View clinical trials related to Dementia.
Filter by:Patients with Alzheimer's disease (AD) perform poorly on tasks dependent on access to, and utilization of, previously acquired knowledge and skills. It has been commonly assumed that impaired knowledge in AD, as well as in other patients with cortical lesions, is due to an actual loss or disorganization of a specific knowledge base or system. This hypothesis has, however, recently been called into question by data from tasks that purport to tap knowledge on a more automatic and implicit level. For example, although AD patients are impaired on object naming and verbal fluency tasks, they show a normal pattern of semantic facilitation on reaction time based priming tasks. In fact, the level of facilitation or activation on these tasks has often been reported to be greater in AD patients than in normal individuals. These and similar data have been used to support arguments that performance decrements in AD patients are due to deficits in attentional and/or retrieval processes rather than a degradation of knowledge stores. The central focus of this project will be to test a model of the semantic representations of object that predicts increased facilitation or hyperpriming in AD patients as a result of degraded representations. The relationship between performance on on-line priming tasks, visual attention and spatial processes, and explicit and implicit measures of memory also will be examined. In addition to normal controls, patients with cognitive and memory impairments, but without semantically-based naming difficulties (elderly depressed, Huntington's disease, Korsakoff's disease) will serve as controls for overall slowness of response and degree of explicit memory deficit.
The purpose of this study is to see if adding stavudine (d4T) to anti-HIV drug regimens (with or without zidovudine, ZDV) can improve symptoms of AIDS Dementia Complex (ADC, problems involving the brain or spinal cord) in HIV-positive patients.
To evaluate the benefit of adding 1592U89 to current antiretroviral therapies for AIDS dementia complex and to assess the safety and tolerance of the treatment regimens.
The purpose of this pilot study is to evaluate the efficacy of Retrovir (AZT) in the treatment of AIDS-related dementia and various neuromuscular complications. HIV is both a lymphotropic and neurotropic virus which can affect both the central and peripheral nervous systems (CNS, PNS). There is evidence that the CNS and PNS may harbor the virus in a latent state, with the potential for continuous reinfection of other body systems. Therefore, effective therapeutic efforts against HIV infection should provide effective antiviral activity within the nervous system.
Dementia refers to a condition where there is a loss of intellectual function (cognition). It is usually a progressive condition that interferes with normal social and occupational activities. Patients with frontal lobe dementia (FLD) suffer from a destruction of the brain cells found in the frontal lobe of the brain. Loss of frontal lobe neurons can cause changes in personality, such as aggressiveness, agitation, and depression. In addition, patients with FLD may have difficulty planning tasks and may have a loss of motivation. Researchers believe that the cells lost in the frontal lobe of the brain are responsible for producing a chemical called serotonin. Serotonin is a neurotransmitter, which means it is used by neurons to communicate with other neurons. Researchers are inclined to believe that by replacing the missing serotonin, symptoms of FLD may be relieved. Drugs known as serotonin uptake inhibitors, help to maintain high levels of serotonin in the body. They have been used successfully to treat patients with depression and patients with violent / impulsive behaviors. Sertraline is a serotonin reuptake blocker that is relatively easy to give (once daily), is safer than most other serotonin reuptake blockers (very little effect on vital enzyme systems [cytochrome P-450]), and has few interactions with other drugs. This study is designed to test the effectiveness of Sertraline for the treatment of symptoms associated with FLD. Patients participating in the study will receive Sertraline for 6 weeks and a placebo "inactive sugar pill" for 6 weeks. During the study, researchers will test psychological and neurological functions to measure the effects of the drug.
Imaging studies of the brain have revealed the different areas involved in the processes of learning and reasoning. However, the specific role these regions play in these processes, or if stimulating these areas can improve these processes is unknown. Researchers would like to use repetitive transcranial stimulation (rTMS) to better understand the roles of individual brain regions on the processes of learning and reasoning. Repetitive transcranial magnetic stimulation (rTMS) involves the placement of a cooled electromagnet with a figure-eight coil on the patient's scalp, and rapidly turning on and off the magnetic flux. This permits non-invasive, relatively localized stimulation of the surface of the brain (cerebral cortex). The effect of magnetic stimulation varies, depending upon the location, intensity and frequency of the magnetic pulses. The purpose of this study is to use rTMS to help determine the roles of different brain regions in the development of implicit learning of motor sequences and analogic reasoning. In addition, researchers hope to evaluate if stimulation of these regions speeds up the process of learning or analogic reasoning.
Glutamate is an amino acid released by brain cells that acts to excite other cells. Glutamate attaches to special sites on cells called AMPA (alpha-amino-2,3-dihydro-5 methyl 3-oxo-4-isoxazolepropanoic acid) receptors. The brain cells responsible for releasing glutamate are damaged in Alzheimer's disease and other conditions affecting thinking and reasoning. Researchers would like to see if giving patients a drug that attaches to AMPA receptors improves the symptoms of Alzheimer's disease. CX516 (Ampalex) is a test drug that affects the AMPA receptors. This study will investigate the effectiveness and safety of CX516 on patients with Alzheimer's disease. Patients will be given capsules of CX516 or placebo (sugar pill that neither harms nor helps) for up to 16 weeks in different amounts. The effectiveness of the drug will be measured by neurological tests. Safety will be monitored by frequent check-ups and lab examinations.
The purpose of this study is to improve understanding of neurological conditions. Patients participating in this study will continue receiving medical care, routine laboratory tests, and diagnostics tests (X-rays, CT-scans, and nuclear imaging), from their primary care physician. Doctors at the NIH plan to follow these patients and offer advice and assistance to their primary care physicians.
The purpose of this study is to evaluate people with mild memory problems, those with dementia, those at risk for developing Alzheimer's disease (AD), and healthy volunteers to identify markers of AD before the changes that occur with the disease begin. The origin and markers of progression for Alzheimer's disease (AD) are relatively obscure. Despite increased understanding of the underlying biology of AD, its clinical diagnosis is still made only after progressive cognitive decline; definitive diagnosis is confirmed at autopsy. This study will examine biomarker changes over time in a distinct cohort of people with an increased risk of developing AD. The study will also identify and track biological changes that occur with progressive dementia and compare those changes to the known cognitive and emotional disturbances that characterize AD. Individuals with a first-degree relative with AD will be recruited into an at-risk cohort. They will be followed and compared to a group of healthy volunteers for a minimum of 8 years.
This study is divided into two parts. The first part of the study will use MRI technology to view the brain structure of patients with neurological disorders and normal volunteers. This portion of the study will attempt to detect specific areas of damage in the brains of patients with amnesia and dementia. It will also try to correlate the amount of brain damage with performance on tests used to measure memory. In the second part of the study, researchers plan to use MRI technology to study brain function of patients with neurological disorders and normal volunteers when they perform tasks. MRI signals during task performance will be used to record areas of the brain receiving more blood flow indicating increased activity. Researchers believe this study will help improve existing methods of evaluating patients with neurological disorders. In addition, this study may contribute information about areas of the brain involved in thought processing and motor and sensory function.