There are currently no effective treatments for CBD. CBD is usually thought of as a movement disorder, however, often during life the most prominent symptoms are language impairments or dementia due to a syndrome called frontotemporal lobar degeneration (FTLD). CBD is thought to be caused by accumulation of toxic forms a protein called tau in the brain. The goal of this study is to test a new drug called NAP (AL-108) in patients with CBD. NAP blocks formation of toxic forms of tau protein in brain cells and is able to improve disease in animal models of tau-related brain disease. NAP has recently been tested in humans for treatment of a precursor to Alzheimer's disease called mild cognitive impairment (MCI). This study showed that NAP is safe, has few significant side effects and can improve a number of cognitive deficits. Because the biochemical mechanism of NAP is thought to be even more specific for CBD than for MCI, we hypothesize that NAP may be an effective treatment for CBD. This study will investigate the effects of 6 months of NAP treatment in humans with CBD and forms of FTLD with a high likelihood of underlying CBD pathology. The size of the study (28 subjects due to funding limitations), diminishes the likelihood that the findings will be definitively positive, unless NAP has a large effect on those who receive treatment. Nonetheless, this study will provide access to a promising new treatment for patients with few other options, and will probe potential sensitive biomarkers that might demonstrate treatment effects. Therefore, it will provide invaluable data on how to best design a subsequent clinical trial that would be large enough to determine whether NAP is an effective treatment for CBD and related forms of FTLD.