What determines recovery time for a child after a traumatic brain injury?

This article explains why it takes children different amounts of time to recover from traumatic brain injury.

Why do some youngsters bounce back quickly from a traumatic brain injury, while others suffer devastating side effects for years?

New UCLA/USC research suggests that damage to the fatty sheaths around the brain's nerve fibers--not injury severity-- may explain the difference. Published in the July 15 edition of the Journal of Neuroscience, the finding identifies possible biomarkers that physicians could use to predict higher-risk patients who require closer monitoring.

The study is the first to combine imaging scans with recording of the brain's electrical activity to reveal how damage to the protective coating around the brain's circuitry affects how quickly children and teens can process and recall information after a concussion or other head trauma.

"Just as electricians insulate electrical wires to shield their connections, the brain's nerve fibers are encased in a fatty tissue called myelin that protects signals as they travel across the brain," explained Dr. Christopher Giza, director of the UCLA Steve Tisch BrainSPORT Program and a professor of pediatrics and neurosurgery at UCLA's David Geffen School of Medicine and Mattel Children's Hospital. "We suspected that trauma was damaging the myelin and slowing the brain's ability to transmit information, interfering with patients' capacity to learn."

To test their hypothesis, the scientists assigned a series of mental tasks to 32 youngsters ages 8 to 19. Each had suffered a moderate to severe brain injury in the past five months. The tests evaluated the children's processing speed, short-term memory, verbal learning and cognitive flexibility.

The UCLA team recorded the kids' brains' electrical activity to test how quickly their nerve fibers could transmit information, and then imaged the wiring to assess its structural soundness.

When the scientists compared the patients' results to those of a matched control group of 31 healthy children, they discovered dramatic differences.

Half of the brain-injury group showed widespread damage to the myelin insulating their brain's circuitry. These patients performed 14 percent more poorly on the cognitive tests and their wiring worked three times slower than healthy children's.

Scans of the other 16 patients in the brain-injury group showed their myelin was nearly intact; and their brains were able to process information as quickly as healthy children's. They performed 9 percent better on the cognitive tasks than the youngsters with more myelin damage, though not as well as the uninjured kids.

"Our research suggests that imaging the brain's wiring to evaluate both its structure and function could help predict a patient's prognosis after a traumatic brain injury," said first author Emily Dennis, a postdoctoral researcher at USC's Keck School of Medicine.

"Our next step will be to explore how brain biomarkers change during a patient's first year of recovery when most people recapture some cognitive function," said principal investigator Robert Asarnow, a professor of psychiatry and psychology at UCLA's Semel Institute for Neuroscience and Human Behavior and College of Letters and Science.

Traumatic brain injury is the single most common cause of death and disability in children and teens, according to the U.S. Centers for Disease Control.

The research was supported by funding from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Biomedical Imaging and Bioengineering, and the National Cancer Institute.

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Brain scan in development to diagnose autism

A two minute brain imaging test is being developed to diagnose autism.

Virginia Tech Carilion Research Institute scientists have developed a brain-imaging technique that may be able to identify children with autism spectrum disorder in just two minutes.

This test, while far from being used as the clinical standard of care, offers promising diagnostic potential once it undergoes more research and evaluation.

"Our brains have a perspective-tracking response that monitors, for example, whether it's your turn or my turn," said Read Montague, the Virginia Tech Carilion Research Institute professor who led the study.

"This response is removed from our emotional input, so it makes a great quantitative marker," he said. "We can use it to measure differences between people with and without autism spectrum disorder."

The finding, slated for online publication next week in Clinical Psychological Science, demonstrates that the perspective-tracking response can be used to determine whether someone has autism spectrum disorder.

Usually, diagnosis -- an unquantifiable process based on clinical judgment -- is time consuming and trying on children and their families. That may change with this new diagnostic test.

The path to this discovery has been a long, iterative one. In a 2006 study by Montague and others, pairs of subjects had their brains scanned using functional magnetic resonance imaging, or MRI, as they played a game requiring them to take turns.

From those images, researchers found that the middle cingulate cortex became more active when it was the subject's turn.

"A response in that part of the brain is not an emotional response, and we found that intriguing," said Montague, who also directs the Computational Psychiatry Unit at the Virginia Tech Carilion Research Institute and is a professor of physics at Virginia Tech. "We realized the middle cingulate cortex is responsible for distinguishing between self and others, and that's how it was able to keep track of whose turn it was."

That realization led the scientists to investigate how the middle cingulate cortex response differs in individuals at different developmental levels. In a 2008 study, Montague and his colleagues asked athletes to watch a brief clip of a physical action, such as kicking a ball or dancing, while undergoing functional MRI.

The athletes were then asked either to replay the clips in their mind, like watching a movie, or to imagine themselves as participants in the clips.

"The athletes had the same responses as the game participants from our earlier study," Montague said. "The middle cingulate cortex was active when they imagined themselves dancing -- in other words, when they needed to recognize themselves in the action."

In the 2008 study, the researchers also found that in subjects with autism spectrum disorder, the more subdued the response, the more severe the symptoms.

Montague and his team hypothesized that a clear biomarker for self-perspective exists and that they could track it using functional MRI. They also speculated that the biomarker could be used as a tool in the clinical diagnosis of people with autism spectrum disorder.

In 2012, the scientists designed another study to see whether they could elicit a brain response to help them compute the unquantifiable. And they could: By presenting self-images while scanning the brains of adults, they elicited the self-perspective response they had previously observed in social interaction games.

In the current study, with children, subjects were shown 15 images of themselves and 15 images of a child matched for age and gender for four seconds per image in a random order.

Like the control adults, the control children had a high response in the middle cingulate cortex when viewing their own pictures. In contrast, children with autism spectrum disorder had a significantly diminished response.

Importantly, Montague's team could detect this difference in individuals using only a single image.

Montague and his group realized they had developed a single-stimulus functional MRI diagnostic technique. The single-stimulus part is important, Montague points out, as it enables speed. Children with autism spectrum disorder cannot stay in the scanner for long, so the test must be quick.

"We went from a slow, average depiction of brain activity in a cognitive challenge to a quick test that is significantly easier for children to do than spend hours under observation," Montague said. "The single-stimulus functional MRI could also open the door to developing MRI-based applications for screening of other cognitive disorders."

By mapping psychological differences through brain scans, scientists are adding a critical component to the typical process of neuropsychiatric diagnosis -- math.

Montague has been a pioneering figure in this field, which he coined computational psychiatry. The idea is that scientists can link the function of mental disorders to the disrupted mechanisms of neural tissue through mathematical approaches. Doctors then can use measurable data for earlier diagnosis and treatment.

An earlier diagnosis can also have a tremendous impact on the children and their families, Montague said.

"The younger children are at the time of diagnosis," Montague said, "the more they can benefit from a range of therapies that can transform their lives."

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Study: Brain scans show difference between those who have recovered from ADHD and those who have not

Very interesting news about ADD!! We have observed that half of kids grow out it.- JR

A study looked into brain scans from adults who recovered from ADHD versus those who have not recovered from ADHD and noted differences in the brain scan results.

About 11 percent of school-age children in the United States have been diagnosed with attention deficit hyperactivity disorder (ADHD). While many of these children eventually "outgrow" the disorder, some carry their difficulties into adulthood: About 10 million American adults are currently diagnosed with ADHD.

In the first study to compare patterns of brain activity in adults who recovered from childhood ADHD and those who did not, MIT neuroscientists have discovered key differences in a brain communication network that is active when the brain is at wakeful rest and not focused on a particular task. The findings offer evidence of a biological basis for adult ADHD and should help to validate the criteria used to diagnose the disorder, according to the researchers.

Diagnoses of adult ADHD have risen dramatically in the past several years, with symptoms similar to those of childhood ADHD: a general inability to focus, reflected in difficulty completing tasks, listening to instructions, or remembering details.

"The psychiatric guidelines for whether a person's ADHD is persistent or remitted are based on lots of clinical studies and impressions. This new study suggests that there is a real biological boundary between those two sets of patients," says MIT's John Gabrieli, the Grover M. Hermann Professor of Health Sciences and Technology, professor of brain and cognitive sciences, and an author of the study, which appears in the June 10 issue of the journal Brain.

Shifting brain patterns

This study focused on 35 adults who were diagnosed with ADHD as children; 13 of them still have the disorder, while the rest have recovered. "This sample really gave us a unique opportunity to ask questions about whether or not the brain basis of ADHD is similar in the remitted-ADHD and persistent-ADHD cohorts," says Aaron Mattfeld, a postdoc at MIT's McGovern Institute for Brain Research and the paper's lead author.

The researchers used a technique called resting-state functional magnetic resonance imaging (fMRI) to study what the brain is doing when a person is not engaged in any particular activity. These patterns reveal which parts of the brain communicate with each other during this type of wakeful rest.

"It's a different way of using functional brain imaging to investigate brain networks," says Susan Whitfield-Gabrieli, a research scientist at the McGovern Institute and the senior author of the paper. "Here we have subjects just lying in the scanner. This method reveals the intrinsic functional architecture of the human brain without invoking any specific task."

In people without ADHD, when the mind is unfocused, there is a distinctive synchrony of activity in brain regions known as the default mode network. Previous studies have shown that in children and adults with ADHD, two major hubs of this network -- the posterior cingulate cortex and the medial prefrontal cortex -- no longer synchronize.

In the new study, the MIT team showed for the first time that in adults who had been diagnosed with ADHD as children but no longer have it, this normal synchrony pattern is restored. "Their brains now look like those of people who never had ADHD," Mattfeld says.

"This finding is quite intriguing," says Francisco Xavier Castellanos, a professor of child and adolescent psychiatry at New York University who was not involved in the research. "If it can be confirmed, this pattern could become a target for potential modification to help patients learn to compensate for the disorder without changing their genetic makeup."

Lingering problems

However, in another measure of brain synchrony, the researchers found much more similarity between both groups of ADHD patients.

In people without ADHD, when the default mode network is active, another network, called the task positive network, is suppressed. When the brain is performing tasks that require focus, the task positive network takes over and suppresses the default mode network. If this reciprocal relationship degrades, the ability to focus declines.

Both groups of adult ADHD patients, including those who had recovered, showed patterns of simultaneous activation of both networks. This is thought to be a sign of impairment in executive function -- the management of cognitive tasks -- that is separate from ADHD, but occurs in about half of ADHD patients. All of the ADHD patients in this study performed poorly on tests of executive function. "Once you have executive function problems, they seem to hang in there," says Gabrieli, who is a member of the McGovern Institute.

The researchers now plan to investigate how ADHD medications influence the brain's default mode network, in hopes that this might allow them to predict which drugs will work best for individual patients. Currently, about 60 percent of patients respond well to the first drug they receive.

"It's unknown what's different about the other 40 percent or so who don't respond very much," Gabrieli says. "We're pretty excited about the possibility that some brain measurement would tell us which child or adult is most likely to benefit from a treatment."

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Portable brain scanners may be present in more locker rooms

A portable brain scanner could become present in more locker rooms which could change the way concussions are understood in the long-term.

A portable imaging tool could change the way the medical community analyzes and understands the long-term effects of sports-related concussions.

Research conducted by Humboldt State Kinesiology professor Rock Braithwaite has played a significant role in demonstrating the usefulness of computerized neurocognitive testing in determining the extent of the effects of concussion on cognition and performance among student athletes and military personnel.

"This preliminary study, although small, showed us where in the brain a patient is affected and to what cognitive extent," said Michael Collins, director of a current study being conducted on functional near infrared spectroscopy (fNIRS) as a low-cost, portable device for imaging sports and military concussions.

Braithwaite collaborated with former HSU professor Anthony Kontos, a professor for the University of Pittsburgh Schools of the Health Sciences, and two other University of Pittsburgh professors, on the fNIRS research that is considered the largest statistical review of computerized testing to date. The study, published in the March Journal of International Neuropsychological Society, supplied data for Kontos' study.

Braithwaite's study evaluated prior research of published computerized concussion testing to date, covering 37 studies and 3,960 participants all within the first week of sustaining a concussion. The study produced two key findings:

- Middle school and younger high-school students displayed more pronounced cognitive effects and greater performance deterioration according to neurocognitive testing after a concussion than their senior high school and college-aged counterparts.

- ImPACT® -- a computerized neurocognitive test battery designed to assess mild traumatic brain injury -- demonstrated the strongest performance for detecting cognitive impairment because it measured the types of tasks that this meta-analysis identified as most effective at detecting post-concussion issues including: processing speed, verbal memory, visual memory and recall. The success of this technology indicates computerized testing -- as conducted with the fNIRS -- is the most accurate evaluation method.

"ImPACT found the largest effects for individuals who had been concussed -- across all outcomes," said Braithwaite, who conceived of the idea for this study. "Memory, processing speed, recall … ImPACT was able to better detect changes compared to the other computerized tests."

"In the past decade and a half, many in the field of concussion science have tried to find an imaging tool that could help us in a clinical setting -- and failed to find anything with consistency," said Collins. "[Braithwaite's study] was enough evidence for us to keep pushing further with this potential tool."

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Brain abnormalities seen in late pre-term infants

A study looked into MRI scans of late pre-term infant and found that they have brain abnormalities.

Babies born 32 to 36 weeks into gestation may have smaller brains and other brain abnormalities that could lead to long-term developmental problems, according to a new study published online in the journal Radiology.

Much of the existing knowledge on preterm birth and brain development has been drawn from studies of individuals born very preterm, or less than 32 weeks into gestation at birth.

For the new study, researchers in Australia focused on moderate and late preterm (MLPT) babies -- those born between 32 weeks, zero days, and 36 weeks, six days, into gestation. MLPT babies account for approximately 80 percent of all preterm births and are responsible for much of the rise in the rates of preterm birth over the last 20 years. Despite this, to date there have been no large-scale studies published on brain alterations associated with MLPT birth that may provide insight into brain-behavior relationships in this group of children.

"In those very preterm babies, brain injury from bleeding into the brain or a lack of blood flow, oxygen or nutrition to the brain may explain some of the abnormal brain development that occurs," said the study's lead author, Jennifer M. Walsh,M.B.B.Ch., B.A.O., M.R.C.P.I., from the Royal Women's Hospital in Melbourne, Australia. "However, in some preterm babies, there may be no obvious explanation for why their brain development appears slow compared with babies born on time."

To learn more, the researchers performed magnetic resonance imaging (MRI) exams on 199 MLPT and 50 term-born infants (greater than 37 weeks gestation) between 38 to 44 weeks of gestation. They looked for signs of brain injury and compared the size and maturation of multiple brain structures in the two groups.

While injury rates were similar between the two groups, MLPT birth was associated with smaller brain size at term-equivalent age. In addition, MLPT infants had less developed myelination in one part of the brain and more immature gyral folding compared with term-born controls. Myelination -- the formation of a fatty insulating sheath around some nerve fibers -- and gyral folding -- the folding of the cerebral cortex to increase the brain's surface area -- are important processes in early brain development.

The findings suggest that MLPT birth may disrupt the expected trajectory of brain growth that would normally occur in the last two or so months in utero, according to Dr. Walsh.

"Given that brain growth is very rapid in the last one-third of pregnancy, it is perhaps not surprising that being born during this potentially vulnerable period may disrupt brain development," she said. "Brain growth is very complex, involving not only the neurons with which we think and do things, but also the other brain cells that support the neurons and are vital for normal brain function."

The researchers are hoping to learn in greater depth the impact that moderate to late preterm birth has on the brain, so that they can then begin to try different treatments designed to improve brain function and long-term outcome in these infants.

"Medications, along with early intervention to help parents understand their baby's needs, have been effective in helping very preterm babies catch up to their term-born peers," Dr. Walsh said. "However, whether any of the existing treatments will help babies born between 32 and 36 weeks is unknown, as they have not been studied very much at all."

The researchers plan to follow the infants in the study group through childhood to learn more about the relationship between brain abnormalities and later outcomes. They also are assessing additional MRI information about brain structure and function in these children.

"Understanding what problems they have and what might be causing them is the first step in trying to improve their long-term outcome," Dr. Walsh said.

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Children with ADHD show specific MRI Patterns

Children with ADHD show specific MRI patterns indicating that ADHD may be diagnosable though MRI scans.

A new study has found that children and adolescents with attention deficit hyperactivity disorder (ADHD) have disrupted connections between different areas of the brain that are evident on resting-state functional magnetic resonance imaging (rfMRI). The results of this research are published online in the journal Radiology.

The findings point to the potential of rfMRI to help provide objectively accurate, early diagnosis of a disorder that affects approximately 5 percent of children and adolescents worldwide.

ADHD is a disorder characterized by age-inappropriate degrees of inattention, hyperactivity and impulsivity. Functional MRI studies, which measure brain activity when a person is focused on a particular task, have implicated the brain's frontostriatal circuit, a collection of neural pathways in the frontal lobe of the brain that helps control behavior. However, the specific brain physiology underlying ADHD remains poorly understood.

For the new study, researchers used rfMRI, a relatively new technique that assesses neural function when the brain is not focused on a specific task. The technique is useful for exploring the brain's functional organization independent of task performance.

The researchers compared rfMRI results in 33 boys with ADHD, ages 6 to 16, with those of 32 similarly aged, healthy controls. They correlated the MRI findings with results from tests of executive function, a term for the set of mental processes involved in planning, organizing, time management and regulating emotions, among other things. People with ADHD often have abnormal executive function.

The results showed that the patients with ADHD had altered structure and function located in areas of the brain like the orbitofrontal cortex, which is primarily involved in the cognitive processing of strategic planning, and the globus pallidus, which is involved in executive inhibitory control.

"Our study suggests that the structural and functional abnormalities in these brain regions might cause the inattention and hyperactivity of the patients with ADHD, and we are doing further analysis on their correlation with the clinical symptoms," said Qiyong Gong, M.D., Ph.D., a neuroradiologist from the Department of Radiology at West China Hospital of Sichuan University in Sichuan, China. "Our preliminary results show the association between imaging findings and symptoms."

The researchers also found abnormalities in the connections between resting-state brain networks associated with executive dysfunction. These abnormalities indicate more widespread brain alterations in ADHD than previously had been shown, Dr. Gong said.

Exploration of the association between brain activity and executive function might be useful in better characterizing patients with ADHD and in understanding the pathophysiology underlying the condition, according to Dr. Gong.

"Our results suggest the potential clinical utility of the rfMRI changes as a useful marker, which may help in diagnosis and in monitoring disease progression and, consequently, may inform timely clinical intervention in the future," he said.

Dr. Gong indicated that larger studies are needed to validate the results. The researchers also plan to study changes in connectivity over time in ADHD patients and explore the potential differences of functional connectivity between the clinical subtypes of ADHD, such as inattentiveness and hyperactivity.

The ADHD study is part of a larger project from Dr. Gong's group at Huaxi MR Research Center of the West China Hospital to explore MRI's diagnostic and prognostic potential in psychiatric disorders.

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$1 billion spent on brain scans each year for headache sufferers

A study shows that $1 billion is spent each year on brain scans for those who suffer from headaches when most of the scans may be unnecessary.

One in eight visits to a a doctor for a headache or migraine end up with the patient going for a brain scan, at a total cost of about $1 billion a year, a new study finds. 

And many of those MRI and CT scans -- and costs -- are probably unnecessary, given the very low odds that serious issues lurk in the patients' brains.

In fact, several national guidelines for doctors specifically discourage scanning the brains of patients who complain of headache and migraine. But the new study shows the rate of brain scans for headache has risen, not fallen, since guidelines for doctors came out. This may mean that patient demand for scans drives much of the cost.

The researchers suggest that better education of the public, and insurance plan designs that ask patients to pay part of the cost based on the likely value of the scan for them, may be needed to reduce unnecessary use and spending.

The research, published in JAMA Internal Medicine by a team from the U-M Department of Neurology, uses national data on headache-related doctor visits and neuroimaging scans by people over age 18, and calculates estimated total costs across multiple years.

In all, 51.1 million headache-related patient visits occurred between 2007 and 2010 -- nearly half of them related to migraine. The vast majority were by people under the age of 65, and more than three-quarters of the patients were women. In those same four years, 12.4 percent of these visits resulted in a brain MRI or CT.

The researchers estimated the total cost of the four years' worth of scans at $3.9 billion, based on typical Medicare payments to doctors for imaging.

"This is a conservative cost estimate based on what Medicare would pay for these tests. CTs and MRIs are commonly ordered for headache and migraine, and increasing over time, despite the fact that there are rare circumstances where imaging should be used," says Brian Callaghan, M.D., M.S., the U-M neurologist who led the team performing the study.

"Lots of guidelines say we shouldn't do this -- including ones from neurology and radiology groups -- but yet we still do it a lot. This is a source of tremendous cost in health care without a lot of evidence to justify the cost," he notes.

A billion dollars' worth of reassurance?

Doctors might order a CT or MRI scan for a headache or migraine to put patients' minds at ease about fears that a malignant brain tumor, aneurysm, arteriovenous malformation or other issue might be causing their symptoms.

And even if the patient doesn't meet the conditions that guidelines say can benefit most from brain imaging -- for instance, someone with an abnormal neurological exam or a known cancer -- doctors might order a scan at a patient's request to protect themselves legally.

But past research shows that only 1 percent to 3 percent of scans of patients with repeated headaches find that a growth or blood vessel problem in the brain is to blame. And many of the issues that scans spot turn out not to pose a serious threat -- or may not require treatment right away.

"There's solid research showing that the number of times you find serious issues on these scans in headache patients is about the same as that for a randomly chosen group of non-headache patients," he says. "And a lot of the things we find on such scans aren't necessarily something we will do something about."

Callaghan notes that the current study, based on data from the Centers for Disease Control & Prevention's National Ambulatory Care Medical Survey, couldn't detect which scans met guidelines and which didn't.

But the fact that 14.7 percent of people who saw a doctor for headache or migraine in 2010 went on to have a brain scan would not be expected if guidelines were being followed, he says. The team is working on further research into the appropriateness of the scans ordered for patients.

He also notes that the $1 billion a year estimate doesn't include other costs, including follow-up tests and any treatment that might be ordered if a scan finds something. And, CT imaging comes with a radiation exposure that itself carries risks, while MRI scans are more costly and have a higher chance of finding things that turn out to be of no concern.

"But doctors typically don't consider costs, and patients usually aren't paying directly for these scans," he notes. "Insurers may require prior authorizations but still cover the scans if they are ordered." In fact, he and his colleagues last year published a study showing that the cost of medical imaging ordered by neurologists cost more than the cost of all visits to neurologists added together.

The bottom line for headache patients who think they might want to have a brain scan, says Callaghan: if the doctor treating your headache doesn't think you need a scan, don't push them.

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Retired American football players have unusual brain scans

A study of brain scans of retired American football players with no known neurological conditions shows their brain activity is very different than expected.

A new study has discovered profound abnormalities in brain activity in a group of retired American football players.

Although the former players in the study were not diagnosed with any neurological condition, brain imaging tests revealed unusual activity that correlated with how many times they had left the field with a head injury during their careers.

Previous research has found that former American football players experience higher rates of neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The new findings, published in Scientific Reports, suggest that players also face a risk of subtle neurological deficits that don't show up on normal clinical tests.

The study involved 13 former National Football League (NFL) professionals who believed they were suffering from neurological problems affecting their everyday lives as a consequence of their careers.

The former players and 60 healthy volunteers were given a test that involved rearranging coloured balls in a series of tubes in as few steps as possible. Their brain activity was measured using functional magnetic resonance imaging (fMRI) while they did the test.

The NFL group performed worse on the test than the healthy volunteers, but the difference was modest. More strikingly, the scans showed unusual patterns of brain activity in the frontal lobe. The difference between the two groups was so marked that a computer programme learned to distinguish NFL alumni and controls at close to 90 per cent accuracy based just on their frontal lobe activation patterns.

"The NFL alumni showed some of the most pronounced abnormalities in brain activity that I have ever seen, and I have processed a lot of patient data sets in the past," said Dr Adam Hampshire, lead author of the study, from the Department of Medicine at Imperial College London.

The frontal lobe is responsible for executive functions: higher-order brain activity that regulates other cognitive processes. The researchers think the differences seen in this study reflect deficits in executive function that might affect the person's ability to plan and organise their everyday lives.

"The critical fact is that the level of brain abnormality correlates strongly with the measure of head impacts of great enough severity to warrant being taken out of play. This means that it is highly likely that damage caused by blows to the head accumulate towards an executive impairment in later life."

Dr Hampshire and his colleagues at the University of Western Ontario, Canada suggest that fMRI could be used to reveal potential neurological problems in American football players that aren't picked up by standard clinical tests. Brain imaging results could be useful to retired players who are negotiating compensation for neurological problems that may be related to their careers. Players could also be scanned each season to detect problems early.

The findings also highlight the inadequacy of standard cognitive tests for detecting certain types of behavioural deficit.

"Researchers have put a lot of time into developing tests to pick up on executive dysfunction, but none of them work at all well. It's not unusual for an individual who has had a blow to the head to perform relatively well on a neuropsychological testing battery, and then go on to struggle in everyday life.

"The results tell us something very interesting about the human brain, which is that after damage, it can work harder and bring extra areas on line in order to cope with cognitive tasks. It is likely that in more complicated real world scenarios, this plasticity is insufficient and consequently, the executive impairment is no longer masked. In this respect, the results are also of relevance to other patients who suffer from multiple head injuries.

"Of course, this is a relatively preliminary study. We really need to test more players and to track players across seasons using brain imaging."

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Brain scans can determine which letter a person is reading

fMRI brain scans can be used to determine which letter a person regarding. This technology may be the first step to determining what a person is thinking.

By analysing MRI images of the brain with an elegant mathematical model, it is possible to reconstruct thoughts more accurately than ever before. In this way, researchers from Radboud University Nijmegen have succeeded in determining which letter a test subject was looking at.

The journal Neuroimage has accepted the article, which will be published soon.

Functional MRI scanners have been used in cognition research primarily to determine which brain areas are active while test subjects perform a specific task. The question is simple: is a particular brain region on or off? A research group at the Donders Institute for Brain, Cognition and Behaviour at Radboud University has gone a step further: they have used data from the scanner to determine what a test subject is looking at.

The researchers 'taught' a model how small volumes of 2x2x2 mm from the brain scans -- known as voxels -- respond to individual pixels. By combining all the information about the pixels from the voxels, it became possible to reconstruct the image viewed by the subject. The result was not a clear image, but a somewhat fuzzy speckle pattern. In this study, the researchers used hand-written letters.

Prior knowledge improves model performance

'After this we did something new', says lead researcher Marcel van Gerven. 'We gave the model prior knowledge: we taught it what letters look like. This improved the recognition of the letters enormously. The model compares the letters to determine which one corresponds most exactly with the speckle image, and then pushes the results of the image towards that letter. The result was the actual letter, a true reconstruction.'

'Our approach is similar to how we believe the brain itself combines prior knowledge with sensory information. For example, you can recognise the lines and curves in this article as letters only after you have learned to read. And this is exactly what we are looking for: models that show what is happening in the brain in a realistic fashion. We hope to improve the models to such an extent that we can also apply them to the working memory or to subjective experiences such as dreams or visualisations. Reconstructions indicate whether the model you have created approaches reality.'

Improved resolution; more possibilities

'In our further research we will be working with a more powerful MRI scanner,' explains Sanne Schoenmakers, who is working on a thesis about decoding thoughts. 'Due to the higher resolution of the scanner, we hope to be able to link the model to more detailed images. We are currently linking images of letters to 1200 voxels in the brain; with the more powerful scanner we will link images of faces to 15,000 voxels.'

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Dyslexia diagnosed by brain scans? Examine the arcuate fasciculus

Brain scans showing the brain's structure may soon be able to show a person is dyslexic. JR

About 10 percent of the U.S. population suffers from dyslexia, a condition that makes learning to read difficult. Dyslexia is usually diagnosed around second grade, but the results of a new study from MIT could help identify those children before they even begin reading, so they can be given extra help earlier.

The study, done with researchers at Boston Children's Hospital, found a correlation between poor pre-reading skills in kindergartners and the size of a brain structure that connects two language-processing areas.

Previous studies have shown that in adults with poor reading skills, this structure, known as the arcuate fasciculus, is smaller and less organized than in adults who read normally. However, it was unknown if these differences cause reading difficulties or result from lack of reading experience.

"We were very interested in looking at children prior to reading instruction and whether you would see these kinds of differences," says John Gabrieli, the Grover M. Hermann Professor of Health Sciences and Technology, professor of brain and cognitive sciences and a member of MIT's McGovern Institute for Brain Research.

Gabrieli and Nadine Gaab, an assistant professor of pediatrics at Boston Children's Hospital, are the senior authors of a paper describing the results in the Aug. 14 issue of theJournal of Neuroscience. Lead authors of the paper are MIT postdocs Zeynep Saygin and Elizabeth Norton.

The path to reading

The new study is part of a larger effort involving approximately 1,000 children at schools throughout Massachusetts and Rhode Island. At the beginning of kindergarten, children whose parents give permission to participate are assessed for pre-reading skills, such as being able to put words together from sounds.

"From that, we're able to provide -- at the beginning of kindergarten -- a snapshot of how that child's pre-reading abilities look relative to others in their classroom or other peers, which is a real benefit to the child's parents and teachers," Norton says.

The researchers then invite a subset of the children to come to MIT for brain imaging. The Journal of Neuroscience study included 40 children who had their brains scanned using a technique known as diffusion-weighted imaging, which is based on magnetic resonance imaging (MRI).

This type of imaging reveals the size and organization of the brain's white matter -- bundles of nerves that carry information between brain regions. The researchers focused on three white-matter tracts associated with reading skill, all located on the left side of the brain: the arcuate fasciculus, the inferior longitudinal fasciculus (ILF) and the superior longitudinal fasciculus (SLF).

When comparing the brain scans and the results of several different types of pre-reading tests, the researchers found a correlation between the size and organization of the arcuate fasciculus and performance on tests of phonological awareness -- the ability to identify and manipulate the sounds of language.

Phonological awareness can be measured by testing how well children can segment sounds, identify them in isolation, and rearrange them to make new words. Strong phonological skills have previously been linked with ease of learning to read. "The first step in reading is to match the printed letters with the sounds of letters that you know exist in the world," Norton says.

The researchers also tested the children on two other skills that have been shown to predict reading ability -- rapid naming, which is the ability to name a series of familiar objects as quickly as you can, and the ability to name letters. They did not find any correlation between these skills and the size or organization of the white-matter structures scanned in this study.

Brian Wandell, director of Stanford University's Center for Cognitive and Neurobiological Imaging, says the study is a valuable contribution to efforts to find biological markers that a child is likely to need extra help to learn to read.

"The work identifies a clear marker that predicts reading, and the marker is present at a very young age. Their results raise questions about the biological basis of the marker and provides scientists with excellent new targets for study," says Wandell, who was not part of the research team.

Early intervention

The left arcuate fasciculus connects Broca's area, which is involved in speech production, and Wernicke's area, which is involved in understanding written and spoken language. A larger and more organized arcuate fasciculus could aid in communication between those two regions, the researchers say.

Gabrieli points out that the structural differences found in the study don't necessarily reflect genetic differences; environmental influences could also be involved. "At the moment when the children arrive at kindergarten, which is approximately when we scan them, we don't know what factors lead to these brain differences," he says.

The researchers plan to follow three waves of children as they progress to second grade and evaluate whether the brain measures they have identified predict poor reading skills.

"We don't know yet how it plays out over time, and that's the big question: Can we, through a combination of behavioral and brain measures, get a lot more accurate at seeing who will become a dyslexic child, with the hope that that would motivate aggressive interventions that would help these children right from the start, instead of waiting for them to fail?" Gabrieli says.

For at least some dyslexic children, offering extra training in phonological skills can help them improve their reading skills later on, studies have shown.

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Trouble concentrating in people with insomnia

A study using brain scans helps to explain why people with insomnia have 'wandering minds' and trouble concentrating.

A new brain imaging study may help explain why people with insomnia often complain that they struggle to concentrate during the day even when objective evidence of a cognitive problem is lacking.

"We found that insomnia subjects did not properly turn on brain regions critical to a working memory task and did not turn off 'mind-wandering' brain regions irrelevant to the task," said lead author Sean P.A. Drummond, PhD, associate professor in the department of psychiatry at the University of California, San Diego, and the VA San Diego Healthcare System, and Secretary/Treasurer of the Sleep Research Society. "Based on these results, it is not surprising that someone with insomnia would feel like they are working harder to do the same job as a healthy sleeper."

The research team led by Drummond and co-principal investigator Matthew Walker, PhD, studied 25 people with primary insomnia and 25 good sleepers. Participants had an average age of 32 years. The study subjects underwent a functional magnetic resonance imaging scan while performing a working memory task.

Results published in the September issue of the journal Sleepshow that participants with insomnia did not differ from good sleepers in objective cognitive performance on the working memory task. However, the MRI scans revealed that people with insomnia could not modulate activity in brain regions typically used to perform the task.

As the task got harder, good sleepers used more resources within the working memory network of the brain, especially the dorsolateral prefrontal cortex. Insomnia subjects, however, were unable to recruit more resources in these brain regions. Furthermore, as the task got harder, participants with insomnia did not dial down the "default mode" regions of the brain that are normally only active when our minds are wandering.

"The data help us understand that people with insomnia not only have trouble sleeping at night, but their brains are not functioning as efficiently during the day," said Drummond. "Some aspects of insomnia are as much of a daytime problem as a nighttime problem. These daytime problems are associated with organic, measurable abnormalities of brain activity, giving us a biological marker for treatment success."

According to the authors, the study is the largest to examine cerebral activation with functional MRI during cognitive performance in people with primary insomnia, relative to well-matched good sleepers. It also is the first to characterize functional MRI differences in working memory in people with primary insomnia.

The American Academy of Sleep Medicine reports that about 10 to 15 percent of adults have an insomnia disorder with distress or daytime impairment. Most often insomnia is a comorbid disorder occurring with another problem such as depression or chronic pain, or caused by a medication or substance. Fewer people suffering from insomnia are considered to have primary insomnia, which is defined as a difficulty falling asleep or maintaining sleep in the absence of a coexisting condition.

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Concussion damage looks like early Alzheimer's

Damage from concussions seen in brain scans of children resembles early Alzheimer's.

Concussion can lead to damage in the white matter of the brain that resembles abnormalities found in people in the early stages of Alzheimer's disease, a new study suggests.

Researchers at the University of Pittsburgh School of Medicine said their findings should prompt a re-evaluation of the long-term effects of concussion, which affects more than 1.7 million people in the United States annually. About 15 percent of concussion patients suffer persistent neurological symptoms.

"The previous thinking before was you get a concussion, and that causes a certain damage from bopping your head and you get these symptoms," said study author Dr. Saeed Fakhran, an assistant professor of radiology at the University of Pittsburgh School of Medicine. "We found it acts as a kind of trigger, and lights a fuse that causes a neurodegenerative cascade that causes all these symptoms down the line. Once you've hit your head, the injury isn't done."

The findings are published online June 18 in the journal Radiology.

The study drew some criticism from concussion and Alzheimer's disease experts who said the findings, while provocative, should not be interpreted as drawing a clear link between a concussion suffered early in life with the development of Alzheimer's.

"I don't want a mom to pick this up and say, 'Oh my god, my 10-year-old is going to get Alzheimer's now,' because that is not the case," said Dr. Ken Podell, a neuropsychologist and co-director of the Methodist Concussion Center in Houston. "It's very inconclusive at this time, and there's no clinical application of this at this point of time."

White matter serves as the tissue through which messages pass between different areas of gray matter within the brain and spinal cord. Think of gray matter as the individual computers in a network, and white matter as the cables that connect the computer.

The researchers reviewed past brain scans of 64 people who had suffered a concussion, focusing on scans that used an advanced MRI technique called diffusion-tensor imaging, which spots microscopic changes in the brain's white matter.

The investigators then compared these brain scans to symptoms reported by concussed patients in a post-concussion questionnaire. They focused on symptoms shared with Alzheimer's patients, including memory problems, disturbances in sleep cycles and hearing problems.

The results showed a significant correlation between high concussion symptom scores and reduced water movement in the parts of the brain's white matter related to auditory processing and sleep-wake disturbances. Further, the researchers said, the distribution of white matter abnormalities in mildly concussed patients resembled the distribution of abnormalities in people with Alzheimer's disease.

"Basically, it looks a lot like Alzheimer's," said study co-author Dr. Lea Alhilali, an assistant professor of radiology at the University of Pittsburgh School of Medicine. "You get the same distribution of damage in the way that Alzheimer's disease affects the brain."

These abnormalities could spark a series of reactions that lead to long-term problems with thinking and memory. "The cascade is what is the important factor," Alhilali said. "It doesn't appear what you're symptomatic from is the injury itself. What you're symptomatic from is how the brain responds to that injury."

However, brain experts believe that researchers may be going too far in trying to draw a link between the concussion damage they found and the chronic damage found in Alzheimer's.

"It's an interesting observation, but I think they are making a leap that the pattern of changes they see on the scan are indicative of what we see in Alzheimer's disease," said Dr. Ron Petersen, director of the Mayo Alzheimer's Disease Research Center. "Their correlation between the scores on the concussion instrument and white matter changes, that's nice and good and makes sense. But then they go into a rather extensive anatomical explanation of how this might be similar to Alzheimer's disease, and I find that a bit tenuous."

Podell listed a number of concerns with the article, including:

• The researchers' reliance on existing brain scans and symptom charts created by other people. "You don't know what questions were asked, who asked the questions, how they were asked," he said. "There are a lot of things you can't control for."
• The inclusion of young patients in the pool of subjects, who ranged in age from 10 to 38. "White matter is not fully developed in people until they are adults," he said. "You have 10-year-olds in this study. It is highly, highly unusual to mix young kids with adults, because the brain is so different."
• The use of sleep disturbance as a comparable symptom between concussion and Alzheimer's. "What's a common co-injury in concussion? Whiplash. You have neck pain, back pain," he said. "If you go to sleep, you don't think that pain wakes you up?"

"The issue is, does a single concussion in an individual mean they are at risk for developing Alzheimer's?" Podell said. "There are so many other factors involved, including genetic factors, management of a concussion and the general health and well-being of the individual throughout their life."

The study authors agreed that their findings are tentative.

"This is not a definitive study. This is not the end at all. This is the first step," Alhilali said. "We hope this will lead to more research that will further explore this potential link."

The researchers do believe their findings could lead to better treatments in the future, however.

"The first step in developing a treatment for any disease is understanding what causes it," Fakhran said. "If we can prove a link, or even a common pathway, between mild traumatic brain injury and Alzheimer's, this could potentially lead to treatment strategies that would be potentially efficacious in treating both diseases."

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