Gamma-Induction in FrontoTemporal Dementia Trial

This is an interventional, multi-site, randomized, double-blind, placebo-controlled study of tACS in patients with FTD. The main aim of this study is to investigate the safety, tolerability and efficacy of gamma-tACS in patients with behavioral variant (bv)-FTD, demonstrating tACS potential mechanisms of action, target engagement, and thus informing the design of larger clinical trials. Participants will be screened at trial sites for determination of eligibility to enter the study on the basis of diagnostic evaluations, according to current diagnostic criteria for probable bv-FTD and safety assessments. Baseline assessments will consist of behavioral/cognitive evaluations, blood biomarkers, actigraphy, voice biomarkers, EEG and TMS-EEG and tACS with EEG measures, MRI, FDG-PET imaging (5-8 visits). Once participants have met all inclusion and exclusion criteria, they will be randomly assigned to either 6 weeks of daily tACS sessions or 6 weeks of daily Sham tACS sessions. Post-intervention visits will include FDG-PET scans, MRI, cognitive testing, tACS with EEG, blood biomarkers and TMS-EEG (5-8 visits). A follow-up visit will occur 3 months after the post-invention visit. This visit will include an EEG registration, cognitive testing and behavioral markers. tACS is a way of stimulating the brain externally using weak electric currents. Electrodes are placed into a cap that you wear on your head. A weak electrical current travels back and forth through the electrodes to your head. FDG-PET is a way of taking pictures of your brain using a special dye that is absorbed into your body. In this study, the dye will help us to see the glucose uptake in your brain. The PET scans for this study will be done at Massachusetts General Hospital (MGH). TMS is a noninvasive way of stimulating the brain and will be used in this study to measure your brain's plasticity. Brain plasticity is the brain's ability to change and learn through experience. TMS uses a magnetic field to cause changes in the brain activity. The magnetic field is produced by a coil that is held next to your scalp. We will measure how your brain responds to the TMS before and after the tACS treatment. EEG is used in routine clinical care to measure the brain's electrical activity. EEG involves placing a cap with electrodes onto your head. The investigators will enroll a sample of 20 age-matched healthy controls, who will undergo evaluations similar to the bv-FTD baseline assessment except for PET imaging. Healthy subjects will not have the tACS intervention.