Neuropsychological follow-up in early-treated congenital hypothyroidism: Aproblem-oriented approach

Screening programs for congenital hypothyroidism (CH) dramatically improved the neuropsychological prognosis in affected children. However, mild impai rments in cognitive performances, poorer motor skills, defective language a bilities, and learning problems have been reported in some studies of early -treated CH children. The occurrence df these defects makes neuropsychologi cal follow-up mandatory. The aim of the present study was to identify those neuropsychological functions that are more frequently affected in early-tr eated CH children and that might require prompt rehabilitation treatment to prevent permanent defects. The study group involved 24 CH children. Levoth yroxine (LT4) treatment (initial dose 8-10 mu g/kg per day) was started at mean age of 28 days (range 15-45) and was then adjusted with the goal to ke ep thyrotropin (TSH) and free thyroid hormone levels in the normal range. C ognitive evaluation was performed at 3, 5, and 7 years of age and did not s ignificantly differ from that of controls. Mean neurological scores were lo wer in children 5 years of age than in controls. Children with severe neona tal hypothyroidism (serum thyroxine [T-4] < 2 mu g/dL) had significantly lo wer neurological scores compared to less affected CH children and normal co ntrols. The most affected functions were balance, extremity coordination, f ine motricity, quality of movements, associated movements, and head movemen ts. Language disorders were observed in half of CH children at 3 and 5 year s of age, but moderately severe defects were restricted to those with sever e neonatal hypothyroidism. In conclusion, a problem-oriented, simplified ne uropsychological follow-up of early-treated children with CH should not sys tematically 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 no rmal 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 b e 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 s hould receive specific rehabilitation treatment. No further motor and langu age evaluation is warranted in CH children with normal tests at age 5 years .