title: Quantitative EEG asymmetry correlates with clinical severity in unilateral Sturge-Weber syndrome.
abstract: OBJECTIVE
  Sturge-Weber syndrome (SWS) is a neurocutaneous disorder with vascular malformations of the skin, brain, and eye. SWS results in ischemic brain injury, seizures, and neurologic deficits. We hypothesized that a decrease in quantitative EEG (qEEG) power, on the affected side, correlates with clinical severity in subjects with SWS.
  
  
  METHODS
  Fourteen subjects had 16-channel scalp EEG recordings. Data were analyzed using fast Fourier transform and calculation of power asymmetry. Blinded investigators assigned scores for clinical neurological status and qualitative assessment of MRI and EEG asymmetry.
  
  
  RESULTS
  The majority of subjects demonstrated lower total power on the affected side, usually involving all four frequency bands (delta, theta, alpha, and beta). qEEG asymmetry correlated strongly with neurologic clinical severity scores and MRI asymmetry scores. qEEG data generally agreed with the MRI evidence of regional brain involvement. In MRI-qEEG comparisons that did not agree, decreased power on qEEG in a brain region not affected on MRI was more likely to occur in subjects with more severe neurologic deficits.
  
  
  CONCLUSIONS
  qEEG provides an objective measure of EEG asymmetry that correlates with clinical status and brain asymmetry seen on MRI. These findings support the conclusion that qEEG reflects the degree and extent of brain involvement and dysfunction in SWS. qEEG may potentially be a useful tool for early diagnosis and monitoring of disease progression in SWS. qEEG may prove useful, in severely affected individuals with SWS, for determining regions of brain dysfunction.
authors.affiliation: Department of Neurology, Kennedy Krieger Institute, Baltimore, MD 21205, USA.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Hatfield
authors.forename: Nathan E
authors.initials: NE
authors.lastname: Crone
authors.forename: Eric H
authors.initials: EH
authors.lastname: Kossoff
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Ewen
authors.forename: Paula L
authors.initials: PL
authors.lastname: Pyzik
authors.forename: Doris D M
authors.initials: DD
authors.lastname: Lin
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Kelley
authors.forename: Anne M
authors.initials: AM
authors.lastname: Comi
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D004569:Electroencephalography / Q000706:statistics & numerical data*; D004827:Epilepsy / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005583:Fourier Analysis; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D008297:Male; D008991:Monitoring, Physiologic; D012720:Severity of Illness Index; D013341:Sturge-Weber Syndrome / Q000175:diagnosis* / Q000503:physiopathology