Diagnosing Frontotemporal Lobar Degeneration

Inclusion Criteria: * Participant must have a reliable study partner who can provide an independent evaluation of functioning. * Able to read, understand and speak English for neuropsychological testing. * All subjects must meet one of these diagnostic criteria (A) probable behavioral variant FTD, (B) MRI-supported non-fluent variant PPA; (C) MRI-supported semantic variant PPA and \[18F\]T807 negative (D) probable CBS: using current criteria for CBS(27); (E) PSP: inclusion criteria for PSP are based upon the National Institute of Neurological Disorders and Stroke Society of Progressive Supranuclear Palsy (NINDS-SPSP) (F) FTD-MND * Control subjects must have a normal neurological exam, a CDR sum of boxes = 0, and MMSE score equal to or greater than 28 Exclusion Criteria: * Patients with clinical, imaging or CSF A beta/ tau profile consistent with AD * History of traumatic brain injury, brain tumors, stroke or other neurological or psychiatric disorders that can explain symptoms will be excluded. * Premenopausal women will be asked to consent to a pregnancy test prior to each scan as pregnant women will be excluded from study because of potential harm to fetus from PET study. * Presence of pacemakers, aneurysm clips, artificial heart valves, ear implants, metal fragments or foreign objects in the eyes, skin or body.