249 Clinical Trials for Various Conditions
This study explores the effects of telerehabilitation and a study medication on rehabilitation outcomes in patients with stroke resulting in arm weakness. Patients with arm weakness due to a stroke that happened in the past 30 days will be randomized into one of three groups: \[1\] TR and placebo (a sugar pill) on top of usual care; \[2\] TR and a medication (Sinemet 25/100) on top of usual care; \[3\] or usual care alone (no TR and no pill, but people in this group will be offered TR once the study is done). TR consists of 70 minutes/day of activities targeting arm function, 6 days a week for 6 weeks.
Chronic pain is associated with plasticity in the brain limbic system composed mainly of the amygdala, hippocampus, ventral striatum, and cingulate cortex (ACC) /medial prefrontal cortex (mPFC). These brain areas, especially the ventral striatum, receive dopaminergic input from the ventral-tegmental area (VTA). Although there is a significant literature now showing that limbic brain tracks chronic pain intensity and predicts the risk of transition from sub-acute to chronic pain, the role of dopaminergic input to the limbic brain and the change thereof which occurs in chronic pain, is still not clear. Given the role of dopamine in motivational control and the loss of motivation associated with chronic pain understanding how dopaminergic transmission is altered in the limbic brain of chronic pain patients is critical to the understanding of the pathophysiology of chronic pain. Therefore, the overall aim of this project is to use brain imaging to study how dopaminergic transmission through the oral administration of pro-dopaminergic medications carbidopa/levodopa (CD/LD) and methylphenidate will modulate the brain signature of chronic pain. Chronic pain subjects will be scanned at baseline (no drug administration) and three times after treatment with the two drugs or placebo. The protocol will follow a randomized double-blind approach.
Developing theoretical, quantitative models of the basic cognitive mechanisms underlying human social decision-making, and understanding the influence of neuromodulators such as dopamine on these mechanisms, has important ramifications for both healthy and patient populations. In this proposal the investigators combine quantitative social measures, computational models, neuroimaging, and a pharmacological intervention to define the mechanisms of social decision-making.
Patients that have undergone a Fontan procedure (surgical correction for single ventricle congenital heart disease) may develop a complication known as protein-losing enteropathy (PLE). Some studies suggest PLE is primarily caused by impaired lymph flow. Use of continuous dopamine infusion can improve PLE. Evidence suggests the effect of dopamine may be through its effect on lymphatic function. This observational study looks at markers of lymph flow and PLE symptoms after treatment using dopamine and other standard therapies during disease exacerbations.
The present study would be the first to investigate the relationship between reward- and or social stimuli-induced dopamine (DA) release and neural function using a combined PET/fMRI approach. Data from this project conducted in healthy subjects will provide preliminary data for a larger grant application to study patient populations with known abnormalities in DA including schizophrenia, major depressive, substance use, and eating disorders.
This is a clinical study of a drug named dopamine and how it affects our bodies ability to make and secrete insulin. Insulin is a hormone made in the pancreas that helps our body regulate sugar levels. We think that this drug decreases the amount of insulin our body makes and causes our sugar levels to be high. When you are critically ill there can be many adverse effects if you have sugar levels that are too high.
Heart Failure with preserved Ejection Fraction (HFPEF) accounts for 40-50% of all heart failure patients with a frequency of hospital admissions for acute decompensation and short and long term mortality similar to patients with heart failure with reduced ejection fraction (HFREF). Patients with HFPEF are often preload dependent and despite admission to the hospital for acute decompensated heart failure (ADHF), are typically difficult to diurese due to the development of acute kidney injury. No studies have been performed evaluating treatment strategies for these patients. The investigators hypothesize that changing the method of diuresis and/or the addition of low-dose dopamine for the treatment of ADHF in patients with HFPEF will reduce renal injury, resulting in a shorter length of stay, and decrease hospital readmissions over the ensuing year. This trial will randomize patients to either bolus or continuous infusion furosemide and then to either dopamine or no dopamine. The primary endpoint will be renal function at 72 hours as measured by change in Glomerular Filtration Rate (GFR). Secondary endpoints for readmission, functional capacity, quality of life, and amount of diuresis will also be collected.
The purpose of the study is to evaluate and document physiologic and functional changes in visual performance and retinal function of patients diagnosed with albinism (a dopamine deficiency state) following a trial of oral Levodopa/carbidopa treatment.
The overall aim of this study is to utilize an integrative research model in order to dynamically assess reward-related dopamine (DA) transmission in major depressive disorder (MDD) and test the role of dysfunctional DA release in depression and anhedonia. The first arm of this line of research (PET scan) aims to investigate phasic DA release in MDD during incentive motivation. The investigators will utilize an established molecular imaging technique to measure striatal DA release dynamically during performance of testing and control versions of a monetary incentive delay task, which involves anticipation and receipt of monetary rewards. In doing so, this experiment will link together independent lines of research that have associated depression with decreased hedonic responsiveness, impaired reinforcement learning and dysfunctional DA transmission. We hypothesize that, relative to matched controls, unmedicated MDD subjects will show reduced reward-related ligand (11C-raclopride) displacement. Reduced ligand displacement will be interpreted as indicating reduced task-induced release of endogenous striatal DA in response to reward-predicting cues and unpredictable reward in MDD subjects. In the second arm of this research (EEG recording), the investigators aim to probe the spatio-temporal dynamics of brain mechanisms underlying positive and negative reinforcement learning in MDD and their relations to phasic DA. Participants will perform the probabilistic stimulus selection task (PSST) while event-related potentials (ERPs) are collected. The investigators expect that, relative to matched controls, unmedicated MDD subjects will show reduced positive reinforcement learning, potentiated negative reinforcement learning, and larger (i.e., more negative) feedback-related negativity (FRN) in response to positive reinforcement (indicative of reduced DA transmission). Moreover, the investigators hypothesize that a more negative FRN in response to positive reinforcement will be associated with decreased striatal raclopride displacement (i.e., lower release of endogenous DA) as measured by PET in the first part of the study. This experiment will investigate the effects of blunted DA transmission on behavioral and ERP markers of both positive and negative reinforcement learning.
Alcohol use disorders (AUDs) are highly prevalent among U.S. civilians, and even more prevalent in the U.S. Veteran population. AUDs are frequently co-morbid with depressive symptoms in psychiatric clinical populations, resulting in an increased severity of both conditions. Indeed, returning Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF) Veterans have extraordinarily high rates of alcohol misuse and co-morbid psychiatric symptoms, indicating that future Veteran clinical populations will be particularly affected by AUDs. While FDA-approved medications are available to treat AUDs, their efficacy is low compared to available psychosocial treatments. Despite the lack of evidence for efficacy from controlled trials, antidepressants are frequently prescribed to clinical populations (including Veterans) with active AUDs. A better understanding of patient-level clinical variables that may confer poor response to treatment with antidepressants would allow clinicians better tools to distinguish those alcohol-dependent Veterans likely to do worse with antidepressant treatment.
This study will use positron emission tomography imaging to investigate the dopamine systems in people with bulimia nervosa.
Dystonia is a disabling movement disorder characterized by repetitive patterned or sustained muscle contractions causing twisting or abnormal postures that may afflict 250,000 people in the U.S. While the pathophysiology of dystonia remains uncertain the treatment is rather rudimentary. A better understanding of neural mechanisms of dystonias is not only an invaluable prerequisite for developing better treatment options but also a step toward better understanding of the complex network of basal ganglia. In this study I will investigate if there is any difference between the dopamine receptors and dopamine in people with dystonia and healthy subjects.
Low blood pressure or hypotension is a very important problem that is often seen in premature babies, especially those with low birth weight. Severe hypotension leads to significant problems including brain bleeds, developmental delays, kidney and liver problems, and other issues that can affect babies for the rest of their lives. An important aspect in the management of infants with hypotension is the decision of when to treat and with what agent. Research is being conducted to try to find the best medication to use in these situations. Dopamine is often used first, but it does not always prove to be effective, and it has several concerning side effects. This study will look at vasopressin, which has fewer side effects, as a first-line medication for low blood pressure in extremely low birth weight infants. Hypotheses and Specific Aims: This study will show superiority of vasopressin to dopamine in preterm, extremely low birth weight infants who have hypotension within the first 24 hours of life. We will specifically look at its ability to raise blood pressure values, improve clinical symptoms seen, any adverse effects, and clinical outcomes of babies being treated.
The aim of this study is to compare the effects of 1) high-dose furosemide, 2) low-dose furosemide, and 3) low-dose furosemide combined with low-dose dopamine on diuresis, clinical status, renal function, electrolyte balance, length of stay, and 60-day post-discharge outcomes in patients hospitalized with acute decompensated heart failure.
Background: * Chronic nicotine exposure through cigarette smoking affects the level of the brain chemical dopamine. Smokers who attempt to quit experience lower levels of dopamine, which increases anxiety and triggers nicotine cravings that make quitting more difficult. * Varenicline (Chantix) is a smoking cessation medication that is designed to reduce nicotine craving and withdrawal by slightly increasing levels of dopamine in the brain. Research has shown that varenicline is a safe, well-tolerated, and effective treatment for nicotine dependence, but researchers are interested in learning more about how it affects the brain and its function. Functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) will help researchers study the brain s response to nicotine and varenicline. Objectives: - To explore how varenicline affects brain function and behavioral performance in current smokers and healthy volunteers. Eligibility: - Individuals between 18 and 55 years of age who are either current smokers (10 or more cigarettes per day) or healthy nonsmoking volunteers. Design: * The study will involve nine testing and research visits over 5 to 6 weeks. The first visit will provide an initial assessment and training on the tasks that will be completed during the study. * Six testing visits will involve fMRI and EEG measurements of brain activity. Each visit will contain two 2-hour scanning sessions, and each session will involve thinking tests. During these visits, participants will receive varenicline and placebo tablets, and wear nicotine patches and placebo patches that do not contain nicotine. Participants will not be told which tablet or patch they are given. This is a crossover study so all participants eventually get nicotine and placebo, as well as varenicline and placebo. * Two other visits involve different thinking tasks. These visits will not require fMRI or EEG scans.
The purpose of the proposed research is to determine how changes in kidney dopamine (DA) activity influence urinary sodium excretion. We will decrease DA activity in the kidney by inhibiting DA synthesis via carbidopa administration. We want to compare findings in normal volunteers and in patients with postural tachycardia syndrome (POTS). We will test the null hypothesis (Ho) that the effects of oral carbidopa administration on urinary sodium excretion will not differ between patients with POTS and healthy volunteers.
This study will use positron emission tomography imaging to investigate changes in dopamine systems in people with anorexia nervosa before and after weight restoration.
Dr. Kevin J. Black at Washington University is conducting a study to learn whether we can use MRI scans to test dopamine function in the brain and to determine whether the brain performs memory tasks differently in Tourette Syndrome (TS). TS is a movement disorder characterized by vocal tics (sounds) and motor tics (movements). We will measure how and where brain activity changes using magnetic resonance imaging (MRI) scans during memory tasks and after taking levodopa. Levodopa is a drug commonly used for the treatment of Parkinson's disease (PD), a very different movement disorder.
The purpose of the study is to investigate the functional state of dopamine cells and the dopamine transporter in ADHD subjects and controls to assess the effects of chronic methylphenidate treatment on dopamine cell function and dopamine transporter levels in ADHD subjects.
This study will examine the relationship between variations in a gene called OPRM1 and the response to alcohol. The OPRM1 (Mu-opioid Receptor-1) gene helps regulate brain pathways involved in experiencing pleasure. Brain pathways use a chemical called dopamine. Different forms of the OPRM1 gene may lead to differences in how dopamine is released and subsequently to differences in a person's response to alcohol. Healthy non-smokers between 21 and 45 years of age may be eligible for this study. Candidates are screened with a medical and psychiatric history and physical examination, blood and urine tests, and breathalyzer (breath alcohol test). A blood test is also done to determine the variant of OPRM1 gene. Participants undergo the following procedures in three study sessions: Session 1 " Breathalyzer test, urine test for illicit drugs and pregnancy test for women who can become pregnant. " Insertion of catheters (plastic tubes) into a vein in one arm for infusing alcohol and into the other arm for drawing blood samples. " Completion of questionnaires on how intoxicated the subject feels. " Blood draw for research studies. " Eye movement test (a visor with a digital camera tracks the subject's eye movements while he or she watches lights on a computer screen). " 45-minute alcohol infusion (up to 0,08 grams per deciliter - a level considered in most states as driving under the influence of alcohol). " Repeat breathalyzer, questionnaires, eye movement test and blood draw every 15 minutes during the infusion and again after the infusion is complete. " Subjects remain in the clinic until their blood alcohol content falls below 0.02 g/dL, determined by a breathalyzer test done every 15 minutes. Subjects can usually return home about 3 to 4 hours after the alcohol infusion stops. Sessions 2 and 3 The procedure is the same as for session 1, except subjects receive an infusion of alcohol one session and an infusion of saline (salt water) the other. Also, subjects undergo positron emission tomography (PET) scanning during the infusions. For this test, the subject lies on a bed that slides in and out of a doughnut-shaped scanner. A custom-molded mask is used to support the head and prevent it from moving during the scanning. A small amount of radioactive substance called C-11 raclopride is injected through one of the catheters to trace brain dopamine activity. ...
This study will examine how the brain chemical dopamine affects memory, reasoning, and other thought processes in people with Parkinson's disease with and without dementia and in healthy control subjects. Healthy normal volunteers and people with Parkinson's disease who are between 40 and 85 years of age may be eligible for this study. Pregnant women with Parkinson's disease and breastfeeding normal volunteers are excluded. Candidates are screened with a physical and neurological examination, blood tests, a brief mental test called the Mini Mental Status Examination, and other tests designed to assess memory, learning, reasoning, and other thought processes. Patients with Parkinson's disease also undergo a more thorough mental evaluation called the Mattis Dementia Rating Scale. The study requires about 15 hours over 4 or 5 outpatient visits to NIH. Participants undergo two positron emission tomography (PET) scans on two separate days and a magnetic resonance imaging (MRI) scan, as follows: PET Scans The two PET procedures are done the same way, except one uses a radioactive tracer called \[(18)F\]DOPA and one uses a tracer called \[(11)C\]NNC-112. A catheter (small plastic tube) is placed in a vein in the subject's arm for injection of the tracer. The subject lies on the scanner bed and a special mask is fitted to his or her head to hold it in place during the procedure. Just before injecting the tracer, a 10-minute "transmission scan" is done of the head using a tracer called (68)Ge. Then, a series of scans using one of the two study tracers (\[(18)F\]DOPA or \[(11)C\]NNC-112 are done for about 90 minutes. About 1 hour before injection of the \[(18)F\]DOPA tracer, subjects take 200 mg of the drug carbidopa by mouth to help the tracer work properly. Blood pressure, breathing and heart are monitored before and after injection of the \[(11)C\]NNC-112 tracer. Patients with Parkinson's disease are taken off all Parkinson's medications the night before the \[(18)F\]DOPA scan and their motor function is tested the following morning before the scans are done, using the Unified Parkinson's Disease Rating Scale. Patients can resume all medications except L-DOPA (including Sinemet) after the movement test, and they can resume L-DOPA after the PET scan is finished. MRI Scan MRI uses a strong magnetic field and radio waves to obtain images of the brain. The subject lies still on a table that slides inside the scanner, a metal cylinder. They wear ear plugs to muffle loud knocking sounds that occur during the scanning and can communicate with the MRI staff at any time through an intercom.
This study will examine the role of the brain chemical dopamine in people's response to alcohol consumption. Dopamine is thought to influence whether people have a strong or weak response to alcohol and how pleasurable that response is. The findings of this study may shed light on why some people are at higher risk of developing problem drinking behaviors. Healthy normal volunteers between 21 and 25 years of age who have never had a serious problem with alcohol abuse or drug abuse may be eligible for this study. Candidates will be screened with a medical history and physical examination, and will be interviewed about their smoking and drinking behaviors. Participants will undergo test procedures on two separate days, as follows: Test Day 1 Upon arrival at the Clinical Center, participants will take a breathalyzer test for alcohol and provide a urine sample for a drug screen. Women will also have a urine pregnancy test. They will then lie on a hospital bed and two intravenous catheters (IV lines) will be placed, one into each arm. One line will be used to collect blood samples during the test session; the other will be used to infuse alcohol into the bloodstream. The alcohol will rapidly increase the blood alcohol level to between 0.06 and 0.08 grams per deciliter. (0.08 g/dL is the level at which a person is charge with driving under the influence of alcohol in all States.) Before, during, and after the infusion, subjects will be asked about their feelings in response to the alcohol, such as confusion, elation, level of discomfort or dizziness, ability to concentrate, and so forth. At 35 and 60 minutes after the infusion begins, subjects will take a body sway test. This involves standing on a machine to determine how the alcohol has affected the sense of balance. Subjects will then relax in the clinic for a few hours. During this time, a blood sample will be collected and a questionnaire will be given hourly until the blood alcohol level has gone down to 0.02 g/dL. When the alcohol level has declined to 0.02 g/dL (usually 3 to 4 hours after the infusion), the subject will be sent home in a taxi. Test Day 2 Participants will again take a breathalyzer test for alcohol and provide a urine sample for drug screen and, for women, a pregnancy test. Subjects will lie on a hospital bed and three IV lines will be inserted, one to draw blood samples, one to infuse alcohol, and one to give raclopride, a radioactive substance used for positron emission tomography (PET) scanning. For PET, the subject lies on a table in the scanner with a mask placed over his or her head to help hold the head still during the scan. After a brief scan to adjust the machine, a small amount of radioactive water (O-15 water) is injected through the IV line and a series of pictures is taken over a period of about 1 minute. These images show how the radioactive water distributes in the brain, indicating blood flow. After the water scan, raclopride is given through the IV line and more pictures of the brain are taken over the next 2 hours. Blood samples are collected during and after the raclopride scan. During this procedure, subjects are asked the same questions about their feelings in response to the alcohol as they did during the earlier session. After he scans, they will be monitored in the clinic with hourly blood tests and questionnaires until the blood alcohol concentration decreases to 0.02 g/dL and will then be sent home in a taxi.
The purpose of this trial is to determine if patients who received embryonic dopamine cell implant surgery showed significantly greater improvement in their Parkinson's disease than a control group undergoing the placebo treatment, and to determine if the cell implant surgery was more effective in younger or older patients.
This study is an exploratory proof of mechanism (POM) study using PET/functional magnetic resonance imaging (fMRI) in a 2-period, 2-sequence, crossover design. The aim of the study is to confirm the potential of Ralmitaront to decrease dopamine synthesis capacity (DSC) - as measured by levels of F-DOPA - in the striatum of participants with schizophrenia.
The study aims to observe changes in dopaminergic genes expression in peripheral tissue upon prolonged dopamine agonist treatment on patients with Restless Legs Syndrome (RLS). Similar studies in Parkinson's disease have shown changes in alpha-synuclein expression, which might offer insights into the dopaminergic gene regulation seen in RLS. The dopamine agonist drugs to be included in this study are: Pramipexole (Mirapex), Ropinirole (Requip), Rotigotine (Neupro), Apomorphine (Apokyn), Bromocriptine (Parlodel). Specifically, the study will collect nasal swabs of participants partitioned into two groups, those who have not used a dopamine agonist or been on a dopamine agonist for less than 1 month compared to those who have been on the medication for 6 or more months. This research could provide insight into changes in dopaminergic gene expression associated with Augmentation Syndrome (AS) which occurs after long term dopamine agonist treatment in RLS patients.
The goal of this clinical trial is to assess the safety and tolerability of the surgical transplantation of dopaminergic progenitor cells into the brains of participants with Parkinson's disease. The transplanted dopaminergic cells will be derived from the participant's own skin cells.
Walking with age becomes both slower and less 'automated', requiring more attention and brain resources. As a result, older adults have a greater risk of negative outcomes and falls. There is an urgent need to identify factors that can help compensate for these harmful factors and reduce walking impairments, as there are currently no effective treatments available. Investigators have recently discovered that \~20% of older adults maintain fast walking speed even in the presence of small blood vessel brain changes and leg problems, thus appearing to be protected against these harmful factors. The investigators work suggests that the brain dopamine (DA) system may be a source of this protective capacity. Investigators have also shown that lower levels of dopamine are associated with slow walking. Investigators will be investigating the role of dopamine on slow walking and other parkinsonian signs in this open-label study using detailed clinical assessment, assessment of dopamine activity, and clinical interventions.
SUSTAIN (Studying Solriamfetol Modulation of TAAR-1, Dopamine, and Norepinephrine in Shift Work Disorder) is a Phase 3, multi-center, randomized, double-blind, placebo-controlled, parallel- group trial to assess the efficacy and safety of solriamfetol in adults with excessive sleepiness associated with shift work disorder (SWD).
To evaluate the safety and efficacy of transplantation of human induced pluripotent stem cell-derived dopaminergic progenitors, CT1-DAP001, into the corpus striatum in patients with Parkinson's disease
This research study is evaluating an investigational cell product called autologous induced pluripotent stem cell (iPSC)-derived dopamine neurons. This research study is a single-center Phase 1 clinical trial, which will test the safety of injecting the investigational cell product into the brain of subjects with Parkinson's disease.