Severe hypothyroidism due to atrophic thyroiditis from second year of life influenced developmental outcome.

<bold>Unlabelled: </bold>From the second year of life a girl showed an insidious development of clinical hypothyroidism due to a non-goitrous lymphocytic thyroiditis without traceable circulating levels of thyroid antibodies measured by routine immunoassays. The diagnostic delay of this rare variant of atrophic thyroiditis caused persistent neuropsychological deficits.<bold>Conclusion: </bold>Her difficulties with speed of processing and working memory in particular could suggest a frontal deficit, possibly in the dorsolateral prefrontal circuit. This contrasts with findings in congenital hypothyroidism, suggesting a relatively preserved frontal function, and could illustrate different neuropsychological deficits of hypothyroidism at different ages in early childhood. [ABSTRACT FROM AUTHOR]