What is a Post-Concussive Headache?

Jul 28

A concussion is a form of mild traumatic brain injury (mTBI). Up to 15% of concussions result in what is called Post-Concussion Syndrome, or PCS. A concussion results in abnormal brain function, and can have a profound impact on an individual’s quality of life.

A post-concussive or post-traumatic headache is pain in the head or neck that results from the concussion. It may appear suddenly or gradually following the concussion. It may be present continuously or on a fluctuating basis. The headache may feel like a tension-type headache or a full-blown migraine. These headaches are a common feature of post-concussive syndrome.

How Common Are Post-Concussive Headaches?

Traumatic brain injuries and concussions are serious problems. There are millions of mTBIs each year in the United States. According to the CDC, there were 2.87 million TBI-related emergency department visits, hospitalizations, and deaths in the US, including over 837,000 involving children (1). Headaches are the most common symptom of concussions (7). Increasing age is a risk factor for post-concussive headaches, which also seem to affect women more than men (8). Over 30% of people who have had a concussion report having headaches that continue long after their concussion (9).

What Causes Post-Concussive Headaches?

Concussions are very common in sports, are often seen in motor vehicle collisions, and in falls among older adults, which can lead to post-concussive headaches. Persistent post-concussive headaches are often caused by structural damage to the brain or brainstem, disrupting the nerves sending important information to and from the brain (8). They may occur because of injuries to the skull or neck, tension, stress, impaired autonomic nervous system regulation, or side effects from medication.

What Are The Symptoms Of A Post-Concussive Headache?

Symptoms of post-concussive headaches vary, depending on the type of headache being experienced. The most common types of post-concussive headache are tension-type and migraine without aura, although cervicogenic headaches are also extremely common if a neck injury is involved (17).

A migraine headache may or may not have an aura present before or during the experience of head pain. Most auras involve spontaneous firing of neurons in the visual cortex, including changes to visual clarity, loss of vision or seeing bright spots or lights. The pain then becomes dull and throbbing, usually on one side of the head. It is common to have nausea and vomiting, as well as light and sound sensitivity. Pain can range from moderate to severe intensity, and can reach a truly debilitating level (18).

A tension-type headache is associated with muscle tension, muscle spasms or stress. It will feel like a tight, squeezing sensation around the entire head or one side of the head. Pain levels associated with them are mild to moderate. Tension headaches usually get progressively worse throughout the day. Many researchers are now questioning if tension-type headaches exist on a continuum with migraines (19).

Cervicogenic headaches are rooted in the muscles and structures of the neck. The cervical spinal area is loaded with potential pain-generating structures that can cause intense localized discomfort. Cervicogenic headaches can be caused by whiplash injuries, sports injuries, inflammation of the muscles and joints, or irritation of nerves. The pain is usually associated with a reduced range of neck motion, which can lead to fibrotic tissue formation that reduces the range of motion even further. When this happens pain usually radiates from the neck to the back and sides of the head, as well as to the forehead. By this point your perception of neck pain usually fades behind your awareness of the headache. Most people focus on their headache and tend to ignore the pain generators in their cervical spine (20).

Rebound headaches occur following suddenly stopping the very medications we take to get rid of the headache. They can occur if we miss a dose or two doses when we have been consistently taking pain medicine on a regular schedule. These may also be experienced with a sudden decrease in caffeine intake (21).

Dealing with chronic pain can be exhausting and many patients with chronic post-concussive headaches are fatigued by them (2).

What are the Consequences of Post-Concussive Headaches?

Headaches are an enormous source of disability and lost productivity. Approximately 157 million days of work are lost each year due to headaches, costing approximately $50 billion in work absenteeism and medical benefits (3).

Headaches can have profound impacts on your mental health. There are well-established links between chronic headaches and conditions such as depression and anxiety (4). Chronic sleep disruption has been associated with cervicogenic headaches, which reinforces a cycle of depression, further sleep disturbance, and further headache (5). Persistent post-concussion syndrome has even been implicated as a risk factor for suicide (6).

What Happens to the Brain in Post-Concussive Headaches?

People usually think of their pain system as a series of on-off switches, in that either something hurts and there is something wrong, or it doesn’t hurt and everything is fine. That’s not really the way your pain system works.

A better analogy is that the experience of pain is more like trying to ring the bell at the amusement park. You hit the hammer on the striker, the puck goes up, and if you hit it hard enough, the puck goes all the way up and rings the bell. Your pain receptors are the hammer, and your pain threshold is the height of the bell. We want as little firing of pain receptors as possible, so the hammer does not hit the striker hard. We also want the bell to be as high as possible, so that the hammer needs to hit really hard to send the puck up to ring the bell.

The pain receptors for head and face pain fire through your Trigeminal Nerve (10). This nerve also carries pain inputs from the brain’s blood vessels and meninges. When pain receptors are compressed or irritated by inflammation, they fire inputs into the spinal trigeminal nucleus (11). This collection of neurons functions as the striker for your headache pain. It is always being hit with pain inputs from the trigeminal nerve, from pain receptors being compressed through movement, from chemical waste products, and so on.

The only pain receptors in this system that are not constantly firing are the dead ones. All neurons need to be constantly firing to stay healthy, including pain neurons. The firing rates of these will increase with tissue damage and so on, but even if there is nothing stimulating them they will still have an inherent rate of activity. Because of this, your pain system needs the ability to modulate these inputs, otherwise we would be in pain 24/7.

In order to keep pain under control we have a series of pathways from the brain that fire down to inhibit the trigeminal nucleus. These make sure that normal background firing rates of your pain receptors are not enough for you to experience pain. When this system is working effectively, the “bell” in your pain system is very high, and the striker needs to be hit very hard for you to experience pain.

Your trigeminal nerve doesn’t just map your head, face, and brain. It also receives pain input from the top three segments of your neck. The sub-occipital spine at the base of your skull sends input into your spinal trigeminal nucleus. If there is enough pain input from your upper cervical spine, the bell can start to ring and you experience a headache.

If this pain input is bad enough to ring the bell hard, pain can start to refer throughout the trigeminal system. This means that you will experience pain not just at the base of your skull, but behind your eyes, in your forehead, in your jaw, and potentially everywhere else that receives input from this nerve.

This pain referral is basically crosstalk within your trigeminal system. In the same way that during a heart attack you can have pain go down your left arm even though there is nothing wrong with your arm, if the pain inputs from your neck are high enough you can experience pain throughout your trigeminal system. Most of the pain receptors in your brain surround blood vessels, and if the trigeminal system is stimulated hard enough, you can start to experience throbbing pain every time blood is pumped through your brain’s arteries.

Your pain system works just like everything else in your system, in that if you use it over and over, it gets better at what it does. Unfortunately, that means that if you keep ringing the bell for an extended period of time, the bell gets lower, and it takes less pain input to trigger a headache. Your pain threshold can become low enough that even background noise from normal compression of pain fibers can start to trigger headaches.

There are many ways that your cervical spine can promote firing of pain receptors. In many cases, the causes of pain can be hard to detect without advanced diagnostics. Increased tone of sub-occipital muscles can be from injured tissue, but it may also be from something as subtle as impaired eye movements, inappropriate inputs from the inner ear, inability to hold the eyes still on targets, or failure to synchronize eye and head movements properly to follow moving targets. There are a host of ways that your nervous system can poorly adapt to the environment, with the result being increased tone of upper neck muscles resulting in headaches [12].

Eye movements have been shown to be significantly compromised in post-concussive headaches. Saccades are fast eye movements that we use to create our visual world and localize ourselves within it. There are versions of saccades that involve reflexes, and others that require conscious control, including self-paced saccades. Research shows that in post-concussion syndrome, the number of self-paced saccades that can be created in a given time is decreased, and this correlates with increased symptom burden. Imaging studies reveal that this is the result of damage to a number of important pathways involved in saccade generation, which may be a hallmark of post-concussion syndrome (22). Impaired saccades are often present in virtually all forms of post-concussive head pain syndromes, including migraine (24), tension-type (25), and cervicogenic headaches (26).

Additional research shows that eye movement function in PCS does not follow the normal recovery path of eye movements after concussions. Persistent dysfunction in eye movements is indicative of ongoing cerebral impairment. Testing of eye movement may be even more sensitive in establishing post-concussion syndrome than neuropsychological tests, as eye movements showed additional dysfunction in motor/visuospatial areas, response inhibition, visual attention and subcortical function (23). Rehabilitation of eye movements thus becomes critically important in post-concussion syndrome.

Other reflexes that are important for maintaining normal muscle tension in our necks are accurate and efficient vestibulo-ocular reflexes (VORs) (13). The receptors of our vestibular system are encased in the skull near our ears. They lie close to the auditory system which conducts sound. There is a vestibular mechanism on each side, and each contains two separate receptor mechanisms, the otoliths and the semicircular canals (SCC). Each side has an anterior, horizontal and posterior SCC, which is the only system that gives our brain an x, y and z axis for movement of our head. It is very important and closely ties into our visual system.

The reflex that combines inputs from both systems is called the vestibulo-ocular reflex. The reflex occurs when we try to keep our eyes fixated on a target but want to move our head, so it developed such that we could maintain good focus while moving. The information from our vestibular and visual systems come together at the brainstem, which is unfortunately, frequently injured in a traumatic brain injury.

VORs are sensitive and vulnerable in TBIs of all severities (14). Injury to the neurons in the brainstem occur whenever there is a torsional or whiplash force as the mechanism of injury. This can make it very challenging to have stable eye movements after a concussion and patients often describe blurry vision, dizziness, lightheadedness or unsteadiness with this type of injury.

As a way to compensate for this issue, we have to increase the number of eye movements we make to find the target we are trying to focus on. This is problematic because for every eye movement, there is a slight contraction of the muscles at the base of the skull in order to stabilize our head (15). These reflexes can become significantly disrupted in cases of mTBI, leading to a significant disruption in control of the eyes, the inner ear reflexes, and neck muscle tone (16). An abnormal increase in the number of eye movements leads to an abnormal increase in firing of the muscles at the base of the skull, resulting in tight muscles, decreased range of motion and pain.

At the same time, the reflexes that determine the amount of head movement that takes place during an eye movement can be damaged in post-concussion syndrome. When saccades are short of their target, we generally substitute cervical motion to help our eyes reach the target. The integration between the eyes and head is commonly disrupted in neck injuries and concussions, leading to inappropriate levels of tone in neck muscles that can further provoke headaches (27).

Fortunately, all of these factors can be addressed with proper neurorehabilitation. Research on exactly the kind of visual-vestibular-proprioceptive integration therapies that we employ in your NeuroRescue Program shows that all of these factors can be modified in a short period of time, often leading to marked improvement in symptoms (28).

How are Post-Concussive Headaches Usually Treated?

There are many different types of treatment for headaches. These range from commonly prescribed pain medications to surgical destruction of pain nerves. Most traditional therapies for post-concussive headaches have limited success. We regularly see patients that have been chasing a solution for their headaches for years, often seeing dozens of providers and having attempted both conservative and invasive forms of therapies.

Many people get better with therapy, but unfortunately many others have incomplete recoveries. Millions of people suffer with long-term effects of brain injuries, and many of them have given up hope of ever living a life like they once had.

We have created the NeuroRescue Program to help these people maximize their concussion and mTBI recovery, so they can get out of pain and get back to doing what they love.

How is the NeuroRescue Program Different?

We design your unique NeuroRescue program to address every structural and neurological factor involved in your post-concussive headaches. We also evaluate the influences of metabolism, inflammation, and other chemical factors that may be promoting your pain. We evaluate the function of all of the muscles, joints, ligaments, and nerves in your cervical spine and jaw, the neurological mechanisms that control their function, and the central brain and brainstem systems that normally function to shut off pain and ensure eye movements are stable and accurate. We combine all of this information into a comprehensive protocol that does not just help you mask your headache symptoms. Instead, we get to the unique root of your problem, address it at a foundational level, and help you rebuild the functional integration necessary for your headaches to finally be resolved.

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.

We employ a wide variety of therapies to help resolve your post-concussive headaches. All of our therapies are validated by current neuroscience research. The therapies chosen for you will be determined by the specifics of your case and your diagnostic findings. Your NeuroRescue Program will be unique to only one nervous system, that being yours.

We may engage in various forms of electrical stimulation, such as trigeminal nerve stimulation (29), transcutaneous vagal nerve stimulation (30), or transcutaneous occipital nerve stimulation (31) to help get your pain under control.

We may employ laser photobiomodulation devices (32), or hyperbaric oxygen therapy (33) to decrease pain and improve endurance.

We may also use transcranial magnetic stimulation to reduce your symptoms (34), and to decrease your headache frequency (35).

Your therapies will be dictated by your unique presentation. No two brains are alike, and every NeuroRescue Program is different.

How Does the NeuroRescue Program Work?

We design your unique NeuroRescue Program to be 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 headaches under control, and return you to living a healthy, vibrant, and fulfilling life.

Your Next Best Step:

Living with post-concussive headaches is challenging, but there is hope for recovery and remission. 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.