Resolving chronic concussion symptoms
Written by Dr. Cornelius van de Wall, BSc, DC, CCM (Complete Concussion Management)
There are times that even when we follow the best acute concussion protocols (see here on navigating a new concussion), our symptoms still persist. Newer studies estimate that this happens around 30-40% of the time, which is quite a bit higher than the previously thought 10%. When concussion symptoms last beyond 3 months, we say that an individual is dealing with post-concussive syndrome. Any significant symptoms lasting beyond 2-3 weeks is a strong indication that some testing and rehabilitation may be required to resolve your concussion (in other words, resting and graded activity protocols are often not enough at this point!).
This post highlights the four most common causes of chronic concussion symptoms that researchers and clinicians have identified, and how we can work on reducing the impact each has on our symptoms and function.
Explanation of how our vision, vestibular, and cervical systems work with our general brain physiology.
#1 - Visual Dysfunction
When we think of vision issues the first thing that comes to mind is how well you can see, but for concussions we’re interested in different types of eye functions, specifically those involving movement of the eyes. These are known as our oculomotor functions. These functions involve things like tracking objects, focusing while your head moves, and converging inward when you bring something close. One study showed around 70% of adolescents will have an oculomotor issue following a concussion.
Some of the common post-concussive visual dysfunctions include:
Eyes have trouble tracking objects across our visual field
Trouble converging inward when something is closer to us
Trouble focusing on an object while our head moves
Trouble when objects are quickly passing through our visual field
Visual dysfunction after a concussion typically causes:
Headache, neck pain or tension
Dizziness, unsteadiness, balance issues
Nausea and/or vomiting
Vertigo
Light sensitivity and eye strain
Vision problems
If you have visual dysfunction after a concussion you might notice:
An increase in the above symptoms with visually stimulating environments. For example, going to the shopping mall, grocery store, or walking through a crowd.
An increase in symptoms when tracking objects across your visual field, such as watching sports or action movies.
An increase in symptoms when reading, on the computer, or on your phone.
An increase in symptoms when motion is passing across your visual field, such as being the passenger in a moving car or scrolling on a screen.
How is visual dysfunction after a concussion tested?
Visual dysfunctions can be tested for by isolating each of the visual functions, checking for proper function, and seeing if the particular function reproduces familiar symptoms. In the clinic we run through a series of tests that have been studied for their reliability and validity in identifying post-concussive visual issues. Tests include gaze fixation, rapid eye movement, smooth target tracking, convergence, accommodation, motion sensitivity tests, combined vestibular and visual tests.
How is visual dysfunction after a concussion treated?
Visual dysfunctions are treated by stimulating the particular dysfunction(s) that are problematic. This is done by performing the function in a more low grade way that stimulates our brain enough for the area to heal and recalibrate, but not so much as to flare up or aggravate. After low grade visual tasks are tolerated, these are progressed to harder exercise to mimic what you might do in real life. Once an individual has stimulated and practiced the function enough, they no longer have issues with it in their day to day, and it no longer causes symptoms. These treatments collectively known as oculomotor training and have been studied for their effectiveness in concussion treatment. See below for an example of one level of diagonal smooth pursuit training.
Training visual tracking (diagonal smooth pursuits) for upper right and lower left visual quadrants. This exercise would start slow at a limited range of movement, with a close target, and a neutral background while sitting. Over time it could be progressed with a farther target, bigger range, faster speed of movement, and while standing or balancing to further stimulate the visual centers of the brain affected by a concussion.
#2 - Vestibular Dysfunction
Vestibular dysfunction refers to issues with our vestibular system, which functions to detect the position and movement of our head in space. It sends this information to our brain as well as our neck and visual centers, which have reflexes of their own that communicate back to help orient us in space. Issues here are common after a concussion, and cause symptoms such as balance issues, vertigo, or dizziness. Because our vestibular system works so closely with our neck and eyes, it can also contribute to issues in other systems such as neck issues or vision problems when not functioning well.
Vestibular system dysfunction after a concussion often leads to:
Headache, neck pain or tension
Dizziness, unsteadiness, balance issues
Nausea and/or vomiting
Vertigo
Vision problems
If you have vestibular dysfunction after a concussion you might notice:
Triggering the above symptoms with changing position of our body - getting up from lying down, bending over, rolling over in bed, walking with our head turned one way, or even standing with our head turned one way.
Increase in the above symptoms when fixating on an object while our head is moving - this may happen while in a visually stimulating environment, during sports, while driving, etc.
How is vestibular dysfunction after a concussion tested?
Vestibular testing is done by isolating various vestibular functions. This includes but is not limited to testing of static and dynamic balance control, positional change testing, combined visual-vestibular function testing, and motion sensitivity testing.
How is vestibular dysfunction after a concussion treated?
Like vision therapy, whichever particular vestibular function recreates symptoms or is not performed well, is addressed through targeted rehabilitation. For some people this means balance control training, and for others it might mean repetition of positions and movements that cause symptoms to normalize your vestibular systems response over time (a treatment known as habituation). Collectively these treatments are called vestibular rehabilitation therapy and have been studied for their effectiveness in concussion treatment.
Vestibular Rehabilitation Therapies offered by Dr. van de Wall:
Habituation exercises - exercises that allows you to gradually desensitize yourself to vestibular movement and stimulation if you are repeatedly exposed to it.
Adaptation exercises - an exercise process where nerve impulses in the brain are able to shift or “adapt” to the incorrect signals from the damaged vestibular system. This gradual shift allows your brain to recalibrate itself.
#3 - Cervical Dysfunction
Cervical dysfunction refers to issues with our neck function. The forces involved in causing a concussion almost always also cause whiplash to the neck (it takes around 60-160 g (gravity) of linear acceleration to cause a concussion, and only 4.5 g to cause whiplash). Our neck muscles, joints, and nerves become injured and irritated, leading to a number of whiplash symptoms that can mimic or add to concussion symptoms. Sometimes, we even have a concussion-type presentation after neck trauma, that ends up being whiplash alone.
Our upper neck muscles and joints are extremely rich in nerve endings that also communicate with our vision and vestibular systems. When injured, our neck can not only cause symptoms we would normally expect (neck pain, headaches), but other concussion-type symptoms like dizziness, vertigo, fatigue, balance issues, and others.
At present, cervical dysfunction is the most neglected source of chronic concussion symptoms by healthcare practitioners due to a lack of prior research and gaps in training. However, newer studies and training programs are increasingly emphasizing its importance. As a result, it is not uncommon for individuals who’s concussion symptoms persist despite going through visual, vestibular, and physiologic training to have a misdiagnosed cervical dysfunction that when addressed resolves their remaining symptoms.
Dysfunction in our cervical spine is common after a concussion, and often leads to:
Neck pain, jaw pain
Headaches
Dizziness, sometimes vertigo
Balance problems
Light sensitivity
Feeling as if in a "fog", fatigued
If you have concussion-related neck dysfunction, you might notice:
Limitations in your neck mobility (hard to look at the ceiling, over your shoulder, or bring your chin to your chest).
An increase in the above symptoms when moving your neck and head, especially if quickly, far, or while bent forward.
Poor awareness of your neck posture, and of how much muscle tension you are holding. People may comment you look tense, or that your head is tilted one direction.
Chronic neck symptoms that do not resolve with usual neck treatments (ie. standard neck treatments alone are not working).
How is cervical dysfunction after a concussion tested?
Cervical testing includes a standard cervical spine exam:
Passive and active range of motion
Palpation of muscles and joints
Posture, and strength assessments
Plus concussion and whiplash specific testing:
Cervical joint position error testing - uses targets and a laser mounted on your head to test your ability to detect where your head is in space without the help of vision
Cervical motor control dysfunction testing - tests deeper muscles on the front and back of the neck that stabilize the spine. These are often injured and dysfunctional post injury and when weak often lead to excessively tight superficial neck muscles.
How is cervical dysfunction after a concussion treated?
Like with visual and vestibular dysfunctions, treatment varies with each person based on their symptoms and what is found on their exam. If cervical dysfunction is present, then treatment usually includes gentle hands on therapies to joints and muscles, and progressive exercises. These exercises may target muscle weaknesses, proprioception (joint position-sense), posture, or strength of the neck and upper back. See below for an overview of cervical dysfunction rehabilitation. These treatments are called cervicovestibular rehabilitation.
Overview of the cervical rehabilitation part of the concussion program
#4 - Physiologic or Exertional Dysfunction
Finally, the fourth most common issue after a concussion is an exertional intolerance (also known as post-concussive physiologic or autonomic dysfunction). With this issue, when our heart rate gets elevated from physical activity or stress, our concussion symptoms flare up and worsen. Often this leads to a “crash” after the activity, sometimes for days if if the activity was provocative enough. This is one of the most important issues to treat after a concussion, because exertional dysfunction not only prevents us from engaging fully in our daily life, but is also theorized to set the rate of healing of other areas in the brain. The presence of an ongoing physiologic or exertional intolerance can make visual, vestibular, or cervical rehab less effective if not addressed.
Exertional intolerance - aka Dysautonomia. We have an inability to both exert ourselves, but also to rest deeply and recover. Treatment focuses on building up these thresholds over time to improve our autonomic nervous system function back to normal.
Exertional dysfunction often causes:
Sleep difficulties - can be both excessive sleep and loss of sleep
Inability to exert oneself physically or mentally without a spike in symptoms
Chronic fatigue
Headaches, neck tension
Feeling as if in a fog, feeling drowsy
Cognitive difficulties
Emotional difficulties
If you have exertional intolerance after a concussion, you might notice:
"Crashing" after mental, emotional, or physical exertion.
Sleeping in but still feeling unrested.
Trouble staying asleep and/or feeling energized at night when you should be resting.
Difficulty returning to full workloads or usual sports
Persistent concussion symptoms even when having done vestibular, cervical, or visual rehab
How is vestibular dysfunction after a concussion tested?
The gold standard for identifying exertional dysfunction is the buffalo concussion treadmill test. This is a supervised test on either a treadmill or a stationary bike, with a heart rate monitor attached. The test involves gradually increasing your heart rate, while tracking symptoms and effort level. It allows us not to only to rule in or rule out an exertional intolerance, but also tells us what heart-rate threshold it exists at.
How is vestibular dysfunction after a concussion treated?
Using the results from the exertion testing (buffalo concussion treadmill or bike test), we now know where an individuals threshold for exercise sits. We can start rehabilitation through controlled cardiovascular exercise slightly below this threshold to stimulate healing and recovery, but not to overload the system and cause a symptom flare. Over time, the level of exertion tolerated improves as our autonomic system heals, and our exertional difficulties subside. This treatment method is well supported by research for being both safe and effective when a post-concussive exertional intolerance is present.
Putting it all together
The above four dysfunctions have been identified as the most common issues and causes of chronic concussion symptoms. Addressing each through targeted rehab can lead to meaningful symptom reduction and even symptom resolution in many individuals. The treatments include oculomotor training, vestibular rehabilitation therapy, cervical spine treatment and rehabilitation, and heart-rate threshold cardiovascular exercise.
The testing and treatments above may look overwhelming, but in reality most people only have dysfunction in an average of 2 (sometimes 1 or 3, rarely 4) of the above areas. Some individuals may have an exertional intolerance alone, while others may have neck and vision issues. Everyone’s post-concussion presentation is different, hence why specific testing is so helpful and general concussion advice is often not.
As concussion-trained practitioners, our job is to help you identify which area(s) are causing your main concerns through using the testing mentioned above. Once we know your situation, we can then prescribe a rehabilitation plan targeted to your specific presentation and work toward recovery.
Are you interested in concussion rehabilitation in Chilliwack BC?
Click here to find more about Optimum Sport & Dr. van de Wall’s concussion program.
