Protocol Number: 03-N-0004
Healthy normal volunteers and patients with primary CAF who are 18 years of age or older may be eligible for this study. Candidates will be screened with a medical history, physical examination, and possibly a neurological examination. Participants will be admitted to the NIH Clinical Center for about a week of tests, which will be from among those listed below. Participants will give their consent for each test individually. - Arterial catheter: insertion of a catheter (plastic tube) into an artery in the elbow crease for continuous blood pressure measurement. -Bladder catheter (patients only): insertion of a catheter into the bladder before PET scanning (see below) in patients who have urinary problems in order to protect the patient and others from radioactivity. - Bladder motility (patients only): ultrasound (sound wave) examination of bladder function. - Blood drawing: collection of blood samples through the arterial catheter (see above). The total amount of blood collected does not exceed 225 milliliters (15 tablespoons). - Blood flows: measurement of blood flow in the forearm or calf using sensors applied to the skin and a blood pressure cuff around the limb. To measure limb blood flow, the pressure cuff is blown up and the air released several times. - DNA extraction and storage (patients only) - collection of a blood sample for extracting and storing DNA for future studies of primary CAF and other disorders, as permitted by the subject. - Echocardiogram: ultrasound test of the heart. - Electrocardiogram (EKG): test of the electrical activity of the heart, using electrodes (sensors) applied to the skin of the chest and limbs. - Environmental temperature manipulation: test of responses to changes in temperature. Watertight pads are applied to the back and front of the body. Warm water and then room temperature water are passed through the pads and body temperatures are measured. - Gastrointestinal motility (patients only): recording of bowel sounds using a microphone placed on the abdomen. - Lower body negative pressure (LBNP): test of autonomic function in which the lower body is placed in a barrel-like chamber. The barrel is made airtight, using a Plexiglas shield, rubberized sheeting, and duct tape, and some air is sucked out of the barrel with a vacuum cleaner. This causes blood to pool in the legs, as occurs during standing. LBNP is done for about 15 minutes at a time. - Lumbar puncture (spinal tap): test done to obtain spinal fluid for chemical tests. A local anesthetic is given and a needle is inserted in the space between the bones in the lower back where the CSF circulates below the spinal cord. A small amount of fluid is collected through the needle. - Microdialysis: test to measure levels of chemicals in particular tissues, such as the fatty tissue under the skin. - PET scanning: type of nuclear medicine scan that uses a radioactive drug, x-rays, and computer technology to create images of body organs. - Pupillometry: test of the size of the pupil of the eye, measured by using a special digital camera in a light-controlled room, with the lights of and the lights on. - Quantitative sudomotor axon reflex test (QSART): diagnostic test of a particular aspect of autonomic nervous system function. A small amount of a brain chemical called acetylcholine is applied to the skin with a tiny amount of electricity. The sweat in a nearby patch of skin is measured by following the amount of humidity in a chamber applied to the skin. - Salivation: measurement of how much saliva a person produces. A piece of cotton-like material is placed between the teeth and gums. As the material absorbs saliva, its weight increases and the material is weighed to measure the amount of saliva produced. - Skin electrical conduction: test of sweat production. Sweat conducts electricity, so changes in sweating can be measured by the resistance of the skin to the flow of electricity. This is done with sensors placed on the skin. - Skin and core temperature: tests for measuring body core temperature and skin temperature. Skin temperature is measured with sensors placed on the skin, and core temperature is measured with sensors in a cotton ball that is placed in the ear canal against the eardrum. - Speech and swallowing assessment (patients only): testing by rehabilitation medicine specialists for patients with speech and swallowing difficulties. - Stress echocardiogram: test of the heart's response to exercise stress. A catheter is placed in the subject's arm for sampling blood or giving a drug during the bicycle-type exercise. While the subject exercises, blood pressure, pulse rate, and EKG are continuously monitored. Various drugs may be administered during the above tests, including chemical messengers such as acetylcholine, epinephrine and norepinephrine; radioactive chemicals drugs in imaging studies, drugs to examine specific mechanisms in autonomic failure, drugs that affect blood vessels, heart rate, and force of heart contractions; and drugs that affect the skin, glands, bowel motility, urinary bladder tone, and salivation.
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