Tag: head injury

Death Of Cricketer Phillip Hughes: Why Are Some Brain Injuries Worse Than Others?

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Australian cricketer, Phillip Hughes.

Australian cricketer, Phillip Hughes.

Australian cricketer Phillip Hughes has died two days after being struck in the head by a bouncer while batting for South Australia at the The Sydney Cricket Ground. Hughes, 25, had been in an induced coma since the accident on Tuesday afternoon.

Two of the most tragic events within Australian cricket in just over the past decade have involved catastrophic head injuries: firstly to David Hookes in a hotel altercation, secondly to Phillip Hughes while batting. According to research published in The Lancet, approximately a fifth of adults with a severe traumatic brain injury make a good recovery. But many more die or are left with enduring disability.  

So why are some brain injuries worse than others?

The effects of brain injury fall into three main categories:

  • Cognitive – problems with memory, concentration, information processing
  • Emotional and behavioural problems – anxiety, explosive anger and irritability, lack of awareness or empathy
  • Physical – problems with movement, balance and co-ordination, fatigue, epilepsy

Sometimes a head injury which seems severe is followed by a good recovery while a seemingly small head injury can have very serious, long-lasting consequences.  Why is this?

Location, location, location.

The reason is that brain injury operates a bit like the property market in that the three most important things to consider are location, location and location. When nerve pathways are damaged, those brain areas served by those pathways may wither or have their functions taken over by other brain regions. Nerve pathways are also called ‘white’ pathways or ‘white matter’ because they are covered by an insulating sheath of myelin and appear white to the naked eye.

The challenge is to determine the location of key ‘scaffold’ pathways and to understand what makes them so vulnerable and important. This is not an easy task given the total length of nerve pathways in the average 20-year old human brain is 160,000 km. A recent study provides new findings on the brain’s network scaffold that will help inform clinicians about the neurological impacts of brain diseases such as multiple sclerosis, Alzheimer’s disease and brain injury.

 

Weekly Neuroscience Update

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human-brain-120329

MRIs work by aligning the magnetic spin of the hydrogen molecules in the body. Credit: Image courtesy of MGH-UCLA Human Connectome Project.

Brain scans are now starting to peer down to the molecular level, revealing what brain cells are telling one another, researchers say.

A new study has provided insight into the behavioral damage caused by repeated blows to the head. The research provides a foundation for scientists to better understand and potentially develop new ways to detect and prevent the repetitive sports injuries that can lead to the condition known as chronic traumatic encephalopathy (CTE).

Sufferers of a common sleep-breathing disorder have diminished activity among neurons responsible for keeping heart rate low, reveals a new study published in The Journal of Physiology. The research discovered that in obstructive sleep apnoea (OSA), neurons in the brainstem that control heart rate experience a blunting of their activity. The reduction of neuronal activity likely contributes to the increased heart rate,blood pressure and risk of adverse cardiovascular events that occur in patients with OSA.

A variant of the gene KLOTHO is known for its anti-aging effects in people fortunate enough to carry a copy. Now researchers have found that it also has benefits when it comes to brain function.

Humans who lack the corpus callosum, a bundle of 200 million fibers that connect the left and right hemispheres of the brain, have long fascinated physicians, neuroscientists and other curious minds. Now, a group of researchers puts an end to the Sperry’s paradox, which describes major differences between individuals born with reduced or absent brain connections and those who acquire this condition later in life.

A study has shown that a long-overlooked form of neuron-to-neuron communication called miniature neurotransmission plays an essential role in the development of synapses, the regions where nerve impulses are transmitted and received.

The way that your heart rate increases in response to alertness in the brain has been recently discovered by researchers. Specifically, this study looked at the interactions between neurons that fire upon increased attention and anxiety and neurons that control heart rate to discover the “why,” “how,” and “where to next” behind this phenomenon. The results may have important implications for how certain conditions are treated in the future, such as post-traumatic stress disorder, chronic anxiety, or even stress.

A growing body of evidence suggests nonhuman animals can group living and inanimate things based on less than obvious shared traits, raising questions about how creatures accomplish this task.

Researchers at the University of Liverpool found musical training can increase blood flow in the left hemisphere of the brain, suggesting the area of the brain responsible for music and language share common pathways.

Why Are Some Brain Injuries Worse Than Others?

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Image A: 3-D models of how the white matter in the brain connects, paired with a "connectogram" visualizing linkages between different areas of the brain / USC

3-D models of how the white matter in the brain connects, paired with a “connectogram” visualizing linkages between different areas of the brain / USC

According to research published in The Lancet, approximately a fifth of adults with a severe traumatic brain injury make a good recovery. But many more die or are left with enduring disability. Although doctors caring for Michael Schumacher, the Formula One World Champion who sustained a severe head injury while skiing, haven’t commented on how he is responding to their latest tests and treatment, Dr Peter Kirkpatrick, a leading British neurosurgeon based at Addenbrooke’s hospital in Cambridge, says that it is “extremely unlikely” that Schumacher will return to his previous level of health, although he insists it is “medically possible”.

The effects of brain injury fall into three main categories:

  • Cognitive – problems with memory, concentration, information processing
  • Emotional and behavioural problems – anxiety, explosive anger and irritability, lack of awareness or empathy
  • Physical – problems with movement, balance and co-ordination, fatigue, epilepsy

Sometimes a head injury which seems severe is followed by a good recovery while a seemingly small head injury can have very serious, long-lasting consequences.  Why is this?

Location, location, location.

The reason is that brain injury operates a bit like the property market in that the three most important things to consider are location, location and location. When nerve pathways are damaged, those brain areas served by those pathways may wither or have their functions taken over by other brain regions. Nerve pathways are also called ‘white’ pathways or ‘white matter’ because they are covered by an insulating sheath of myelin and appear white to the naked eye.

The challenge is to determine the location of key ‘scaffold’ pathways and to understand what makes them so vulnerable and important. This is not an easy task given the total length of nerve pathways in the average 20-year old human brain is 160,000 km. A recent study provides new findings on the brain’s network scaffold that will help inform clinicians about the neurological impacts of brain diseases such as multiple sclerosis, Alzheimer’s disease and brain injury.

 

Weekly Neuroscience Update

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Functional magnetic resonance imaging (fMRI) and other brain imaging technologies allow for the study of differences in brain activity in people diagnosed with schizophrenia. The image shows two levels of the brain, with areas that were more active in healthy controls than in schizophrenia patients shown in orange, during an fMRI study of working memory. Credit: Kim J, Matthews NL, Park S./PLoS One.

Functional magnetic resonance imaging (fMRI) and other brain imaging technologies allow for the study of differences in brain activity in people diagnosed with schizophrenia. The image shows two levels of the brain, with areas that were more active in healthy controls than in schizophrenia patients shown in orange, during an fMRI study of working memory. Credit: Kim J, Matthews NL, Park S./PLoS One.

Researchers from the Broad Institute and several partnering institutions have taken a closer look at the human genome to learn more about the genetic underpinnings of schizophrenia. In two studies published in Nature, scientists analyzed the exomes, or protein-coding regions, of people with schizophrenia and their healthy counterparts, pinpointing the sites of mutations and identifying patterns that reveal clues about the biology underlying the disorder.

A new brain region that appears to help humans identify whether they have made bad decisions has been discovered by researchers.

New research finds that the brains of autistic children generate more information at rest – a 42% increase on average. The study offers a scientific explanation for the most typical characteristic of autism – withdrawal into one’s own inner world. The excess production of information may explain a child’s detachment from their environment.

The brain appears to synchronize the activity of different brain regions to make it possible for a person to pay attention or concentrate on a task, scientists have learned.

Researchers at the Albert Einstein College of Medicine are investigating the effects of repeated combat-related blast exposures on the brains of veterans. Mild traumatic brain injuries can cause problems with cognition, concentration, memory and emotional control. Scientists are using advanced MRI technology and psychological tests to investigate the structural and biological impact of repeated head injury and to assess how these injuries affect cognitive functions. Final results of the study have not yet been published, but researchers hope it will lead to more scientifically valid diagnostic techniques that could potentially allow for detection of both the underlying brain injury and its severity.

Weekly Round-Up

Your brain is more responsive to your friends than to strangers

Researchers from UT Southwestern Medical Center have described for the first time how the brain’s memory center repairs itself following severe trauma – a process that may explain why it is harder to bounce back after multiple head injuries.

People with autism use their brains differently from other people, which may explain why some have extraordinary abilities to remember and draw objects in detail, according to new research from the University of Montreal.

Five more genes which increase the risk of developing Alzheimer’s disease have been identified, according to research published in Nature Genetics. This takes the number of identified genes linked to Alzheimer’s to 10 – the new genes affect three bodily processes and could become targets for treatment. If the effects of all 10 could be eliminated the risk of developing the disease would be cut by 60%, although new treatments could be 15 years away.

The sudden understanding or grasp of a concept is often described as an “Aha” moment and now researchers from New York University are using a functional MRI (fMRI) scanner to study how these moments of insight are captured and stored in our brain.

Mark Changizi is asking the question how do we have reading areas for a brain that didn’t evolve to read?

In order to develop new medications for alcoholism, researchers need to understand how alcohol acts on the brain’s reward system. A previously unknown mechanism has been shown to block the rewarding effects of alcohol on the brain, reveals a thesis from the University of Gothenburg, Sweden.

Researchers from the University of Valencia (UV)  investigating the brain structures involved with empathy have concluded that the brain circuits responsible are in part the same as those involved with violence.

And finally…your brain is more responsive to your friends than to strangers, even if those strangers have more in common with you, says a new study. Researchers looked at the brain areas associated with social information. The results of the study show that social connections override similar interests.

Exercise doesn’t just make you fitter – it makes you smarter too!

Exercise is important in keeping your heart and lungs healthy. We know for decades that the effort required in exercise allows life-giving oxygen to travel quicker and in greater amounts to all the tissues of the body – allowing the cells in them to grow and divide. A noticeable exception to this rule is the brain.

Neurons are different

Nerve cells or neurons are notoriously bad at dividing. Rather than divide, a neuron survives by making up to 10,000 connections to neighbouring neurons – and this is the key to how we learn and recall as memories are created and strengthened.  This compromise works well for the first four decades of life however by your 50’s a gradual loss of neurons and their connections starts to take it toll resulting in a noticeable reduction in cognition as we find it harder to remember, especially recent events. 

An unexpected finding

Recent scientific findings from Columbia University show that exercise is important in helping to reverse this age-related loss of neurons. In this study in a small group of middle-aged people, exercising just an hour a day, four times a week, for three months triggers the growth of new neurons – a feat which has previously proved almost impossible for neuroscientists to achieve using drugs. Neuroscientists are still working out the possible reasons why simple exercise is so powerful at triggering the birth of neurons but a clue may be that the brain is very well supplied by blood vessels needed to deliver the food and oxygen to help make and maintain the trillions of synapses in the brain. In fact the brain is one of the most oxygen-sensitive organs of the body. It receives 20% of the cardiac output and accounts for about 25% of overall resting oxygen consumption. In addition, the brain as a highly vascular organ is very sensitive to changes in blood perfusion. It seems the extra increase in blood perfusion and life-giving oxygen associated with exercise may invigorate the brain to such a degree that it starts to actually grow new neurons again.

Exercise is as important as drugs

The finding that exercise triggers the brain to grow new nerve cells is a truly stunning discovery that will have implications for public healthcare policies for an increasingly ageing population. In addition, new treatments for brain illness such as Alzheimer’s disease and head injury may involve a combination of different therapies such as medication, psychological therapies, social support, self-help techniques and now, most importantly exercise. This combined approach will treat the person as a whole, and marks the beginning of the journey back to wellness and a normal life.

So the message is simple –if you want to stay smart just get out there and exercise.

Neuroscience research may help brain injury recovery

New research shows that the way the brain first captures and encodes a situation or event is quite different from how it processes subsequent similar events.

I was interested to read a special report from the Center for Neuro Skills which describes the latest developments into how the brain registers new memory and equally importantly, how it strengthens older memories.

It has been known for years that the so-called NMDA receptor – a  lock on the skin of the nerve cell which is ‘opened’ by a special key – the neurotransmitter glutamate – is involved in new learning and memory.

However this research shows that the way the brain first captures and encodes a situation or event is quite different from how it processes subsequent similar events,  and suggests a whole new NMDA-independent system involving the so-called AMPA receptor – a less powerful type of NMDA receptor –  involved in strengthening older memories.
Why is this so important?   

Well, this new system is known to be critically involved in Alzheimer’s disease and other kinds of brain deficit memory impairment including stroke and head injury.

In fact, you may be interested to know that several drug companies have developed drugs that open the AMPA receptors called ampakines – a class of compounds known to enhance attention span and alertness, and facilitate learning and memory.

Unlike earlier stimulants such as caffeine, methylphenidate (Ritalin), and the amphetamines, ampakines do not seem to have unpleasant, long-lasting side effects such as sleeplessness.

These new memory enhancing drugs will be coming to a pharmacy near you within the next few years!

Don’t forget!