Effects of Tolcapone on Frontotemporal Dementia

This study will test the effects of a medication called tolcapone on cognitive, behavioral, and language problems seen in patients with frontotemporal dementia (FTD). Tolcapone increases the amount of dopamine, a brain chemical that may be lowered in FTD. The study will see if tolcapone can improve thinking, behavior, and language in people with FTD and will look at the effects of the drug on brain activity. Patients with FTD who are between 40 and 85 years of age may be eligible for this study. Participants will be seen as outpatients at the Columbia University Medical Center approximately one a week for 4 weeks. They take tolcapone or a placebo (a look-alike pill with no active ingredient) during study week 1. During study week 3, those who took placebo during week 1 now take tolcapone for 1 week and those who took tolcapone now take placebo. In addition, patients undergo the following tests and procedures: * Neurological tests to evaluate attention, problem-solving and memory. These tests are repeated several times during the course of the study. * Test to look for a gene that affects the amount of dopamine in the brain, using blood samples collected in a previous study. * Blood draws four times during the study. * Functional MRI (fMRI) to learn about changes in brain regions that are involved in performing tasks. For fMRI, the patient lies on a table that can slide in and out of the scanner, a narrow metal cylinder surrounded by a magnetic field. The procedure takes about 60 minutes and is performed four times over the course of the . FMRI involves taking pictures of the brain during MRI while the subject performs a task so that changes in the brain that occur during these tasks can be studied.