MAPT and early-onset autosomal dominant Alzheimer disease: However, fluctuations in patients with Lewy body disease and rapid progression with overlapping MRI findings in Creutzfeldt-Jakob disease can make this distinction challenging.24 Imaging and CSF analysis for amyloid and tau and CSF prion detection with real-time quaking-induced conversion are novel biomarkers that aid diagnosis of Alzheimer disease and Creutzfeldt-Jakob disease, respectively.25,26