title: Regional brain volumes and cognition in childhood epilepsy: does size really matter?
abstract: OBJECTIVE
  Recent studies have correlated neurocognitive function and regional brain volumes in children with epilepsy. We tested whether brain volume differences between children with and without epilepsy explained differences in neurocognitive function.
  
  
  METHODS
  The study sample included 108 individuals with uncomplicated non-syndromic epilepsy (NSE) and 36 healthy age- and gender-matched controls. Participants received a standardized cognitive battery. Whole brain T1-weighted MRI was obtained and volumes analyzed with FreeSurfer (TM).
  
  
  RESULTS
  Total brain volume (TBV) was significantly smaller in cases. After adjustment for TBV, cases had significantly larger regional grey matter volumes for total, frontal, parietal, and precentral cortex. Cases had poorer performance on neurocognitive indices of intelligence and variability of sustained attention. In cases, TBV showed small associations with intellectual indices of verbal and perceptual ability, working memory, and overall IQ. In controls, TBV showed medium associations with working memory and variability of sustained attention. In both groups, small associations were seen between some TBV-adjusted regional brain volumes and neurocognitive indices, but not in a consistent pattern. Brain volume differences did not account for cognitive differences between the groups.
  
  
  CONCLUSIONS
  Patients with uncomplicated NSE have smaller brains than controls but areas of relative grey matter enlargement. That this relative regional enlargement occurs in the context of poorer overall neurocognitive functioning suggests that it is not adaptive. However, the lack of consistent associations between case-control differences in brain volumes and cognitive functioning suggests that brain volumes have limited explanatory value for cognitive functioning in childhood epilepsy.
authors.affiliation: Department of Child and Adolescent Psychiatry, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States. Electronic address: fzelko@luriechildrens.org.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Zelko
authors.affiliation: Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; New York University School of Medicine, New York, NY, United States.
authors.forename: Heath R
authors.initials: HR
authors.lastname: Pardoe
authors.affiliation: Department of Public Health, Northern Illinois University, DeKalb, IL, United States.
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Blackstone
authors.affiliation: Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Department of Medicine, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Graeme D
authors.initials: GD
authors.lastname: Jackson
authors.affiliation: Epilepsy Center, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States; Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
authors.forename: Anne T
authors.initials: AT
authors.lastname: Berg
mesh_terms: D000293:Adolescent; D001288:Attention / Q000502:physiology; D001921:Brain / Q000473:pathology*; D002648:Child; D003071:Cognition / Q000502:physiology*; D004827:Epilepsy / Q000473:pathology* / Q000523:psychology; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D036421:Nerve Fibers, Unmyelinated / Q000473:pathology*; D009483:Neuropsychological Tests; D009929:Organ Size / Q000502:physiology; D055815:Young Adult
keywords: Case–control study; Children; Cognitive function; Epilepsy; MRI volumetrics