Active clinical trials for "Encephalitis"

Background: - Studies have shown that inflammation plays an important role in depression. Brain inflammation may contribute to depression, and may make it more difficult to treat some kinds of depression with current therapies. Researchers want to use magnetic resonance imaging (MRI) and positron emission tomography (PET) scanning to study inflammation in the brain. To do so, they will use a contrast agent, which is a chemical that can show inflammation during an imaging study. Objectives: - To see if people with major depressive disorder have increased inflammation in the brain. Eligibility: - Individuals at least 18 years of age who have major depressive disorder. Design: Participants will be screened with a physical exam and medical history. They will provide blood samples before the scanning sessions. Participants will have a PET scan after the screening visit. They will have a dose of the contrast agent before the study. This scan will look for possible brain inflammation. Participants will also have an MRI scan. This scan will take pictures of the brain for comparison studies. Treatment will not be provided as part of this study.

The aim of this project is to investigate humoral and cellular immune responses before and after immunisation with the Japanese encephalitis vaccine IXIARO in subjects above 60 years of age and 18-40 years old subjects.

Neurological and psychiatric diseases are one of the major health problems worldwide. Decades of fundamental and clinical research have led to the model that these disorders results from synaptic imbalance between excitatory, inhibitory and modulatory systems in key brain structures. Although the network and neurotransmitter systems involved have been delineated, the mechanisms leading to improper neurotransmissions remain poorly understood. One major limitation lays in the difficulty to transpose the identified dysregulation in humans to relevant animal models in which molecular and cellular targets can be manipulated. The amino-acid glutamate mediates the vast majority of excitatory neurotransmission in the mammalian brain. We know that the glutamatergic synapses can change their strength by regulating surface expression and dynamics of their postsynaptic receptors, through changes in receptor recycling and/or lateral diffusion. This synaptic plasticity underlies higher cognitive functions such as learning and memory and is likely compromised in several disease states. Regulating glutamate receptor number and function is thus of primary importance. New subcellular imaging technique rendered possible the study of receptor trafficking and receptor regulation in various conditions including pathological models opening new fundamental questions. Moreover, recent breakthroughs on glutamate receptor structure offer unprecedented clues on the molecular and structural mechanisms underpinning receptor dysfunction at the atomic level. Recently, description of encephalitis associated with specific autoantibodies (Abs) directed against neuronal synaptic receptors or proteins (NSA-Abs) opens new lights in the pathophysiological mechanisms of some human brain disorders. The best example and the most frequent syndrome is the synaptic autoimmune encephalitis associated with autoantibodies against extracellular domains of the glutamatergic NMDA receptor (NMDAR-Abs). Classically, patients first present psychiatric symptoms with hallucinations and bizarre behavior before development of neurological symptoms such as seizures, dyskinesia, and autonomic instability. Despite the severity of neuropsychiatric symptoms, more than 80% of patients fully recover after immunomodulatory treatments and many arguments suggest a direct role of NMDAR-Abs in the symptoms. The investigators recently demonstrated that NMDAR-Abs directly modify, at the synaptic level, NMDAR lateral diffusion by disruption of the interaction between NMDAR and EphrinB2 receptor, a synaptic protein anchoring NMDAR at the synapse (Mikasova et al, Brain 2012; Dupuis et al, EMBOJ 2014). These data suggest that NMDAR-Abs could directly participate in the neuropsychiatric disorders observed in patients and that NMDAR dysfunctions could be directly responsible for the observed symptoms. Furthermore, these data suggest that other NSA-Abs directed against other synaptic proteins could explain specific neurological symptoms in patients with encephalitis that are not associated with NMDAR-Abs. The aim of MECANO is to combine multidisciplinary approaches (clinical, immunological, and neurobiological ones) to identify new NSA-Abs, to characterize their specific pathological roles and to decipher acute and chronic NMDAR-Abs effects on biophysical and structural properties of the NMDA receptor, synaptic plasticity, neuronal morphology, and cognitive performance. This project should provide key insights onto the effects of patients' NSA-Abs on the cellular dynamic and regulation of synaptic proteins or receptors and on the molecular cascades activated during synapse dysfunction. The investigators will investigate how NSA-Abs binding alter receptor activity, modify surface receptor mobility and dynamically regulate the maturation of synapses and circuitries. For that purpose, The investigators will use a unique combination of high-resolution imaging (single nanoparticle tracking), receptor engineering, cellular electrophysiology, computational (structural modeling) and cellular and molecular biology approaches and finally behaviour assays. Based on both cutting-edge neurobiology and clinical expertise of autoimmune disorders, and strengthened by promising preliminary experiments, the MECANO project will likely open new avenues of fundamental research in the understanding of synaptic dysfunction and clinical research for the treatment of neuropsychiatric disorders.

Most of patients with autoimmune encephalitis are left with permanent cognitive deficits of varying severity. The patients' life and career would be affected definitely by cognitive deficits. Recently, more and more clinical physician have begun to focus on cognitive impairment of patients with autoimmune encephalitis. Generally, the outcome was measured by the modified Rankin Scale (mRS). However, the mRS are commonly used to evaluate the degree of disability or dependence in the daily activities of the patients suffering from a stroke and cognition function were minimally evaluated in this scale. It is crucial to adopt detailed cognition tools to study the long-term cognitive outcomes and as an indicator of overall curative effect judgment in autoimmune encephalitis. Currently, only early immunotherapy is uniformly and consistently considered to produce favorable cognitive outcomes. However, studies concerning the association of second-line immunotherapy with cognitive outcomes have been scarce and have shown conflicting results regarding autoimmune encephalitis. Hence, the goal of this study was to explore cognitive neural mechanism of autoimmune encephalitis by using neuropsychological tests and multi-mode MRIs.

This study is being conducted to collect safety and immunogenicity data for the WEE vaccine, TSI-GSD 210. Enrollment in this protocol is offered for personnel who enter areas where this virus is used in research or is endemic (an area where this disease process is found to occur frequently).

The phenomenon of no- and low-responsiveness has been described after applications of different vaccines (e.g. hepatitis B, TBE) and is concerning about 2-10% of the vaccinees. The aim of this project is to investigate the humoral and cellular immune responses of low-responders after TBE vaccination in order to find parameters regarding immunoregulation against TBE. It is of interest if non-responsiveness is a general immunological deficit of a distinct patient group or if it is a antigen-specific phenomenon.

This study will examine how West Nile virus (WNV) infection affects the body. Some people infected with WNV have no symptoms. In others, symptoms may vary from fever and headache to a polio-like syndrome with paralysis, to coma and brain changes like those of a stroke. Many patients recover with no lasting effects, while a few can have long-lasting neurological damage or may die. This study will collect clinical, laboratory, diagnostic, and radiographic information on people thought to have WNV to better understand the disease. Patients 18 years of age and older diagnosed with or suspected of having West Nile virus infection may be eligible for this study. Patients will be hospitalized until they are well enough to go home and will undergo the following tests and procedures: Medical history and physical examination: A thorough history and physical examination will be done on the first day of the study. Then, brief physical exams, including measures of blood pressure, heart rate, breathing rate, and temperature, will be done during each day of hospitalization and at every follow-up clinic visit (at 2 weeks and at 1, 3, and 6 months). Blood tests: Blood samples will be collected on the first day of the study, at day 7, at hospital discharge, and at follow-up visits to determine if virus remains in the blood and how it is affecting the body. Magnetic resonance imaging (MRI): MRI scans will be done within 72 hours of beginning the study and 1 month after that. This test uses a strong magnetic field and radio waves to produce images of the brain that might show abnormalities in the brains of patients with WNV and reveal whether the abnormalities can predict how an individual will recover. For the procedure, the patient lies on a table that is moved into the narrow tunnel-like scanner. During the procedure, a contrast agent that brightens the images is injected through a catheter placed in an arm vein. Neurological examination and neurological function tests: Participants will be tested to see if the West Nile virus has affected their thinking and ability to perform normal daily activities. These tests will be done at the start of the study, on days 3 and 7 (also days 2, 4, 5, and 6 if patients are still in the hospital), at discharge, and at follow-up visits. The tests involve answering a number of questions and performing simple tasks, such as squeezing a hand or lifting a foot. Patients who develop weakness in their arms or legs will also have the following studies: Electromyography (EMG) to study the electrical activity of the muscle. For this test, needles are placed into a muscle to record the electrical activity at that site. Nerve conduction studies to measure how well the nerves are working. A small charge of electricity is delivered to a nerve in the affected limb, triggering a muscle to tighten or bend. Small wire electrodes are attached to the skin to measure the time is takes for the nerve to move the electrical current from one part of the limb to another. Spinal MRI to see if the virus is affecting the spinal cord. Results of other tests done by the patient's local doctor (such as lumbar puncture, electroencephalogram, x-rays, etc.) will be requested. If a lumbar puncture is done, a small amount of cerebrospinal fluid will be requested for testing for WNV.

The purpose of this study is to determine whether there are persisting antibodies against Japanese Encephalitis 6 years after the last vaccination with IXIARO(R) and to adapt or confirm mathematical models accordingly.

Refractory epilepsy, meaning epilepsy that no longer responds to medication, is a common neurosurgical indication in children. In such cases, surgery is the treatment of choice. Complete resection of affected brain tissue is associated with highest probability of seizure freedom. However, epileptogenic brain tissue is visually identical to normal brain tissue, complicating complete resection. Modern investigative methods are of limited use. An important subjective assessment during surgery is that affected brain tissue feels stiffer, however there is presently no way to determine this without committing to resecting the affected area. It is hypothesized that intra-operative use of a tonometer (Diaton) will identify abnormal brain tissue stiffness in affected brain relative to normal brain. This will help identify stiffer brain regions without having to resect them. The objective is to determine if intra-operative use of a tonometer to measure brain tissue stiffness will offer additional precision in identifying epileptogenic lesions. In participants with refractory epilepsy, various locations on the cerebral cortex will be identified using standard pre-operative investigations like magnetic resonance imagin (MRI) and positron emission tomography (PET). These are areas of presumed normal and abnormal brain where the tonometer will be used during surgery to measure brain tissue stiffness. Brain tissue stiffness measurements will then be compared with results of routine pre-operative and intra-operative tests. Such comparisons will help determine if and to what extent intra-operative brain tissue stiffness measurements correlate with other tests and help identify epileptogenic brain tissue. 24 participants have already undergone intra-operative brain tonometry. Results in these participants are encouraging: abnormally high brain tissue stiffness measurements have consistently been identified and significantly associated with abnormal brain tissue. If the tonometer adequately identifies epileptogenic brain tissue through brain tissue stiffness measurements, it is possible that resection of identified tissue could lead to better post-operative outcomes, lowering seizure recurrences and neurological deficits.

Background: The investigators have found that obesity and insulin resistance result in significantly increased brain insulin-stimulated glucose uptake, whereas in every other tissue glucose uptake is lower in the obese compared to lean individuals. One possible explanation to this could be central inflammation and activation of brain glial cells, which has been shown to occur in animal models of obesity. Aims: The objective of this study is to investigate whether there is brain inflammation in human obesity, and whether weight loss following bariatric surgery decreases brain inflammation. Methods: A total of 60 morbidly obese subjects, assigned for Roux-en-Y gastric bypass or for sleeve gastrectomy according to routine treatment protocols will be recruited for this study. A control group of 30 healthy subjects will also be recruited. The following studies will be performed to patients and healthy subjects: 1) structural MRI and MRS, 2) functional MRI, 3) PET imaging of cerebral inflammation and astrocyte activation using [11C]-PK11195, 4) measurement of whole-body and tissue insulin sensitivity by combining hyperinsulinemic, euglycemic clamp with [18F]-FDG-PET, 5) neuropsychological testing. The study procedures will be repeated for the morbidly obese 6 months postoperatively.