The primary goal of this study is to develop and test methods for differentiating Creutzfeldt-Jakob disease (CJD) from other diseases and to learn how to diagnose CJD as early as possible. Because CJD is a rare condition and very rapidly progressive, diagnosis of the disease is often made very late in the illness. If any future treatments for CJD are to be successful, they likely will need to be given to patients as early as possible, before the disease progresses too far. It is therefore important that we learn how to make an accurate diagnosis earlier.

The purpose of this study is to collect information from various tests of brain function with the goal of improving early detection and clinical care for patients with dementia. Information is collected longitudinally and includes clinical, imaging, behavioral and autopsy data. Depending on the individual, there will be 2 to 4 visits over a three month period of time, each year for up to five years.