View clinical trials related to fMRI.
Filter by:Background: - The therapeutic modalities of cannabis have received more research attention recently with the discovery of its ability to stimulate appetite and to provide pain and nausea relief in patients with AIDS, cancer, and multiple sclerosis, among other diseases. Sativex(Registered Trademark), an experimental drug derived from the marijuana plant, contains tetrahydrocannabinol (THC) and cannabidiol (CBD), both of which affect brain activity. Sativex(Registered Trademark) is being tested to determine how and to what extent it affects brain activity. - Functional magnetic resonance imaging (fMRI) uses magnetic waves to study brain activity. Researchers are interested in using fMRI to study how Sativex(Registered Trademark) affects regional brain activity, including thinking abilities and behavior. Objectives: - To study changes in regional brain activity produced by Sativex(Registered Trademark) compared with THC and placebo. - To determine how Sativex(Registered Trademark) is processed by the body. Eligibility: - Individuals between 18 and 45 years of age who are either current users of cannabis (less than daily) or healthy volunteers who do not use cannabis. Design: - The study will involve one training session and five testing sessions on separate days. - At every session, subjects will receive either THC or placebo capsules and either Sativex(Registered Trademark) or placebo spray. - Participants will complete a training session in a mock fMRI scanner to adapt to the fMRI scanning environment. In the training session, participants will practice the tests that will track thinking ability, attention, working memory, and other cognitive tasks. - Participants will have five fMRI scanning sessions with the tests they have practiced previously, and will provide blood, urine, and saliva samples as required by the researchers. Participants will be discharged approximately 12 hours after they arrive for the study sessions....
The purpose of this investigation is to develop improved magnetic resonance imaging (MRI) techniques and hardware for studying brain function. MRI is a diagnostic tool that provides information about brain chemistry and physiology. This study will evaluate new MRI methods for monitoring blood flow to regions of the brain in response to simple tasks. The MRI machine used in this study is more powerful than those in most hospitals, permitting a higher visual resolution. Normal healthy volunteers over 18 years old may be eligible for this study. Candidates will be screened with a medical history and questionnaire, and a neurological examination. Study participants will have a yearly MRI scan. For this procedure, the subject lies on a stretcher that is moved into a donut-shaped machine with a strong magnetic field. A lightweight circular or rectangular coil a device that improves the quality of the images may be placed on the head. The scan time varies from 20 minutes to 3 hours; most scans last between 45 and 90 minutes. During the scan, the subject may perform simple tasks, such as listening to tapes, tapping a finger, moving a hand, watching a screen, or smelling a fragrance. More complex tasks may require thinking about tones or pictures and responding to them by pressing buttons. Information from this study will be used to develop better imaging methods that will, in turn, permit a greater understanding of normal and abnormal brain behaviors.
The purpose of this study is to use brain imaging technology to compare differences in brain structure, chemistry, and functioning in individuals with brain and mental disorders compared to healthy volunteers. Schizophrenia is a brain disorder that results from subtle changes and abnormalities in neurons. These deficits likely occur in localized regions of the brain and may result in widespread, devastating consequences. The neuronal abnormalities are inherited through a complex combination of genetic and environmental factors. Brain imaging technologies can be used to better characterize brain changes in individuals with schizophrenia. This study will use magnetic resonance imaging (MRI) scans to identify predictable, quantifiable abnormalities in neurophysiology, neurochemistry and neuroanatomy that characterize schizophrenia and other neurological and neuropsychiatric disorders....