Category: Neurology

Categories : Neurology

The Geometry of the Brain May Influence Brain Functions

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For over 100 years, scientists have thought that the brain activity patterns that define human consciousness arose from how different brain regions communicate with each other through trillions of cellular connections.

Now, by examining more than 10 000 different maps of human brain activity, Monash University-led researchers found that the overall shape of a person’s brain has a much greater influence on thought and behaviour than its neuronal connectivity. This may sound like the old pseudoscience of phrenology, which based theories of personality and cognition on the shape of the head and its bumps.

Not so for this study, which combines approaches from physics, neuroscience and psychology to overturn the century-old model revolving around complex brain connectivity, instead revealing a relationship between brain shape and activity. The researchers published their ground-breaking findings in the journal Nature.

Lead author Dr James Pang said the findings were significant because they greatly simplified the way that we can study how the brain functions, develops and ages.

“The work opens opportunities to understand the effects of diseases like dementia and stroke by considering models of brain shape, which are far easier to deal with than models of the brain’s full array of connections,” Dr Pang said.

“We have long thought that specific thoughts or sensations elicit activity in specific parts of the brain, but this study reveals that structured patterns of activity are excited across nearly the entire brain, just like the way in which a musical note arises from vibrations occurring along the entire length of a violin string, and not just an isolated segment,” he said.

Using magnetic resonance imaging (MRI), the researchers studied eigenmodes, which are the natural patterns of vibration or excitation in a system, where different parts of the system are all excited at the same frequency. Eigenmodes are normally used in areas such as physics to study physical systems only recently have they been applied to studying brain.

Their study focused on developing the optimal way to construct the eigenmodes of the brain.

“Just as the resonant frequencies of a violin string are determined by its length, density and tension, the eigenmodes of the brain are determined by its structural – physical, geometric and anatomical – properties, but which specific properties are most important has remained a mystery,” said co-lead author, Dr Kevin Aquino, of BrainKey and The University of Sydney.

‘Like the shape of a drum influences the sounds that it can make’

The team, led by Professor Alex Fornito, compared how well eigenmodes derived from models of brain shape could account for different patterns of activity as opposed to eigenmodes from models of brain connectivity.

“We found that eigenmodes defined by brain geometry – its contours and curvature – represented the strongest anatomical constraint on brain function, much like the shape of a drum influences the sounds that it can make,” said Fornito.

“Using mathematical models, we confirmed theoretical predictions that the close link between geometry and function is driven by wave-like activity propagating throughout the brain, just as the shape of a pond influences the wave ripples that are formed by a falling pebble,” he said.

“These findings raise the possibility of predicting the function of the brain directly from its shape, opening new avenues for exploring how the brain contributes to individual differences in behavior and risk for psychiatric and neurological diseases.”

The research team found that, across over 10 000 MRI activity maps, obtained as people performed different tasks developed by neuroscientists to probe the human brain, activity was dominated by eigenmodes with spatial patterns that have very long wavelengths, extending over distances exceeding 40 mm.

“This result counters conventional wisdom, in which activity during different tasks is often assumed to occur in focal, isolated areas of elevated activity, and tells us that traditional approaches to brain mapping may only show the tip of the iceberg when it comes to understanding how the brain works,” Dr Pang said.

Source: MedicalXpress

Categories : Implants and Prostheses NeurologyTags :

Elon Musk’s Neuralink Brain-computer Interface Receives Human Testing Approval

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Elon Musk’s company Neuralink had finally received approval for human testing of its brain-computer interface (BCI). After initially rejecting the application, the US Food and Drug Administration finally gave the company the go-ahead on Thursday.

Neuralink, which aims to develop an implant that would allow humans to interface directly with computers as well as enabling medical applications such as controlling prostheses. Last year, the company showed off a monkey that was able to play the simple video game Pong on a monitor using its mind.

Neuralink is by no means the first company to try to achieve these goals. Many other institutions have made advances over the past decades, but the field is a difficult one and progress is slow. In its previous rejection, the FDA cited concerns such as the devices using lithium for their batteries, migration of the wires inside the brain and the difficulty of extracting the devices without harming brain tissue.

The company’s use of animals to develop the technology has infuriated activists, but this is a standard practice in development of BCI technology. Last year, whistleblowers accused the company of killing 1500 animals since its inception.

In a guidance document, the FDA says that, “The field of implanted BCI devices is progressing rapidly from fundamental neuroscience discoveries to translational applications and market access. Implanted BCI devices have the potential to bring benefit to people with severe disabilities by increasing their ability to interact with their environment, and consequently, providing new independence in daily life.”

China is also aggressively pursuing the development of BCIs as part of their ‘China Brain Project’, as discussed in the journal Neuron. It has a significant advantage as it has a large population of macaques to draw on, along with fewer ethical concerns and policies expediting biotech research.

Categories : Neurology Obstetrics & GynaecologyTags :

Low Maternal Vitamin D Levels may Increase Schizophrenia Risk of Offspring

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Neuroscientists published in the Journal of Neurochemistry, shows that maternal levels of vitamin D are key in the development of dopaminergic neurons, which are thought to be involved in schizophrenia.

Professor Darryl Eyles has built on past research out of his laboratory at the Queensland Brain Institute linking maternal vitamin D deficiency and brain development disorders, such as schizophrenia, to understand the functional changes taking place in the brain.

Schizophrenia is associated with many developmental risk factors, both genetic and environmental. While the precise neurological causes of the disorder are unknown, what is known is that schizophrenia is associated with a pronounced change in the way the brain uses dopamine, the neurotransmitter often referred to as the brain’s ‘reward molecule’.

Professor Eyles has followed the mechanisms that might relate to abnormal dopamine release and discovered that maternal vitamin D deficiency affects the early development and later differentiation of dopaminergic neurons.

The team at the Queensland Brain Institute developed dopamine-like cells to replicate the process of differentiation into early dopaminergic neurons that usually takes place during embryonic development.

They cultured the neurons both in the presence and absence of the active vitamin D hormone. In three different model systems they showed dopamine neurite outgrowth was markedly increased. They then showed alterations in the distribution of presynaptic proteins responsible for dopamine release within these neurites.

“What we found was the altered differentiation process in the presence of vitamin D not only makes the cells grow differently, but recruits machinery to release dopamine differently,” Professor Eyles said.

Using a new visualisation tool known as false fluorescent neurotransmitters, the team could then analyse the functional changes in presynaptic dopamine uptake and release in the presence and absence of vitamin D.

They showed that dopamine release was enhanced in cells grown in the presence of the hormone compared to a control.

“This is conclusive evidence that vitamin D affects the structural differentiation of dopaminergic neurons.”

Leveraging advances in targeting and visualising single molecules within presynaptic nerve terminals has enabled Professor Eyles and his team to further explore their long-standing belief that maternal vitamin D deficiency changes how early dopaminergic circuits are formed.

The team is now exploring whether other environmental risk factors for schizophrenia such as maternal hypoxia or infection similarly alter the trajectory of dopamine neuron differentiation.

Eyles and his team believe such early alterations to dopamine neuron differentiation and function may be the neurodevelopmental origin of dopamine dysfunction later in adults who develop schizophrenia.

Source: University of Queensland

Categories : Ageing NeurologyTags :

Instead of Dying, Motor Neurons Just Lose Connectivity with Age

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A new study published in the Journal of Clinical Investigation Insight offers a blueprint to help scientists prevent and reverse motor deficits that occur in old age. Their findings showed that loss of connectivity of motor neurons in the spinal cord – not the death of those neurons, as was previously thought – is what impairs voluntary movements during aging.

As humans age, tasks that require coordinated motor skills, such as navigating stairs or writing a letter, become increasingly difficult to perform. Reduced mobility caused by aging is strongly associated with adverse health outcomes and a diminished quality of life.

Researchers at Brown University led by Gregorio Valdez, an associate professor of molecular biology, cell biology and biochemistry, discovered that motor neurons start to have fewer synapses.

“This is an important fundamental discovery because it tells us that treatments are possible to prevent and reverse motor deficits that occur as we age,” said Valdez, who is affiliated with both the Center for Translational Neuroscience and the Center for Alzheimer’s Disease Research at the Carney Institute and Brown’s Center on the Biology of Aging. “The primary hardware, motor neurons, are spared by aging. If we can figure out how to keep synapses from degenerating, or mimic their actions using pharmacological interventions, we may be able to treat motor issues in the elderly that often lead to injuries due to falls.”

For the study, researchers examined spinal motor neurons in three species, including humans, rhesus monkeys and mice.

“These findings revealed that, as individuals age, motor neurons lose many of the connections that direct their function,” said Ryan Castro, first author of the study, who earned a PhD in neuroscience from Brown in 2022.    

Because of their critical function, Valdez said, the loss of either motor neurons or their synapses would impair voluntary movements. 

The number and size of motor neurons do not significantly change during aging, the researchers discovered. However, they undergo other processes that contribute to aging.

“Aging causes motor neurons to engage in self-destructive behaviour,” Valdez said. “While motor neurons do not die in old age, they progressively increase expression of molecules that cause degeneration of their own synapses and cause glial cells to attack neurons, and that increases inflammation.” 

Some of these aging-related genes and pathways are also found altered in motor neurons affected with amyotrophic lateral sclerosis (ALS).

The researchers now plan to pursue studies to target molecular mechanisms they found altered in motor neurons that could be responsible for the loss of their own synapses with advancing age.  

Source: Brown University

Categories : NeurologyTags :

Study Measures the True Facial Processing Ability of ‘Super-recognisers’

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So-called ‘super-recognisers’ are people with a much greater ability to recognise faces in a variety of contexts, but their ability has not been empirically tested. A new study in PNAS shows that super-recognisers do in fact possess greatly superior facial recognition compared to normal peers.

While police departments have known of their abilities for quite some time, it was just over a decade ago, when super-recognisers were described in the literature as having exceptional facial processing abilities. With the increasing use of CCTV in police investigations and the potential for human error, there have been questions raised as to whether super-recognisers could do a better job – or indeed, whether they have empirically superior abilities. A means for actually identifying and defining a super-recogniser as opposed to someone who merely seems to better at recalling faces is therefore needed.

The performance of people with normal facial recognition abilities is not very impressive. While performance is good when people are familiar with the person pictured, studies report an error as high as 35% with unfamiliar faces. Even when people are asked to compare a live person standing in front of them with a photo, a recent study found they still got more than 20% of their answers wrong.

For this study, researchers enrolled 73 super-recogniser and 45 control participants. They compared the two groups on performance on three challenging tests of face identity processing recommended for super-recogniser identification; as well as performance for perpetrator identification using four CCTV sequences depicting five perpetrators and police line-ups created for criminal investigation purposes. They found that the face identity processing tests used here are valid in measuring such abilities and identifying super-recognisers. In addition, they determined that super-recognisers excel at perpetrator identification relative to control participants, with more correct perpetrator identifications, the better their performance across lab tests.

Categories : NeurologyTags :

Navigating the Maze of the Brain’s Glymphatic System

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Like the lymphatic system in the body, the glymphatic system in the brain clears metabolic waste and distributes nutrients and other important compounds. Impairments in this system may contribute to brain diseases, such as neurodegenerative diseases and stroke.

A team of researchers has found a noninvasive and nonpharmaceutical method to influence glymphatic transport using focused ultrasound, opening the opportunity to use the method to further study brain diseases and brain function. Their findings are published in PNAS.

Hong Chen, associate professor of biomedical engineering in McKelvey Engineering and of neurological surgery in the School of Medicine, and her team, including Dezhuang (Summer) Ye, a postdoctoral research associate, and Si (Stacie) Chen, a former postdoctoral research associate, found the first direct evidence that focused ultrasound, combined with circulating microbubbles (FUSMB) could mechanically enhance glymphatic transport in the mouse brain.

Focused ultrasound can penetrate the scalp and skull to reach the brain and precisely target a defined region within the brain. Previously, Chen’s team found that microbubbles injected into the bloodstream amplify the effects of the ultrasound waves on the blood vessels and generate a pumping effect, which helps with the accumulation of intranasally delivered agents in the brain, such as drugs or gene therapy treatments.

“Intranasal delivery provides a novel, noninvasive route to investigate the glymphatic pathway in intact brains,” Chen said. “This route for investigating glymphatic transport has the potential to be utilised in the study of glymphatic function in humans, which is currently limited by the absence of noninvasive approaches to access the glymphatic system.”

In the new research, the team administered a fluorescently labelled tracer intranasally. Then they administered focused ultrasound waves aimed deep in the brain at the thalamus after intravenous injection of microbubbles. When they conducted 3D imaging of the brain tissue on the treated side, they found that FUSMB boosted the transport of the tracer in the perivascular space.

They compared this with three control groups with various combinations of focused ultrasound, microbubbles and the tracer. All of the mice in the three control groups showed lower tracer accumulation, which verified to the team that the enhanced tracer transport was the result of the focused ultrasound with microbubbles.

To further validate their results, they used the FUSMB treatment after injecting the tracer directly to the cerebral spinal fluid, an invasive yet commonly used method. They found that FUSMB also enhanced the transport of tracers along the vessels at the focused-ultrasound targeted brain site by about two- to threefold compared with the non-targeted side.

“Regardless of whether tracers were delivered via the intranasal or injected route, FUSMB consistently improved glymphatic transport,” Ye said. “Our study using confocal microscopy imaging combined with brain-tissue clearing obtained direct evidence that unequivocally proved that FUSMB enhanced the glymphatic transport of a labeled protein agent in mice.”

The team also investigated various types of vessels, including arterioles, capillaries and venules, that facilitate FUSMB-enhanced transport of the tracer using both intranasal and injected delivery of the tracer. They saw improved glymphatic transport of the tracer in both arterioles and capillaries with both types of delivery. They found that the fluorescence intensity was higher along arterioles than capillaries and venules.

“This study opens new opportunities to use ultrasound combined with microbubbles as a noninvasive and nonpharmacological approach to manipulate glymphatic transport,” Ye said. “Focused ultrasound-activated microbubbles have the promise to enhance waste clearance in the brain and potentially mitigate brain diseases caused by impairments in glymphatic system function.”

Chen said the team will now focus on applying this noninvasive and nonpharmacological method for brain waste clearance to potentially combat neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases.

Source: University of Washington in St. Louis

Categories : Mental Health NeurologyTags :

Brain Transmission Speeds Increase Until Middle Age

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It has been believed speed of information transmitted among regions of the brain stabilised during early adolescence. A study in Nature Neuroscience has instead found that transmission speeds continue to increase into early adulthood, which may explain the emergence of mental health problems over this period. In fact, transmission speeds increase until around age 40, reaching a speed twice that of a 4-year old child.

As mental health problems such as anxiety, depression and bipolar disorders can emerge in late adolescence and early adulthood, a better understanding of brain development may lead to new treatments.

“A fundamental understanding of the developmental trajectory of brain circuitry may help identify sensitive periods of development when doctors could offer therapies to their patients,” says senior author Dora Hermes, PhD, a biomedical engineer at Mayo Clinic.

Called the human connectome, the structural system of neural pathways in the brain or nervous system develops as people age. But how structural changes affect the speed of neuronal signalling has not been well described.

“Just as transit time for a truck would depend on the structure of the road, so does the transmission speed of signals among brain areas depend on the structure of neural pathways,” Dr Hermes explains. “The human connectome matures during development and aging, and can be affected by disease. All these processes may affect the speed of information flow in the brain.” In the study, Dr Hermes and colleagues stimulated pairs of electrodes with a brief electrical pulse to measure the time it took signals to travel among brain regions in 74 research participants between the ages of 4 and 51. The intracranial measurements were done in a small population of patients who had electrodes implanted for epilepsy monitoring at University Medical Center Utrecht, Netherlands.

The response delays in connected brain regions showed that transmission speeds in the human brain increase throughout childhood and even into early adulthood. They plateau around 30 to 40 years of age.

The team’s data indicate that adult transmission speeds were about two times faster compared to those typically found in children. Transmission speeds also were typically faster in 30- or 40-year-old subjects compared to teenagers.

Brain transmission speed is measured in milliseconds, a unit of time equal to one-thousandth of a second. For example, the researchers measured the neuronal speed of a 4-year-old patient at 45 milliseconds for a signal to travel from the frontal to parietal regions of the brain. In a 38-year-old patient, the same pathway was measured at 20 milliseconds. For comparison, the blink of an eye takes about 100 to 400 milliseconds.

The researchers are working to characterise electrical stimulation-driven connectivity in the human brain. One of the next steps is to better understand how transmission speeds change with neurological diseases. They are collaborating with paediatric neurosurgeons and neurologists to understand how diseases change transmission speeds compared to what would be considered within the normal range for a certain age group.

Source: Mayo Clinic

Categories : NeurologyTags :

Functional MRI is Now Able to Read People’s Minds

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In a study in Nature, researchers reported being able to identify words and phrases in volunteers undergoing fMRI imaging reasonable accuracy. The process is non-invasive, unlike implanted electrodes, but requires hours of preparation and scanning.

This technology would be a significant breakthrough for people suffering debilitating conditions that prevent them from speaking or otherwise communicating. Previously, decoding language required the use of extensive electrode implants.

The participants, two male and one female, listened to recordings of radio shows. This was used to train a language model which was based on an early version of ChatGPT. By looking at the brain’s responses, the language model was able to capture the gist of what the participants were thinking, sometimes replicating exact words or entire phrases.

Marked safe from ‘Big Brother’… for now

At this stage, the technology used requires the subject to cooperate, the researchers wrote, allaying concerns over any malicious use of this technology to tap into people’s private thoughts. Testing the decoding model on people who it hadn’t been trained on produced unintelligible results, as was the case when the trained participants put up resistance.

While the technology cannot be used for nefarious mind-reading, the march of progress means that one day such concerns will become real.

Nita Farahany, JD, PhD, of Duke University in Durham, North Carolina, told MedPage Today that the technology could one day be used against people. “This research illustrates the rapid advances being made toward an age of much greater brain transparency, where even continuous language and semantic meaning can be decoded from the brain.

“While people can employ effective countermeasures to prevent decoding their brains using fMRI, as brain wearables become widespread that may not be an effective way to protect us from interception, manipulation, or even punishment for our thoughts.”

While lugging around a massive MRI machine would be a challenge for future thought police, smaller, more portable means of measuring brain activity remotely. Senior author Alexander Huth, PhD, of the University of Texas at Austin, says that one such technology could be functional near-infrared spectroscopy (fNIRS).

“fNIRS measures where there’s more or less blood flow in the brain at different points in time, which, it turns out, is exactly the same kind of signal that fMRI is measuring,” Huth said. “So, our exact kind of approach should translate to fNIRS,” but the resolution with fNIRS would be lower.

Categories : Neurology Substance UseTags :

How Psychedelics Alter Brain Activity to Produce ‘Trips’

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In a study published in the journal PNAS, detailed brain imaging data from 20 healthy volunteers revealed how the potent psychedelic compound, DMT (dimethyltryptamine), alters brain function. During the immersive DMT experience, there was increased connectivity across the brain, with more communication between different areas and systems. The changes to brain activity were most prominent in areas linked with ‘higher level’ functions, such as imagination.

DMT is a potent psychedelic found naturally in certain plants and animals, and unlike classic psychedelics, such as LSD or psilocybin, DMT’s has shorter-lasting effects on the brain, measured in minutes, rather than hours. It occurs in trace amounts in the human body and is the major psychoactive compound in ayahuasca.

The study is the first to track brain activity before, during and after the DMT experience in such detail.

Dr Chris Timmerman, from the Centre for Psychedelic Research at Imperial College London, and first author on the study, said: “This work is exciting as it provides the most advanced human neuroimaging view of the psychedelic state to-date.

“One increasingly popular view is that much of brain function is concerned with modelling or predicting its environment. Humans have unusually big brains and model an unusually large amount of the world. For example, like with optical illusions, when we’re looking at something, some of what we’re actually seeing is our brain filling in the blanks based on what we already know. What we have seen with DMT is that activity in highly evolved areas and systems of the brain that encode especially high-level models becomes highly dysregulated under the drug, and this relates to the intense drug ‘trip’.”

DMT can produce intense and immersive altered states of consciousness, with the experience characterised by vivid and bizarre visions, a sense of ‘visiting’ alternative realities or dimensions, and similarities with near death experiences. But exactly how the compound alters brain function to account for such effects has been unclear.

In the latest study, 20 healthy volunteers were given an injection of the drug while researchers from Imperial’s Centre for Psychedelic Research captured detailed imagery of their brains, enabling the team to study how activity changes before, during and after the trip.

Volunteers intravenously received a high dose of DMT (20mg), while simultaneously undergoing functional magnetic resonance imaging (fMRI) of their brain and electroencephalography (EEG). The total psychedelic experience lasted about 20 minutes, and at regular intervals, volunteers provided a rating of the subjective intensity of their experience (on a 1 to 10 scale).

The fMRI scans found changes to activity within and between brain regions in volunteers under the influence of DMT. Effects included increased connectivity across the brain, with more communication between different areas and systems. These phenomena, termed ‘network disintegration and desegregation’ and increased ‘global functional connectivity’, align with previous studies with other psychedelics. The changes to activity were most prominent in brain areas linked with ‘higher level’, human-specific functions, such as imagination.

The researchers highlight that while their study is not the first to image the brain under the influence of psychedelics or the first to show the signatures of brain activity linked to psychedelics, it is the first to combine imaging techniques to study the brain during a highly immersive psychedelic experience. They explain the work provides further evidence of how DMT, and psychedelics more generally, exert their effects by disrupting high level brain systems.

Prof Robin Carhart-Harris, founder of the Centre for Psychedelic Research at Imperial College London, and senior author on the paper (now working at the University of California, San Francisco), commented: “Motivated by, and building on our previous research with psychedelics, the present work combined two complementary methods for imaging the brain imaging. fMRI allowed us to see the whole of the brain, including its deepest structures, and EEG helped us view the brain’s fine-grained rhythmic activity.

“Our results revealed that when a volunteer was on DMT there was a marked dysregulation of some of the brain rhythms that would ordinarily be dominant. The brain switched in its mode of functioning to something altogether more anarchic. It will be fascinating to follow-up on these insights in the years to come. Psychedelics are proving to be extremely powerful scientific tools for furthering our understanding of how brain activity relates to conscious experience.”

The Imperial team is now exploring how to prolong the peak of the psychedelic experience through continuous infusion with DMT, and some are also advising on a commercially run trial to assess DMT for patients with depression.

Source: Imperial College London

Categories : Injury & Trauma NeurologyTags :

Up to Half of Concussions May Have Long-lasting Effects

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Even mild concussion can cause long-lasting effects to the brain, according to a University of Cambridge analysis published in Brain. The study researchers showed that for almost a half of all people who receive a concussion, there are changes in how regions of the brain communicate with each other. This could potential cause long term symptoms such as fatigue and cognitive impairment.

Concussion, a mild traumatic brain injury, can occur as a result of a fall, a sports injury or from a cycling accident or car crash, for example. But despite the ‘mild’ label, it is commonly linked with persistent symptoms and incomplete recovery. Such symptoms include depression, cognitive impairment, headaches, and fatigue.

While some clinicians in recent studies predict that 9 out of 10 individuals who experience concussion will have a full recovery after six months, evidence is emerging that only a half achieve a full recovery. This means that a significant proportion of patients may not receive adequate post-injury care.

Predicting which patients will have a fast recovery and who will take longer to recover is challenging, however. At present, patients with suspected concussion will typically receive either a CT or MRI brain scan to look for structural problems, such as inflammation or bruising. Yet even if these scans show no obvious structural damage, a patient’s symptoms may still persist.

Dr Emmanuel Stamatakis from the Department of Clinical Neurosciences and Division of Anaesthesia at the University of Cambridge said: “Worldwide, we’re seeing an increase in the number of cases of mild traumatic brain injury, particularly from falls in our ageing population and rising numbers of road traffic collisions in low- and middle-income countries.

“At present, we have no clear way of working out which of these patients will have a speedy recovery and which will take longer, and the combination of over-optimistic and imprecise prognoses means that some patients risk not receiving adequate care for their symptoms.”

Dr Stamatakis and colleagues studied functional MRI (fMRI) brain scans taken from 108 patients with mild traumatic brain injury and compared them with scans from 76 healthy volunteers. Patients were also assessed for ongoing symptoms.

The patients and volunteers had been recruited to CENTER-TBI, a large European research project which aims to improve the care for patients with traumatic brain injury.

The team found that just under half (45%) were still showing symptoms resulting from their brain injury, with the most common being fatigue, poor concentration and headaches.

The researchers found that these patients had abnormalities in a region of the brain known as the thalamus, which integrates all sensory information and relays this information around the brain. Counter-intuitively, concussion was associated with increased connectivity between the thalamus and the rest of the brain – in other words, the thalamus was trying to communicate more as a result of the injury – and the greater this connectivity, the poorer the prognosis for the patient.

Rebecca Woodrow, a PhD student in the Department of Clinical Neuroscience and Hughes Hall, Cambridge, said: “Despite there being no obvious structural damage to the brain in routine scans, we saw clear evidence that the thalamus – the brain’s relay system – was hyperconnected. We might interpret this as the thalamus trying to over-compensate for any anticipated damage, and this appears to be at the root of some of the long-lasting symptoms that patients experience.”

Using positron emission tomography (PET) scans, the researchers were able to make associations with key neurotransmitters depending on which long-term symptoms a patient displayed. For example, patients experiencing cognitive problems such as memory difficulties showed increased connectivity between the thalamus and areas of the brain rich in the neurotransmitter noradrenaline; patients experiencing emotional symptoms, such as depression or irritability, showed greater connectivity with areas of the brain rich in serotonin.

Dr Stamatakis added: “We know that there already drugs that target these brain chemicals so our findings offer hope that in future, not only might we be able to predict a patient’s prognosis, but we may also be able to offer a treatment targeting their particular symptoms.”

Source: University of Cambridge