The Hospital for Sick Children, Toronto, Ontario, Canada.
J Clin Endocrinol Metab. 2011 Sep;96(9):E1427-34. doi: 10.1210/jc.2011-0119. Epub 2011 Jun 22.
Despite early diagnosis and treatment of congenital hypothyroidism (CH) after newborn screening, selective and persistent neurocognitive weaknesses may be seen. One area of particular weakness is memory, especially on tasks known to be mediated by the hippocampus. However, the hippocampus has not been directly studied in this population.
Our objective was to use magnetic resonance imaging to determine whether children and adolescents with CH have reduced hippocampal size and abnormal hippocampal growth patterns relative to peers and whether reduced hippocampal volumes in CH predict poor memory performance.
Studied were 35 CH and 44 typically developing controls aged 9-15 yr. All were assessed using standardized tests of intelligence and verbal and visual memory and received an magnetic resonance imaging scan. Parents completed a questionnaire of their everyday memory functioning (EMF). Right and left hippocampal volumes were measured by manual tracing.
CH subjects scored significantly below controls on indices of verbal but not visual memory as well as aspects of EMF. CH subjects also had smaller hippocampal volumes, particularly on the left side. Unlike controls, who showed a positive relationship between age and hippocampal volumes, age was unrelated to hippocampal size in CH. Structure-function correlations revealed significant relationships between hippocampal volumes and EMF in controls and modest correlations between hippocampal volumes and memory test scores but not EMF in CH.
Compromised hippocampal development in CH may contribute to some of the memory weaknesses observed in this population.
尽管新生儿筛查后对先天性甲状腺功能减退症（CH）进行了早期诊断和治疗，但仍可能出现选择性和持续性的神经认知弱点。特别薄弱的一个领域是记忆，尤其是在已知受海马体介导的任务上。然而，在该人群中尚未直接研究海马体。
我们的目的是使用磁共振成像来确定患有 CH 的儿童和青少年的海马体体积是否小于同龄人的海马体体积，以及 CH 中减小的海马体体积是否预测记忆力差。
研究了 35 名 CH 和 44 名年龄在 9-15 岁的典型发育对照者。所有参与者均接受了标准化智力测试、言语和视觉记忆测试，并接受了磁共振成像扫描。家长完成了日常记忆功能问卷（EMF）。通过手动追踪测量右侧和左侧海马体的体积。
CH 组在言语记忆但不在视觉记忆以及 EMF 的某些方面的指标上明显低于对照组。CH 组的海马体体积也较小，特别是在左侧。与对照组不同，对照组的年龄与海马体体积呈正相关，而 CH 组的年龄与海马体大小无关。结构-功能相关性显示，对照组的海马体体积与 EMF 之间存在显著关系，而 CH 组的海马体体积与记忆测试分数之间存在适度的相关性，而与 EMF 无关。
CH 中海马体发育受损可能导致该人群中观察到的一些记忆弱点。
