What is the Vestibular System?

The Vestibular System is responsible for providing sensory information to the brain regarding motion, balance, spatial awareness and motor functions that assist with balance. The Vestibular System is made up of six structures that communicate with one another to allow a person to maintain balance and spatial awareness.1

These structures include:
• Peripheral Vestibular apparatus (small structures in the inner ear)
• The Ocular System (eyes and the central visual system)
• Postural Muscles (core muscles in the abdomen, pelvis and back)
• The Brainstem
• The Cerebellum
• The Cortex

What happens to Vestibular System Function following a TBI?

Following a mild TBI some functions of the vestibular system may be affected with people suffering from dizziness, vertigo and balance problems.

These symptoms are caused by the neurometabolic changes which the brain goes through following a TBI, and it can take weeks or even months for the brain to become stable.2 Following a TBI there is an increase in glucose metabolism, and a decrease in cerebral blood flow which causes an imbalance in energy supply and demand.2 In other words, the body is using more energy than it can create.

Benign Paroxysmal Positional Vertigo (BPPV) is a common cause of vertigo and balance problems. BPPV occurs when granules escape from a gel in the utricle and move into one of the ears canals. When enough of these granules migrate they interfere with the normal functioning of the inner ear, causing it to send false signals to the brain.3

Vestibular System Function

Balance Problems
The most common symptom of a person with a balance problem is that they will have trouble remaining steady on their feet. Standing or walking will be difficult and they may feel a sensation of floating. Those who suffer from a balance problem affecting their vestibular system may also suffer from other symptoms including dizziness, or more specifically, vertigo.

Dizziness
Dizziness is a common side effect of TBI, with up to 80% of patients feeling dizzy in the first few days following their injury.4 Dizziness is considered to be the sensation of a number of different things including faintness, weakness or unsteadiness.3

Vertigo
Vertigo is a type of dizziness when the patient feels that either3:

  • they are moving when they’re not, or
  • things around them are moving but they are not.

Vertigo could also be described as feeling as though you or everything around you is spinning, which in turn can lead to feelings of motion sickness.5

Disclaimer: If you have had a TBI and have experienced any of these symptoms please contact your GP who may refer you to a vestibular physiotherapist for assessment and treatment. It is important that medical attention is sought as dizziness and vertigo may increase a patient’s risk of falls.6

References

  1. Khan, Sarah and Chang, Richard. ‘Anatomy of the Vestibular System: A Review’. 1 Jan. 2013: 437 – 443.
  2. Giza, C. C., & Hovda, D. A. (2001). The neurometabolic cascade of concussion. J Athl Train,36, 228-235
  3. Vestibular Disorders Association: vestibular.org
  4. Fiona Maskell, Pauline Chiarelli & Rosemary Isles (2006) Dizziness after traumatic brain injury: Overview and measurement in the clinical setting, Brain Injury, 20:3, 293-305, DOI: 10.1080/02699050500488041
  5. Health Direct: www.healthdirect.gov.au
  6. Dommaraju S and Eshini P. ‘An Approach to vertigo in general practice’ Australian Family Physician. Volume 45, No.4, April 2016 Pages 190-194