This entry builds upon our first concussion blog post. As of this posting, we continue to see a growing number of children/adolescents who have sustained a concussion.
The Vestibular System
The vestibular system is responsible for sensing and perceiving motion as well as producing reflexive movement of the eyes and limbs in response to head motion as to properly stabilize and orient our bodies to the line of gravity. Meaning the vestibular system is essential for proper balance, especially when we move about in our environment. The vestibular system is also active at rest and responds to movement of the head. There are two parts to the vestibular system: 1. The inner –ear (peripheral vestibular system) and 2. The brainstem (central vestibular system, ie: the brain).
Whether at rest or in motion, the reflexive movement of the eyes produced by the vestibular system allows an individual to maintain clear vision when viewing an object (still object or moving object). A few examples would be driving in a car, reading a book, working on the computer, walking, or viewing a chalk board. When the reflexive movements of the eyes are disrupted due to disease, condition, or trauma, the result can be and most often is dizziness, blurry vision, imbalance, and headache.
When a problem arises in the vestibular system (peripherally and/or centrally) an individual has difficulty orienting to his or her environment because of dizziness, blurry vision, imbalance, and headache. The vestibular system is not the only system that contributes to balance. The other major systems that contribute to proper balance are the visual system, somatosensory system (how we feel through our joints/muscles), and auditory system. When each of these systems is working properly, an individual is properly balanced. The information generated by each of these systems is sent to the brain (central nervous system). It is in the brain where all the information is gathered and made sense of so appropriate responses are generated (ie: moving about in the environment). So naturally balance is a complex and coordinated effort between peripheral and central processes.
This information is important as related to concussion or what we should truthfully call a traumatic brain injury. The vestibular system is compromised both peripherally and centrally because both areas are located within the skull. So reflexive movement of the eyes and limbs are compromised, meaning the individual will experience dizziness, blurry vision, imbalance, and headache. Depending on the degree of injury as well as the number of times an individual has sustained a concussion will play a significant role in recovery (ie: severity/duration of symptoms). Since the brain is involved recovery takes longer than say an isolated peripheral problem.
Symptoms related to vestibular system compromise are made worse when other systems (visual, somatosensory, auditory) are challenged. Visual challenges could be bright lights, moving objects, lack of light, variable colors, etc… Auditory challenges could be background noise, loud noises, etc… These challenges make it difficult for an individual to concentrate because the patient is trying to deal with their vestibular symptoms. This becomes a negative cycle, as the individual either tries to concentrate harder making symptoms worse or just “shuts down” because the symptoms are too much for the individual to handle.
Often times the individual will experience emotional and social problems as no one can “see” their problem. They are not wearing a cast, so nothing is “wrong”. This unfortunately creates more problems for the individual. So a true physiological/physical problem is now complicated by psychosocial issues.
Appropriate changes in an individual’s environment are recommended to allow for optimal recovery. For a student in school, this may mean making reasonable modifications/accommodations so the effects of concussion can be minimized and allow the student the best environment to recover without losing significant academic time in school as well as minimize any psychosocial difficulties that may be experienced.