ABSTRACT
INTRODUCTION: The prevention of mental retardation due to congenital hypothyroidism by treating it at an early stage is one of the great achievements of contemporary preventive medicine. Nevertheless, the children suffering from this disease are affected by selective cognitive deficits whose origin remains a controversial issue. PATIENTS AND METHODS: We describe the results from a cohort of 100 children who have been diagnosed as suffering from congenital hypothyroidism in La Havana since 1989 and whose cognitive performance has since been periodically evaluated. The mean age at each evaluation was as follows: 1.1 years (mean and typical deviation: 0.3) and 8.2 years (mean and typical deviation: 1.2). RESULTS: During the first two years of life the developmental quotients are within the normal range of values, although fine oculomotor coordination is significantly diminished. The duration of fetal hypothyroidism is linked to postural control, and the initial biochemical severity of the disease is associated to language development. Oculomotor coordination is not linked to any variable concerning the severity of the disease or with the effectiveness of therapy. At school age, intelligence quotients (IQ) are also within the normal range of values. A multiple regression analysis indicated that the total IQ can be predicted from the scores in oculomotor coordination during the first two years of life and from the initial doses of levothyroxine. CONCLUSIONS: The relations between the variables capable of forecasting intellectual development in these children are analysed and we also discuss the hypothesis which suggests that some of the persisting neurocognitive deficits are probably due to genetic influences that exist regardless of the effectiveness of the therapy.
Subject(s)
Cognition Disorders/diagnosis , Cognition Disorders/physiopathology , Cognition/physiology , Hypothyroidism , Child , Child, Preschool , Congenital Hypothyroidism , Cuba , Eye Movements/physiology , Humans , Hypothyroidism/diagnosis , Hypothyroidism/drug therapy , Hypothyroidism/physiopathology , Infant , Intelligence , Prognosis , Statistics as Topic , Thyroxine/therapeutic useABSTRACT
Introducción. La prevención del retraso mental por hipotiroidismo congénito mediante su tratamiento precoz es uno de los grandes logros de la medicina preventiva contemporánea. Sin embargo, persisten déficit cognitivos selectivos en los niños afectados de esta enfermedad cuyo origen es todavía controvertido. Pacientes y métodos. Exponemos los resultados de una cohorte de 100 niños con hipotiroidismo congénito diagnosticados en La Habana desde 1989, cuyo rendimiento cognitivo se ha evaluado periódicamente. La edad promedio de cada evaluación fue la siguiente: 1,1 años (desviación típica: 0,3) y 8,2 años (desviación típica: 1,2). Resultados. Durante los dos primeros años de vida, los cocientes de desarrollo están en rangos normales, aunque la coordinación oculomotora fina se ve significativamente disminuida. La duración del hipotiroidismo fetal se asoció con el control de la postura, y la gravedad bioquímica inicial de la enfermedad, con el desarrollo del lenguaje. La coordinación oculomotora no se asoció con ninguna variable de gravedad de la enfermedad ni con la eficacia del tratamiento. En la edad escolar, los cocientes de inteligencia (CI) también están en rangos normales. Un análisis de regresión múltiple indicó que el CI total puede predecirse a partir de las puntuaciones de la coordinación oculomotora en los dos primeros años y por la dosis inicial de levotiroxina. Conclusiones. Se analizan las relaciones entre las variables que pueden pronosticar el desarrollo intelectual en estos niños y se discute la hipótesis de que algunos de los déficit neurocognitivos que persisten son probablemente debidos a influencias genéticas, independientemente de la excelencia del tratamiento (AU)
Introduction. The prevention of mental retardation due to congenital hypothyroidism by treating it at an early stage is one of the great achievements of contemporary preventive medicine. Nevertheless, the children suffering from this disease are affected by selective cognitive deficits whose origin remains a controversial issue. Patients and methods. We describe the results from a cohort of 100 children who have been diagnosed as suffering from congenital hypothyroidism in La Havana since 1989 and whose cognitive performance has since been periodically evaluated. The mean age at each evaluation was as follows: 1.1 years (mean and typical deviation: 0.3) and 8.2 years (mean and typical deviation: 1.2). Results. During the first two years of life the developmental quotients are within the normal range of values, although fine oculomotor coordination is significantly diminished. The duration of fetal hypothyroidism is linked to postural control, and the initial biochemical severity of the disease is associated to language development. Oculomotor coordination is not linked to any variable concerning the severity of the disease or with the effectiveness of therapy. At school age, intelligence quotients (IQ) are also within the normal range of values. A multiple regression analysis indicated that the total IQ can be predicted from the scores in oculomotor coordination during the first two years of life and from the initial doses of levothyroxine. Conclusions. The relations between the variables capable of forecasting intellectual development in these children are analysed and we also discuss the hypothesis which suggests that some of the persisting neurocognitive deficits are probably due to genetic influences that exist regardless of the effectiveness of the therapy (AU)
