The primary objective of this protocol is to provide a resource of patients for enrollment into new research protocols throughout the NGB and other NIH laboratories. Evaluating and diagnosing participants will allow the NGB specialists to maintain their expertise and gain additional knowledge of the course of various neurological disorders. The information obtained will allow for the evaluation and diagnosis of the studied neurological diseases. This understanding may lead to ideas for future protocols. In some cases, blood or other biologic samples (including urine, saliva, or a cheek swab) will be obtained for future laboratory studies.