What is Post-Concussive Brain Fog?

Jul 27

Written By Dr. Glen Zielinski DC, DACNB, FACFN, CBIS

Brain fog is a term for a poorly-defined series of medical conditions in which a person struggles with thinking and mental effort. This may include poor concentration, inability to focus and memory issues (1). For symptoms lasting longer than 3 months, this is considered a part of post-concussion syndrome.

Brain fog is one of the most common things people experience after a concussion. People usually have difficulty describing exactly what their brain fog feels like, however as soon as the term brain fog is mentioned, people living with the condition immediately know what you are describing. They report difficulty concentrating, difficulty learning new information, struggles with memory slow thought processes, and fatigue with mental tasks.

How Common is Post-Concussive Brain Fog?

Concussions occur in roughly 1.8 - 3.8 million people. Brain fog is a key symptom used to diagnose a concussion, but many people continue to suffer with brain fog long after their other concussion symptoms have resolved. Brain fog has been estimated to occur in at least 11% and as high as 38% of concussions (14).

What Causes Post-Concussive Brain Fog?

Brain fog can be from multiple different regions that have been impacted in a concussion. The frontal lobe is where many of our thought processes take place. When the brain has been jarred around in the skull, this can impact that frontal lobe and temporarily slow down our cognitive functions.

The inner ear is an important system of our vestibular system. This sysetm tells our brain about our head’s location in space. The inner ear has two systems of receptors, known as the otoliths and the vestibular canals. The otoliths sense the head’s tilt in relation to gravity and movement in translational planes, such as up, down, and side-to-side. They require tiny crystals called otoconia in order to function. The vestibular canals are receptors that sense head movement in rotational planes.

Brain fog is very commonly a sign of central vestibular dysfunction. Central vestibular disorders involve mismatches between the visual, vestibular, and proprioceptive systems (5). Dizziness and vertigo can be the result of lesions in the peripheral vestibular receptors of the inner ear, or they can involve problems in the central cerebellar, brainstem, and brain systems that process vestibular input. These systems combine input from the inner ear with feedback from the visual system and from muscles and joints to create a coherent picture of where the body is in space and how it is moving. When there are mismatches in the inputs from the eyes, the inner ear, and feedback from the body, the brain needs to work extremely hard to localize where it is in space. This process robs the frontal lobe of resources that it would ordinarily put towards cognitive processes, leading to the development of fatigue and brain fog.

There are a number of diagnostic findings that help reveal the presence of central vestibular disorders, such as changing patterns of a type of reflexive eye movement called nystagmus, problems with the ability to visually follow moving targets, problems with keeping our eyes steady on a target, and so on (2). While central disorders are generally considered harder to treat than peripheral vestibular issues, we have some of our best successes resolving central vestibular issues.

Another important structure in the brainstem is called the Nucleus Prepositus Hypoglossi. This nucleus is responsible for maintaining gaze stability, and functions to hold the eyes still when looking at targets (3). Damage to this area causes the eyes to twitch back and forth with small movements that may be subconscious. This small amount of motion creates visual fog, which is very fatiguing as the brain struggles to hold the eyes still, which ultimately is experienced as brain fog.

Blood flow to the brain is another important aspect to consider when assessing brain fog. Cerebral blood flow is critical, as blood provides the oxygen and glucose to the brain’s neurons needed for them to fire efficiently. Our autonomic nervous system must be able to reliably send blood up to the brain. This function is frequently compromised following a TBI, resulting in what is known as post-concussive dysautonomia. When postural changes such as going from sitting to standing result in lightheadedness, fainting or dizziness, these are signs that the brain is not being perfused with enough blood quickly and is a sign of underlying cerebral blood flow issues (6). A lack of appropriate blood flow to the brain forces it to perform cognitive tasks without the necessary resources to keep neurons firing efficiently. This can easily result in marked fatigue and brain fog.

What are the Symptoms of Post-Concussive Brain Fog?

Some people develop brain fog immediately after their concussion, but for others it may develop weeks or even months later. Symptoms usually fluctuate in severity depending on the amount of mental effort involved in a task. Cognitively demanding activities like computer work, multitasking, managing more than one conversation, or being in complicated sensory environments frequently provoke brain fog.

Brain fog can often be described as the sensation of living in a cloud. It is usually accompanied by slow thinking, difficulty focusing, confusion, lack of concentration, forgetfulness and haziness of thought processes. Chronic exhaustion usually accompanies brain fog and people feel the need to sleep a lot more and patients may have received the diagnosis of chronic fatigue syndrome (6).

How is Post-Concussive Brain Fog Diagnosed?

Brain fog is a clinical diagnosis. While imaging may be used to rule out anything else that may be causing disturbances with attention and focus, such as a tumor or neurodegenerative disease process, providers usually make this diagnosis after taking a history and performing a neurological examination.

What are the Consequences of Post-Concussive Brain Fog?

Concussions can have profound impacts on every aspect of your life. Without your ability to place your attention and focus on things like work or school, you can lose the ability to engage with your life and function in the world. Simple tasks such as reading can become exhausting and provoke your brain fog. Following conversations or even basic mental tasks can be exhausting. Going to a grocery store can become a special level of hell. Driving or riding in cars can make your symptoms worse, and even provoke headaches, dizziness, and panic attacks. Using screens or working on computers can cause all of your symptoms to increase. In short, after a concussion even the simplest tasks can become insurmountable.

Depression, anxiety, post-traumatic stress disorder, and emotional distress are common long-term consequences of concussions. Rates of substance abuse are higher following concussions (8).

Sleep disorders are common long-term consequences of concussion [9], as is chronic pain (10). Job and academic performance are frequently decreased, leading to wage losses and increased rates of unemployment (11). Concussions also tragically increase the risk of suicide (12).

What Happens to the Brain in Post-Concussive Brain Fog?

Brains are made up of several types of cells. The type that most people think of when they hear “brain cell” is a neuron, the primary cell involved in the electrical activity of the brain. You brain has billions of individual neurons, all continuously sending electrical messages back and forth between each other. There are also several types of supporting cells called glia. Glial cells provide important structural functions, and do things ranging from helping neurons communicate with each other more efficiently to cleaning out metabolic waste.

Neurons have cell bodies, sites where other neurons attach called dendrites, and long thin projections called axons. Most of the brain’s cell bodies are found in the cerebral cortex, in the hills and valleys of the first few millimeters of the brain, also known as gray matter. The majority of the rest of the brain is white matter, made up of axons running back and forth between neurons in pathways. These axons can range from extremely short to several inches long. As axons are projections from a single cell, they are very fragile, and have poor resistance to stretch and shearing forces.

When the brain undergoes either an impact, a fast twisting force, or both, axons can become damaged. Depending on the trauma, this may injure an individual group of axons, or create a diffuse axonal injury that affects multiple brain regions and pathways. Neurons within particular pathways may be damaged such that they lose efficiency, or be lost altogether.

When brain cells are injured, a number of important processes take place. Cells called microglia become activated to promote inflammatory processes that help heal damaged tissue. Depending on the individual’s previous level of inflammation, sometimes the microglial response is exaggerated and leads to further damage. Fragile neurons have different needs for oxygen, nutrients, and blood sugar. In many cases the ability for the brain to properly fuel brain cells can be damaged, resulting in further injury (13).

As the brain heals, the neurons that remain are forced to take on the function of the damaged and lost cells. Depending on the extend of the injury, this may be easy or impossible. At times neurons are forced to do more than they can handle, which can overstimulate them and cause further injury. Neurons are not like muscle cells, in that with muscles the best way to build strength is to push them to the point of failure. When neurons are stimulated past their point of fatigue, they generally die off. One of the main problems we see in post-concussion syndrome is neural pathways that are continuously fatiguing as they are required to perform not only their previous functions but those of lost cells as well.

Neurons involved to create post-concussive brain fog are part of the major systems our brain utilizes to figure out where we are in space; the vestibular system, the visual system and proprioceptive system. These systems all come together at the level of the brainstem, which is susceptible to injury in concussions. Any level of injury to any number of these systems will create a sensory mismatch and cause brain fog.

How is Post-Concussive Brain Fog Usually Treated?

In most cases, the primary type of treatment offered to post-concussive patients are medications. These can be vestibular suppressants, anti-nausea agents, or medications that suppress anxiety. In many cases, patients are prescribed anti-depressants as well. While these may provide some benefit in reducing the symptoms, they usually do little to address the actual cause of the problem. There is no widely accepted treatment for brain fog.

People may be referred to physical therapists that perform various types of vestibular therapy. This can be helpful in some situations, however still in most cases therapy programs are designed more towards reducing symptoms through habituation therapy. This helps the brain build compensations for underlying problems, but again in most cases does not directly address the impaired reflexes that are creating the problem at a fundamental level.

How is the NeuroRescue Program Different?

One of the main things your brain does, and maybe even the primary thing, is help you determine where you are in the world. Your brain uses inputs from your inner ear to figure out where your head is in relation to gravity and how it is moving. It uses inputs from your muscles and joints to figure out where your body is in relation to your head and what your body is doing. It uses inputs from your eyes to figure out where your body is in relation to the visual environment.

Your brain needs to put all of that together to make sense of where the world is, and where you are in relation to the world. It needs to be able to localize you effectively in the environment, in order for you to be able to respond to the environment properly.

When your brain is injured in a concussion, we regularly see damage to pathways that involve the eyes, the inner ear, muscles and joints, among many others. It is important to understand that concussions are rarely only about injuries to the visual system, the inner ear, or the neck. Perhaps the primary problem in concussion and mTBI is damage to the neurological mechanisms that allow all of these systems to work together. In most cases of mTBI and post-concussion syndrome, at a foundational level a failure of integration exists between the eyes, the vestibular system, and proprioceptive feedback from muscles and joints.

This is why many patients fail to fully resolve their concussion and mTBI challenges with vision therapy, vestibular therapy, physical therapy, chiropractic treatment, manual or massage therapy, and medication management, even if all of their therapies are performed at the same time. While all of these therapies can help with problems in the individual systems, none of them take the comprehensive NeuroRescue Program approach to address all of the systems involved in a brain injury and their ability to work together in harmony.

How Does the NeuroRescue Program Work?

We design your unique NeuroRescue Program to be among the most comprehensive diagnostic and therapeutic protocols available today. We create individual NeuroRescue Programs based on a comprehensive analysis of every relevant neurological system and pathway, using gold-standard, cutting edge neurodiagnostic technologies and examination procedures and state-of-the-art therapies.

We begin with your Discovery Day, wherein we perform a comprehensive history of not only your condition, but your life on a timeline. This allows us to dive deeply into your case and see all of the factors that led to where you are now. It helps us uncover hidden problems and associated conditions that may be making it difficult for you to move your recovery forward.

Our examination allows us to identify the areas and pathways of your brain that have been impacted by your injury. We begin by precisely quantifying the function of your visual, vestibular, and proprioceptive systems through computerized analysis of your eye movements, your inner ear reflexes, and your balance in a host of different sensory conditions.

We employ technologies including Videooculography and Saccadometry to measure several classes of eye movements. We use Video Head Impulse Testing to measure the function of your inner ear, and Computerized Dynamic Posturography to assess your balance in different sensory conditions.

We use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and perception of vertical in a virtual reality environment.

We combine all of this with a comprehensive physical and neurological examination of your sensory, motor, autonomic, and cognitive systems. We review any relevant laboratory testing, radiological imaging, and prior neurodiagnostic testing, and integrate that information with our findings.

We use this information to identify which parts of your brain are working properly, which systems are struggling, and the precise point at which your systems fatigue.

We can then design a NeuroRescue Program that is unique and specific to your brain, and yours alone. Your NeuroRescue Program works to rejuvenate and reintegrate the damaged neurons and pathways in your brain. It works to improve energy, endurance, and functional capacity within your fragile systems.

All of our therapies are backed by the latest neuroscience research. Our therapies may involve eye exercises designed to improve gaze stability (8), or the ability to successfully hit targets with your eyes (9). They may involve exercises to restore reflexes involving your inner ear, your neck, or both (10). They may include exercises to improve your balance under specific conditions (11). They may involve vision training exercises using specific therapies that integrate several modalities at the same time (12). They may involve things like specific types of electrical stimulation (13), transcranial magnetic stimulation (14), or even specific exercises performed in a virtual reality environment (15). Research shows that taking a multimodal functional neurological approach to treating traumatic brain injuries is extremely effective, and that the effects are lasting (16, 17, 18).

We use our technologies and procedures to not only see what we need to address, but also when it is time to stop and let you rest. We address your impaired neurological function from multiple angles of therapy, and provide metabolic support to improve neurological recovery.

While we cannot bring back neurons that have been lost, your NeuroRescue Program allows us to take the pathways that remain and maximize their efficiency and endurance. And by focusing on the integration of systems, we can do more than just get pathways working better, we can get them working together again. This gives us our best opportunity to get your brain fog under control, and return you to living a healthy, vibrant, and fulfilling life.

Your Next Best Step:

Living with post-concussion syndrome is challenging, but with the NeuroRescue program, the symptoms can almost always be improved, and in some cases, resolved. To see if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.

And remember, it’s never too late to start getting better.