Attentional processing in hyperthyroid children before and after treatment.

To determine whether specific components of attentional processing may be differentially disrupted during thyrotoxicosis, nine children with hyperthyroidism were assessed for intelligence and attention before and after one year of therapy. The attention test allowed for measurement of sustain, disengage, and shift subcomponents of attentional processing. Comparison with pediatric controls revealed lower nonverbal intelligence during thyrotoxicosis, which improved to normal following euthyroidism. On the attention task, an effect was observed during thyrotoxicosis only on the shift and disengage functions of attentional processing but not sustain. Attention results were unrelated to self-reported anxiety at time of testing. Results are discussed in terms of thyroid hormone activation of the prefrontal cortex, which is thought to be the cerebral substrate underlying the shift and disengage functions of attentional processing.