Contrary to common belief, concussions can have an effect on multiple systems in the body. The diagram above breaks down the various systems that can be affected by a concussion. One system can drive the other and symptoms can present differently for each individual.
Here is how concussions can affect each system:
Vestibulo-ocular
- Vestibular- Common vestibular complaints include dizziness, nausea, and instability (walking or still).
- Oculomotor- Common visual complaints include blurred and double vision, difficulty reading, eye strain, trouble focusing on objects ahead, and tracking moving objects.
These two systems are often grouped together when discussed because they are so closely related in the development of concussion symptoms. Sensory organs in the ears and eyes work together to coordinate body movements and position whether static or dynamic.
Daily activities such as driving, looking around a room, or cooking in a kitchen can be difficult because of trouble with gaze stabilization during accelerated head movements. With impairments to the vestibulo-ocular system, it’s hard for the body to maintain good awareness of position when the head is moving quickly. In children, we see them having trouble in school with reading, a general feeling of being behind, and even nausea in the hallways with a lot of people moving around them. Vestibular rehabilitation has been recommended to help recalibrate spatial perception, improve the function of gaze-stabilization, improve stability with dynamic gait or walking, and help to re-condition patients who may have been deconditioned in the process of injury.
Cognitive/Fatigue
Typically, cognitive and energy deficits come from a physiologic post-concussion disorder caused by alterations in the cerebral metabolism. In other words, there is an energy deficiency in and around the brain and nervous systems, and all of the working parts including blood flow, neurotransmitter release, and membrane permeability no longer function smoothly and efficiently.
Because there is a dysfunction in the autonomic nervous system (resting state) and sympathetic nervous system (alert state), people may present with a higher resting heart rate, as well as an increased heart rate during cognitive and physical activity than what’s considered normal. Research has recently demonstrated the necessity of creating an individualized regimen of exercise at the sub-symptom threshold. This consistent aerobic exercise has been shown to possibly hasten the recovery for those who fall into this category.
Post-Traumatic Migraine
Patients with post concussion syndrome may present with a post-traumatic migraine which is most commonly characterized as a unilateral headache with any of the following:
- Nausea
- Vomiting
- Photosensitivity (intolerance to light)
- Phonosensitivity (intolerance to noise)
- Memory deficits with cognitive tasks.
People who are experiencing post-traumatic migraines can have extreme difficulty performing daily tasks. Individuals with a predisposition for migraines may have increased susceptibility to post traumatic migraines. There is no set time frame that concussed individuals can expect to experience a post traumatic migraine and they can occur for weeks up to months post trauma. Most individuals who experience post traumatic migraines do not need extensive testing such as an MRI or CT scan, however, a thorough exam including history, neurologic exam and symptom evaluation with cognitive testing is recommended.
Cervical
Patients with post concussion syndrome may present with cervical deficits which can include but are not limited to neck tension or tightness, neck pain, numbness or tingling in extremities, limited range of motion in the neck/shoulders and headaches from muscle tension. This cervicogenic injury is often associated with a whiplash or rotational movement during injury. When these movements occur there is an acceleration and deceleration of the head resulting in stress on the soft tissue structures surrounding the head and neck. Individuals suffering from cervicogenic deficits would benefit from physical therapy for postural correction, stretching, massage and strengthening.
Anxiety/Mood
Patients with post concussion syndrome may present with a variety of character changes. These differences in mood and behavior are most commonly correlated to biochemical changes surrounding the brain or structural changes in the brain post concussion.
Some of these behavior or mood changes include:
- Anxiety
- Depression
- Panic
- Lack of interest in normal hobbies/activities
- Hyper-vigilance
- Sleep disruption including difficulty sleeping or increased drowsiness.
Anxiety which is one of the most common character changes can occur secondary to an increased difficulty in doing tasks that were easier prior to injury such as reasoning or concentrating. These situations often make the individual feel like there are too many demands on them that they can’t keep up with. Likewise, environmental situations such as crowds, traffic, bright rooms or noisy environments may trigger symptoms and make individuals more anxious.
Depression is also a common effect of traumatic brain injuries. Depression is most commonly associated with feeling sad or worthless, withdrawing from others or normal activities, changes in sleep, lethargy and thoughts of death or suicide. Individuals suffering from depression post trauma need a good support system and benefit from close relationships and encouragement throughout their healing process.
