What is a Concussion?


What is a Concussion?

An injury to the brain that affects the way the brain FUNCTIONS which is NOT the result of structural damage to the brain. This means that the brain is not functioning normally, but nothing has been damaged within the brain tissue. 

Therefore, if you performed imaging of a concussed person’s head (CT scan, MRI etc) nothing would appear. If it did, this would be more indicative of a more serious brain bleed or stroke. This is one of the reasons we have such difficulty objectively measuring whether someone has sustained a concussion rather than just relying on subjective symptoms. 

How do you sustain a concussion?

There are many ways to sustain a concussion but the important thing to note is that direct impact to the head is not required in order to get a concussion.

Concussion can result from indirect (blow occurs elsewhere on the body and impulsive forces result in injury to the brain) or direct (blow to the head, face or neck) forces.

So what is happening within the brain?

Truthfully, we still have a lot to learn. What we believe is happening is a neuro-metabolic cascade. In our brain (as well as everywhere else in our body) we have sodium/potassium pumps that open up to bring the metabolites in or out. When we get a concussion, all the pumps get stretched so they all open at the same time and the axon gets clogged with sodium resulting in a lot more sodium than normal that we need to get out. The only way we can get it out is by using energy (ATP).  The problem is, we get our energy from blood flow and there is actually decreased blood flow to the brain from the concussion. Therefore we have a mismatch – we need more energy and we are getting less. 

How do we diagnose a concussion?

Diagnosis can only be made clinically. It should be made by a trained professional, ideally at the sideline or later within the clinic/hospital. There is no proven blood test or imaging that can be done to diagnose it.

There must be one or more of the following clinical domains:

1. Symptoms that fall within 3 categories:

  • A) Somatic (i.e. headache)
  • B) Cognitive (i.e. feeling like in a fog)
  • C) Emotional (i.e. lability)

2. Physical signs (i.e. Loss of consciousness, amnesia)

3. Behavioural Changes (i.e. irritability)

4. Cognitive impairment (i.e. slowed reaction times) 

5. Sleep disturbance (i.e. insomnia)

If experiencing symptoms and/or signs in one of the above areas in combination with an appropriate mechanism to induce a concussion, you likely have a concussion.  

A trained professional will use outcome measures such as SCAT5 or Child SCAT5 in order to more objectively diagnose concussion. This can also be a tool used to monitor progress. 

What to do once you suspect a concussion?

  • The number one rule: NO SAME DAY RETURN TO PLAY. If you are in doubt if they have a concussion, sit them out. 
    • If you sustain a second concussion before the first has fully healed you are at risk of developing second impact syndrome. A rare, but fatal, consequence of returning to play too soon. 
  • Monitor the concussed person every 15 min for 4 hours, then regularly for 24-48 hours. 
  • Bring the patient to the ER if any of the following is present:
    • Headache that worsens (one that keeps worsening and worsening)
    • Drowsiness or inability to be woken up
    • Inability to recognize people or places
    • Repeated vomiting 
    • Worsening confusion/ irritability
    • Seizures 
    • Hemiparesis/hemi-sensory loss
    • Unsteadiness
    • Slurred speech 
  • No alcohol or recreational drugs  for 24-48 hours
  • No aspirin, anti-inflammatories or pain killers for 24-48 hours.  This can mask worsening headache or other symptoms. 
  • Do not drive until medically cleared 


While concussion diagnosis needs to be taken seriously, the important thing to remember is that 80-90% of concussions resolve in 7-10 days.

If diagnosed with concussion, the earliest a person can return to sport is 7 days post injury. They should see a trained pofessional to run through a return to play protocol, and will need medical clearance before returning to sport.

If your concussion symptoms are persistent, our treatment can help.  Our physiotherapists will run through a thorough assessment to determine the main cause of your persistent symptoms and come up with an individualised treatment plan to get you back to sport, work or school sooner.

Call 9824-8001 to book with one of our expert practitioners.