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The Vestibular System: Finding Your Balance

Categories: Living with Brain Injury

By Shanti M. Pinto, M.D., Katie L. Sewell, PT, DPT, NCS, CBIS and Kelly M. Crawford, M.D., Carolinas Rehabilitation

Have you ever heard of the vestibular system? Up to 50% of people with a history of traumatic brain injury (TBI) experience vestibular impairments. Individuals with these impairments may feel lightheaded, dizzy, and off-balance. Vertigo, defined as a feeling of the room spinning, is often used to describe these complaints. Persistent impairments to the vestibular system are associated with increased psychologic distress and lower rate of return to work. It’s important to recognize vestibular impairments after a brain injury and seek appropriate treatment to maximize function and quality of life.

The ability to balance the body during everyday activities relies on information from the sensory, vision, and vestibular systems. Often, the symptoms of dizziness and imbalance can be related to vestibular system dysfunction following a brain injury. This system is complex, but it can be simplified into three components for the purposes of this article:

  1. The sensory organ
  2. The nerve that connects the sensory organ to the brain
  3. The area of the brain that processes information from the vestibular system

The sensory organ structures are located in the inner ear and contain different tubes, also called canals, that are filled with fluid and hair cells. Calcium deposits, or “crystals” as they’re often called, move from one end of the tube to the other with the movement of the head. Each sensory organ has three canals – lateral, superior, and posterior semicircular canals – to help the body move in all directions. The calcium deposits shift in the canals when the body moves and stimulate tiny hair cells that carry signals through the nerve to processing centers in the brain. These brain centers combine this information and coordinate appropriate body responses to allow for proper balance and body orientation with movements.

A brain injury can often cause damage to one or more of the parts that make up the vestibular system. In some cases, the calcium deposits shift into the wrong place and cause the brain to receive inaccurate information about where the body is in space, resulting in vertigo when someone moves. A brain injury may also cause dysfunction of the nerve that connects the sensory apparatus to the brain by direct trauma or swelling in this area. The two nerves, one on each side, work like a seesaw. When the left side turns on (“goes up”), the right turns off (“goes down”). The seesaw relationship is particularly important when turning the head and trying to keep the eyes focused on an object, such as reading a sign while walking or driving. If one of the nerves is not working, the other side will often become overactive causing imbalance, a feeling of unsteadiness, or dizziness. Finally, a brain injury can cause damage to the areas of the brain that directly process all the information from the other components of the system, which can manifest as continuous dizziness, vertigo, blurred vision, difficulty reading, and poor balance.

A physical therapist with specialized training in vestibular impairments can evaluate balance problems and dizziness to develop a treatment plan and help the body move better. A physical therapy evaluation will include tests that involve moving the head to different positions to evaluate symptoms and eye movements, examining the quality of eye movements and the ability to focus on a target with a head movement, and assessing balance during tasks that rely heavily on the vestibular system. Based on the results of these tests, the therapist will design a treatment plan or complete more in-depth testing to determine what part of the vestibular system is impaired. As shown in Figure 2, rehabilitation strategies and treatment are selected based on the location of the dysfunction within the vestibular system.

Rehabilitation strategies can improve symptoms of vestibular dysfunction. Treatments are chosen based on the part of the system that is not working correctly.

Evaluation by a trained professional is critical to successful treatment and improvement of symptoms. Effective rehabilitation strategies can include repositioning techniques, gaze stabilization exercises, binocular vision training, and up-training of your other balance system. Symptoms of dizziness or vertigo can increase the risk of falling, which is the leading cause of brain injury, so it’s important to use strategies to lower the risk. Strategies to prevent falls include:

  • Use the assistive device recommended by your therapist or provider
  • Remove rugs and other items from the floor
  • Use a nightlight to help see in the dark

Medications are sometimes used for management of vestibular dysfunction. Typically, medications are only used if symptoms do not improve with rehabilitation or, in severe cases, where a person cannot tolerate rehabilitation exercises. Options should be discussed with a physician. A person may also be referred to an ear, nose, and throat (ENT) doctor, also known as otolaryngologist, if symptoms do not improve with therapy or if there is hearing loss. An ENT doctor can do specialized tests to look for structural damage to the ear canal.

Feeling dizzy or being off-balance are common symptoms after brain injury, and they occur due to damage to the vestibular system. Specialized physical therapists can evaluate the cause of these symptoms and start rehabilitation treatments. Medications can also be used if the symptoms do not improve. If you have difficulties with balance or dizziness after brain injury, talk to your provider about an evaluation and treatment options.

References

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  • Chamelian, L., & Feinstein, A. (2004). Outcome after mild to moderate traumatic brain injury: The role of dizziness. Archives of Physical Medicine and Rehabilitation, 85(10), 1662–1666.

  • Fife, T. D. (2010). Chapter 2—Overview of anatomy and physiology of the vestibular system. In S. D. Z. Eggers & D. S. Zee (Eds.), Handbook of Clinical Neurophysiology (Vol. 9, pp. 5–17). Elsevier.

  • Herdman, S. J. (1989). Exercise strategies for vestibular disorders. Ear, Nose, & Throat Journal, 68(12), 961–964.

  • Herdman, S. J., & Whitney, S. L. (2014). Chapter 22: Physical Therapy Treatment of Vestibular Hypofunction. In S. J. Herdman & R. A. Clendanial (Eds.), Vestibular Rehabilitation (4th Edition, pp. 394–428). F.A. Davis Company.

  • Horak, F. B., Jones-Rycewicz, C., Black, F. O., & Shumway-Cook, A. (1992). Effects of vestibular rehabilitation on dizziness and imbalance. Otolaryngology–Head and Neck Surgery: Official Journal of American Academy of Otolaryngology-Head and Neck Surgery, 106(2), 175–180.

  • Khan, S., & Chang, R. (2013). Anatomy of the vestibular system: A review. NeuroRehabilitation, 32(3), 437–443.
  • Schaadt, A.-K., Schmidt, L., Reinhart, S., Adams, M., Garbacenkaite, R., Leonhardt, E., Kuhn, C., & Kerkhoff, G. (2014). Perceptual Relearning of Binocular Fusion and Stereoacuity After Brain Injury. Neurorehabilitation and Neural Repair, 28(5), 462–471.

This article originally appeared in Volume 15, Issue 2 of THE Challenge! published in 2021.