Evaluation of Diagnostic Criteria for Hashimoto Encephalopathy Among Children and Adolescents

Abstract

BackgroundThe recently proposed adult diagnostic criteria for Hashimoto encephalopathy (HE) include a requirement of subclinical or mild thyroid disease. However, reports indicate that most children treated for HE do not have evidence of thyroid disease. We aim to evaluate the impact of applying the current adult diagnostic criteria to pediatric patients. MethodsPediatric patients with HE were evaluated at time of symptom onset and follow-up at least 1 year after initiation of immunomodulatory treatment for degree of impairment within the neuropsychiatric domains of cognition, language, psychiatric disturbance, seizure, movement disorder, sleep disruption, and overall functionality. We compared the response to treatment among patients stratified by the presence or absence of subclinical or mild thyroid disease using the Modified Rankin Scale, the Liverpool Outcome Score, and a novel multidomain scale designed for the population with pediatric autoimmune brain disorders. ResultsOf 17 pediatric patients treated for HE, 6 met full adult diagnostic criteria, whereas 11 patients did not meet criteria solely owing to the absence of thyroid disease. Using our novel scale, the 6 patients meeting full criteria had statistically significant improvement from time of onset of disease to follow-up in the domain of cognition. The 11 patients who did not meet full criteria based on their absence of thyroid disease exhibited statistically significant improvement from time of onset of disease to follow-up in the domains of cognition, language, psychiatric disturbance, movement, and sleep. ConclusionsRigidly applying the current diagnostic criteria to pediatric patients with suspected HE may result in the failure to treat potential responders. We propose a set of diagnostic criteria for HE in children, which does not require thyroid disease but include abrupt onset cognitive regression with deficits in one or more other neuropsychiatric domains in the setting of antithyroid antibodies.