Fundamentally, an acute concussion can be viewed as a neurometabolic problem. In other words, a concussion creates an energy crisis in the brain. This is why the first step in recovery is rest and preferably absolute rest for a few days. 

A blow to the head or body causes movement of the brain with axonal shearing and lateral fluid percussion. Focal contusions related to coup-contrecoup injury can mimic moderate to severe injury but secondary metabolic effects are also produced at sites distal to the injury. This is to say that how a concussion occurs does not predict the symptoms that one will experience. These injuries must be assessed on a case by case basis. 

A concussion induces massive neuronal firing with release of excitatory neurotransmitters such as glutamate. These neurotransmitters cause the neurons to continue firing while at the same time causing a massive influx of calcium into the cell. Calcium influx disrupts the ability of the mitochondria to make the ATP necessary for returning the cell to homeostasis. Secondary injuries to surrounding cerebrovasculature cause further injury due to ischemia and cytotoxic cascades. Giza and Hovda referred to this as the neurometabolic cascade of concussion. Interpretation: concussions cause a massive energy loss in the brain while simultaneously slowing down energy production in the brain. 

We still don’t know the exact course of neurometabolic recovery of concussions in humans but evidence points towards 30 days as a timeframe for full recovery for most individuals. The consensus is that young brains may take even longer to recover due to brain maturational processes that appear to extend well towards 25 years of age. Unfortunately the time frame for concussion symptom recovery is usually between 3-15 days. When post-concussed individuals with baselines were tested after symptomatic recovery, 38% of them continued to exhibit at least one neurocognitive decrease. 

The worry therefore is when to make the return to play decision. If a second injury is sustained during the period of metabolic recovery then a new metabolic cascade will ensue and will push cellular energy production even lower, possibly below the threshold of cell survival. These injuries can be catastrophic, will very likely be more severe and will take significantly longer to recover. 

Signoretti S1, Lazzarino G, Tavazzi B, Vagnozzi R. The pathophysiology of concussion. PM R. 2011 Oct;3(10 Suppl 2):S359-68. 

Broglio SP1, Macciocchi SN, Ferrara MS. Neurocognitive performance of concussed athletes when symptom free. J Athl Train. 2007 Oct-Dec;42(4):504-8. 

Christopher C. Giza and David A. Hovda.The Neurometabolic Cascade of Concussion. J Athl Train. 2001 Jul-Sep; 36(3): 228–235. 

Vagnozzi R1, Signoretti S, Cristofori L, Alessandrini F, Floris R, Isgrò E, Ria A, Marziali S, Zoccatelli G, Tavazzi B, Del Bolgia F, Sorge R, Broglio SP, McIntosh TK, Lazzarino G. Assessment of metabolic brain damage and recovery following mild traumatic brain injury: a multicentre, proton magnetic resonance spectroscopic study in concussed patients. Brain. 2010 Nov;133(11):3232-42.



At Parkway we work with your doctor following concussion to help him or her with diagnosing various aspects of the injury and with return to play decisions. 

The first step begins with education and reassurance that when managed well, most concussions recover fully. Please see our article on WHAT IS A CONCUSSION for more information including the best available evidence on timelines for concussion recovery. 

Every effort will be made to ensure that any concussed player is seen at Parkway Physiotherapy + Performance Centre within 1-2 days of the injury. This is more difficult over the weekend but we make these injuries our absolute priorities. Team members have time set aside each day of the week for concussion injuries. 

 At the initial visit a history of the injury is recorded and an assessment of the concussion is performed. 

Since concussion is primarily a metabolic injury, the first step is rest. This rest period should not be too long and we suggest that 1 or 2 days is likely all that should be considered. This said, the rest period should minimize any physical or cognitive stress, including avoiding computer games, texting and television. At Parkway we  DO NOT advocate use of the ImPACT tool at this time because it is a lengthy and cognitively demanding test and this is a period for rest. 

The next step includes a return to learning or non physical work phase.  

Once the “Return to Learning” phase is progressing  physical testing is then initiated. The athlete is required  to attend Parkway for this phase and if passed will lead to return to non-contact light exercise. If the testing causes symptoms to worsen then the patient stop exercise and retesting will occur a few days later. 

If symptom-free, the player will then be cleared for intense, non-contact sport that can include weight training.   

The final stages will include a demanding physical test. 

The last step is a  full contact practice before any competitive return. 

Your  practitioner  will communicate with your doctor the various steps that were undertaken to ensure a safe return to sport. We support your doctor making the final call on return to play however our opinion is that only IF ALL OF THE ABOVE STEPS HAVE BEEN CLEARED, CAN WE MAKE A SAFE RETURN TO PLAY DECISION.