Evaluation of Intellectual Function Associated with Maternal and Pediatric Thyroid Dysfunction

Yuko Yamauchi,Keiji Hashimoto

doi:10.4172/2161-0665.1000298

Abstract

Objective: The purpose of this study was to evaluate the characteristics of intellectual function of children whose mother had thyroid dysfunction, as well as children with hypothyroidism. Methods: A total of 47 children aged five to seven, who were referred to the center for developmental evaluation at the national child health and development in Tokyo, Japan, were included in this study. The children were divided into two groups: Group A, children with euthyroidism whose mothers had thyroid dysfunction; Group B, children with hypothyroidism. For each group, unpaired t-test was conducted by comparing with the scores of the Japanese version of the Wechsler intelligence scale for children-fourth edition (WISC-IV). Results: There were 26 children in Group A, 21 in Group B. The scores of Full Scale Intelligence Quotient (FSIQ), Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI) and Processing Speed Index (PSI) by WISC-IV were significantly higher in Group A than Group B (FSIQ, VCI; P < 0.01, PRI, WMI, PSI; P < 0.05). Conclusions: There were differences in intellectual function between the children with hypothyroidism and the children who did not have low thyroid hormone level. Low level of thyroid hormone during the neonatal period may be important for intellectual development.

Highlights

Thyroid hormones impact on intelligence, behavior and cognition and are essential for normal development of the central nervous system [1,2]
We investigated whether intellectual function varies between children whose mothers had thyroid dysfunction and children with and without thyroid dysfunction associated with congenital thyroid disease, using the Japanese version of the Wechsler Intelligence Scale for Children (WISC)-IV
Hypothyroidism in Group B children was either permanent congenital hypothyroidism or transient congenital hypothyroidism, and was treated with oral medicine according to the thyroid hormone levels

Summary

Introduction

Thyroid hormones impact on intelligence, behavior and cognition and are essential for normal development of the central nervous system [1,2]. One study reported Attention Deficit Disorder (ADD)-like symptoms in children with asymptomatic hypothyroidism [6]. That study found panic disorder, depression and disorder add in patients with elevated thyroid stimulating hormone (TSH) levels. The Wechsler Intelligence Scale for Children (WISC) was developed in 1949 as an individually administered intelligence test for children, with the fourth version (WISC-IV) released in 2003 [11]. Using the WISC-IV, the characteristics of an individual’s intellectual development can be comprehensively evaluated based on the scores of the Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI), Processing Speed Index (PSI) and Full Scale Intelligence Quotient (FSIQ)

Methods

Results

Conclusion