A case of steroid-responsive encephalopathy with positive 14-3-3 protein of the cerebrospinal fluid clinically resembling Creutzfelt-Jakob disease]

A 69-year old man developed subacutely progressive dementia, inactivity, and gait disturbance. On admission, he showed flutter-like oscillation of the bilateral eyes and myoclonus with upper extremities. Cerebrospinal fluid (CSF) analysis revealed elevation of protein (73.2mg/dl) and the positive 14-3-3 protein. An electroencephalogram (EEG) revealed diffuse slowing (2-3Hz, 80microV). Brain MRI showed high intensity lesions in the white matter and left thalamus on FLAIR and diffusion imaging. We first suspected Creutzfelt-Jakob disease (CJD), but his symptoms didn't progress and showed no PSD on EEG. Oral corticosteroid therapy (prednisolone 60mg/day) brought him remarkable recovery corresponding with improvement of CSF and EEG findings. Despite of etiology unknown, we made a diagnosis of steroid-responsive encephalopathy.