Pediatric manifestations of Hashimoto's encephalopathy.

Hashimoto's encephalopathy is a steroid-responsive encephalopathy associated with elevated blood concentrations of antithyroid antibodies. The patients are usually euthyroid or mildly hypothyroid. The authors report two pediatric patients with Hashimoto's encephalopathy and review the literature. The clinical picture in adolescents, as with adults, is pleomorphic but frequently associated with seizures, confusion, and hallucinations. Alternatively, progressive cognitive decline manifested by a drop in school performance can be observed. The diagnosis of Hashimoto's thyroiditis is often overlooked at presentation and a high degree of suspicion is necessary for proper diagnosis.