MAPT and multiple system atrophy: It is important to note that exclusion criteria exist for both categories and include the evidence of biomarkers to exclude Alzheimer's disease [AD; such as amyloid positron emission tomography (PET) or tau and amyloid in cerebrospinal fluid (CSF)], structural lesion suggestive of focal causes, granulin mutation or reduced plasma progranulin levels, TDP-43 mutations, fused in sarcoma (FUS) mutations, evidence of Lewy body disease (LBD), multiple system atrophy (MSA), amyotrophic lateral sclerosis, or svPPA (24).