What is Post-Concussive Vertigo?

Jul 27

Vertigo is a sensation of feeling off-balance. Vertigo can make you feel as though you are moving when you physically still or as though your world is moving when it is actually still. Post-concussive vertigo is vertigo that occurs as a result of a concussion or traumatic brain injury.

How Common is Post-Concussive Vertigo?

Concussions occur in roughly 1.8 - 3.8 million people. It is estimated that 40-60% of people who sustain a traumatic brain injury experiences some degree of vertigo in the time after (1). It may occur in short and intermittent episodes, or it may last for years following the event.

What Causes Post-Concussive Vertigo?

The vestibular system is an important system that informs our brain about our head position relative to body position. Post-concussive vertigo can be a result from injury to the peripheral vestibular system or central systems in the brain and brainstem where vestibular information integrates.

There are several different types of post-concussive vertigo, with different causes for each type. It is common to experience more than one type of vertigo after a concussion, often at the same time.

One of the most common causes of post-concussive vertigo is known as Benign Paroxysmal Positional Vertigo, or BPPV (6). 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.

BPPV occurs when these crystals are dislodged and float into one of the canals. This makes the canals respond to gravity, which can create an inappropriate sensation of head movement. The canals are tubes filled with thick fluid, and tiny hair cells live on the bottom of the canals. When the head moves, it takes a second for the fluid to catch up. This bends the hair cells, which fire the vestibular nerve, and this input tells the brain that the head is moving in that direction. In BPPV, when the involved canal is placed in a vertical plane, the crystals float down the side of the tube until they bang into and bend the hair cells. This makes the brain believe that the head is turning in the direction of the canal when the head is still. The canal provides the wrong input to the brainstem, and this creates a vertigo-producing sensory mismatch.

Post-traumatic BPPV is very common, as a whiplash and blunt force to the head can cause the crystals to become loose (2). It is also very common for polycanal BPPV to occur following trauma. BPPV is usually easy to fix with Epley Maneuvers, also known as Canalith Repositioning Maneuvers, wherein the head is placed in a sequence of positions that allow the crystals to float back where they belong. More complicated cases of BPPV involve more than one canal. We successfully resolve complicated BPPV on a regular basis.

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 pathways 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.

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, and so on (25). While central disorders are generally considered harder to treat than peripheral vestibular issues, we have some of our best successes resolving central vestibular issues.

Cervicogenic Dizziness

Cervicogenic dizziness involves injuries to the neck. Neck injuries and cervicogenic dizziness are common consequences of concussions and other traumatic brain injuries (7). Neck injuries can create severe sensory mismatches between mechanoreceptors in the neck and the vestibular and visual systems. We frequently see patients that have suffered injuries to all of these systems simultaneously, and specific rehabilitation strategies need to be employed in sequence to properly resolve these more complicated cases (26).

What are Symptoms of Post-Concussive Vertigo?

Post-concussive vertigo can create a sensation of falling, tilting, swaying back and forth, being pulled in one or several directions, or being generally unstable. It can also manifest as anxiety, panic, and depersonalization in complicated sensory environments.

What Are the Consequences of Post-Concussive Vertigo?

Concussions can have profound impacts on every aspect of your life. You can lose the ability to function in the world. Simple tasks such as reading can become exhausting and provoke your headache and dizziness. 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 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 with Post-Concussive Vertigo?

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 extent 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 vertigo 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 vertigo and dizziness.

How is Post-Concussive Vertigo Usually Treated?

In most cases, the primary type of treatment offered to dizziness and vertigo 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 (27).

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 (28).

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 (29).

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.

All of our therapies are backed by the latest neuroscience research. Our therapies may involve eye exercises designed to improve gaze stability (14), or the ability to successfully hit targets with your eyes (15). They may involve exercises to restore reflexes involving your inner ear, your neck, or both (16). They may include exercises to improve your balance under specific conditions (17). They may involve vision training exercises using specific therapies that integrate several modalities at the same time (18). They may involve things like specific types of electrical stimulation (19), transcranial magnetic stimulation (20), or even specific exercises performed in a virtual reality environment (21). Research shows that taking a multimodal functional neurological approach to treating traumatic brain injuries is extremely effective, and that the effects are lasting (22,23,24).

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.

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 post-concussive vertigo under control and return you to living a healthy, vibrant, and fulfilling life.