(S,S)-[11C]Mener

Background:
The autonomic nervous system controls automatic body functions. Researchers want to improve the tests used to diagnose autonomic failure. Orthostatic hypertension is a drop in blood pressure when a person stands up. Researchers want to focus on this sign of autonomic failure.
Objective:
To improve testing for conditions that cause autonomic nervous system failure.
Eligibility:
People ages 18 and older in one of these categories:
* Their blood pressure drops when they get up.
* They have had a heart transplant or bilateral endoscopic thoracic sympathectomies or have had or will have renal sympathetic ablation
Design:
All participants will be screened with:
* Medical history
* Physical exam
* Blood and urine tests
Some participants will be screened with:
* Heart and breathing tests
* IV placement into an arm vein
* Tilt table testing: Participants lie on a table that tilts while an IV is used to draw their blood.
Participants may stay in the hospital for up to 1 week depending on their tests. Tests may include repeats of screening tests and:
* Sweat testing: A drug is placed on the skin to cause sweating. Sensors on the skin measure moisture.
* Lumbar puncture: A needle is inserted between the bones in the back to collect fluid.
* MRI and PET/CT scan: Participants lie on a table that slides into a scanner. For the PET/CT, a small amount of a radioactive chemical will be injected with a small amount of a radioactive chemical.
* Bladder catheter placement to collect urine
* Skin biopsies: A punch tool removes a small skin sample.
* Tests to see how the pupils react to light
* Smelling tests
* Thinking and memory tests
* Questionnaires
Participants may have a visit about 2 years later to repeat tests.

This study aims to use [C-11]MRB PET (positron emission tomography) imaging to look at brain injury in patients with Multiple Sclerosis (MS) and healthy individuals. The overarching hypothesis is that there is decreased radioligand binding to the norepinephrine transporter in multiple sclerosis, reflecting injury to the noradrenergic system and that it plays a role in disease pathogenesis, its clinical manifestations and severity. This strategy is targeted to address an unmet need because currently available MRI techniques lack sensitivity and specificity for assessing such changes in the brains of people with MS.
The specific aims of the study are:
1. To determine norepinephrine transporter binding in the brains of MS patients using [C-11]MRB PET and compare it with age, and sex matched healthy controls.
2. To determine correlation of norepinephrine transporter binding with clinical severity and MRI parameters in MS.
3. To determine correlation of norepinephrine transporter binding with fatigue and cognitive impairment in MS patients.