From Impact to Recovery: A Dive into Concussions and the Vestibular System

by Kaylie Yung

It is common for individuals to bump their heads occasionally from everyday activities. One may obtain a small bruise and then proceed with their day. However, it is easy to overlook signs of a concussion when symptoms may not appear immediately, creating more damage than the initial incident due to the delay in treatment. 

What is a concussion?

A concussion is a minor traumatic brain injury that occurs when the brain shifts back and forth within the skull. Common causes include sport contact injuries, vehicle accidents, or falls. However, concussions can also occur without direct impact to the head through acceleration-deceleration injury, blast injuries from explosions, or any mechanism aggressive enough to shift the brain in its place. Studies show a loss of consciousness is not necessary to sustain a concussion. Compared to a major traumatic brain injury, concussion symptoms often subside within 2 weeks, with full recovery within 14-21 days after the concussive event.

Common Symptoms:

• Headaches

• Dizziness

• Light and noise sensitivity

• Blurred vision

• Difficulty remembering and concentrating

• Brain “fog”

• Anxiety

• Sleep problems 

• Confusion 

• Easily frustrated or irritated 

When symptoms last for longer than three months, the individual is often considered to have persistent post-concussive syndrome (PPCS), where symptoms become more chronic, and the healing period is prolonged. Other symptoms associated with PPCS include difficulties sleeping, concentrating and remembering, brain fog, fatigue, anxiety, and depression. According to the National Library of Medicine, sports-related concussions are most commonly associated with prolonged recovery, as the injury can be associated with the vestibular system dysfunction, where the vestibular nerve damage can cause dizziness and vertigo. 

Studies show that in addition to vestibular system malfunctions, other causes include an altered control of blood flow to the brain resulting in exercise intolerance. There may also be dysregulation of fluids within the brain, or impaired transmission of nerves due to the physiological changes from the concussive event (Danielli 2023 et al.).

What is the vestibular system?

According to Gard 2022, the vestibular system is a complicated sensorimotor system associated with the inner ear and vestibular nerves. This system detects the position of an individual's head and body position in space. It is associated with motor responses, maintaining balance, and stabilizing gaze through the connection of the peripheral and central vestibular systems. When either of these systems are disrupted (the disconnection between the neurons and the nerves due to vestibular nerve damage) dizziness and vertigo can occur. 

The central vestibular system is made up of the cerebellum and vestibular nuclei in the brainstem. Its specific roles include maintaining balance, proprioception, and postural equilibrium to coordinate head and body position in space. When the central vestibular system malfunctions, it causes central vertigo, or feelings of motion or spinning in surroundings when stationary.

The peripheral vestibular system consists of semicircular canals within the inner ear. These parts detect angular motions. Within the inner ear canals, sensory hair cells project into a gelatinous cup-shaped structure, transmitting the pressure of endolymph fluid within the inner ear canal. Within this fluid, calcium carbonate crystals are embedded and associated with the calcium channels connected to the vestibular ganglion and nerve neurotransmission. When this peripheral vestibular system malfunctions, it can cause peripheral vertigo, a spinning or dizziness sensation. 

Concussion Recovery:

Although several complex systems may be involved with concussion injuries, if one is suspected, seek the medical advice of a physician, neurologist and/or a physiotherapist, who would be able to provide appropriate exercises for concussion rehabilitation. 

For vertigo specifically, performing the Epley maneuver, which readjusts fluids in the inner ear, may help relieve vertigo symptoms. To perform this maneuver at home, a bed and pillow will be needed. More information on how to perform this maneuver can be found at this link.  

Generally, studies show initial mental and physical rest is important. But more importantly, ensuring both mental and physical stimuli to the brain, ones that do not increase concussion symptoms, are vital to recovery. Some examples of such stimuli include activities such as painting, colouring, or doing a puzzle. For physical rest, having enough sleep, 8 hours or more, as well as going on walks to increase blood circulation will aid in concussion recovery. 

For additional information visit:  https://www.mayoclinic.org/diseases-conditions/concussion/diagnosis-treatment/drc-20355600 

Sources:

Casale, Jarett. “Physiology, Vestibular System.” StatPearls [Internet]., U.S. National Library of Medicine, 1 May 2023, www.ncbi.nlm.nih.gov/books/NBK532978/#:~:text=Function,signals%20from%20its%20individual%20components. 

“Concussion.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 12 Jan. 2024, www.mayoclinic.org/diseases-conditions/concussion/symptoms-causes/syc-20355594#dialogId63395982.

Danielli, Ethan, et al. “A Review of Brain Regions and Associated Post-Concussion Symptoms.” Frontiers in Neurology, U.S. National Library of Medicine, 3 Aug. 2023, www.ncbi.nlm.nih.gov/pmc/articles/PMC10435092/#:~:text=Thus%2C%20concussion%2Drelated%20brain%20damage,(11)%20and%20decreased%20blood%2D. 

Diaz-Artiles, Ana, and Faisal Karmali. “Peripheral Vestibular System.” Peripheral Vestibular System - an Overview | ScienceDirect Topics, 2021, www.sciencedirect.com/topics/neuroscience/peripheral-vestibular-system#:~:text=The%20peripheral%20vestibular%20system%20encodes,Lowenstein%20and%20Sand%2C%201940). 

Dougherty, Joseph M. “Vestibular Dysfunction.” StatPearls [Internet]., U.S. National Library of Medicine, 4 July 2023, www.ncbi.nlm.nih.gov/books/NBK558926/. 

Gard, Anna, et al. “Post-Concussive Vestibular Dysfunction Is Related to Injury to the Inferior Vestibular Nerve.” Journal of Neurotrauma, U.S. National Library of Medicine, 7 Mar. 2022, www.ncbi.nlm.nih.gov/pmc/articles/PMC9225415/#:~:text=Symptoms%20of%20vestibular%20dysfunction%20such,parts%20of%20the%20vestibular%20system. 

“Persistent Post-Concussive Symptoms (Post-Concussion Syndrome).” Mayo Clinic, Mayo Foundation for Medical Education and Research, 18 Jan. 2023, www.mayoclinic.org/diseases-conditions/post-concussion-syndrome/symptoms-causes/syc-20353352.

Vestibulocochlear nerve diagram, digital photograph, accessed 4 July 2024, https://healthjade.net/vestibulocochlear-nerve/