title: Neurosurgical conditions and procedures in infancy are associated with mortality and academic performances in adolescence: a nationwide cohort study.
abstract: BACKGROUND
  Few human cohort studies on anesthesia-related neurotoxicity and the developing brain have focused on and compared specific surgeries and conditions. These studies cannot disentangle the effects of anesthesia from those of the surgery and underlying conditions. This study aimed at assessing the impact of specific neurosurgical conditions and procedures in infancy on mortality and academic achievements in adolescence.
  
  
  METHODS
  A nationwide unselected register-based follow-up study of the Danish birth cohorts 1986-1990 compared academic performances of all children having undergone neurosurgeries as infants with a randomly selected, age-matched 5% sample of the same cohorts. The two groups were compared regarding mortality prior to June 1st, 2006, average test scores at ninth grade, and finally the proportion of children not attaining test scores.
  
  
  RESULTS
  The exposure group comprised 228 and the control group 14 698 individuals. Hydrocephalus (n = 130), craniotomy (n = 43), and myelomeningocele/encephalocele children (n = 55) had a higher mortality (18.5.0%, 18.6%, and 7.3%, respectively) vs controls (1.3%; P < 0.00001, P < 0.00001, and P = 0.0052, respectively). Average test scores were significantly lower than controls in hydrocephalus and craniotomy (P = 0.0043 and P = 0.0077) but not myelomeningocele/encephalocele children (P = 0.2785); the proportion of available test scores were significantly lower in all three groups (40.8%, 60.0%, and 67.3%, respectively) vs 86.8% in controls (P < 0.00001, P = 0.000077, and P = 0.000064).
  
  
  CONCLUSIONS
  Neurosurgery in infancy was associated with high mortality and significantly impaired academic achievements in adolescence. When studying anesthesia-related neurotoxicity and the developing brain, focus on specific surgeries/conditions is important. Pooling of major/minor conditions and major/minor surgeries should be avoided.
authors.affiliation: Department of Anesthesia and Intensive Care, Odense University Hospital, Odense C, Denmark; Clinical Institute - Anesthesiology, University of Southern Denmark, Odense C, Denmark.
authors.forename: Tom G
authors.initials: TG
authors.lastname: Hansen
authors.forename: Jacob K
authors.initials: JK
authors.lastname: Pedersen
authors.forename: Steen W
authors.initials: SW
authors.lastname: Henneberg
authors.forename: Neil S
authors.initials: NS
authors.lastname: Morton
authors.forename: Kaare
authors.initials: K
authors.lastname: Christensen
mesh_terms: D000124:Achievement; D000293:Adolescent; D015331:Cohort Studies; D003399:Craniotomy / Q000706:statistics & numerical data; D003718:Denmark / Q000453:epidemiology; D004521:Educational Measurement / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus; D007223:Infant; D008297:Male; D008591:Meningomyelocele; D009422:Nervous System Diseases / Q000453:epidemiology* / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000706:statistics & numerical data*
keywords: age: infant; neonates; neurodevelopment; neurosurgery; outcome