Double vision (diplopia) is a common complaint after concussion and often part of post-concussion syndrome
February 19, 2021
Double vision is a common complaint seen in our office and is often observed in patients after concussion and post-concussion syndrome. It may be difficult for these individuals to focus on objects, especially at near distance and may appear fuzzy, blurry or double. These patients may complain of headaches, often around the forehead and behind the eyes as their muscles strain to focus.
Concussion and damage to certain areas of the brain may be the cause, yet the specific problem that causes these compaints to arise is due to a weakness, or imbalance in the eye muscles, known as strabismus. Strabismuis occurs when the eyes don't equally align with one another when looking at an object. And, as you can imagine, this makes it very difficult to follow targets, read, endure busy environments, grocery or department stores, changing from far to near targets (vice versa), computer work along with other daily activities. We often observe what is known as convergence insufficiency, where one or both eyes diverge when attempting to look at a near target, creating visual disturbance and fatigue.
The area of the brain involved in these activities is known as the mesencephalon, which contains the convergence centers for vision that allow us to move our eyes in a dysconjugate way to look at a near target. Try looking at the bridge of your nose and you will have just activated your convergence centers. Or, look at your thumb in front of your nose at any distance beyond 3-4" and you should be able to see a crisp, clear thumb. If it does not look that way, or you see blurry or double, then you may be experiencing strabismus.
This is a common clinical finding seen with our concussion patients and is treatable through functional neurological rehabilitation and vestibular rehabilitation. We're often able to restore this function which can reduce many of your symptoms and restore normal brain activity and balance within your eye muscle control. We're able to accomplish this by diagnosing and locating weaker, dysfunctional areas of the brain affected by the concussion that are not properly stimulating the area of the brain responsible for convergence, the mesencephalon (brainstem). This area is also responsible for light and sound integration so many poeple also notice light and sound sensitivity. In many cases, it's not about performing more convergence activities that may have already been attempted through prior intervention, but more importantly we must locate the source of the dysfunction, which is often "pre-synaptic" to the convergence area of our brain. Pre-synaptic is describing an area within the pathways of the brain involved with convergence that must be activated prior to or in addition to the desired neurological activity. For instance, if I predomaintely stimulate the right cerebellum hemipshere through various exercises, a left exophoria may improve due to it's synpatic connections to the left mesencephalic hemisphere.
An analogy would be that if the dam at the head of a river prevents water from flowing, pouring more water downstream will not change the dried up riverbed, but you must reset the dam in order to return to normal water flow.
The source is always the concern and we're able to achieve this through various rehabilitaton techniques that allow us to strengthen synaptic connections between brain regions and create neuroplasticity and return the brain to normal function, allowing for normal converging eye movements. It is important to understand that all eye movements start in the brain, therefore most strabismus issues are not a problem with the eye muscle itself, but in the areas of our brainstem that control them and their connecting nerves. In the case of convergence insufficiency it is either cranial nerves 3 or 4 that cause adduction of the eyes.
Possible Symptoms of convergence insufficiency:
-double vision (diplopia)
-near vision difficult
-computer screen difficulty
-headache (especially frontal sinus(forehead) and peri-orbital (around the eyes)
Treatment consists of proper diagnosis to locate the regions involved in your dysfunction and specific targeted neurological exercises/stimulation to treat the pre-synaptic regons and mesencephalon to improve convergence insufficiency related to the concussion. Our clinic provides specific comprehensive treatment that often involves neurological/neuroplasticity rehabilitaton, vestibular rehabilitation, physical therapy, chiropractic care and hyperbaric oxygen therapy.
If you have questions, please contact our office -
Portland Chiropractic Neurology, located in Portland, Maine