IGLON5 and Mental deterioration: <h4>Objective</h4>We present the case of a patient with clinical and imaging features of sporadic Creutzfeldt-Jakob disease (sCJD) and positive IgLON5 antibodies (Abs) in the serum and CSF.<h4>Case report</h4>A 66-year-old Chinese man presented to the hospital with a stroke-like episode, followed by rapidly progressive cognitive decline, mutism, and parkinsonism.