Why are we more susceptible to developing dementia after brain injury?

BY: SOPHIA VOUMVAKIS

A post on this blog by Alison discussed research which suggests that those of us who have sustained a Traumatic Brain Injury (TBI) have a higher risk of developing dementia, including Alzheimer’s, one of the causes of dementia.

Alison also provided some great advice on maintaining a healthy lifestyle and how participating in key activities can help reduce the risk of dementia from Alzheimer’s.

I’ve also read that those who have sustained a TBI are at higher risk of developing dementia. To clarify, dementia is a set of symptoms that consistently occur together. It is not a specific disease. Dementia is caused by damage to the brain cells, Alzheimer’s disease is the most common cause of dementia. Other causes are Parkinson’s disease, Multiple Sclerosis, Huntington’s Disease and stroke.

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I recently came across some interesting new research which sheds light on the possible cause of increased risk of Alzheimer’s in people who have sustained a TBI, and a couple of more suggestions we can employ to reduce the risk of dementia caused by Alzheimer’s.

The Glymphatic Network – A New Discovery

The research is out of the University of Helsinki in Finland, and its findings were published in the Washington Post on May 21, 2017. Like many breakthrough discoveries in science, this finding was accidental.

Kari Alitalo, a scientist at the University of Helsinki had studied the lymphatic network for two decades. The lymphatic network carries immune cells throughout our body and removes waste and toxins. For over three hundred years it was believed that the lymphatic network stopped at the brain. It was accepted wisdom.

Three years ago, Alitalo wanted to develop a more precise map of the lymphatic network. To do this, he used genetically modified mice, whose lymphatic vessels glowed when illuminated by a specific wavelength of light.

When viewing the modified mice under the light, a medical student in Alitalo’s lab noticed that the heads of the mice also glowed. This went against the common wisdom that the lymphatic network did not extend to the brain. At first the scientists suspected that there was something wrong with their equipment, and when they repeated the experiment, they got the same result – the lymphatic network does indeed include the brain.

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Working independently, several scientists, including Maiken Nedergaard at the University of Rochester and Jonathan Kipnis of the University of Virginia School of Medicine, have also shown that the lymphatic vessels extend into the brain.

This discovery has major implications for a variety of brain diseases, such as Alzheimer’s, Multiple Sclerosis, and stroke which cause dementia. It also provides an explanation of why those of us who have sustained a TBI may be more susceptible to developing Alzheimer’s.

Researchers have identified two networks: the vessels that lead into and surround the brain, and those in the brain itself. The first network is the lymphatic system for the brain, and the second is called the glymphatic system – the addition of the “g” is for the glia neuron, that makes up the lymphatic vessels in the brain.

The glymphatic vessels carry cerebrospinal fluid and immune cells into the brain and remove cellular trash from it. The analogy that Nedergaard employs to describe this system is a dishwasher for the brain. When the lymphatic and glymphatic systems do not function properly, the brain can become clogged with toxins and suffused with inflammatory immune cells. Over decades, this process may play a key role in Alzheimer’s disease, Huntington’s disease, Parkinson’s disease and other neurodegenerative diseases.

Nedergaard told the Washington Post, “This is a revolutionary finding. This system plays a huge role in the health of the brain.”

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Malfunctioning of the Lymphatic and Glymphatic Systems and the link to Alzheimer’s Nedergaard and Helene Benveniste, a scientist at Yale University, have found evidence that links the malfunctioning of the lymphatic and glymphatic systems to the development of Alzheimer’s. In a study of mice, they found that glymphatic dysfunction contributes to the buildup of amyloid beta, a protein that plays a key role in the disease.

In 2016, Jeff Iliff, a neuroscientist at Oregon Health & Science University, along with several colleagues examined post mortem tissue from 79 human brains. They zeroed in on aquaporin – a key protein in glymphatic vessels. In the brains of those with Altzhiemer’s, this protein was jumbled – in those without the disease, the protein was well organized. This suggests that glymphatic breakdown plays a key role in the disease.

The link to TBI

How does all this relate to TBI and an increased risk of Alzheimer’s? The scientists have shown that in mice, a TBI can produce lasting damage to the glymphatic vessels, which are quite fragile. Mice are a good model, Nedergaard explains, because their glymphatic systems are very similar to humans. She has found that months after a TBI, the brains of these animals were not clearing waste efficiently, leading to a buildup of toxic compounds, including amyloid beta. Returning to the dishwasher analogy, Nedergaard likens it to using only a third of the water required, you’re not going to get clean dishes!

Strategies to improve the functioning of our Glymphatic System Sleep

Important to the healthy functioning of the glymphatic system is sleep. Nedergaard has demonstrated, at least in mice, that the system processes twice as much fluid during sleep than it does during wakefulness. She suggests, that over time, sleep dysfunction may contribute to Alzheimer’s and other brain diseases. We clean our brain when we are sleeping – this is probably an important reason we sleep.

Man sleeping on his side

Nedergaard and Benveniste have also found that sleep position is crucial. In an upright position – sitting in a chair – waste is removed less efficiently. Sleeping on your stomach is not very effective; sleeping on your back is somewhat better, while sleeping on your side proves to be the most effective, although why this is the case isn’t known.

Other ways to improve glymphatic flow

Other ways to improve glymphatic flow are also being studied. In January, Chinese researchers reported that in mice, omega-3 fatty acids improved glymphatic functioning. I relate this to other advice about staving off the risk of dementia I’ve come across – following a “Mediterranean” diet, which is high in omega-3 fatty acids.

Benveniste is also examining the anesthetic dexmedetomidine’s ability to improve glymphatic flow, while in a separate, small human study, researchers have found that deep breathing significantly increases the glymphatic transport of cerebrospinal fluid into the brain.

Alitalo is experimenting with growth factors – these are compounds that can foster regrow the of vessels around the brain. He is currently using this to repair lymphatic vessels in pigs, and is now testing this approach in the brain’s of mice who have a version of Alzheimer’s.

Currently, there are no clinical therapies in treating Alzheimer’s and other brain diseases, however this particular mechanism of brain disease has only just been discovered and as Alitalo says “give it a little time.”

In the meantime follow Alison’s advice on strategies to prevent, slow down, and possibly even reverse cognitive decline and remember to include good sleep hygiene and a diet rich in omega 3 fats, and take some deep breaths.

Source: Washington Post


Since her TBI in 2011, Sophia has educated herself about TBI. She is interested in making research into TBI accessible to other survivors.

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Having Trouble Focusing? Here are some tips that can help

BY: SOPHIA VOUMVAKIS

One of the struggles I faced after sustaining my Traumatic Brain Injury (TBI) was difficulty focusing. Apparently this isn’t a problem only those who have sustained a TBI face, but also impacts many non-TBI survivors.

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PHOTO: TRANMAUTRITAM via PEXELS

The world around us is not helping with this struggle. I observe people bouncing around between the apps on their phones, checking their emails, Twitter, Snapchat, and Facebook, texting, all while working or socializing with friends and families. These are not just annoying habits – it’s a little more insidious than that – these habits are denigrating our ability to focus.

Georgetown professor Cal Newport explains that too much bouncing around doing different tasks degrades our ability to concentrate when we need to.

People who do a lot of attention switching, they believe they can focus when they need to, but the reality is they have lost that ability. When you give them a task that requires focus, they perform worse than people that don’t spend a lot of time fragmenting their attention.

According to Professor Newport, focus is a skill that has to be trained. You can’t just decide, “Now I’m going to go focus intensely for the next three hours on something.” If you haven’t built up your capability to do that, you’re going to have a very hard time. Bouncing around on your apps, checking your email, texting all at the same time has an impact on your ability to focus when dedicated focus is needed. Much like lifting weights at the gym, the more time you spend doing it, the stronger you’ll become. And if you haven’t been spending much time focusing, it can take a little while to get that skill back up to speed.

So to be more focused you need to spend more time focusing. But how do we build up our focus muscle?

Clear Your Head

You want to focus but you’re worried about all the other things you have to do. So we often decide to work on multiple tasks at the same time. While writing this article, I’m also thinking about the bills I have to pay, getting my income taxes done, what I’m going to make for dinner, etc. I am tempted to go online to pay some of those bills, look up some recipes, and plan my shopping list. I may feel like I’m getting a lot accomplished, but focusing on these other tasks is taking me away from the task at hand and making it harder to complete. Research suggests that when I switch from writing this post to going online to pay my bills, and back to writing, my attention doesn’t immediately follow—a residue of my attention remains stuck thinking about the bills I just paid – did I pay them from the right account, did I get the date right?

cal-newport-sm
CAL NEWPORT

When I am thinking about these other tasks it reduces the amount of mental firepower I have to devote to writing this article.

One approach to combating “residual attention” is to get the concerns about all the other tasks out of my head by writing them down. Neuroscientist Daniel J. Levitin explains that writing things down deactivates “rehearsal loops” in my brain.

When we have something on our minds that is important, such as a to-do item, we’re afraid we’ll forget it. Our brain rehearses it, tossing it around and around in circles in what cognitive psychologists actually refer to as the rehearsal loop, a network of brain regions that ties together the frontal cortex just behind your eyeballs and the hippocampus in the center of your brain.

The problem is that it works too well, keeping items in rehearsal until we attend to them. Writing them down gives both implicit and explicit permission to the rehearsal loop to let them go, to relax its neural circuits so that we can focus on something else.

Having a plan for how I’ll take care of these other tasks also helps. Apparently, committing to a plan to complete my incomplete tasks can help me to complete the task of finishing this article. Another neat strategy that I learned from my occupational therapist is to set aside a specific chunk of time to work on the task at hand. My limit for focused attention is an hour. So, I set the timer on my phone for an hour. When the time is up, I will stop working on this post, and consult my recipe collection to plan dinner.

Location, Location, Location

We’ve all heard this adage when it comes to real estate – but it is also important when it comes to focusing.

A number of experts agree that the biggest part of focus is merely removing distractions. Productivity guru and author of The 4-Hour Workweek, Tim Ferriss explains:

Focus is a function, first and foremost, of limiting the number of options you give yourself for procrastinating… I think that focus is thought of as this magical ability. It’s not a magical ability. It’s putting yourself in a padded room, with the problem that you need to work on, and shut the door. That’s it. The degree to which you can replicate that, and systematize it, is the extent to which you will have focus.

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photo credit: Eustaquio Santimano Study via photopin (license)

What does research show the most productive computer programmers have in common? They had employers who created an environment free from distraction. In her book Quiet: The Power of Introverts in a World That Can’t Stop Talking, Susan Cain notes that:

…top performers overwhelmingly worked for companies that gave their workers the most privacy, personal space, control over their physical environments, and freedom from interruption.

One of the most powerful ways to improve your ability to focus is to pick the right environment. After my daughter moved out, I converted her bedroom into a den. I painted the room a beautiful grey-green, bought a lovely glass desk, brought in a comfy chair from another part of the house, and hung some of my favourite art work. This is where I go when I want to focus.

Stop Being Reactive

Turn smartphone notifications off. Your computer should not be chiming when you get a new email. You need to stop being in a mode where you are reacting to things. This leads to attention residue, as discussed above; anytime you are reacting to new stimuli it pulls you out of focus. The new stimulus can linger in your head, draining your ability to concentrate on what’s important.

It might seem harmless to take a quick glance at your inbox every ten minutes or so. But that quick check introduces a new target for your attention. Even worse, by seeing messages that you cannot deal with at the moment (which is almost always the case), you’ll be forced to turn back to the primary task with a secondary task left unfinished. The state that almost every knowledge worker spends their day in is a terrible state if your goal is to actually focus with any intensity. I think it’s the equivalent of having a professional athlete who’s coming to most games hungover.

So maybe you try all this and you still can’t focus today. It might not be due to anything going on right now. It might all be the result of what you didn’t do last night …

Get Your Sleep!

 

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photo: nomao saeki via UNSPLASH.COM

What’s one of the main reasons we spend so much time aimlessly surfing the Internet? Studies say it’s lack of sleep. Not getting enough reduces willpower and depletes the self-control you need to avoid bad habits like watching cat videos.

Sleepiness slows down your thought processes. Scientists measuring sleepiness have found that sleep deprivation leads to lower alertness and concentration. It’s more difficult to focus and pay attention, so you’re more easily confused. This hampers your ability to perform tasks that require logical reasoning or complex thought. In his book The Brain’s Way of Healing, Norman Doidge explains that during sleep our sympathetic nervous system (our fight or flight reaction) is turned off, allowing for our parasympathetic system to turn on. When our parasympathetic system is turned on, a number of chemical reactions that promote growth and reenergize our neurons occur, leading to relaxation and preparing for the growth of new neural pathways and connections.

Sleepiness also impairs judgment. Making decisions is more difficult because you can’t assess situations as well and pick the right behavior.

To Sum Up

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Post completed! Now off to deal with all those other ‘to-dos!’


Since acquiring her traumatic brain injury in 2011, Sophia has educated herself about TBI. She is interested in making research accessible to other survivors.

References

Barker, E. (2014) How To Focus: 5 Research-Backed Secrets to Concentration. Retrieved from www.bakadesuyo.com

Cain, S. (2012) Quiet: The Power of Introverts in a World That Can’t Stop Talking. Danvers, MA: Crown Publishing Group.

Doidge, N. M.D. (2015) The Brain’s Way of Healing. New York, N.Y.:Viking.

This simple, pain-free brain stimulation technique may one day lead to a personalized treatment for brain injury

BY: SOPHIA VOUMVAKIS

We know that every brain injury is different – which is why aspects of brain injury, such as prognosis and treatment, can be so complicated – if every brain injury is unique, how we find effective ways to treat each individual?

Now, promising research suggests that a deeper understanding of interconnected brain networks may lead to personalized treatments for brain injury.

In a previous post, we discussed how a greater understanding of interconnected brain networks may one day be used as a diagnostic tool for brain injury. As discussed, these networks allow for communication across long distances in the brain. They enable us to direct our attention to important information in our internal and external environments, allowing us to plan and problem solve.

A PATIENT RECEIVING TRANSCRANIAL DIRECT CURRENT STIMULATION; PHOTO:
A PATIENT RECEIVING TRANSCRANIAL DIRECT CURRENT STIMULATION; PHOTO: NEUROPLASTICITY, REHABILITATION AND CAREERS IN RESEARCH

The brain’s natural response to injury includes the activation of cell repair mechanisms to reduce edema (the build-up of fluid in the brain) and inflammation. As the brain heals, it modifies  previously existing intrinsic connectivity networks (ICN), forming new connections.

Recent evidence from cognitive neuroscience suggests that noninvasive brain stimulation techniques help these networks recover following TBI. One of these techniques, transcranial direct-current brain stimulation (tDCS) involves the application of a weak electrical DC current to the scalp to control the excitability of ICNs. Research suggests this treatment helps the network regions prepare for, and respond optimally to, cognitive rehabilitation.

Relatively brief periods of tDCS (30 min) have been found to enhance learning in a variety of perceptual, cognitive and motor tasks. The research suggests that tDCS triggers learning by enhancing attention to critical stimuli and events within new tasks, helping patients learn new things faster and better.

PHOTO: SPECIAL ED POST
CHILD RECEIVIVING tDCS TREATMENT; PHOTO: SPECIAL ED POST

tDCS is usually well tolerated by patients, and is minimally invasive to the point that it does not interupt rehab activities, as the above picture demonstrates. Currently, however, its potential in TBI treatment is limited by poor control over the location of the stimulation. New high definition t-DCS may be able to overcome this limitation, using specialized HD electrode arrays.

Modeling studies have shown that HD electrodes can generate a higher intensity on cortical targets as compared to conventional sponge electrodes. Once the precise target is established, computational models are used to maximize the intensity of the stimulation on a precise target.

The benefit of maximizing intensity on a target, such as a damaged ICN, could lead to benefits such as increased attention span in people living with brain injury.

PHOTO: THE APASHIA CENTRE
PHOTO: THE APASHIA CENTRE

The focus of current research is to identify the ICNs that are altered by TBI, and then to determine how these networks react to the HD-tDCS treatment.

Eventually, this could lead to a personalized treatment approach for TBI that examines network diagnostics along with biomarkers of the traits (such as a person’s health status, nutrition, genetics, etc.) and states of the patient (such as their sleep quality and energy level) in an effort to optimize clinical therapy.

Excerpted from Current Opinion in Behavioral Sciences 2015, 4:92–102 A themed issue on Cognitive enhancement, Edited by Barbara Sahakian and Arthur Kramer, 2015 Elsevier Ltd.


Since acquiring her traumatic brain injury in 2011, Sophia has educated herself about TBI. She is interested in making research accessible to other survivors.

 

Damage to white matter leads to poorer cognitive performance in youth

BY: BHANU SHARMA

If you’re reading this blog, chances are you’re familiar with the fact that injuries to specific areas of the brain result in specific impairments, such as vision loss or memory problems.

The brain is a complex organ made up of different cells, tissues and structures. Despite this, it can be organized into two main parts: white matter and grey matter. New research suggests that damage to the white matter areas of the brain results in poorer cognitive performance in youth.

WHITE MATTER FIBER ARCHITECTURE AS SEEN BY THE CONNECTOME SCANNER DATASET
WHITE MATTER FIBER ARCHITECTURE AS CAPTURED BY THE CONNECTOME SCANNER DATASET; PHOTO: HUMAN CONNECTOME PROJECT

White matter consists of bundles of nerve cells that are sheathed by a white fatty substance called myelin, which helps conduct electrical signals between brain cells. On the other hand, grey matter is made of different kinds of nerve cells that do not contain the myelin coating. Grey matter is involved with a range of processes, from muscle control to sensory perception to cognition or thinking.

Traumatic brain injury (TBI) can result in damage to both white and grey matter. However, brain trauma affects white and grey matter differently. In a recently published study in the Journal of Neuroscience, the impact of moderate-to-severe TBI on white matter and cognitive functioning in 32 youth (one to five months post-injury) was examined.

SIDEWAYS VIEW OF CORPUS COLLOSUM
SIDEVIEW OF CORPUS COLLOSUM; PHOTO: SCIENCE OVER A CUPPA

In the study, the authors investigated the effects of moderate-to-severe TBI on the corpus callosum, a white matter brain structure that connects the right and left hemispheres – or halves – of the brain. The corpus callosum is known to be very vulnerable to damage after brain trauma. It is a structure vital for relaying information from one half of the brain to the other, and when it is damaged it can impair cognitive abilities.

In the study, the authors used a technique called electroencephalography (which measures electrical activity or brain signals) to measure the amount of time required for information to be communicated from one hemisphere of the brain to the other via the corpus callosum. They also used a neuroimaging technique called diffusion-weighted imaging (DWI) to test the structural integrity – or the health of – the corpus callosum. Finally, the authors used a series of common standardized tests to assess the cognitive performance of study participants.

FRONTAL VIEW OF CORPUS COLLOSUM;
FRONTAL VIEW OF CORPUS COLLOSUM; PHOTO: SCIENCE OVER A CUPPA

Compared to a group of healthy youth, signals took longer to transmit across the corpus callosum in half the youth with moderate-to-severe TBI. This indicated that in these youth, the corpus callosum was damaged and weakened by brain trauma. This finding was reinforced by DWI results, which showed that this sub-group of injured youth had noticeable structural damage to the corpus callosum.

Furthermore, cognitive performance was also lower in this group of injured youth. In sum, this study showed that in half the youth with moderate-to-severe TBI, it took longer for signals to be relayed from one half of the brain to the other, and this was statistically related to white matter damage and poorer cognitive performance.

It is important to note that only half of the youth with moderate-to-severe TBI had damage to the corpus callosum and cognitive impairment. This highlights that outcome following moderate-to-severe TBI in youth can vary greatly, as some youth demonstrate impairments that others do not.

Promisingly, this study has identified that improving the health of the corpus callosum through therapy or medicine may be able to improve cognitive performance in youth with moderate-to-severe TBI.


Bhanu is involved in traumatic brain injury research and is interested in learning more about – and helping promote – recovery following brain injury. 

Having a spouse, longer time in rehab increases community integration post-TBI

BY: BHANU SHARMA

There’s more evidence that having a spouse, and being able to stick it out for the long-run in rehab,  is good for you.

Often, traumatic brain injury (TBI) results in a number of symptoms, problems, and complications. Among the most well-known of these are those which impair or compromise cognitive processes such as memory, attention, and thinking, and to a lesser extent, affective functions such as emotion and mood. But TBI can also have a negative impact on how a person engages in their community.

photo credit: The Lover via photopin (license)
photo credit: The Lover via photopin (license)

Changes in community integration – meaning the extent to which one participates in their community, society, and home – have long been identified as a consequence of TBI. Given that higher levels of community integration following a TBI are positively related to life satisfaction, physical health and perceived success in transitioning from hospital to home, improving community integration should be a primary rehabilitation goal following brain injury. However, to improve community integration, it is first important to understand the factors that influence levels of community integration following TBI. One recent study did just this.

In the study, the authors examined levels of community integration two-years following a brain injury. The study participants had either a moderate or a severe TBI. Although there are a number of ways to measure community integration, the authors of the study used the Community Integration Questionnaire (CIQ), a widely used and valid measure of community integration for patients with brain injury. Using this questionnaire was a strength of the study.

After a series of statistical analyses, the study identified five main predictors of higher levels of community integration two-years following a TBI.

community integration

Promisingly, many factors can contribute positively to community integration. Certain family dynamics (such as living with a spouse) and accessing some healthcare services (i.e., rehabilitation programs) can improve community integration two-years following a brain injury.

Importantly, this study indicates that there can be improvement in community integration and therefore recovery over time. The results of this study can perhaps be used to ensure that TBI patients receive the supports they need to achieve a high level of community integration in the years following their injury.

 Bhanu is involved in traumatic brain injury research and is interested in learning more about – and helping promote – recovery following brain injury. 

Interconnected brain regions – an end to the GCS?

BY: SOPHIA VOUMVAKIS

Traumatic Brain Injury (TBI) can often lead to problems with a person’s cognitive control, affecting their attention, memory, thought, behaviour and emotion. Cognitive control is our ability to modify our behaviour and actions to adapt to the situation we are in. It provides the basis for planning, problem solving and adaptive behaviour (our ability to be self sufficient and independant, based on our age group).

person in MRI machine
photo credit: P4250960 via photopin (license)

Accumulating neuroscience evidence suggests that cognitive control functions are carried out within a network of highly interconnected brain regions. These networks allow for
communication across long distances within the brain and enable us to direct attention to important information in our internal and external environments, to plan and to problem solve. Three such networks have been identified: the salience network, the default-mode network (DMN) and the central-executive network (CEN).

Traumatic brain injury often leads to deficits in cognitive control. The salience network plays a vital role in controlling our emotions and our awareness to the physiological state of our body. Damage to the salience network produces deficits in awareness, such as difficulty with focusing and attention span.

The DMN allows for an internal focus of attention during self-reflective cognitive activity, and is responsible for our autobiographical memory (recalling events that happened to us, as well as facts about the time and place where the event occured), and social cognition (how people process social information). Damage to the DMN results in difficulties with remembering our personal histories, problems understanding time and space, and imagining the perspective of others.

The CEN supports an external focus of attention during goal directed, cognitively demanding tasks. Damage to this network results in impairment to flexibility of thought, working memory, and problem solving.

The different brain areas which comprise these networks communicate with each other via axons, the part of the cell which allows neurons to send electrical impulses to each other. Recent advances in neuroimaging techniques have shown that TBI results in damage to axons, and depending on where in the brain the damaged axons lie, damage to one of these networks, which, in turn, will result in specific deficits.

photo credit: Brain Animation via photopin (license)
photo credit: Brain Animation via photopin (license)
A New Approach to Diagnosing TBI

Since the mid-1970’s the severity of TBI has been diagnosed using The Glasgow Coma Scale (GCS). The GCS measures eye opening, verbal response, and motor response. The test is objective and correlates well with outcomes following severe TBI. It does not, however, predict the specific deficits that will develop in a brain injury survivor. In one recent study, researchers  propose moving away from using the GCS to indentifying the structural and functional integrity of each of the interconnected brain region. If damage is seen in a specific integrated brain region, then treatment can be better targeted and started earlier to deal with the specific deficits that will arise because of the location of the damage.

In a future post we will discuss new neuroscience research on interconnected brain regions and how this can be translated into effective interventions for TBI.

Since acquiring her traumatic brain injury in 2011, Sophia has educated herself about TBI. She is interested in making research accessible to other survivors.