Track topics on Twitter Track topics that are important to you
After a stroke, the balance between the two halves of the brain can be lost. This may cause people to lose the ability to perceive a side of space. This is called neglect. Having people wear prism glasses (called PA) can reduce neglect symptoms. Researchers want to find out more about how PA, and whether it restores the balance in the brain.
To learn how prism adaption temporarily changes vision and connections in the brain.
People ages 18 75 with brain damage of the right side of the brain from a stroke or other cause, leading to neglect.
Healthy volunteers ages 18 75.
Participants will have 1 3 visits.
Participants will be screened with a neurological exam. They may also have:
Tests of thinking and vision
Tests to see which eye and hand they prefer
A pregnancy test
All participants will:
Answer questions about their personality, style of thinking, and beliefs.
Do simple tasks on paper or computer
Have magnetic resonance imaging. They will lie on a table that can slide in and out of a cylinder in a strong magnetic field. Participants will lie still or do computer tasks in the scanner.
Participants may also have:
Transcranial magnetic stimulation. A brief electrical current passes through a wire coil on the scalp. This creates a magnetic pulse that affects brain activity. Participants may be asked to tense certain muscles or perform simple actions or tasks.
PA. They will sit in front of a board and point to a dot on it while they wear prism glasses that shift vision to the left or right.
The ability to efficiently select information from the environment relies on a balanced interaction between the right and left hemispheres. Hemispatial neglect, most frequently following damage to the right hemisphere, has been hypothesized to result from the breakdown of this interhemispheric balance. There is evidence from transcranial stimulation studies that the breakdown of this interhemispheric balance is reflected in fronto-parietal connectivity. The primary goal of this study is to test whether altering the balance between the left and right hemispheres, with repetitive transcranial magnetic stimulation (rTMS) or prism adaptation (PA), will affect functional connectivity measured with functional magnetic resonance imaging (fMRI). We will also explore the relationship between the changes in functional connectivity and behavioral performances.
Study population: Healthy adult volunteers and patients with neglect after a right hemisphere damage.
Design: The study contains three experiments. Experiment 1 is designed to investigate the mechanism of the changes induced by PA in both resting state functional connectivity in neglect patients and healthy volunteers (a two-arm parallel study). Experiment 2 is designed to investigate the mechanism of the changes in resting state functional connectivity induced by lPA, rPA, nPA in healthy volunteers with right dominant eyes and lPA in healthy volunteer with left dominant eye (a four-arm parallel study). Experiment 3 is designed to see if inhibitory rTMS over the right posterior parietal cortex (PPC) can influence functional connectivity and visuospatial bias in healthy volunteers (a crossover study).
Outcome measures: For all three experiments the primary outcome measure is the change (or difference) in fronto-parietal resting state connectivity between post and pre PA or rTMS procedure. The secondary outcome measures are the changes in visual field representation and in visuo-motor and cognitive behavior accompanying these manipulations.
Time Perspective: Cross-Sectional
National Institutes of Health Clinical Center
National Institutes of Health Clinical Center (CC)
Published on BioPortfolio: 2016-09-22T20:53:31-0400
To evaluate the maternal blood concentrations of brain natriuretic peptide (BNP) during the second and third trimesters of a normal pregnancy. We will attempt to define a normal range for...
Pilot Trial in Sleep Laboratory Setting to Compare the Physiology of Night Time Bladder Function in Subjects With Overactive Bladder (OAB) Versus Subjects That Have Insomnia and Healthy Normal Subjects
This is an observational, physiology pilot study of subjects with overactive bladder, insomnia and normal subjects. No study drug will be given. All subjects will complete a one week slee...
Lung isolation technique and one-lung ventilation (OLV) are the mainstays of thoracic anesthesia. Two principal lung isolation techniques are mainly use by clinicians, the double lumen tub...
This is a physiology study of two commercially available dialysate acid concentrates. It is a prospective, single center single blind, cross-over, two week investigation of intradialytic a...
The Human Blood Cell Disorder Tissue Bank will provide a convenient, comprehensive source of tissue containing populations of human blood cells from patients with various types of lymphoid...
Pulmonary artery (PA) impedance provides detailed information on right ventricular (RV) afterload in pulmonary hypertension (PH). This study aimed to examine PA impedance in a rat model of monocrotali...
Coronary microvascular dysfunction (CMD) has been proposed as an important component of diabetes mellitus (DM) and hypercholesterolemia-associated coronary artery disease (CAD). Previously we observed...
Urine represents an ideal source of clinically relevant biomarkers as it contains a large number of proteins and low molecular weight peptides. The comprehensive characterization of the normal urinary...
Functional magnetic resonance imaging of mice requires that the physiology of the mouse (body temperature, respiration and heart rates, blood pH level) be maintained in order to prevent changes affect...
Microglia, commonly known as the tissue resident macrophages of the central nervous system (CNS), are ubiquitously expressed in the CNS. Microglia, in their resting, or surveilling, stage, play a crit...
Microorganisms that have undergone greater changes than normal in morphology, physiology, or cultural characteristics.
A medical-surgical specialty concerned with the physiology and disorders primarily of the female genital tract, as well as female endocrinology and reproductive physiology.
Normal cellular isoform of prion proteins (PRIONS) encoded by a chromosomal gene and found in normal and scrapie-infected brain tissue, and other normal tissue. PrPC are protease-sensitive proteins whose function is unknown. Posttranslational modification of PrPC into PrPSC leads to infectivity.
The study of the heart, its physiology, and its functions.
The scientific discipline concerned with the physiology of the nervous system.
Stroke - Cerebrovascular Disease (CVA)
A stroke is a serious medical condition that occurs when the blood supply to part of the brain is cut off. Strokes are a medical emergency and prompt treatment is essential because the sooner a person receives treatment for a stroke, the less damage is ...
Neurology - Central Nervous System (CNS)
Alzheimer's Disease Anesthesia Anxiety Disorders Autism Bipolar Disorders Dementia Epilepsy Multiple Sclerosis (MS) Neurology Pain Parkinson's Disease Sleep Disorders Neurology is the branch of me...
Obstetrics and gynaecology
Fertility Menopause Obstetrics & Gynaecology Osteoporosis Women's Health Obstetrics and gynaecology comprises the care of the pregnant woman, her unborn child and the management of diseases specific to women. Most consultant...