Hashimoto’s Encephalopathy with Positive 14-3-3 Protein in the Cerebrospinal Fluid and Atypical Course Mimicking Creutzfeldt-Jakob Disease

Abstract

Background Creutzfeldt-Jakob disease (CJD) shares common clinical features with Hashimoto’s encephalopathy (HE). The 14-3-3 proteinis a relatively sensitive and specific marker of CJD but is not commonly detected in HE. We report the case of a patient with HE with unusualfeatures including positive 14-3-3 protein in the cerebrospinal fluid (CSF) and an atypical course mimicking that of CJD. Case Report A 64-year-old male was admitted due to acute-onset cognitive dysfunction. HE was suspected based on increased titers ofanti-thyroid microsomal antibody and an excellent response to steroid. However, 14-3-3 protein was detected in the CSF and a recurrent attackwith progressive cognitive decline, pyramidal symptoms and myoclonus mimicking CJD occurred. Cognitive dysfunction showed progressiveworsening and the response to steroid treatment was decreased. Conclusions 14-3-3 protein could be considered a general marker of neuronal destruction and not specific to CJD. The clinical manifestationsof HE are variable and its diagnosis is difficult due to the lack of a specific phenotype and reliable diagnostic criteria. We recommendthat patients with clinical features of CJD and antithyroid antibodies should be considered for empirical steroid treatment for HE, despite apositive result for 14-3-3 protein.