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NCT01087281
Background: \- Previous studies have shown that people with certain types of brain damage may have particular problems paying attention and processing things that they see. Researchers are interested in comparing how people with brain damage and without brain damage process visual images. Objectives: \- To better understand the areas of the brain involved in paying attention to things that are seen. Eligibility: \- Individuals at least 18 years of age who either have had damage to one or both sides of specific parts of the brain (e.g., stroke, injury, certain neurosurgery procedures) or are healthy volunteers. Design: * The study involves 4 to 10 visits to the NIH Clinical Center over 1 to 2 years. Each visit will last approximately 2 hours. * Participants will be screened with a medical history and physical examination, and may have the cognitive testing described below during the same visit. * On the first visit and for at least one visit thereafter, participants will have cognitive testing to evaluate thinking and memory. These tests will be either written tests or computer-based tests. * Some participants will qualify for functional magnetic resonance imaging (fMRI) as part of the study. This part will involve a decision-making task that will be performed on a computer during the fMRI scan. Additional scans may be required as directed by the study doctors. * Some randomly selected participants will be asked to have magnetoencephalography (MEG), a procedure to record very small magnetic field changes produced by brain activity. * During the behavioral training, or fMRI or MEG scanning, participants may be monitored with equipment to track eye movements.
NCT07097077
Lower limb injuries represent the majority of sports-related injuries, with knee injuries being among the most common. In particular, anterior cruciate ligament (ACL) injuries are considered highly devastating and career-threatening for both professional and amateur athletes. Current surgical and rehabilitation treatments often fail to provide fully satisfactory short- and long-term outcomes. A very high risk of re-injury exists, especially in younger patients, with up to 35% experiencing a second ACL injury, alongside a significant long-term risk of early knee osteoarthritis. Most ACL injuries are non-contact or indirect contact injuries, implicating biomechanical factors and neuromuscular control as key determinants of injury mechanisms. Recent literature shows that patients suffering a non-contact ACL injury have a higher risk of re-injury compared to those with contact injuries, suggesting a significant cognitive component in injury processing, surgery, rehabilitation, and return to sport. Recent rehabilitation studies have introduced targeted neuromotor training designed to "rebuild" biomechanical and neuromuscular patterns to avoid mechanisms leading to re-injury. Movement quality tests are used post-training to confirm the reduction of risky biomechanical patterns, often resulting in a score indicating movement quality. Given the brain's involvement in such injuries, pioneering studies have used functional magnetic resonance imaging (fMRI) to investigate changes in cortical brain areas following ACL injury and reconstruction. Evidence shows adaptations in both central and peripheral nervous systems, with altered sensorimotor cortex activation in patients during simple motor tasks, differing from healthy subjects. Prefrontal cortex alterations correlate with severe quadriceps muscle activation asymmetries, linking these brain patterns to post-injury return-to-sport outcomes. However, no studies have yet evaluated the interaction between cortical activation (neural compensations) measured by fMRI and outcomes from targeted neuromotor training during ACL rehabilitation. Understanding brain activation implications is crucial for developing large-scale rehabilitation protocols to reduce the risk of a second, potentially more devastating, knee injury. This study aims to reveal whether a neuromotor training protocol can positively influence cognitive brain areas related to human movement, particularly by reducing risky injury patterns. It will be the first to test whether dedicated neuromuscular training effectively reduces neural compensations and cortical activation related to non-automated movement, favoring automation areas important for a safe return to sport. Patients will directly benefit from participating in the innovative neuromotor training program, with functional MRI scans conducted before training begins (post-surgery) and after training completion. Indirectly, the study will assess whether neuromotor training can adapt patient neuromotor patterns to reduce re-injury risk, ultimately benefiting future patients undergoing ACL reconstruction.
NCT06923254
This clinical trial study aims to detect the imaging characteristics of patients with hepatic encephalopathy (HE) using 7-Tesla (7T) magnetic resonance imaging (MRI).
NCT05441865
The cognitive trajectory varies among non-demented older adults. In a 12-year follow-up study, we found approximately 5% participants presented rapid cognitive decline. Cardiovascular diseases increased the risk of cognitive decline. However, the influence of cardiovascular risk factors on cognitive decline remained inconsistent. Besides, the potential mechanism of the cardiovascular risk factors and cognitive function has not been fully investigated. Therefore, the proposed program will include two sub-studies. The first sub-study will use the longitudinal data from the Chinese Longitudinal Healthy Longevity Survey to evaluate the influence of cardiovascular risk factors on the trajectories of cognitive function. The second sub-study will recruit cognitive intact older adults with different levels of cardiovascular risk factors. The association among cardiovascular risk factors, cerebral blood flow, brain functional connectivity and cognitive function will be investigated with structural equation modeling. The findings of the proposed program will provide novel insight on preventing cognitive decline from the angle of maintaining healthy vascular function, and will provide evidence in elucidating the potential neurovascular mechanism between cardiovascular risk factors and cognitive function.
NCT06691490
Objectives and research hypothesis Physical inactivity is a major health concern that has been linked to a variety of chronic diseases, including obesity, diabetes, cancer, cardiovascular diseases, and mental disorders. Recent studies have shown that regular physical activity can decrease the risk of SARS-CoV-2 infection, and severe COVID-19 illnesses, as well as improve antibody response to vaccine. As such, the adoption of a physically active lifestyle carries potential health benefits and has even been referred to as a "miracle cure" by the Academy of Royal Medical Colleges. Despite the implementation of policies that aimed to encourage regular physical activity, the prevalence of insufficient physical activity in high-income countries has increased since 2001 (32% in 2001 vs. 37% in 2018). Given the limited impact of health policies on physical activity engagement, it is essential to explore other avenues of research that can contribute to understanding this high level of inactivity and driving innovative strategies for encouraging physical activity. In this context, the automatic attraction of individuals toward activities associated with low-effort exertion is thought to play a key role in physical inactivity. Physical activity involves exerting physical effort, i.e., intensifying physical energy to achieve certain goals, such as increasing the force to lift a heavy object. This physical intensification is associated with the phenomenological experience of energy exertion. Higher effort perception is thought to be aversively valued by inactive individuals, inhibiting their engagement in regular physical activity. However, there is a lack of knowledge regarding the neural correlates of effort perception and how they relate to physical inactivity. It is crucial to gain insights into these neural correlates, especially to enhance our comprehension of the significance of effort minimization in physical inactivity. This project aims to decrease effort perception and improve the valuation of effort, incentivize regular physical activity, and improve overall health outcomes. Objective 1. Despite ongoing research, there is a lack of agreement on the neural mechanisms underlying effort perception as well as the role of sensorial feedback. Tasks EEG and fMRI aim to address this issue with original experimental methods in order to identify this neural mechanism. Hypothesis 1. Following A) muscle vibration and B) Induced ischemic paralysis and anesthesia, we expect decreased effort perception associated with a lower cortical S1 activation, unchanged activation in premotor structures, and preserved functional connectivity between premotor regions and S1. Objective 2. To unravel the neural interaction between efference copy and reafferent muscle spindle signals that contribute to effort perception Hypothesis 2. The neural correlates of effort perception involve interactions between premotor and sensory brain structures. Neural activation patterns of the brain regions implicated in effort perception vary depending on an individual's inclination to engage in physical activity. Objective 3. Task 3 will examine the potential of non-invasive brain stimulation techniques (TMS) to reduce effort perception in turn increase its perceived value quantified with the CR100 scale, the outcome variable of this study. Hypothesis 3. Vibration-induced desensitization of muscle spindles and the SMA cTBS reduce effort perception and improve the subjective value of physical effort.
NCT06732817
The goal of this clinical trial is to evaluate the efficacy of personalized dual-target rTMS for treating patients with refractory schizophrenia and to investigate its underlying neural mechanisms using functional MRI. The main questions it seeks to address are: Does the dual-target rTMS protocol improve clinical symptoms in patients with refractory schizophrenia? What neural circuit changes, as assessed by functional MRI, occur following rTMS treatment? Participants will: Undergo personalized, dual-target rTMS treatment daily for 3 weeks. Complete baseline and post-treatment assessments, including clinical symptom scales (PANSS, HAMA, HAMD) and neuropsychological tests (MoCA, DST, VFT, Stroop Test, and AVLT). Have structural and resting-state functional MRI scans before and after treatment. Be monitored for any treatment-related adverse events.
NCT06649071
This is an observational study to explore the etiology and clinical classification in patients with obesity and to achieve personalized treatment.
NCT05255692
Urinary incontinence is the most frequently observed lower urinary tract symptom (LUTS) in children with cerebral palsy (CP) (Samijn et al., 2016). Higher brain centers responsible for bladder function may be related to the presence of incontinence. The current pilot study is the first study of a research project focusing on correlations between brain damage and incontinence.
NCT03341247
The proposed research will follow healthy weight children who vary by family risk for obesity to identify the neurobiological and appetitive traits that are implicated in overeating and weight gain during the critical pre-adolescent period. The investigator's central hypothesis is that increased intake from large portions of energy dense foods is due in part to reduced activity in brain regions implicated in inhibitory control and decision making, combined with increased activity in reward processing pathways. To test this hypothesis, the investigators will recruit 120 healthy weight children, aged 7-8 years, at two levels of obesity risk (i.e., 60 high-risk and 60 low-risk) based on parent weight status. This will result in 240 participants: 120 children and their parents.
NCT04164680
Recently introduced hybrid PET/MR scanners provide the opportunity to measure simultaneously, and in direct spatial correspondence, both metabolic demand and functional activity of the brain, hence capturing complementary information on the brain's physiological state. Here we exploited PET/MR simultaneous imaging to explore the relationship between the metabolic information provided by resting-state fluorodeoxyglucose-PET (FDG-PET) and fMRI (rs-fMRI) in patients with disorders of consciousness.
NCT03338634
This is a single, un-replicated visit to the Children's Metabolic Kitchen and Eating Behavior Lab designed to gather data on children's responses to images used in MRI studies. Additionally, a demographic questionnaire for parents will be piloted.
NCT04810234
Transcutaneous vagal nerve stimulation (tVNS) has been applied to a number of disease areas including visceral pain, depression, cluster headache and Alzheimer's disease. However, there is marked heterogeneity in these studies pertaining to i) the anatomical site of stimulation (neck, inner concha or tragus of ear), and ii) the waveform parameters of the stimulating impulse. This exploratory cross-sectional study will address these knowledge gaps by comparative functional neuroimaging of the neural correlates of tVNS with disparate anatomical sites and electrical waveform characteristics during rest in healthy participants.
NCT02089776
Background: \- People can learn to use feedback about brain activity to change that activity. Researchers want to see if people who have had a stroke can change their brain activity by practice and thought with feedback, and if that improves motor control. They will study brain activity in people who have and have not had strokes. Objectives: \- To see if people with stroke can change their brain activity and improve motor control by practice and thought. Eligibility: * Adults 18 80 years old who have had a stroke. * Healthy volunteers 18 80 years old. Design: * Participants will be screened with a medical history, MRI, and physical exam. For MRI, a magnetic field and radio waves take pictures of the brain. Participants lie on a table that slides in and out of a cylinder. They will be in the scanner less than 2 hours, lying still for up to 15 minutes at a time. The scanner makes loud noises. Participants will get earplugs. * Participants will have up to 3 scanning visits and up to 3 follow-up visits within 24 weeks. Visits may include screening, MRI, functional MRI (fMRI), questionnaires, and simple motor tests. Stroke participants may take additional motor tests, including transcranial magnetic stimulation (TMS). * fMRI: During this MRI, small metal disks may be taped to the skin or a fabric glove with small wires in it may be used to monitor hand movements. Heart rate and breathing may also be monitored. Participants may be monitored by video and asked to perform tasks. * TMS: A brief electrical current goes through a coil on the scalp. It creates a magnetic pulse that stimulates the brain. Participants may be asked to perform simple actions. Finger or hand movements may be recorded.
NCT01867398
Background: \- Some children and teenagers have conditions known as conduct disorders. They often have long-term chronic behavior problems, such as defiant behavior or violence. Conduct disorders are often treated with antipsychotic medication. Researchers want to study two types of newer antipsychotics (aripiprizole and risperidone) for children and adolescents with conduct disorders. They will look at how these drugs affect brain activity. To do so, they will give brain activity tests using magnetic resonance imaging (MRI). The tests will compare the results from healthy volunteer children and teens to those of others with behavior problems. Objectives: \- To see how atypical antipsychotics affect brain activity of children and teenagers with conduct disorders. Eligibility: * Children and teenagers between 10 and 18 years of age who have a conduct disorder and are taking aripiprizole. * Children and teenagers between 10 and 18 years of age who have a conduct disorder and are taking risperidone. * Children and teenagers between 10 and 18 years of age who have a conduct disorder and are not taking an atypical antipsychotic. * Healthy volunteers between 10 and 18 years of age. Design: * Participants will be screened with a physical exam and medical history. Parents/guardians will be asked questions about their child s feelings, experiences, and behavior. Participants will also answer questions about their feelings and moods. * This study will involve two visits. Each visit will involve MRI scanning. * At the first visit, participants will have memory and thinking tests. The tests will involve making decisions or playing games. Some of these tests will use MRI scanning to look at brain activity. * The second visit will be 3 to 5 months after the first visit. The tests from the first visit will be repeated.
NCT01260740
Background: \- Two areas on the surface of the brain, the dorsolateral prefrontal cortex (DLPFC) and motor cortex (MC), play a key role during learning. Researchers are interested in determining the effect that transcranial magnetic stimulation (TMS) on the DLPFC and MC has on participants' performance of learning tasks. By studying the effect of TMS on reaction time, learning, and memory, researchers hope to better understand how to treat conditions such as Parkinson's disease and traumatic brain injury that affect these parts of the brain. Objectives: * To study the effects of transcranial magnetic stimulation on the dorsolateral prefrontal cortex and motor cortex. * To learn which areas of the brain are used to perform certain learning and memory tasks. Eligibility: \- Healthy, right-handed individuals between 18 and 70 years of age. Design: * Participants will be screened with a physical and neurological examination and a medical and psychiatric history. * Participants will be asked to take part in one of five different parts of this study. Most participants will have four 2-hour visits to the National Institutes of Health Clinical Center. Some participants (those involved in Part 5) will have only one 2-hour visit. * Parts 1 and 2 (four visits): Participants will have TMS, and then do a learning task that may provide a small monetary reward. On the first visit, before the TMS, participants will take an intelligence test based on reading aloud the words given on a card. Participants who have not had a routine magnetic resonance imaging (MRI) scan of the brain within the past year will also have a scan. * Parts 3 and 4 (four visits): Participants will have a functional MRI scan while doing a learning task that may provide a small monetary reward. On the first visit, before the functional MRI, participants will take an intelligence test based on reading aloud the words given on a card. Participants who have not had a routine magnetic resonance imaging (MRI) scan of the brain within the past year will also have a scan. * Part 5 (one visit): Participants will take an intelligence test based on reading aloud the words given on a card. Then, participants will have TMS followed by a functional MRI scan. During the functional MRI, participants will do a button-pressing task that may provide a small monetary reward. * Participants will also be asked to provide a small blood sample for genetic analysis.
NCT01037608
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....
NCT00736203
The purpose of this study is to obtain a database of brain function from a sample of non-smokers while they do tasks in an MRI (magnetic resonance imaging) machine. Our hypothesis is that among nonsmokers, reactivity to smoking cues will be highly similar to control cues but may vary as a function of attitudes toward smoking and/or family history of smoking. We also hypothesize that brain activity during the n-back task will be more similar to data collected during this task when smokers are not abstinent.