Posts tagged brain damage
Articles and news from the latest research reports.
New EEG electrode set for fast and easy measurement of brain function abnormalities
A new, easy-to-use EEG electrode set for the measurement of the electrical activity of the brain was developed in a recent study completed at the University of Eastern Finland. The solutions developed in the PhD study of Pasi Lepola, MSc, make it possible to attach the electrode set on the patient quickly, resulting in reliable results without any special treatment of the skin. As EEG measurements in emergency care are often performed in challenging conditions, the design of the electrode set pays particular attention to the reduction of electromagnetic interference from external sources.
EEG measurements can be used to detect such abnormalities in the electrical activity of the brain that require immediate treatment. These abnormalities are often indications of severe brain damage, cerebral infarction, cerebral haemorrhage, poisoning, or unspecified disturbed levels of consciousness. One of the most serious brain function abnormalities is a prolonged epileptic seizure, status epilepticus, which is impossible to diagnose without an EEG measurement. In many cases, a rapidly performed EEG measurement and the start of a proper treatment significantly reduces the need for aftercare and rehabilitation. This, in turn, drastically improves the cost-effectiveness of the treatment chain.
Although the benefits of EEG measurements are indisputable, they remain underused in acute and emergency care. A significant reason for this is the fact that the electrode sets available on the markets are difficult to attach on the patient, and their use requires special skills and constant training. This new type of an electrode set is expected to provide solutions for making EEG measurements feasible at as an early stage as possible.
The EEG electrode set was produced using screen printing technology, in which silver ink was used to print the conductors and measurement electrodes on a flexible polyester film. The EEG electrode set consists of 16 hydrogel-coated electrodes which, unlike in the traditional method, are placed on the hair-free areas of the patient’s head, making it easy to attach. The new EEG electrode set significantly speeds up the measurement process because there is no need to scrape the patient’s skin or to use any separate gels. As the electrode set is flexible and solid, the electrodes get automatically placed in their correct places. Furthermore, there is no need to move the patient’s head when putting on the EEG electrode set, which is especially important in patients possibly suffering from a neck or skull injury. Due to the fact that the disposable electrode set is easy and fast to use, it is particularly well-suited to be used in emergency care, in ambulances and even in field conditions. Thanks to the materials used, the electrode set does not interfere with any magnetic resonance or computed tomography imaging the patient may undergo.
The performance of the electrode set was tested by using various electrical tests, on several volunteers, and in real patient cases. The results were compared to those obtained by traditional EEG methods.
The PhD study also focused on the use of screen printing technology solutions to protect electrodes against electromagnetic interference. The silver or graphite shielding layer printed to the outer edge of the electrode set was discovered to significantly reduce external interference on the EEG signal. This shielding layer can be easily and cost-efficiently introduced to all measurement electrodes produced with similar methods. Protecting the electrode with a shielding layer is beneficial when measuring weak signals in conditions that contain external interference.
(Source: uef.fi)
Cooling of Dialysis Fluids Protects Against Brain Damage
While dialysis can cause blood pressure changes that damage the brain, cooling dialysis fluids can protect against such effects. The findings come from a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The cooling intervention can be delivered without additional cost and is simple to perform.
While dialysis is an essential treatment for many patients with kidney disease, it can cause damage to multiple organs, including the brain and heart, due to the sudden removal of bodily fluids.
To characterize dialysis-induced brain injury and to see whether cooled dialysis fluids (called dialysate) might help reduce such injury, Christopher McIntyre, DM, and his colleagues randomized 73 new dialysis patients to dialyze with body temperature dialysate or dialysate cooled to 0.5◦C below body temperature for 1 year.
The study demonstrated that dialysis drives progressive white matter brain injury due to blood pressure instability; however, patients who dialyzed at 0.5◦C below body temperature were completely protected against such white matter changes.
“This study demonstrates that paying attention to improving the tolerability of dialysis treatment—in this case by the simple and safe intervention of reducing the temperature of dialysate—does not just make patients feel better, but also can completely protect the brain from progressive damage,” said Dr. McIntyre.
(Source: newswise.com)
Xenon gas protects the brain after head injury
Head injury is the leading cause of death and disability in people aged under 45 in developed countries, mostly resulting from falls and road accidents. The primary injury caused by the initial mechanical force is followed by a secondary injury which develops in the hours and days afterwards. This secondary injury is largely responsible for patients’ mental and physical disabilities, but there are currently no drug treatments that can be given after the accident to stop it from occurring.
Scientists at Imperial College London found that xenon, given within hours of the initial injury, limits brain damage and improves neurological outcomes in mice, both in the short term and long term. The findings, published in the journal Critical Care Medicine, could lead to clinical trials of xenon as a treatment for head injury in humans.
Although xenon is chemically inert, this does not mean it is biologically inactive. Xenon has been known to have general anaesthetic properties since the 1950s. Previous studies at Imperial have found that xenon can protect brain cells from mechanical injury in the lab, but this new study is the first time such an effect has been shown in live animals, a vital step before any new treatments can be tested in humans.
Mice were anaesthetised before having a controlled mechanical force applied to the brain. Some were then treated with xenon at different concentrations and at different times after injury.
Mice treated with xenon performed better in tests assessing their neurological deficits, such as movement and balance problems, in the days after injury and after one month. They also had less brain damage, even if treatment was delayed up to three hours after the injury.
Dr Robert Dickinson from the Department of Surgery and Cancer at Imperial College London, who led the study, said: “After a blow to the head, most of the damage to the brain doesn’t occur immediately but in the hours and days afterwards. At present we have no specific drugs to limit the spread of the secondary injury, but we think that is the key to successful treatment.
“This study shows that xenon can prevent brain damage and disability in mice, and crucially it’s effective when given up to at least three hours after the injury. It’s feasible that someone who hits their head in an accident could be treated in the hospital or in an ambulance in this timeframe.
“These findings provide crucial evidence to support doing clinical trials in humans.”
How studying damage to the prefrontal lobe has helped unlock the brain’s mysteries
Until the last few decades, the frontal lobes of the brain were shrouded in mystery and erroneously thought of as nonessential for normal function—hence the frequent use of lobotomies in the early 20th century to treat psychiatric disorders. Now a review publishing August 28 in the Cell Press journal Neuron highlights groundbreaking studies of patients with brain damage that reveal how distinct areas of the frontal lobes are critical for a person’s ability to learn, multitask, control their emotions, socialize, and make real-life decisions. The findings have helped experts rehabilitate patients experiencing damage to this region of the brain.
Although fairly common, damage to the prefrontal lobes (also called the prefrontal cortex) is often overlooked and undiagnosed because patients do not manifest obvious deficits. For example, patients with prefrontal brain damage do not lose any of their senses and often have preserved motor and language abilities, but they may manifest social abnormalities or difficulties with high-level planning in everyday life situations.
"In this review, we aimed to highlight a blend of new studies using cutting edge research techniques to investigate brain damage, but also to relate these new studies to original studies, some of which were published more than a century ago," said lead author Dr. Sara Szczepanski, of the University of California, Berkeley. "There is currently a large push to better understand the functions of the prefrontal cortex, and we believe that our review will make an important contribution to this understanding."
In addition to revealing the functions of different areas within the prefrontal cortex, studies have also demonstrated the flexibility of the region, which has helped experts optimize cognitive therapy techniques to enable patients with brain damage to learn new skills and compensate for their impairments.
The review indicates that by studying patients with damage to the prefrontal cortex, investigators can gain insights into this still-mysterious region of the brain that is critical for complex human skills and behavior.
Scientists Pinpoint How Genetic Mutation Causes Early Brain Damage
Scientists from the Florida campus of The Scripps Research Institute (TSRI) have shed light on how a specific kind of genetic mutation can cause damage during early brain development that results in lifelong learning and behavioral disabilities. The work suggests new possibilities for therapeutic intervention.
The study, which focuses on the role of a gene known as Syngap1, was published June 18, 2014, online ahead of print by the journal Neuron. In humans, mutations in Syngap1 are known to cause devastating forms of intellectual disability and epilepsy.
“We found a sensitive cell type that is both necessary and sufficient to account for the bulk of the behavioral problems resulting from this mutation,” said TSRI Associate Professor Gavin Rumbaugh, who led the study. “Because we found the root biological cause of this genetic brain disorder, we can now shift our research toward developing tailor-made therapies for people affected by Syngap1 mutations.”
In the study, Rumbaugh and his colleagues used a mouse model to show that mutations in Syngap1 damage the development of a kind of neuron known as glutamatergic neurons in the young forebrain, leading to intellectual disability. Higher cognitive processes, such as language, reasoning and memory arise in children as the forebrain develops.
Repairing damaging Syngap1 mutations in these specific neurons during development prevented cognitive abnormalities, while repairing the gene in other kinds of neurons and in other locations had no effect.
Rumbaugh noted prenatal diagnosis of some infant genetic disorders is on the horizon. Technological advances in genetic sequencing allow for individual genomes to be scanned for damaging mutations; it is possible to scan the entire genome of a child still in the womb. “Our research suggests that if Syngap1 function can be fixed very early in development, this should protect the brain from damage and permanently improve cognitive function,” said TSRI Research Associate Emin Ozkan, a first author of the study, along with TSRI Research Associate Thomas Creson. “In theory, patients then wouldn’t have to be subjected to a lifetime of therapies and worry that the drugs might stop working or have side effects from chronic use.”
Mutations to Syngap1 are a leading cause of “sporadic intellectual disability,” resulting from new, random mutations arising spontaneously in genes, rather than faulty genes inherited from parents. Intellectual disability affects approximately one to three percent of the population worldwide.
Rumbaugh and his colleagues are continuing to investigate. “Our findings have also identified exciting potential biomarkers in the brain of cognitive failure, allowing us to test new therapeutic strategies in our Syngap1 animal model,” said Creson.
(Source: newswise.com)
Strokefinder quickly differentiates bleeding strokes from clot-induced strokes
The results from the initial clinical studies involving the microwave helmet Strokefinder confirm the usefulness of microwaves for rapid and accurate diagnosis of stroke patients. This is shown in a scientific article published on Monday. Strokefinder enables earlier diagnosis than current methods, which improves the possibility to counteract brain damage.
In the article, researchers from Chalmers University of Technology, Sahlgrenska Academy and Sahlgrenska University Hospital present results from the initial patient studies completed last year. The study included 45 patients, and the results show that the technique can with great certainty differentiate bleeding strokes from clot-induced strokes in patients with acute symptoms.
Strokefinder is placed on the patient’s head where it examines the brain tissue by using microwaves. The signals are interpreted by the system to determine if the stroke is caused by a blood clot or bleeding.
“The results of this study show that we will be able to increase the number of stroke patients who receive optimal treatment when the instrument makes a diagnosis already in the ambulance,” says Mikael Persson, professor of biomedical engineering at Chalmers University of Technology. “The possibility to rule out bleeding already in the ambulance is a major achievement that will be of great benefit in acute stroke care. Equally exciting is the potential application in trauma care.
Diagnosis and treatment already in the ambulance
The initial patient studies have been performed inside hospitals, and this autumn the research groups at Chalmers and Sahlgrenska Academy will test a mobile stroke helmet on patients in ambulances.
“Our goal with Strokefinder is to diagnose and initiate treatment of stroke patients already in the ambulance,” says Mikael Elam, professor of clinical neurophysiology at Sahlgrenska University Hospital. “Since time is a critical factor for stroke treatment, the use of the instrument leads to patients suffering less extensive injury. This in turn can shorten the length of stay at hospitals and reduce the need for rehabilitation, thus providing a number of other positive consequences for both the patient and the health care system.”
Studies involving Strokefinder are currently being conducted at Sahlgrenska University Hospital and Södra Älvsborg Hospital in Borås. The research is being conducted in close collaboration between Chalmers University of Technology, Sahlgrenska Academy, Sahlgrenska University Hospital, Södra Älvsborg Hospital and MedTech West, which is a platform for collaboration in medical device R&D, with premises at Sahlgrenska University Hospital.
A new product, based on the results of the present study, has been developed, and further studies will be conducted in several countries in preparation for the CE approval that Medfield Diagnostics, a spin-off from Chalmers, expects to obtain later this year.
(Illustration: Boid)
How Strokefinder differentiates bleeding strokes from clot-induced strokes
The antennas of the helmet sequentially transmit weak microwave signals into the brain. At the same time, the receiving antennas listen for reflected signals. The brain’s different structures and substances affect the microwave scattering and reflections in different ways. The received signals give a complex pattern, which is interpreted with the help of advanced algorithms. Based on these data, the system can diagnose bleeding or a clot. Bleeding is particularly pronounced, but an area with a clot and oxygen deficiency can also be distinguished. (Watch the video).
Research lays foundations for brain damage study
Researchers at The University of Queensland have made a key step that could eventually offer hope for stroke survivors and other people with brain damage.
The international study, led by researchers at UQ, could help explain a debilitating neurological condition known as unilateral spatial neglect, which commonly occurs after a stroke causing damage to the right side of the brain.
People with this condition become unaware of the left side of their sensory world, making everyday tasks such as eating and dressing almost impossible to perform.
ARC Discovery Early Career Research Fellow Dr Marta Garrido from UQ’s Queensland Brain Institute (QBI) said this lack of awareness on the left side, might be caused by an uneven brain network that involves interactions between different brain regions.
“Patients with spatial neglect are impaired in attending to sensory information on the left or the right side of space, but this inability is a lot stronger for objects coming from the left,” she said.
“This research has enabled us to establish what happens in a healthy brain, so that we can then further understand exactly what goes on in the brain of someone who is experiencing spatial neglect.”
QBI co-investigator and ARC Australian Laureate Fellow Professor Jason Mattingley said the human brain performed many functions in an uneven way.
“We already know that in a healthy brain even basic perception can be lopsided. For example, when we look at others’ faces we tend to focus more on the left than the right side,” he said.
“Research like this helps us take a key step in understanding some of the puzzling symptoms observed in people following brain damage.”
The researchers at QBI collaborated with UQ’s School of Psychology, and colleagues from Aarhus University in Denmark, and University College London in the UK.
The study involved recording electrical activity in the brains of healthy adult volunteers using electroencephalography (EEG) while listening to sequences of sounds from the left, right or centre.
The next step for the researchers will be to study how people with brain damage use the left and right sides of the brain when perceiving visual objects and sounds.
Findings of the study were published in The Journal of Neuroscience.
(Source: uq.edu.au)
Unlocking the potential of stem cells to repair brain damage
A QUT scientist is hoping to unlock the potential of stem cells as a way of repairing neural damage to the brain.
Rachel Okolicsanyi, from the Genomics Research Centre at QUT’s Institute of Health and Biomedical Innovation, said unlike other cells in the body which were able to divide and replicate, once most types of brain cells died, the damage was deemed irreversible.
Ms Okolicsanyi is manipulating adult stem cells from bone marrow to produce a population of cells that can be used to treat brain damage.
"My research is a step in proving that stem cells taken from the bone marrow can be manipulated into neural cells, or precursor cells that have the potential to replace, repair or treat brain damage," she said.
Ms Okolicsanyi’s research has been published in Developmental Biology journal, and outlines the potential stem cells have for brain damage repair.
"What I am looking at is whether or not stem cells from the bone marrow have the potential to differentiate or mature into neural cells," she said.
"Neural cells are those cells from the brain that make everything from the structure of the brain itself, to all the connections that make movement, voice, hearing and sight possible."
Ms Okolicsanyi’s research is looking at heparin sulfate proteoglycans - a family of proteins found on the surface of all cells.
"What we are hoping is that by manipulating this particular family of proteins we can encourage the stem cells to show a higher percentage of neural markers indicating that they could mature into neural cells rather than what they would normally do, which is form into bone, cartilage and fat," she said.
"We will manipulate these cells by modifying the surrounding environment. For example we will add chemicals such as complex salts and other commonly found biological chemicals to feed these cells and this will either inhibit or encourage cellular processes."
Ms Okolicsanyi said by doing this, it would be possible to see the different reactions stem cells had to particular chemicals and find out whether these chemicals could increase or decrease the neural markers in the cells.
"The proteins that we are interested in are almost like a tree," she said.
"They have a core protein that is attached to the cell surface and they have these heparin sulfate chains that branch off.
"So when the chemicals we add influence the stem cell in different ways, it will help us understand the interactions between proteins and the resulting changes in the cell.
"In the short-term it is proof that simple manipulations can influence the stem cell and in the long-term it is about the possibility of increasing the neural potential of these stem cells."
Ms Okolicsanyi said the big picture plan was to be able to introduce stem cells into the brain that would be able to be manipulated to repair damaged brain cells.
"The idea, for example, is that in stroke patients where the patient loses movement, speech or control of one side of their face because the brain’s electrical current is impaired, that these stem cells will be able to be introduced and help the electrical current reconnect by bypassing the damaged cells."
(Image: Fotolia)
Losing the left side of the world: Rightward shift in human spatial attention with sleep onset
Unilateral brain damage can lead to a striking deficit in awareness of stimuli on one side of space called Spatial Neglect. Patient studies show that neglect of the left is markedly more persistent than of the right and that its severity increases under states of low alertness. There have been suggestions that this alertness-spatial awareness link may be detectable in the general population. Here, healthy human volunteers performed an auditory spatial localisation task whilst transitioning in and out of sleep. We show, using independent electroencephalographic measures, that normal drowsiness is linked with a remarkable unidirectional tendency to mislocate left-sided stimuli to the right. The effect may form a useful healthy model of neglect and help in understanding why leftward inattention is disproportionately persistent after brain injury. The results also cast light on marked changes in conscious experience before full sleep onset.
(Image: ALAMY)
Beyond the Damaged Brain
Until the past few decades, neuroscientists really had only one way to study the human brain: Wait for strokes or some other disaster to strike people, and if the victims pulled through, determine how their minds worked differently afterward. Depending on what part of the brain suffered, strange things might happen. Parents couldn’t recognize their children. Normal people became pathological liars. Some people lost the ability to speak — but could sing just fine.
These incidents have become classic case studies, fodder for innumerable textbooks and bull sessions around the lab. The names of these patients — H. M., Tan, Phineas Gage — are deeply woven into the lore of neuroscience.
When recounting these cases today, neuroscientists naturally focus on these patients’ deficits, emphasizing the changes that took place in their thinking and behavior. After all, there’s no better way to learn what some structure in the brain does than to see what happens when it shorts out or otherwise gets destroyed.