Theta-burst Stimulation on Cognitive Function in the Patients with Young-onset Alzheimer's Disease Dementia

Inclusion Criteria: 1. Any patient has a definite diagnosis of AD dementia according to the NIA-AA criteria for intermediate-to-high levels of biological evidence of probable and possible AD dementia (McKhann et al. 2011). 2. Dementia onset before age 65 years old. 3. Age between 50-75 years old for patient and control group. 4. The severity of dementia is limited to mild to moderate stage in current project. The definition of mild to moderate stage of dementia is based on the clinical dementia rating scale (CDR) from 0.5-2. 5. Cognitively normal controls MMSE≧24, CDR should be 0. 6. Informed consent provided by the patient and family. Exclusion Criteria: 1. Any subject has a definite diagnosis of epilepsy or history of seizure attack. 2. Current or past history of clinically significant neurological insults affecting brain structure or function like completed stroke, head injury or brain tumor. 3. Any subject has clinically significant or unstable medical diseases including metabolic, renal, liver, lung or cardiovascular disorders including metabolic, renal, liver, lung or cardiovascular disorders 4. Any subject has current alcohol or other substances abuse and/ or dependence within the recent one year, or previously prolonged history of substances abuse 5. Any females who is pregnant or lactating 6. General MRI, TMS and/or PET exclusion criteria including subjects who had received brain aneurysm surgery, or implanted pacemaker, mechanical valves, cochlear implant or other metal devices/ objects that are not magnetic resonance (MR) compatible in the body. 7. Any subject has allergic reaction to 18F-florbetapir or 18F-FDG radiotracers.