Unexplained seizures, confusion or hallucinations: think Hashimoto encephalopathy

Aim: Hashimoto encephalopathy (HE) is a serious but treatable condition that is probably underdiagnosed. We summarize and review all published cases to delineate the disease and to alert paediatricians so that they recognize the disease in children. Methods: We searched three data sources, PubMed, Cochrane and Embase, to find the articles on the subject. Results: Twenty-five children (85.8% girls) were reported being diagnosed with HE. The median age was 14 years (range 9-18 years). The most frequent clinical symptoms were seizures (80%), confusion (52%), headache (40%), hallucinations (32%) and ataxia (36%). Antimicrosomal antibodies were demonstrated in all patients, other diagnostic methods were not specific. Treatment with steroids was effective with 55% of patients showing complete recovery. Conclusion: We recommend measuring antimicrosomal antibodies in all children with unexplained seizures, hallucinations or confusion and, if positive, initiating treatment with prednisolone.