Abstract: Objective　To explore the clinical features and diagnosis of acute disseminated encephalomyelitis (ADEM) in children with thyroid dysfunction. Methods　The clinical data of ADEM with thyroid dysfunction in 3 children were retrospectively analyzed, and the related literature was reviewed. Results　There were two boys (3 years and 10 months old, 12 years old) and one girl (8 years old). All the children had fever prior to theonset, 2 patients hadincreased sleep, 1 patient hadirritability, and 1 patient hadfacial nerve abnormality. Thyroperoxidase was elevated in all 3 children and correlated with the severity of symptoms. During the recovery period, thyroperoxidase was decreased in 2 children and not significantly changed in 1 child. Electroencephalogram showed that the background activity was decreased in 3 cases. Brain magnetic resonance imaging (MRI) showed abnormal in 3 cases, and neck MRI showed abnormal in 2 cases. Conclusions　ADEM with thyroid dysfunction is rare and should be differentiated from Hashimoto encephalopathy.

Key words: 　acute disseminated encephalomyelitis;　thyroid dysfunction;　Hashimoto’s encephalopathy;　child