6 Clinical Trials for Various Conditions
The primary objective of this study is to develop new ways to acquire MRI data and/or new ways to analyze the acquired data.
The structural/RSN study involves Structural and Resting State Neuroimaging. The purpose of Structural Neuroimaging is to use MRI technology to identify cortical and white matter morphometric differences between patients with chronic pain conditions and healthy control subjects. The purpose of the Resting State Neuroimaging study is to use functional MRI to identify possible disease related differences in various resting state networks in the brain. In addition we are looking at the effect gut microbiota on brain function in healthy and IBS participants. The overall goal is to identify structural and functional brain differences in persons with chronic pain conditions such as Irritable Bowel Syndrome (IBS, Cyclical Vomiting Syndrome(CVS) and vestibulodynia/vulvodynia. We are also looking at Inflammatory Bowel Disease(ulcerative colitis and Crohn's disease. We will be comparing differences between these conditions and matched healthy control subjects.
Current American College of Cardiology/American Heart Association guidelines recommend that patients with severe degenerative mitral regurgitation be considered for mitral valve surgery. There remains a debate within the cardiology community regarding the appropriate management of patients who remain asymptomatic. In this study the investigators will perform longitudinal follow-up data with cardiac MRI to inform the prophylactic surgery vs. close follow-up debate and to better define the natural history of this condition. The investigators hypothesize, that in the majority of patients mitral regurgitation will not worsen overtime, left ventricular hemodynamics will remain stable, exercise capacity will not decline, and symptoms will not worsen during follow-up. This finding would have a significant impact on the current recommendations for treatment in patients with mitral regurgitation by supporting a conservative management approach.
This study will use magnetic resonance imaging (MRI) and ultrasound to examine changes in tongue volume and blood circulation during tongue exercises that require the use of different tongue muscle movements and contractions. More information on the structure and function of the human tongue is needed to develop better treatments for people with certain diseases affecting speech and swallowing. Normal volunteers between 21 and 80 years old who live in the metropolitan Washington, D.C., area may be eligible for this study. Candidates will be screened with a brief medical history and physical examination, including suitability for MRI testing, and a brief examination of tongue, lip and jaw movements. Participants will undergo ultrasound and MRI studies. During both tests, they will perform tongue exercises, such as holding a soft round object on the tongue or exerting tongue pressure against the back of the throat or roof of the mouth. During the ultrasound, the subject lies on a flattened dental chair. A small transducer is placed under the chin to take images of the tongue during the exercises. A thin rubber strip with air-filled pressure bulbs is attached to the roof of the mouth (with dental adhesive) to measure tongue pressure. For the MRI, the subject lies on a table that slides inside a donut's machine containing a magnetic field. MRI coils-special padded sensors that improve image quality-are placed around the head and neck. A pressure cuff placed around the arm measures blood pressure. The subject wears earplugs to muffle loud thumping noises that occur during electrical switching of the magnetic fields. The subject is in constant visual contact with the researchers and MR technologist and may request to stop the study at any time. Participants may undergo another procedure, called magnetic resonance diffusion tensor imaging, to examine how the fluid (water) in the tongue tissue shifts during tongue maneuvers. This procedure is essentially the same as the first MRI study, but two small round coils are placed in the mouth (one on each side) between the cheeks and the teeth.
The purpose of this study is to examine the role of brain MRI findings in predicting treatment outcomes among individuals with cocaine dependence.
This study will focus on acute effects of added sugars on brain health in a specific age group (30-64 years old). We will provide participants two meals (one meal containing 16 g of added sugars and the other containing 61 g of added sugars) and examine blood vessel function and brain structure using a MRI.