ABSTRACT

Congenital hypothyroidism (CH) is an important cause of preventable intellectual disability. Implementation of CH neonatal screening programs leading to early treatment has improved cognitive outcome. However, more subtle cognitive impairments are still reported, and there is lack of clarity regarding factors that impact long-term cognitive outcome. Research to better understand these factors can lead to further improvements in the cognitive prognosis for these patients. The current study aimed to evaluate the cognitive performance of adolescents who were early-treated for primary permanent CH and possible associated variables. Neurocognitive evaluation was carried out in 66 adolescents, 11 to 16 years old: 34 with CH and 29 paired controls. Intellectual quotient (IQ), verbal fluency, processing speed, executive functions, and memory were investigated. CH patients and control subjects were comparable regarding sex, age, schooling, family’s socioeconomic status and caregiver’s educational level. Both groups presented not only similar IQ scores but also equivalent performances regarding Perceptual Reasoning, Working Memory and Processing Speed index scores. Patients presenting different CH etiologies (dysgenesis and dyshormonogenesis) showed similar cognitive performance. Socioeconomic aspects along with the initial levothyroxine dose were the main variables to positively influence the cognitive performance, the family’s socioeconomic status having the strongest association with patients’ cognitive skills.

摘要

先天性甲状腺功能减退症（CH）是可预防的智力残疾的重要原因。CH新生儿筛查计划的实施导致早期治疗，改善了认知结局。然而，仍然有更细微的认知障碍报道，并且关于影响长期认知结果的因素缺乏明确性。更好地了解这些因素的研究可以导致这些患者的认知预后得到进一步改善。当前的研究旨在评估早期接受主要永久性CH和可能的相关变量治疗的青少年的认知能力。在66名11至16岁的青少年中进行了神经认知评估：34名患有CH和29名配对对照。智商（IQ），语言流利度，处理速度，执行功能，和记忆进行了调查。CH患者和对照受试者在性别，年龄，学历，家庭的社会经济地位和看护者的教育水平方面具有可比性。两组不仅表现出相似的智商得分，而且在感知推理，工作记忆和处理速度指数得分方面表现均相当。表现出不同的CH病因（发育不全和营养失调）的患者表现出相似的认知表现。社会经济方面以及最初的左甲状腺素剂量是影响认知能力的主要变量，家庭的社会经济状况与患者的认知能力之间存在最强的关联。两组不仅表现出相似的智商得分，而且在感知推理，工作记忆和处理速度指数得分方面表现均相当。表现出不同的CH病因（发育不全和营养失调）的患者表现出相似的认知表现。社会经济方面以及最初的左甲状腺素剂量是影响认知能力的主要变量，家庭的社会经济状况与患者的认知能力之间存在最强的关联。两组不仅表现出相似的智商得分，而且在感知推理，工作记忆和处理速度指数得分方面表现均相当。表现出不同的CH病因（发育不全和营养失调）的患者表现出相似的认知表现。社会经济方面以及最初的左甲状腺素剂量是影响认知能力的主要变量，家庭的社会经济状况与患者的认知能力之间存在最强的关联。