Posts Tagged neurology

[WEB SITE] Study uncovers genetic trigger that may help the brain to recover from stroke, other injuries

Scientists have found a genetic trigger that may improve the brain’s ability to heal from a range of debilitating conditions, from strokes to concussions and spinal cord injuries.

A new study in mice from UT Southwestern’s O’Donnell Brain Institute shows that turning on a gene inside cells called astrocytes results in a smaller scar and – potentially – a more effective recovery from injury.

The research examined spinal injuries but likely has implications for treating a number of brain conditions through gene therapy targeting astrocytes, said Dr. Mark Goldberg, Chairman of Neurology & Neurotherapeutics at UT Southwestern.

“We’ve known that astrocytes can help the brain and spinal cord recover from injury, but we didn’t fully understand the trigger that activates these cells,” Dr. Goldberg said. “Now we’ll be able to look at whether turning on the switch we identified can help in the healing process.”

The study published in Cell Reports found that the LZK gene of astrocytes can be turned on to prompt a recovery response called astrogliosis, in which these star-shaped cells proliferate around injured neurons and form a scar.

Scientists deleted the LZK gene in astrocytes of one group of injured mice, which decreased the cells’ injury response and resulted in a larger wound on the spinal cord. They overexpressed the gene in other injured mice, which stimulated the cells’ injury response and resulted in a smaller scar. Overexpressing the gene in uninjured mice also activated the astrocytes, confirming LZK as a trigger for astrogliosis.

Dr. Goldberg said a smaller scar likely aids the healing process by isolating the injured neurons, similar to how isolating a spreading infection can improve recovery. “But we don’t know under what circumstances this hypothesis is true because until now we didn’t have an easy way to turn the astrocyte reactivity on and off,” he said.

Further study is needed to analyze whether a compact scar tissue indeed improves recovery and how this process affects the neurons’ ability to reform connections with each other.

Dr. Goldberg’s lab will conduct more research to examine the effects of astrogliosis in stroke and spinal cord injuries. The researchers will determine whether turning up LZK in mice in advance of an injury affects its severity. They will then measure how the formation of the compact scar helps or hinders recovery.

“It has been a big mystery whether increasing astrocyte reactivity would be beneficial,” said Dr. Meifan Amy Chen, the study’s lead author and Instructor of Neurology at the Peter O’Donnell Jr. Brain Institute. “The discovery of LZK as an on switch now offers a molecular tool to answer this question.”

 

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[WEB SITE] New brain cells are added in elderly adult brains too

According to a new study from the Columbia University however, brain cells are continuously added to our brains even when we reach our 70s. This is a process called neurogenesis. Their work is published in a study that appeared in the latest issue of the journal Cell Stem Cell this week.

Neuron detailed anatomy illustrations. Neuron types, myelin sheath formation, organelles of the neuron body and synapse. Image Credit: Tefi / Shutterstock

Lead author Dr. Maura Boldrini, a research scientist at the department of psychiatry, Columbia University and her colleagues investigated the brains of 28 dead people aged between 14 and 79 years. They were studying the effects of aging on the brain’s neuron production. The team examined the brains that were donated by the families of the deceased at the time of death. The brains were frozen immediately at minus-112 degrees Fahrenheit before they could be examined. This preserved the tissues.

Neurogenesis has been shown to decline with age in lab mice and rats as well as in experimental primates. The team wanted to explore if same rates of decline are seen in human brains as well. So they checked the brains samples for developing neurons. These developmental stages included stem cells, intermediate progenitor cells, immature neuronal cells and finally new mature neurons. They focused on the hippocampus region of the brain that deals with memory and emotional control and behavior.

The results revealed that for all age groups, the hippocampus shows new developing neurons. The researchers concluded that even during old age, the hippocampus continues to make new neurons. The differences that they noted with age include reduction in the development of new blood vessels as people got older. The proteins that help the neurons to make new connections are reduced with age. This was a finding that differentiated ageing brains from younger ones, they explained. Boldrini said the new neurons are there in older brains but they make fewer connections than younger brains. This explains the memory losses and decrease in emotional resiliency in older adults she said.

An earlier study last month came from another set of researchers led by University of California San Francisco researcher Arturo Alvarez-Buylla. The study titled, “Human hippocampal neurogenesis drops sharply in children to undetectable levels in adults,” was published first week of March this year in the journal Nature.

The team found that after adolescence there is little or no neurogenesis in the brain. They examined the brains of 17 deceased individuals and 12 patients with epilepsy part of whose brains had been surgically resected. The debate between the two teams continues. Boldrini explained that Buylla’s team had examined different types of samples that were not preserved as her samples had been.

Further the other team examined three to five sections of the hippocampus and not the whole of it she explained. More studies on this needed to make concrete conclusions regarding neurogenesis in the elderly say experts.

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[WEB SITE] Can MRI Brain Scans Help Us Understand Epilepsy?

epilepsy

A massive meta-analysis of global MRI imaging data on epilepsy patients seeks to clarify a complicated and mysterious neurological disorder.

Epilepsy is a neurological disorder characterized by seizures, which can vary from mild and almost undetectable to severe, featuring vigorous shaking. Almost 40 million people worldwide are affected by epilepsy. Epileptic seizures are caused by an abnormally high level of activity in nerve cells in the brain. A small number of cases have been tied to a genetic defect, and major trauma to the brain (such as an injury or stroke) can also induce seizures. However, for the majority of cases, the underlying cause of epilepsy is not known. In many instances, epilepsy can be treated with the use of anti-convulsant medication. Some people will experience an improvement in their symptoms to the point of no longer requiring medication, while others will not respond to medication at all. The variability of the disease with regards to physiology and progression makes it difficult to accurately diagnose.

How Does Epilepsy Affect the Brain?

There are multiple types of epilepsies, some more common than others, which affect different parts of the brain cortex. The disorder has been studied by using techniques such as magnetic resonance imaging (MRI), and analyses of brain tissue. The latter requires post-mortem collection of tissue, as biopsies are not routinely performed on living patients’ brains. A brain scan via MRI imaging can provide detail about pathological markers of epilepsy, but the massive amount of data collected worldwide by imaging has not yet been consolidated and analyzed in a robust manner. Gaining an understanding of distinct or shared disease markers for different forms of epilepsy could help clinicians identify targets for therapy and increase the personalization of treatment.

The ENIGMA Study

A recent study published in the journal BRAIN represents the largest neuroimaging analysis of epilepsy conducted to date.This study, called ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis)summarizes contributions from 24 research centers across 14 countries in Europe, North and South America, Asia, and Australia. Similar wide-ranging studies have revealed structural brain abnormalities in other neurological conditions such as schizophrenia, depression, and obsessive-compulsive disorder. The researchers had several goals in putting this meta-analysis together:

  1. To look at distinct types of epilepsy to see whether they share similar structural abnormalities of the brain.
  2. To analyze a well-known specific type of epilepsy, mesial temporal lobe epilepsy (MTLE) for differences between people afflicted with this disorder on different sides of the brain.
  3. To analyze idiopathic generalized epilepsies (IGE), which are thought to have a genetic component to their cause and aren’t often detectable via MRI.

The researchers compiled imaging data from 2,149 people with epilepsy and 1,727 healthy control subjects. The large sample size allowed them to perform high-powered statistical analysis of the data.

For analysis (1), the results showed that a diverse array of epilepsies showed common structural anomalies across several different regions of the brain. This suggested that distinct disease types share a common neuroanatomical signature.

For analysis (2), they found that people with mesial temporal lobe epilepsy on the right side of the hippocampus did not experience damage to the left side, and vice-versa. However, somewhat unexpectedly, they saw that damage extended to areas outside the hippocampus, suggesting that even a region-specific disorder like mesial temporal lobe epilepsy may be a network disease.

In analysis (3), the researchers found that contrary to many reports of a “normal” MRI for patients with idiopathic generalized epilepsy, several structural irregularities were observable over a large number of samples. These included reduced brain volume and thickness in several regions.

One Step Closer to Understanding Epilepsy

The authors noted some limitations to their study, such as the fact that all results were derived from cross-sectional data, meaning that it was not possible to determine whether certain features were the cause of severe brain damage at one point in time, or whether they were the product of progressive trauma. In addition, this study could not account for the possible contribution of other factors, such as medications, seizure type and frequency, and disease severity. However, this wide-scale meta-analysis represents an important step towards understanding how different types of epilepsies affect the brain, and hopefully can lead to more personalized and effective medical interventions.

Written by Adriano Vissa, PhD

Reference: Whelan CD, et al. Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study. Brain. 2018; 141(2):391-408

 

via Can MRI Brain Scans Help Us Understand Epilepsy? – Medical News Bulletin | Health News and Medical Research

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[WEB SITE] Learning stress-reducing techniques may benefit people with epilepsy

Learning techniques to help manage stress may help people with epilepsy reduce how often they have seizures, according to a study published in the February 14, 2018, online issue of Neurology®, the medical journal of the American Academy of Neurology.

“Despite all the advances we have made with new drugs for epilepsy, at least one-third of people continue to have seizures, so new options are greatly needed,” said study author Sheryl R. Haut, MD, of Montefiore Medical Center and the Albert Einstein College of Medicine in the Bronx, NY, and member of the American Academy of Neurology. “Since stress is the most common seizure trigger reported by patients, research into reducing stress could be valuable.”

The study involved people with seizures that did not respond well to medication. While all of the 66 participants were taking drugs for seizures, all continued to have at least four seizures during about two months before the study started.

During the three-month treatment period all of the participants met with a psychologist for training on a behavioral technique that they were then asked to practice twice a day, following an audio recording. If they had a day where they had signs that they were likely to have a seizure soon, they were asked to practice the technique another time that day. The participants filled out daily electronic diaries on any seizures, their stress level, and other factors such as sleep and mood.

Half of the participants learned the progressive muscle relaxation technique, a stress reduction method where each muscle set is tensed and relaxed, along with breathing techniques. The other participants were the control group-;they took part in a technique called focused attention. They did similar movements as the other group, but without the muscle relaxation, plus other tasks focusing on attention, such as writing down their activities from the day before. The study was conducted in a blinded fashion so that participants and evaluators were not aware of treatment group assignment.

Before the study, the researchers had hypothesized that the people doing the muscle relaxing exercises would show more benefits from the study than the people doing the focused attention exercises, but instead they found that both groups showed a benefit-;and the amount of benefit was the same.

The group doing the muscle relaxing exercises had 29 percent fewer seizures during the study than they did before it started, while the focused attention group had 25 percent fewer seizures, which is not a significant difference, Haut said. She added that study participants were highly motivated as was shown by the nearly 85 percent diary completion rate over a five-month period.

“It’s possible that the control group received some of the benefits of treatment in the same way as the ‘active’ group, since they both met with a psychologist and every day monitored their mood, stress levels and other factors, so they may have been better able to recognize symptoms and respond to stress,” said Haut. “Either way, the study showed that using stress-reducing techniques can be beneficial for people with difficult-to-treat epilepsy, which is good news.”

Haut said more research is needed with larger numbers of people and testing other stress reducing techniques like mindfulness based cognitive therapy to determine how these techniques could help improve quality of life for people with epilepsy.

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[WEB SITE] Virtual Reality for Stroke Rehabilitation

stroke rehabilitation

Researchers piloted a study to investigate the potential of using virtual reality (VR) training systems in stroke rehabilitation.

Following a stroke, survivors are often left with physical and mental disabilities. Nine out of ten stroke survivors are left with some degree of upper limb motor impairment, thus making it the most prevalent post-stroke disability suffered. Not only does stroke rehabilitation training need to be long-lasting, repetitive, task-specific and challenging, the training must also be motivating and intensive.

What is the Role of Virtual Reality?

Virtual reality (VR) is a relatively new approach to stroke rehabilitation that has shown to have moderate effectiveness in improving motor functions. VR can allow for embodied sensorimotor feedback where patients’ movements are reproduced in a virtual environment via motion capture technology. This enhanced VR experience has previously demonstrated an ability to increase patient motivation and stimulate neural circuits in the motor system to aid in functional recovery.

Can Virtual Reality Help with Stroke Rehabilitation?

In a pilot study published in the Journal of NeuroEngineering and Rehabilitation, researchers in Switzerland investigated the potential use of a VR-based stroke rehabilitation training targeted to the upper motor limbs. The study’s main goal was to assess the training intensity (the number of repetitions divided by the number of minutes of active therapy) and rehabilitation dose (number of repetitions). They also examined VR-based training improvements in functional upper limb outcomes and the safety and tolerance of this technology.

Ten stroke patients with one-sided weakness were included in the study, utilizing the Mind Motion PRO VR-based motor rehabilitation system. The intervention consisted of two one-hour sessions per week for five weeks with a physical therapist to guide the tasks according to the patient’s needs and abilities. Assessments were conducted at baseline (prior to training), post-treatment, and at a four-week follow-up. The participants engaged in VR treatment exercises that stimulated shoulder, elbow, forearm, and wrist movements at varying difficulties through game-like scenario tasks that included pointing, reaching, and grabbing objects in virtual space.

How Effective was the Virtual Reality Therapy?

All ten of the study’s participants completed the full ten training sessions in the treatment. The study found that the median duration of training increased by approximately ten minutes and the median effective training time (number of minutes that the participants actively trained, excluding breaks) per session doubled by the last session of the intervention. The intensity of the training (number of goal-directed movements per minute of effective training time) progressively increased from the first to last training session.

Secondarily, the study evaluated upper limb function, active range of motion and muscle strength, which all showed an increase from baseline. No adverse events were reported and pain and stress levels were low throughout the treatment, thus indicating that VR treatment is well tolerated. Lastly, the participants showed a high degree of concentration and comfort with the movements and expressed interest in continuing the training after the ten sessions, suggesting a high level of adherence and motivation for VR treatment – a key component to stroke rehabilitation treatment outcomes.

Overall, this pilot study demonstrated the ability of VR-based treatment to provide efficient training sessions, as the efficiency rate (relation between time of therapy session and time in active therapy) was 86.3%, which is higher than conventional therapies. The study supports the potential for VR-based intervention as stroke rehabilitation therapy to improve functional and motor outcomes. This should be further explored in future studies that incorporate control groups, a larger sample size, stratified groups and more intensive interventions with a variety of motor assessments.

Written by Maggie Leung, PharmD

Reference: Perez-Marcos, D., Chevalley, O., Schmidlin, T., Garipelli, G., Serino, A., Vuadens, P., . . . Millán, J. D. (2017). Increasing upper limb training intensity in chronic stroke using embodied virtual reality: a pilot study. Journal of NeuroEngineering and Rehabilitation,14(1). doi:10.1186/s12984-017-0328-9

via Virtual Reality for Stroke Rehabilitation – Medical News Bulletin | Health News and Medical Research

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[WEB SITE] Monthly cycles of brain activity linked to seizures in patients with epilepsy

January 8, 2018
UC San Francisco neurologists have discovered monthly cycles of brain activity linked to seizures in patients with epilepsy. The finding, published online January 8 in Nature Communications, suggests it may soon be possible for clinicians to identify when patients are at highest risk for seizures, allowing patients to plan around these brief but potentially dangerous events.

“One of the most disabling aspects of having epilepsy is the seeming randomness of seizures,” said study senior author Vikram Rao, MD, PhD, an assistant professor of neurology at UCSF and member of the UCSF Weill Institute for Neurosciences. “If your neurologist can’t tell you if your next seizure is a minute from now or a year from now, you live your life in a state of constant uncertainty, like walking on eggshells. The exciting thing here is that we may soon be able to empower patients by letting them know when they are at high risk and when they can worry less.”

Epilepsy is a chronic disease characterized by recurrent seizures — brief storms of electrical activity in the brain that can cause convulsions, hallucinations, or loss of consciousness. Epilepsy researchers around the world have been working for decades to identify patterns of electrical activity in the brain that signal an oncoming seizure, but with limited success. In part, Rao says, this is because technology has limited the field to recording brain activity for days to weeks at most, and in artificial inpatient settings.

At UCSF Rao has pioneered the use of an implanted brain stimulation device that can quickly halt seizures by precisely stimulating a patient’s brain as a seizure begins. This device, called the NeuroPace RNS® System, has also made it possible for Rao’s team to record seizure-related brain activity for many months or even years in patients as they go about their normal lives. Using this data, the researchers have begun to show that seizures are less random than they appear. They have identified patterns of electrical discharges in the brain that they term “brain irritability” that are associated with higher likelihood of having a seizure.

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The new study, based on recordings from the brains of 37 patients fitted with NeuroPace implants, confirmed previous clinical and research observations of daily cycles in patients’ seizure risk, explaining why many patients tend to experience seizures at the same time of day. But the study also revealed that brain irritability rises and falls in much longer cycles lasting weeks or even months, and that seizures are more likely to occur during the rising phase of these longer cycles, just before the peak. The lengths of these long cycles differ from person to person but are highly stable over many years in individual patients, the researchers found.

The researchers show in the paper that when the highest-risk parts of a patient’s daily and long-term cycles of brain irritability overlap, seizures are nearly seven times more likely to occur than when the two cycles are mismatched.

Rao’s team is now using this data to develop a new approach to forecasting patients’ seizure risk, which could allow patients to avoid potentially dangerous activities such as swimming or driving when their seizure risk is highest, and to potentially take steps (such as additional medication doses) to reduce their seizure risk, similar to how people with asthma know to take extra care to bring their inhalers when pollen levels are high.

“I like to compare it to a weather forecast,” Rao said. “In the past, the field has focused on predicting the exact moment a seizure will occur, which is like predicting when lightning will strike. That’s pretty hard. It may be more useful to be able tell people there is a 5 percent chance of a thunderstorm this week, but a 90 percent chance next week. That kind of information lets you prepare.”

Source:
https://www.ucsf.edu/

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[WEB SITE] New method uses advanced noninvasive neuroimaging to localize and identify epileptic lesions

Epilepsy affects more than 65 million people worldwide. One-third of these patients have seizures that are not controlled by medications. In addition, one-third have brain lesions, the hallmark of the disease, which cannot be located by conventional imaging methods. Researchers at the Perelman School of Medicine at the University of Pennsylvania have piloted a new method using advanced noninvasive neuroimaging to recognize the neurotransmitter glutamate, thought to be the culprit in the most common form of medication-resistant epilepsy. Their work is published today in Science Translational Medicine.

Glutamate is an amino acid which transmits signals from neuron to neuron, telling them when to fire. Glutamate normally docks with the neuron, gives it the signal to fire and is swiftly cleared. In patients with epilepsy, stroke and possibly ALS, the glutamate is not cleared, leaving the neuron overwhelmed with messages and in a toxic state of prolonged excitation.

In localization-related epilepsy, the most common form of medication-resistant epilepsy, seizures are generated in a focused section of the brain; in 65 percent of patients, this occurs in the temporal lobe. Removal of the seizure-generating region of the temporal lobe, guided by preoperative MRI, can offer a cure. However, a third of these patients have no identified abnormality on conventional imaging studies and, therefore, more limited surgical options.

“Identification of the brain region generating seizures in location-related epilepsy is associated with significantly increased chance of seizure freedom after surgery,” said the new study’s lead author, Kathryn Davis, MD, MSTR, an assistant professor of Neurology at Penn. “The aim of the study was to investigate whether a novel imaging method, developed at Penn, could use glutamate to localize and identify the epileptic lesions and map epileptic networks in these most challenging patients.”

“We theorized that if we could develop a technique which allows us to track the path of and make noninvasive measurements of glutamate in the brain, we would be able to better identify the brain lesions and epileptic foci that current methods miss,” said senior author Ravinder Reddy, PhD, a professor of Radiology and director of Penn’s Center for Magnetic Resonance and Optical Imaging.

Reddy’s lab developed the glutamate chemical exchange saturation transfer (GluCEST) imaging method, a very high resolution magnetic resonance imaging contrast method not available before now, to measure how much glutamate was in different regions of the brain including the hippocampi, two structures within the left and right temporal lobes responsible for short- and long-term memory and spatial navigation and the most frequent seizure onset region in adult epilepsy patients.

The study tested four patients with medication-resistant epilepsy and 11 controls. In all four patients, concentrations of glutamate were found to be higher in one of the hippocampi, and confirmatory methods (electroencephalography and magnetic resonance spectra) verified independently that the hippocampus with the elevated glutamate was located in the same hemisphere as the epileptic focus/lesion. Consistent lateralization to one side was not seen in the control group.

While preliminary, this work indicates the ability of GluCEST to detect asymmetrical hippocampal glutamate levels in patients thought to have nonlesional temporal lobe epilepsy. The authors say this approach could reduce the need for invasive intracranial monitoring, which is often associated with complications, morbidity risk, and added expense.

“This demonstration that GluCEST can localize small brain hot spots of high glutamate levels is a promising first step in our research,” Davis said. “By finding the epileptic foci in more patients, this approach could guide clinicians toward the best therapy for these patients, which could translate to a higher rate of successful surgeries and improved outcomes from surgery or other therapies in this difficult disease.”

Source: Penn Medicine

Source: New method uses advanced noninvasive neuroimaging to localize and identify epileptic lesions

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[WEB SITE] Seizures Follow Similar Path Regardless of Speed

Summary: By capturing a cell by cell view of seizures propagating through a mouse brain, researchers discovered neurons fire in a sequential pattern, regardless of how quickly the seizure occurs. The findings confirm seizures are not a result of neurons going haywire.

Source: Columbia University.

Of the 50 million people who suffer from epilepsy worldwide, a third fail to respond to medication. As the search for better drugs continues, researchers are still trying to make sense of how seizures start and spread.

In a new study in Cell Reports, researchers at Columbia University come a step closer by showing that the neurons of mice undergoing seizures fire off in a sequential pattern no matter how quickly the seizure propagates — a finding that confirms seizures are not the result of neurons randomly going haywire.

“This is good news,” said the study’s senior author, Dr. Rafael Yuste, a neuroscientist at Columbia. “It means that local neuronal circuits matter, and that targeting the right cells may stop or even prevent some types of brain seizure.”

To induce the seizures, researchers injected a tiny area of cortex in awake mice with two types of drugs–one that increases neuronal firing and another that blocks the inhibitory interneurons that control information flow between cells. Recording the seizures as they rippled outward, researchers found that cells in the mouse’s brain systematically fired one after the other. Under both models, the seizure spread across the top layer of cortex in a wave-like pattern before descending into its lower layers.

Unexpectedly, they found that whether the seizure lasted 10 seconds or 30 seconds, it followed the same route, like a commuter stuck in traffic. The concept of neurons firing in a reliable pattern no matter how fast the seizure is traveling is illustrated on the cover of Cell Reports, drawn by the study’s lead author, Dr. Michael Wenzel.

“The basic pattern of a string stretched between two hands stays the same whether the hands move closer together or farther away,” he says. “Just as neurons maintain their relative firing patterns regardless of how slowly or quickly the seizure unfolds.”

Researchers were able to get a cell-by-cell view of a seizure propagating through a mouse’s brain using high-speed calcium imaging that allowed them to zoom in 100 times closer than electrode techniques used on the human brain.

Image shows brain.

Researchers were able to get a cell-by-cell view of a seizure propagating through a mouse’s brain using high-speed calcium imaging that allowed them to zoom in 100 times closer than electrode techniques used on the human brain. NeuroscienceNews.com image is in the public domain.

It may be the first time that researchers have watched a seizure unfold at this level of detail, and their findings suggest that inhibitory neurons may be a promising area of future research, said Dr. Catherine Schevon, a neurology professor at Columbia University Medical Center who was not involved in the research.

“The role of inhibitory restraint in seizure development is an area that few have studied at micrometer scale,” she said. “This could be a useful treatment target for future drug development or stem cell interneuron implants.”

Source: Seizures Follow Similar Path Regardless of Speed – Neuroscience News

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[BLOG POST] Brain-Computer Interface & Virtual Avatar Offers New Hope to Patients with Gait Disabilities – Neuroscience News

Summary: Coupling a non invasive brain computer interface with a virtual walking avatar may help those with gait disorders to regain control of their movements, a new study reports. Source: University of Houston.Researchers from the University of Houston have shown for the first time that the use of a brain-computer interface augmented with a virtual walking avatar can control gait, suggesting the protocol may help patients recover the ability to walk after stroke, some spinal cord injuries and certain other gait disabilities.

Researchers said the work, done at the University’s Noninvasive Brain-Machine Interface System Laboratory, is the first to demonstrate that a brain-computer interface can promote and enhance cortical involvement during walking. The study, funded by the National Institute of Neurological Disease and Stroke, was published this week in Scientific Reports.

 

a woman

Researchers already knew electroencephalogram (EEG) readings of brain activity can distinguish whether a subject is standing still or walking. But they hadn’t previously known if a brain-computer interface was practical for helping to promote the ability to walk, or what parts of the brain are relevant to determining gait. NeuroscienceNews.com image is adapted from the U of H video.

Jose Luis Contreras-Vidal, Cullen professor of electrical and computer engineering at UH and senior author of the paper, said the data will be made available to other researchers. While similar work has been done in other primates, this is the first to involve humans, he said. Contreras-Vidal is also site director of the BRAIN Center (Building Reliable Advances and Innovation in Neurotechnology), a National Science Foundation Industry/University Cooperative Research Center.

Contreras-Vidal and researchers with his lab use non-invasive brain monitoring to determine what parts of the brain are involved in an activity, using that information to create an algorithm, or a brain-machine interface, which can translate the subject’s intentions into action.

In addition to Contreras-Vidal, researchers on the project are first author Trieu Phat Luu, a research fellow in neural engineering at UH; Sho Nakagome and Yongtian He, graduate students in the UH Department of Electrical and Computer Engineering.

“Voluntary control of movements is crucial for motor learning and physical rehabilitation,” they wrote. “Our results suggest the possible benefits of using a closed-loop EEG-based BCI-VR (brain-computer interface-virtual reality) system in inducing voluntary control of human gait.”

Researchers already knew electroencephalogram (EEG) readings of brain activity can distinguish whether a subject is standing still or walking. But they hadn’t previously known if a brain-computer interface was practical for helping to promote the ability to walk, or what parts of the brain are relevant to determining gait.

In this case, they collected data from eight healthy subjects, all of whom participated in three trials involving walking on a treadmill while watching an avatar displayed on a monitor. The volunteers were fitted with a 64-channel headset and motion sensors at the hip, knee and ankle joint.

The avatar first was activated by the motion sensors, allowing its movement to precisely mimic that of the test subject. In later tests, the avatar was controlled by the brain-computer interface, meaning the subject controlled the avatar with his or her brain.

The avatar perfectly mimicked the subject’s movements when relying upon the sensors, but the match was less precise when the brain-computer interface was used.

Contreras-Vidal said that’s to be expected, noting that other studies have shown some initial decoding errors as the subject learns to use the interface. “It’s like learning to use a new tool or sport,” he said. “You have to understand how the tool works. The brain needs time to learn that.”

The researchers reported increased activity in the posterior parietal cortex and the inferior parietal lobe, along with increased involvement of the anterior cingulate cortex, which is involved in motor learning and error monitoring.

The next step is to use the protocol with patients, the subject of He’s Ph.D. dissertation.

“The appeal of brain-machine interface is that it places the user at the center of the therapy,” Contreras-Vidal said. “They have to be engaged, because they are in control.”

Source: Brain-Computer Interface & Virtual Avatar Offers New Hope to Patients with Gait Disabilities – Neuroscience News

 

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[WEB SITE] Doctors appear to have reached unexpected consensus in prescribing pediatric anti-seizure medications

July 19, 2017

The number of available anti-seizure medications has exploded in the past two decades, going from just a handful of medicines available in the 1990s to more than 20 now. Once the Food and Drug Administration (FDA) approves each new medicine based on trials in adults, it’s available for clinicians to prescribe off-label to all age groups. However, says William D. Gaillard, M.D., division chief of Child Neurology and Epilepsy, Neurophysiology and Critical Care Neurology at Children’s National Health System, trials that lead to FDA approval for adults do not provide any information about which medications are best for children.

“With so many medications and so little data,” Dr. Gaillard says, “one might think doctors would choose a wider variety of medicines when they prescribe to children with epilepsy.”

However, the results from a recent study by Dr. Gaillard and colleagues, published online in Pediatric Neurology on June 27, 2017, show otherwise. The study indicates that doctors in the United States appear to have reached an unexpected consensus about which medication to prescribe for their pediatric patients.

The study is part of a broader effort to collect data on the youngest epilepsy patients — those younger than 3 years old, the age at which epilepsy most often becomes evident. As part of this endeavor, researchers from 17 U.S. pediatric epilepsy centers enrolled in the study 495 children younger than 36 months old who had been newly diagnosed with non-syndromic epilepsy (a condition not linked to any of the commonly recognized genetic epilepsy syndromes).

The researchers mined these patients’ electronic medical records for information about their demographics, disease and treatments. About half of the study participants were younger than 1 year old when they were diagnosed with epilepsy. About half had disease marked by focal features, meaning that their epilepsy appeared to originate from a particular place in the brain. Nearly all were treated with a single medication, as opposed to a cocktail of multiple medicines.

Of those treated with a single medication, nearly all were treated with one of five medicines: Levetiracetam, oxcarbazepine, phenobarbital, topiramate and zonisamide. However, the data showed a clear prescribing preference. About 63 percent of the patients were prescribed levetiracetam as a first choice. By contrast, oxcarbazepine and phenobarbital, the next most frequently prescribed medicines, were taken by patients as a first choice by a mere 14 percent and 13 percent respectively.

Even more striking, of the children who were not prescribed levetiracetam initially but required a second medication due to inadequate efficacy or unacceptable side effects, 62 percent also received this medication. That made levetiracetam the first or second choice for about 74 percent of all the children in the study, despite the availability of more than 20 anti-seizure medications.

It’s not clear why levetiracetam is such a frequent choice in the United States, says Dr. Gaillard. However, in its favor, the drug is available in a liquid formulation, causes no ill effects medically and can be started intravenously if necessary. Studies have shown that it appears to be effective in controlling seizures in about 40 percent of infants.

Yet, levetiracetam’s market dominance appears to be a North American phenomenon, the study authors write. A recent international survey that Dr. Gaillard also participated in suggests that outside of this continent, carbazepine and oxcarbazepine were the most frequently prescribed medications to treat focal seizures.

What’s really necessary, Dr. Gaillard says, is real data on efficacy for each of the medications commonly prescribed to pediatric epilepsy patients–a marked vacuum in research that prevents doctors from using evidence-based reasoning when making medication choices.

“This study identifies current practices, but whether those practices are correct is a separate question,” he explains. “Just because a medication is used commonly doesn’t mean it is the best medication we should be using.”

To answer that question, he says, researchers will need to perform a head-to-head clinical trial comparing the top available epilepsy medications in children. This study sets the stage for such a trial by identifying which medications should be included.

“Uncontrolled pediatric epilepsy can have serious consequences, from potential problems in development to a higher risk of death,” Dr. Gaillard says. “You want to use the optimal medicine to treat the disease.”

Source: Doctors appear to have reached unexpected consensus in prescribing pediatric anti-seizure medications

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