Avaliação cognitiva de crianças e adolescentes com hipotireoidismo congênito triados pelo Programa Estadual de Triagem Neonatal de Minas Gerais (PTN-MG)

Abstract

Thyroid hormone is fundamental to the development of the central nervous system and its deprivation in fetal life and three years of postnatal life leads to lesions in this tissue and can cause irreversible damage to the child's neuropsychomotor development of the child. Early treatment is important. However, there are still doubts about the occurrence of discrete changes in the functioning of the thyroid gland, even after treatment, which could cause cognitive deficits. For this reason it is important to evaluate the cognitive functions of patients with congenital hypothyroidism. The aim of this study was to identify whether the cognitive performance, global and in specific domains, of children and adolescents with permanent primary congenital hypothyroidism, screened by the Neonatal Screening Program of Minas Gerais (PTN-MG) and in regular medical follow-up, is similar to that of healthy participants. It was also sought to verify variables that can predict this performance. Sixty-three children aged 11 to 16 years participated in the study, 34 in the case group and 29 controls, recruited in a public school and matched to the case group by age, sex, schooling and socioeconomic level. The cognitive performance of the participants was analyzed by the following neuropsychological instruments: Wechsler Intelligence Scale for Children - 4th Edition (global cognitive performance), Verbal Fluency test and Five Digits Test (executive functions and processing speed), Rey-Osterrieth Complex Figure Test (visuospatial ability and episodic memory), and Corsi Cubes (short-term visual memory). The non-parametric Mann-Whitney U test was used to compare the results of the cognitive evaluation between the case and control groups and between the case groups of different etiologies. Multiple linear regression analysis was performed to identify an association between the results of the cognitive evaluation and the caregiver's schooling, socioeconomic level, participant age, and laboratory data from the case group. Participants in the case and control groups obtained similar cognitive performance. The Verbal Comprehension Index was the only WISC-IV result that presented a significant difference, with mean effect size between the groups. The groups of different congenital hypothyroidism etiologies differed in the level of serum T4 hormone at the time of cognitive assessment, but also were not different regarding cognitive performance. Variables such as family socioeconomic level, caregiver education, serum TSH level before treatment, patient's age at the start of treatment, and the initial dose of levothyroxine used predict patients' cognitive performance. The etiology of congenital hypothyroidism, the T4 hormone level before treatment, and the time of cognitive evaluation and the median serum TSH in the first 3 years of the patient's life did not predict the cognitive performance of patients with congenital hypothyroidism. The results of this study showed that global cognitive performance and in specific domains of children and adolescents with permanent primary congenital hypothyroidism, triaged by PTN-MG are similar to those of healthy participants of the same age group, gender, schooling and socioeconomic level. Socioeconomic and treatment variables were the main predictors of the cognitive performance of these patients.