseases / Q000473:pathology / Q000503:physiopathology*; D016022:Case-Control Studies; D003700:Delta Rhythm / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D066128:Gray Matter / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D066127:White Matter / Q000473:pathology; D055815:Young Adult
keywords: electroencephalogram; encephalopathy; gray matter; magnetic resonance imaging; white matter