Congenital hypothyroidism and associated visual-motor and intellectual development

Abstract

Background: Congenital hypothyroidism's sequelae include visuomotor and intellectual developmental deficits. Visual-motor perception is a cognitive function related to academic performance. Intellect is the ability to learn and use acquired knowledge to solve and achieve goals. Our objective was to evaluate visual-motor and intellectual development in children with late initiation of treatment for congenital hypothyroidism enrolled in a developmental follow-up and intervention program.

Methods: We evaluated the visual-motor and intellectual development of 75 infants with congenital hypothyroidism, 34 with athyrosis, and 41 with ectopia using the Bender Visual-Motor Development Test and the Weschler Intelligence Scale at eight and nine years of age.

Results: Children with ectopia had a visual-motor delay of -2 years and an Intelligence Quotient (IQ) greater than 98 points. Children with athyrosis had a visual-motor delay equivalent to -3.2 years and an IQ below 90 points. Better performance on Bender's test was positively correlated with IQ. Attending more than 80% of Developmental Intervention Program appointments had a positive impact on intellectual development.

Conclusions: Timely diagnosis and early treatment with the appropriate dose of levothyroxine are determining factors; however, attendance to a development follow-up and intervention program could further support the cognitive development of children with congenital hypothyroidism.

Impact: Visuomotor development influences cognitive functions related to school performance. Deficits in the ability to learn and use acquired knowledge to solve problems and achieve goals are characteristic of children with congenital hypothyroidism. Delayed treatment is associated with more severe sequelae in both visual-motor and intellectual development. Here, we show that treatment with adequate doses of levothyroxine and inclusion in a follow-up and developmental program are highly recommended for patients with delayed treatment. A better understanding of these factors will allow clinicians to target therapeutic interventions.