Concussion is a mild traumatic brain injury and is defined as a complex pathophysiological process affecting the brain, induced by biomechanical forces. Criteria that helps define a concussion include:

• Concussion may be caused either by a direct blow to the head, face, neck or elsewhere on the body with an “impulsive” force transmitted to the head e.g. a tackle where there is no direct blow, but more of a whiplash type movement through the neck causing the brain to rebound back and forwards in the skull. 
• Concussion typically results in the rapid onset of short-lived impairment of neurological function that resolves spontaneously. However, symptoms and signs can evolve over a number of minutes to hours.
• Concussion may result in neuropathological changes, but the acute clinical symptoms largely reflect a functional disturbance rather than a structural injury and, as such, no abnormality is seen on standard structural neuroimaging studies.
• Concussion results in a graded set of clinical symptoms that may or may not involve loss of consciousness. Resolution of the clinical and cognitive symptoms typically follows a sequential course. However, it is important to note that in some cases symptoms may be prolonged.

The people most at risk of sustaining a concussion include males between the ages of 15-24 who play AFL, NFL, hockey, soccer, wrestling and boxing. Females also have a higher rate of reported concussions, particularly over the age of 65 due to an increased risk of falls. Military personal, victims of abuse and those involved in car accidents are also at a higher risk of concussions. 

Signs/symptoms of concussion: 

• Loss of consciousness (only 8-12% of people experience this)
• Headache
• Dizziness
• Balance problems
• Fatigue
• Visual changes (double or blurry vision are most common)
• Insomnia
• Hypersomnia
• Drowsiness
• Attention issues
• Short-term memory and learning problems
• Difficulty multitasking
• Phonophobia
• Photophobia
• Feeling mentally “foggy”
• Emotional changes

Symptoms may not develop immediately so careful monitoring must be done minutes to days after the original injury. Headache is present in 83-86% of all concussions making it the most common symptom. The more symptoms and the more severe the deficits, the greater the chance the person has of developing long term consequences. 

What happens if a concussion is left untreated?
20% of all concussions do not heal spontaneously. When this occurs, post concussion syndrome can result.  Post concussion syndrome has the same signs and symptoms of a concussion except that the symptoms can last for weeks to years. 

Post concussion headaches can vary from tension type headaches (most common) to migraines. These are frequently associated either a direct or indirect neck injury that happened at the same time as the head injury. 

Post concussion syndrome often requires a combination of direct hands on therapy, vestibular rehabilitation and concussion rehabilitation so that you can return to work/school/sport.