title: Evaluation of cognitive and motor development in toddlers with congenital hypothyroidism diagnosed by neonatal screening.
abstract: OBJECTIVE
  The Dutch neonatal congenital hypothyroidism (CH) screening procedure and treatment modality has been adapted several times since its national institution in 1981. These changes enabled us to investigate whether earlier treatment has resulted in improved cognitive and motor outcomes. The present study examined whether the advancement of treatment modality has resulted in improved cognitive and motor outcomes.
  
  
  METHODS
  In 95 toddlers with thyroidal CH (CH-T), born in 2002 through 2004 and treated at a median age of 9 days, cognitive and motor outcomes were assessed with the Bayley Scales of Infant Development-II-NL at 1 and 2 years of age. This outcome was also analyzed in relation to treatment variables.
  
  
  RESULTS
  The mean mental developmental index (MDI) scores of the severe (initial free thyroxine [FT4] ≤0.4 ng/dL (≤5 pmol/L), moderate (0.4 < initial FT4 ≤ 0.8 ng/dL (5.0 < initial FT4 ≤ 10.0 pmol/L), and mild (initial FT4 > 0.8 ng/dL (>10.0 pmol/l) CH-T groups at 1 year and the moderate and mild CH-T groups at 2 years were similar to the population mean. The mean MDI scores of the total CH-T group and severe CH-T group at 2 years were significantly lower than the population mean (p < .0001). In all 3 severity subgroups, significant lower psychomotor developmental index scores (p < .0001) were observed. No correlations were found between starting day of treatment and developmental outcome. Initial T4 concentration and initial T4 dose were weak predictors for developmental outcome.
  
  
  CONCLUSIONS
  Essentially, comparable with our earlier findings, children with CH, especially those with severe CH, are still at risk for motor and cognitive problems, which are probably due to the consequence of the prenatal hypothyroid state or the thyroid hormone deficiency in early life.
authors.affiliation: Psychosocial Department, Emma Children's Hospital AMC, University of Amsterdam, Amsterdam, The Netherlands. l.vandersluijsveer@amc.uva.nl
authors.forename: Liesbeth
authors.initials: L
authors.lastname: van der Sluijs Veer
authors.forename: Marlies J E
authors.initials: MJ
authors.lastname: Kempers
authors.forename: Brenda M
authors.initials: BM
authors.lastname: Wiedijk
authors.forename: Bob F
authors.initials: BF
authors.lastname: Last
authors.forename: Martha A
authors.initials: MA
authors.lastname: Grootenhuis
authors.forename: Tom
authors.initials: T
authors.lastname: Vulsma
mesh_terms: D002657:Child Development / Q000187:drug effects / Q000502:physiology*; D002675:Child, Preschool; D003409:Congenital Hypothyroidism / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007360:Intelligence; D008297:Male; D015997:Neonatal Screening; D009426:Netherlands; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D013974:Thyroxine / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D013974:Thyroxine