What is a Concussion?

A concussion is a form of brain injury (also know as a Mild Traumatic Brain Injury) that causes a temporary disturbance in how the brain functions. Concussions happen due to a hit, bump or blow to the head or elsewhere on the body, with the impact causing the brain to be accelerated and decelerated inside the skull, resulting in what is know as a functional injury. Since concussions cannot be seen on routine X-rays, CT scans or MRIs, it’s important to understand the signs and symptoms.

Dr Cameron Marshall, CCMI President and CEO talks us through the process of a concussion and the implications of the ‘metabolic disturbance’ that occurs within the cells of the brain in the whiteboard edition below:

What are the signs of a concussion:

Signs of a concussion are something that are objectively seen by onlookers, whereas symptoms are something that a person subjectively feels within themselves. Concussion signs (although extremely limited) can generally be observed by onlookers who are acutely aware of a persons movement patterns.

Examples of concussion signs include:

  • Loss of consciousness (LOC) – this can be easily seen when someone is motionless and unresponsive, however it is important to remember LOC is a sign that occurs in less than 10% of all concussion injuries and does NOT need to be present for a concussion to be diagnosed.
  • Fencing Response – can be seen from the sideline as a players arm or arms go rigid (extended straight up in the air while they are lying on their back), and is a tell tale sign of LOC. This is a 100% indication that there has been a LOC and a 100% indication that the person has sustained a concussion. The fencing response also indicates that the brainstem has been involved in the injury. LOC is known to occur in less than 10% of all concussion injuries, and the fencing response is seen in approximately 2/3 of these.
  • Rag-doll sign – a term used when an athlete falls to the ground with no active protection of the head and appears limp (often used in aerial sports to depict the landing of an athlete on a downslope with no muscular tone or movement and is thought to be indicative of an unconscious patient)
  • Clutching of the head following a tackle or fall.
  • Lack of balance or gross in-coordination – this can be seen as the stepping and stumbling a player shows when attempting to stand following a large tackle or hit.

What are the symptoms of a concussion?

Symptoms of a concussion are something that a person subjectively feels within themselves. The initial excitatory phase of a concussion is where some very typical symptoms will present, however every concussion case is different and will present in a different way.

If you experience any one or more of the below 22 symptoms following a significant hit to the head or body, then a concussion should be suspected:


  • Headache
  • Neck pain
  • Sensitivity to light/noise
  • Visual problems
  • Dizziness
  • Balance issues
  • Nausea
  • Vomiting

Thinking (cognitive):

  • Memory issues
  • Difficulty concentrating
  • Confusion
  • Feeling slowed down
  • Feeling “in a fog”
  • Trouble thinking clearly


  • Anxiety
  • Nervousness
  • Depression
  • Sadness
  • Irritability
  • More emotional


  • Fatigue
  • Low energy
  • Sleeping more or less
  • Difficulty falling asleep

When to suspect a concussion?

If you have a mechanism of injury (ie. a significant blow to the head or body) and at least one of the 22 symptoms listed above, there should be a high suspicion of concussion.

Athletes should be immediately removed from play, and must not return until assessed and cleared by a medical doctor or licensed healthcare practitioner with training in concussion management. Continuing to play can increase the risk for more severe, long lasting concussion symptoms, and/or increase the chance of further injury.

How long does a concussion last?

Following a concussion most people will symptomatically recover or feel ‘back to normal’ within 7-10 days after the initial injury; however the question remains does this mean that you have actually recovered and what is a full recovery?

Animal studies have found that brain energy levels do not recover fully until somewhere between 22-45 days, and it is between these two time points (ie. when you feel better and when your brain has fully recovered) that is the most dangerous time period. Further studies have shown that repeat injuries within this period of heightened vulnerability can have additive or cumulative effects and result in a potentially more serious brain injury.

What is the treatment for concussion?

The research on concussions is evolving at an exponential rate and we are realizing that prolonged rest not only doesn’t work; it can actually make you worse. Sadly, many healthcare practitioners are not keeping up with the explosion in concussion research and are still telling their patients that the only treatment for concussion is rest. If you have fallen victim to this, you don’t need more rest; you need a second opinion.

The top five most effective evidence-based treatments for concussion include:

  • Exercise Therapy
  • Manual Therapy and Neck Rehab
  • Diet/Nutritional Changes
  • Vestibular and Visual Rehab
  • Education and Reassurance (due to psychological co-morbidities)

What is post-concussion syndrome?

Post-concussion syndrome is a term that may be used when a patient or athlete is still experiencing the symptoms or effects of a concussion beyond a certain timeline. This has been defined as greater than 2 weeks of ongoing symptoms in adults and greater than 4 weeks in children by the Berlin Consensus Statement, and occurs in approximately 15-30% of people.

Persistent concussion symptoms may present across a variety of realms or domains, which can be categorized into five main areas:

  1. Blood flow – after a concussion there is a significant reduction in blood flow to the brain (shown to be as much as 50% reduction by animal model studies). In most people this recovers in the first 10-14 days, although can linger in people with ongoing symptoms. This is known as a “Physiologic Post-Concussion Syndrome” – which is a dysfunction in how the brain is working.
  2. Metabolic / Inflammatory / Hormonal – a lot of this area is highly dietary related.
  3. Visual system or Vestibular system – these often work together due to the high level of cross over between the systems.
  4. Neck (cervical spine) – the neck is also heavily integrated and crosses over with the visual and vestibular systems, whereby visual and vestibular functions are heightened by movement of the neck.
  5. Psychological – there is a huge overlap between mental health conditions and concussion.

Some risk factors exist for prolonged recovery and persistent symptoms:

  • History of concussions
  • Anxiety or depression
  • Family or life stress
  • Age (i.e., adolescents) 
  • Sex (i.e., females tend to be at higher risk)
  • Misinformation (i.e., return to sport too soon, prolonged rest in a dark room)
  • Improper management

Treatment may involve addressing specific symptoms such a mood issues, anxiety, difficulty concentrating or headaches. If you are experiencing ongoing problems, speak to your doctor or healthcare provider; or  find a recognized Complete Concussion Management treatment clinic near you today.