Author(s): I Costello, R Phadke, N Shah Format Abstract An immunocompromised patient with non-specific neurological symptoms and signs, along with rapid cognitive decline evolving over three to four weeks, can present a diagnostic challenge. Here we report rapidly progressive dementia in a patient with systemic lupus erythematosus, who was subsequently diagnosed with sporadic Creutzfeldt-Jakob disease (sCJD). This case illustrates the need for prompt investigations to consider an alternative diagnosis where significant history fails to yield an explanation. A diagnosis of sCJD drastically alters the prognosis in a subject with a well-controlled connective tissue disease who is otherwise fit and well. Keywords Dementia, sporadic Creutzfeldt-Jakob disease, systemic lupus erythematosus Declarat ion of Interests No conflict of interests declared. PDF https://www.rcpe.ac.uk/sites/default/files/shah.pdf Journal Keywords: Dementiasporadic Creutzfeldt-Jakob diseasesystemic lupus erythematosus