Evaluation of Primary Chronic Autonomic Failure

INCLUSION CRITERIA: The subjects are patients with known or suspected primary CAF, based on referral information and confirmation of the clinical diagnosis at the intake evaluation. They are classified by results of the intake evaluation and then undergo comprehensive autonomic function testing. Patients with primary or iatrogenic CAF are included. Control patients have been previously diagnosed with PD or MSA without OH, confirmed at the time of the intake evaluation. Healthy Volunteers 18 years old or older are included. People at increased risk for PD or CAF consent in this study as if they were patients (e.g., to enable DNA extraction and storage). All subjects must be able to provide their own consent to participate or have an existing Durable Power of Attorney (DPA) in place. EXCLUSION CRITERIA: Age: People younger than 18 years old are excluded. Risk: A candidate subject is excluded if, in the judgment of the Principal Investigator or Clinical Director, protocol participation would place the subject at substantially increased acute medical risk. This includes the risks associated with air travel to the NIH. A candidate subject is excluded if, in the opinion of the Principal Investigator or Clinical Director, the medical risk outweighs the potential scientific benefit. Disqualifying Conditions A candidate subject is excluded if there is a disqualifying condition. Examples of disqualifying conditions are hepatic or renal failure (defined by serum creatinine more than 1.5 g/dL), symptomatic congestive heart failure, severe anemia, psychosis, refractory ventricular arrhythmias, and symptomatic coronary heart disease. Patients are excluded from further participation if the results of the intake evaluation lead to a diagnosis of a secondary form of CAF, such diabetic autonomic neuropathy. Candidate subjects who are unable to give their own consent and who do not have an existing DPA in place are excluded. Pregnant or lactating women are excluded from the study. Medications Patients with known or suspected allergy or hypersensitivity to any test drug are excluded from receiving that drug. Patients are not to discontinue any medications before the patient or the patient s doctor discusses this with the Principal Investigator, Research Nurse, or Nurse Practitioner. If it is decided that discontinuing medications would be unsafe, then the patient may be excluded from all or part of the study. Herbal Medicines and Dietary Supplements Certain herbal medicines or dietary supplements are known or suspected to interfere with the experimental results, and such herbal medicines or dietary supplements may be disallowed before enrollment in the study. For many herbal medicines or dietary supplements, the mechanisms of action and therefore the possible effects on the experimental results are unknown. In cases where the subjects wish to continue their herbal medicines or dietary supplements while on study, and search of the available medical literature fails to identify effects that are known or expected to interfere with the experimental results, then the subjects may participate. Practical Limitations Patients in whom we feel it would be difficult to insert a catheter into a vein may be excluded. Subjects who are not expected clinically to tolerate lying still during the procedures may be excluded. Pregnancy Pregnant or lactating women are excluded from the protocol overall. In women with child-bearing potential, blood testing for pregnancy will be done with 24 hours before initial testing (except for obtaining the medical history and physical examination) or any testing involving radioactivity under the protocol. Repeat pregnancy testing will be done before any procedure or drug administration under the protocol that takes place more than one week from a previous pregnancy test. Participants will not start or remain in the study if pregnancy test is positive. Refusal to Undergo Certain Procedures Candidate subjects are excluded if they refuse to undergo certain procedures. These are: (1) IV catheter; (2) electrocardiogram; (3) blood drawing; (4) DNA extraction and storage (patients and non-HV controls only); and (5) DNA analysis (patients and non-HV controls only).