Screening programs for congenital hypothyroidism (CH) dramatically improved the neuropsychological prognosis in affected children. However, mild impairments in cognitive performances, poorer motor skills, defective language abilities, and learning problems have been reported in some studies of early-treated CH children. The occurrence of these defects makes neuropsychological follow-up mandatory. The aim of the present study was to identify those neuropsychological functions that are more frequently affected in early-treated CH children and that might require prompt rehabilitation treatment to prevent permanent defects. The study group involved 24 CH children. Levothyroxine (LT4) treatment (initial dose 8-10 microg/kg per day) was started at mean age of 28 days (range 15-45) and was then adjusted with the goal to keep thyrotropin (TSH) and free thyroid hormone levels in the normal range. Cognitive evaluation was performed at 3, 5, and 7 years of age and did not significantly differ from that of controls. Mean neurological scores were lower in children 5 years of age than in controls. Children with severe neonatal hypothyroidism (serum thyroxine [T4] < 2 microg/dL) had significantly lower neurological scores compared to less affected CH children and normal controls. The most affected functions were balance, extremity coordination, fine motricity, quality of movements, associated movements, and head movements. Language disorders were observed in half of CH children at 3 and 5 years of age, but moderately severe defects were restricted to those with severe neonatal hypothyroidism. In conclusion, a problem-oriented, simplified neuropsychological follow-up of early-treated children with CH should not systematically include the frequent repetition of time-consuming and expensive psychometric tests because individual IQ scores are in the normal range of tests in almost all CH children and can be differentiated from those of normal controls only on a population-statistic basis. Selected tests of motor proficiency are indicated at 3 and 5 years of age to detect those defects in motor skills that appear to be more specifically affected in CH children. Language performances are at particular risk in CH children, and should be always checked at 3 and 5 years of age. Children with even mild language disorders or delayed language achievements should be regularly reevaluated at 6-month intervals and, if no spontaneous improvement is observed, they should receive specific rehabilitation treatment. No further motor and language evaluation is warranted in CH children with normal tests at age 5 years.

Objective: Evaluation of school attainments in children with congenital hypothyroidism (CH) detected by neonatal screening and treated early in life. Patients and methods:Text comprehension, mathematics, reading, writing and verbal and spatial memory, as indices of school learning, were evaluated in nineteen 5-to 10-year-old children with CH attending nursery or elementary school. L-Thyroxine substitution (starting dose 8-10 mg/kg body weight per day) was initiated at a mean age of 30 Ϯ 10 days of life. The control group included 298 unaffected children matched with the CH children for age and school grade. Thirty per cent of controls were classmates of CH children. Intelligence quotients (IQ), language performances and motor development were evaluated in CH children at age 5 years, and were related to their school attainments. School performances of CH children were also compared with their neonatal serum thyroxine (T 4 ) concentration, and with the social-cultural level of the family. Results: Four out of 19 (21%) children with CH, 3 in the nursery and 1 in the elementary school, displayed a generalized learning disorder. Symbol copy, geometric copy, phrase repetition, dictation writing and spontaneous writing were particularly defective in nursery school CH children, while orthographic error recognition was defective in elementary school CH children. School learning disorders in CH children were significantly correlated with a borderline-low IQ, poor language performances and a low social-cultural level of the family, but not with motor skills or neonatal T 4 concentration. Conclusion: School attainments of early treated CH children were within the normal range in most affected cases. However, about 20% of CH children, most of them attending nursery school, showed a generalized learning disorder. Low IQ scores and poor language performances at age 5 years were associated with defective learning, mainly in CH children living in a poor social-cultural environment. In this subset of CH children, prompt initiation of speech and psychomotor rehabilitation therapy is recommended in order to prevent subsequent school learning disorders.

Because the twins were genetically and phenotypically identical, were raised in the same environment, and received a similar education, it is concluded that hypothyroidism in utero and in the first neonatal month was responsible for the lower neuropsychological achievements of the CH twin. While foetal hypothyroidism is at present unavoidable, earlier diagnosis and initiation of treatment in neonates with CH are important and highly recommended.