AUTHOR=Wiels Wietse A. , Du Four Stephanie , Seynaeve Laura , Flamez Anja , Tousseyn Thomas , Thal Dietmar , D’Haeseleer Miguel TITLE=Early-Onset Creutzfeldt-Jakob Disease Mimicking Immune-Mediated Encephalitis JOURNAL=Frontiers in Neurology VOLUME=Volume 9 - 2018 YEAR=2018 URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2018.00242 DOI=10.3389/fneur.2018.00242 ISSN=1664-2295 ABSTRACT=Objectives: To explore the clinical, radiological, and pathological manifestations of a rare subtype prion disease and their implication for differential diagnosis in case of early-onset neuropsychiatric deterioration. Methods: We discuss a patients’ clinical history, as well as the string of investigations and symptomatological evolution that finally led to a pathological diagnosis. Results: Our patient had the extremely rare VV1 type sporadic Creutzfeldt-Jakob disease. We explain the differential diagnosis of Progressive Encephalomyelitis with Rigidity and Myoclonus and its implications for treatment. Conclusions: Sporadic Creutzfeldt-Jakob disease, especially the VV1 subtype, can present at an early age with an insidious psychiatric onset. Classical findings of prion disease – 14-3-3 protein, PSWC on EEG, and MRI patterns – are not always present. The presence of neural autoantibodies does not always implicate pathogenicity in the presence of other neurological /neurodegenerative conditions.