title: Cognitive impairment in tuberous sclerosis complex is a multifactorial condition.
abstract: OBJECTIVE
  In patients with tuberous sclerosis complex (TSC), associations between tuber number, infantile spasms, and cognitive impairment have been proposed. We hypothesized that the tuber/brain proportion (TBP), the proportion of the total brain volume occupied by tubers, would be a better determinant of seizures and cognitive function than the number of tubers. We investigated tuber load, seizures, and cognitive function and their relationships.
  
  
  METHODS
  Tuber number and TBP were characterized on three-dimensional fluid-attenuated inversion recovery MRI with an automated tuber segmentation program. Seizure histories and EEG recordings were obtained. Intelligence equivalents were determined and an individual cognition index (a marker of cognition that incorporated multiple cognitive domains) was calculated.
  
  
  RESULTS
  In our sample of 61 patients with TSC, TBP was inversely related to the age at seizure onset and to the intelligence equivalent and tended to be inversely related to the cognition index. Further, a younger age at seizure onset or a history of infantile spasms was related to lower intelligence and lower cognition index. In a multivariable analysis, only age at seizure onset and cognition index were related.
  
  
  CONCLUSIONS
  Our systematic analysis confirms proposed relationships between tuber load, epilepsy and cognitive function in tuberous sclerosis complex (TSC), but also indicates that tuber/brain proportion is a better predictor of cognitive function than tuber number and that age at seizure onset is the only independent determinant of cognitive function. Seizure control should be the principal neurointervention in patients with TSC.
authors.affiliation: Rudolf Magnus Institute of Neuroscience, Department of Child Neurology, University Medical Centre, 3508 GA Utrecht, The Netherlands. f.e.jansen@umcutrecht.nl
authors.forename: F E
authors.initials: FE
authors.lastname: Jansen
authors.forename: K L
authors.initials: KL
authors.lastname: Vincken
authors.forename: A
authors.initials: A
authors.lastname: Algra
authors.forename: P
authors.initials: P
authors.lastname: Anbeek
authors.forename: O
authors.initials: O
authors.lastname: Braams
authors.forename: M
authors.initials: M
authors.lastname: Nellist
authors.forename: B A
authors.initials: BA
authors.lastname: Zonnenberg
authors.forename: A
authors.initials: A
authors.lastname: Jennekens-Schinkel
authors.forename: A
authors.initials: A
authors.lastname: van den Ouweland
authors.forename: D
authors.initials: D
authors.lastname: Halley
authors.forename: A C
authors.initials: AC
authors.lastname: van Huffelen
authors.forename: O
authors.initials: O
authors.lastname: van Nieuwenhuizen
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000473:pathology* / Q000503:physiopathology; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D013036:Spasms, Infantile / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology; D014402:Tuberous Sclerosis / Q000150:complications* / Q000235:genetics / Q000473:pathology*