6 Clinical Trials for Various Conditions
This study is being done to look at the relationship between brain structure and brain function in patients with epilepsy or focal brain lesions (abnormal areas) that require surgery. This study will look at an imaging technique called magnetic resonance imaging (MRI) for looking at the brain. Specifically, the study will look at functional MRI, which is an imaging technique that can map brain function by taking pictures of the brain as it performs different tasks such as reading, thinking, or moving a body part and diffusion tensor imaging (DTI), which will look at brain structure. These types of imaging may help us learn more about different areas of the brain and how those areas of the brain are used in children with epilepsy. We plan to study 30 children with epilepsy.
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.
The NIMH is conducting studies aimed at gaining a better understanding of the areas of the brain that are involved in different types of mental processes. This study will focus on brain regions involved in visual perception and attention. Healthy normal volunteers and people who have had a stroke or undergone neurosurgery may be eligible for this study. Candidates must be 18 years of age or older, They must not have a history of a psychiatric disorder, including depression, anxiety, psychosis, or neurological disease other than stroke or the previous neurosurgery. Participants undergo the following tests and procedures during four or more visits to the NIH Clinical Center: * Physical and neurological examinations and depression rating scale. * Cognitive testing: Subjects complete written tests, sit at a computer and make decisions about what they are shown by pressing keys, or answer questions from a test examiner. * Behavioral training: Subjects practice performing a cognitive task that involves looking at and making decisions about visual images that appear on a computer screen. * Magnetic resonance imaging (MRI): Subjects undergo MRI scanning while they perform the task they previously practiced. The MRI scanner is a metal cylinder surrounded by a strong magnetic field. During the procedure, subjects lie still for up to 10 minutes at a time on a table that can slide in and out of the cylinder. The entire MRI scanning session takes about one hour. There are multiple scans which each can take up to 10 minutes. They may be asked to return for one or two additional scanning sessions. During the behavioral training or MRI scanning, special pieces of equipment that monitor eye movements may be used. Some subjects may be asked to return to NIH for an additional visit to participate in a magnetoencephalographic scan. This test uses several sensors applied to the scalp to measure very small changes in magnetic fields. This is another way to measure brain activity.
This study will evaluate the usefulness of two tests in quickly distinguishing whether a patient with HIV infection and focal brain lesions (an injury in a specific area of the brain) has a rare type of cancer called primary central nervous system lymphoma (PCNSL), or a parasitic infection called toxoplasmic encephalitis. Toxoplasmic encephalitis is caused by a parasite and can be treated with antibiotics. PCNSL (lymphoma of the brain or spinal cord) must be definitively diagnosed with a brain biopsy (removal of a small piece of brain tissue), and the treatment is radiation therapy and chemotherapy. The tests under study for diagnosing PCNSL or toxoplasmic encephalitis are measurement of Epstein Barr virus (EBV) DNA in cerebrospinal fluid (CSF) and FDG-PET scan of the brain. EBV is often found in the CSF of people with PCNSL. The study also will compare the accuracy of two imaging techniques-TI-SPECT and FDG-PET-in distinguishing between toxoplasmosis and PCNSL. Patients 18 years of age and older who have HIV infection and at least one focal brain lesion without a prior history of PCNSL or toxoplasmic encephalitis may be eligible for this study. Each candidate is screened with a medical history, physical examination, blood and urine tests and MRI scans of the brain. Upon entering the study, all participants take medication to treat toxoplasmic encephalitis. They undergo lumbar puncture (spinal tap) to obtain CSF for analysis, an FDG-PET scan, and a 201TI-SPECT scan. For the PET scan, a radioactive substance is injected into an arm, followed by scanning in a doughnut-shaped machine similar to a CT scanner. SPECT is similar to PET but uses a different radioactive tracer, and the patient lies on a table while the SPECT camera rotates around the patient's head. Patients whose test results indicate a low risk for lymphoma continue antibiotic therapy for toxoplasmosis. They have repeat MRI scans around 4, 7, and 14 days after starting the drug to monitor the response to therapy. Antiretroviral therapy is initiated in patients who are not already on such a regimen. Patients whose test results indicate a high risk for PCNSL have a CT scan to look for evidence of lymphoma elsewhere in the body and are referred for consultation with a neurosurgeon to discuss undergoing a brain biopsy. The brain biopsy is done in the operating room under general anesthesia. A small cut is made in the scalp and a small opening is made in the skull over the area of the brain to be biopsied. A needle is placed in the opening in the skull and, guided by CT or MRI, moved to the abnormal area of the brain, where a small piece of tissue is removed for study under a microscope. Patients found to have toxoplasmosis are discharged from the hospital to the care of their primary care physician after they are getting better and are tolerating all their medications. They return to NIH for follow-up visits about 4 weeks, and 6 months after discharge. Patients found to have lymphoma are referred to the National Cancer Institute for screening for enrollment in a treatment protocol. Patients who are not eligible for a treatment protocol are referred back to their primary care physician or for another NIH treatment protocol, if one is available. Patients with lymphoma are seen at the NIAID outpatient clinic for follow-up visits and laboratory examinations every 3 months for 2 years.
This study will evaluate a type of Magnetic Resonance Imaging (MRI) sequence called arterial spin labeling (ASL). The investigators hope that ASL can better localize areas of the brain (lesions) that cause epilepsy. This type of MRI does not require contrast, does not use any radiation, and adds on 4 minutes to the routine MRI that is done for patients with epilepsy. The study hypothesis is that in patients with refractory epilepsy, Arterial Spin Labeling (ASL) MRI will show areas of abnormality in the brain to the same degree as single-photon emission computerized tomography (SPECT) and positron emission tomography (PET) studies.
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.