Participants provide a blood sample. The sample, along with masked (anonymous) medical and family history information are sent to the NINDS Respository at the Coriell Cell Repositories in Camden, NJ. This facility collects, stores and distributes medical research information and cell cultures and DNA samples to researchers at hospitals, universities and commercial organizations. The blood sample has an identification number that is unrelated to any identifying information for the patient and cannot be tracked back to the patient.