This study will use positron emission tomography (PET) to measure a brain protein called peripheral benzodiazepine receptor (PBR) in patients with multiple sclerosis. PBR is created during the inflammation process, and brain inflammation is a key feature of multiple sclerosis (MS). PBR usually affects one type of brain cell, but it can also cause damage to surrounding areas of the brain in patients with MS. PET studies of PBRs and brain inflammation may help elucidate the role of these brain cells in patients with MS. Healthy normal volunteers and patients with MS between 18 and 70 years of age may be eligible for this study. Patients with MS must have had onset of disease between 18 and 40 years of age. Patients with MS undergo the following procedures: Visit 1: Medical history, physical examination, blood tests and magnetic resonance imaging (MRI). Visit 2: Blood tests and PET scan. Visits 3 and 4: MRI and physical examination. Visit 5: PET scan and blood tests. Visit 6: MRI and physical examination. Healthy volunteers undergo the following: Visit 1: Medical history, physical examination, blood tests. Visits 2 and 3: PET and blood tests. Magnetic Resonance Imaging MRI uses a magnetic field and radio waves to produce images of body tissues and organs. For this procedure, the subject lies on a table that can slide in and out of the scanner (a metal cylinder), wearing earplugs to muffle loud knocking noises that occur during the scanning process. The procedure lasts about 90 minutes; the patient is asked to lie still for up to 25 minutes at a time. The subject can communicate with the MRI staff at all times during the scan. During part of the scan a contrast agent is administered through a catheter (plastic tube) placed in an arm vein to enhance the images. Positron Emission Tomography (PET) The PET scan gives information on brain and body chemistry and function. The subject lies on a bed that slides in and out of the doughnut-shaped scanner. A catheter is placed in a vein in the arm and another is placed in an artery in the wrist or elbow area. The catheter in the arm is used for injecting a radioactive material that the scanner detects, and the other is used to collect blood samples. A custom-molded plastic mask is used to support the head and prevent it from moving during the procedure. The subject may be asked to perform various tasks during the PET scan or to lie quietly. The scan lasts about 2.5 hours.
Single Group Assignment
There is one SNP
- Homozyous for the low- affinity binding form of TSPO by TSPO genotype analysis ( Ala147Thr polymorphism in rs6971 SNP in exon 4 of the TSPO gene). --- Ala147Thr ---
HEALTHY VOLUNTEERS - EXCLUSION CRITERIA: Homozyous for the low- affinity binding form of TSPO by TSPO genotype analysis ( Ala147Thr polymorphism in rs6971 SNP in exon 4 of the TSPO gene). --- Ala147Thr ---