Intellectual and motor development of young adults with congenital hypothyroidism diagnosed by neonatal screening.
BACKGROUND
Long-term follow-up data on cognitive and motor functioning in adult patients with congenital hypothyroidism, diagnosed by neonatal screening, are scarce. Hence, it is still unclear whether the frequently reported cognitive and motor deficits observed during childhood persist in adulthood.


OBJECTIVE
The objective of this study was to examine cognitive and motor functioning in young adults with congenital hypothyroidism, born in the first 2 yr after the introduction of the Dutch neonatal screening program.


METHODS
Seventy patients were tested (mean age, 21.5 yr); 49 of them were previously tested at 9.5 yr. The median age at the start of treatment was 28 d (range, 4-293 d). Congenital hypothyroidism was classified as severe, moderate, or mild, according to pretreatment T(4) concentrations.


METHODS
The main outcome measurement was the influence of the severity of congenital hypothyroidism and age at which T(4) supplementation was started on cognitive and motor outcome.


RESULTS
Patients, particularly those with severe congenital hypothyroidism, had significantly higher (i.e. worse) motor scores (total score, 7.8; ball skills, 2.0; balance, 4.1) compared with controls (total score, 3.2; ball skills, 0.7; balance, 1.1), and lower full-scale (95.8), verbal (96.4), and performance (95.6) intelligence quotient (IQ) scores than the normal population. No significant change in IQ from childhood to adulthood was found, and for the majority of patients, motor score classification remained the same. The severity of congenital hypothyroidism, but not the starting day of treatment, was correlated with IQ and motor scores.


CONCLUSIONS
It is concluded that the severity of congenital hypothyroidism, but not the timing of treatment initiation, is an important factor determining long-term cognitive and motor outcome. Clearly, detrimental effects on developmental outcome in patients with congenital hypothyroidism persist over time.
Kempers
M J E
MJ
Emma Children's Hospital Academic Medical Center, Department of Pediatric Endocrinology, Academic Medical Center, University of Amsterdam, G8-205, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands. m.j.kempers@amc.uva.nl
van der Sluijs Veer
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L
Nijhuis-van der Sanden
M W G
MW
Kooistra
L
L
Wiedijk
B M
BM
Faber
I
I
Last
B F
BF
de Vijlder
J J M
JJ
Grootenhuis
M A
MA
Vulsma
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T
D000328:Adult; D003409:Congenital Hypothyroidism / Q000503:physiopathology* / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D020249:Hormone Replacement Therapy; D006801:Humans; D007360:Intelligence; D008137:Longitudinal Studies; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D018709:Statistics, Nonparametric; D013974:Thyroxine / Q000627:therapeutic use
D013974:Thyroxine