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

Hashimoto’s encephalopathy (HE) is a rare neurological disorder with a heterogeneous group of neurological symptoms.1 Sporadic Creutzfeldt-Jakob disease (CJD) is the most common human prion disease and usually manifests as a rapidly progressive dementia, with ataxia and myoclonus leading to death in less than 1 year.2 CJD shares common clinical features with HE, and dementia, myoclonus, extrapyramidal signs, ataxia, psychotic phenomena and personality changes characterize both diseases.3 The presence of 14-3-3 protein in the cerebrospinal fluid (CSF) is a useful marker for in vivo diagnosis of CJD. 14-3-3 protein is a relatively sensitive and specific marker of CJD and is not commonly detected in HE. We report the case of a patient with HE with unusual features, including positive 14-3-3 protein in the CSF, and an atypical course mimicking that of CJD.