ABSTRACT
BACKGROUND: Congenital hypothyroidism is one of the most frequent endocrine diseases of the newborn and requires an early diagnosis to avoid its deleterious effects on neurological and intellectual functions. AIM: To evaluate thyroid scintigraphy (TS) findings in newborns with congenital hypothyroidism (CH), detected in the national program of newborn screening, which is working in Chile since 1992. MATERIAL AND METHODS: TS findings of 189 newborns with CH (68% female) were analyzed. Tc99m pertechnetate TS was performed at 19 +/- 11 days of life. The gland was classified as eutopic, ectopic or absence of contrast (AC). Eutopic glands were classified by visual and quantitative criteria as: normal, goiter and decreased contrast (DC). TS results were compared by gender and hormonal levels. RESULTS: Forty seven percent of newborns had ectopy, 29.1% eutopy and 24.3% AC. Eutopic gland predominated in males (44.2% vs 22.7%) and ectopy was more frequent in girls (53.1% vs 32.8%, p < 0.05). Newborns with AC had the most severe hormonal alterations, without gender differences. Newborns with normal TS had less hormonal alterations than those with goiter. CONCLUSIONS: TS allows an etiological classification of CH. Thyroid dysgenesis is the most frequent cause, most of which correspond to ectopy, especially in girls. Eutopic glands are present in one third of newborns with CH. Goiter predominates, especially in males.
Subject(s)
Congenital Hypothyroidism , Hypothyroidism/diagnostic imaging , Radiopharmaceuticals , Sodium Pertechnetate Tc 99m , Thyroid Gland/diagnostic imaging , Chile , Female , Humans , Infant, Newborn , Male , Neonatal Screening , Radionuclide ImagingABSTRACT
Diferentes pruebas inespecíficas de estimulación se emplean para estudiar la capacidad de la hipófisis para secretar hormona del crecimiento, pero ninguno es totalmente confiable. Los autores emplearon factor liberador de hormona del crecimiento (1microng x kg de peso corporal endovenoso) en 6 niños de talla baja pero sin afecciones endocrinas y en 4 pacientes con deficiencia comprobada de hormona del crecimiento. La concentración plasmática máxima de la hormona en los niños normales, durante la prueba, fue de 47,4 + ou - 15,4 ng x ml. Tres de los cuatro pacientes no mostraron respuesta a la provocación y en el cuatro la concentración plasmática máxima alcanzada fue de 5,3 ng x ml sugiriendo un origen hipotalámico para su deficiencia hormonal. El empleo de factor liberador sería de utilidad en el futuro para el diagnóstico y tratamiento de la deficiencia de hormona del crecimiento
