7 Concussion Myths Clinicians Should Stop Believing in 2026

Concussion management has evolved dramatically over the past decade, yet clinical practice often lags behind the evidence. Many of the beliefs that shaped concussion care in the early 2000s have been comprehensively disproven, but they persist -- in textbooks, in clinical protocols, and in the assumptions that guide everyday decision-making.

The problem is not merely academic. When clinicians act on outdated beliefs, patients suffer measurable consequences: prolonged recovery, unnecessary restrictions, missed diagnoses, and premature return-to-play clearances that put athletes at risk. The Amsterdam Consensus Statement (Patricios et al., 2023) and the body of research that surrounds it have given us a clearer evidence base than we have ever had.

These are seven myths that Australian clinicians should stop believing -- and what the evidence says instead.

Why it persists:This belief is deeply embedded in popular culture and was reinforced by older medical definitions that emphasised loss of consciousness (LOC) as a hallmark of concussion. Many clinicians trained before the mid-2010s were taught that LOC was a defining feature, and the association between “being knocked out” and brain injury remains strong in public perception.

What the evidence says:Fewer than 10% of sport-related concussions involve any loss of consciousness (McCrory et al., 2017). The 5th and 6th International Consensus Statements on Concussion in Sport both define concussion as a functional brain disturbance caused by biomechanical forces, with or without LOC. The most common presenting features are headache, confusion, balance disturbance, and feeling “not right” -- not unconsciousness.

Why it persists:Rest-based protocols were the prevailing recommendation for over a decade. They were intuitively appealing -- if the brain is injured, it makes sense to “rest” it. The 2012 Zurich Consensus Statement recommended cognitive and physical rest until symptom resolution, and this message was reinforced across medical education, sports organisations, and public health campaigns.

What the evidence says: The Amsterdam 2023 Consensus Statement (Patricios et al., 2023) explicitly recommends against prolonged rest beyond 24-48 hours. Multiple randomised controlled trials have demonstrated that strict rest beyond this window increases the risk of persistent symptoms by promoting cardiovascular deconditioning, sleep disruption, anxiety, and depression (Leddy et al., 2019; Grool et al., 2016). Sub-symptom threshold aerobic exercise introduced by 72 hours post-injury reduces recovery time by an average of 4-5 days compared to strict rest protocols.

Why it persists:CT scans are the most widely available neuroimaging modality in emergency settings. Clinicians and patients alike can find reassurance in a “clear scan,” and there is a natural tendency to equate normal imaging with the absence of injury. This belief is reinforced every time a patient or parent is told “the scan came back fine” without further context.

What the evidence says: CT detects structural pathology -- skull fractures, intracranial haemorrhage, cerebral contusions. Concussion, by definition, is a functional brain disturbance. It involves neurometabolic dysfunction, ionic flux, and microstructural changes that are entirely invisible to CT. The consensus is unequivocal: concussion is a clinical diagnosis based on the mechanism of injury, symptom presentation, and clinical examination (McCrory et al., 2017; Patricios et al., 2023). A normal CT scan is expected in concussion. Its purpose is to rule out more serious structural injury, not to diagnose or exclude concussion.

Why it persists:The concept of “neuroplasticity” has been broadly (and often incorrectly) applied. Because developing brains demonstrate greater capacity for neural reorganisation in certain contexts, there is an assumption that this translates to faster concussion recovery. This belief is also reinforced by the observation that children are often physically active soon after injury -- which parents and clinicians may misinterpret as recovery.

What the evidence says: The evidence shows the opposite. Children and adolescents typically take longer to recover from concussion than adults (Davis et al., 2017). The developing brain is more vulnerable to the neurometabolic effects of concussion, and the ongoing processes of myelination and synaptic pruning make it more susceptible to disruption. Paediatric concussion recovery times are typically 2-4 weeks, compared to 10-14 days for adults. The Amsterdam Consensus recommends more conservative return-to-play timelines for children, with a minimum of 14 days before full return to contact sport.

Why it persists:The SCAT has become the most widely recognised concussion assessment tool globally. Its structured format and scoring system create an expectation that it functions like a diagnostic test with a clear pass/fail threshold. Clinicians, particularly those without specialised concussion training, may treat a “normal” SCAT score as equivalent to medical clearance.

What the evidence says: The SCAT6 is explicitly designed as an assessment aid, not a clearance mechanism(Echemendia et al., 2023). It does not have a validated cut-off score that defines “concussion” or “no concussion.” Sensitivity decreases significantly after the first few hours. Moreover, the SCAT6 does not assess several critical domains, including vestibular-ocular function (assessed by the SCOAT6 and VOMS), cervical spine involvement, psychological factors, or exercise tolerance. Return-to-play clearance requires a multi-domain assessment including clinical examination, graded exercise testing, sport-specific functional testing, and medical judgment.

Why it persists: Second impact syndrome (SIS) has been heavily emphasised in concussion education materials for decades. It is a dramatic and frightening concept -- catastrophic cerebral oedema following a seemingly minor second impact -- which makes it memorable and frequently cited. It has been used extensively as the primary justification for conservative return-to-play timelines.

What the evidence says: The evidence base for SIS as a distinct pathological entity is extremely thin. Fewer than 20 cases have been reported in the medical literature, and many of these have been challenged on methodological grounds -- including questions about whether a confirmed first concussion actually occurred (McCrory & Berkovic, 1998; McCrory, 2001). The concept remains controversial and is not universally accepted. However -- and this is critical -- the rarity of SIS does not mean premature return to play is safe. Repeat concussion during the recovery window is associated with prolonged symptoms, cumulative cognitive effects, and increased vulnerability to further injury (Guskiewicz et al., 2003). The reasons to avoid premature RTP are well-established; SIS is simply not the strongest one.

Why it persists: Symptom self-report is the most accessible and widely used measure in concussion management. It is understandable that clinicians equate the absence of symptoms with the resolution of the underlying injury. This approach is also simpler and faster than multi-domain assessment, which creates a practical incentive to rely on symptom resolution alone.

What the evidence says: Physiological recovery consistently lags behind symptom resolution. Advanced neuroimaging studies using functional MRI (fMRI), diffusion tensor imaging (DTI), and blood biomarker analysis have demonstrated ongoing neurometabolic and microstructural changes in the brain well after patients report being symptom-free (Churchill et al., 2017; Kamins et al., 2017). The Buffalo Concussion Treadmill Test and other exercise provocation protocols frequently demonstrate physiological abnormalities in patients who are asymptomatic at rest. This is precisely why the Amsterdam Consensus mandates a graded return-to-play protocol that requires patients to complete progressively demanding physical and cognitive challenges before clearance -- even after symptom resolution.

These seven myths are not obscure academic curiosities. They are beliefs that continue to shape clinical decisions in emergency departments, GP clinics, sports medicine practices, and on sidelines across Australia. Each one has the potential to delay recovery, compromise patient safety, or lead to inappropriate clearance decisions.

The common thread is this: concussion is more complex than any single test, symptom, or rule can capture. Effective management requires multi-domain assessment, structured active recovery, graded return-to-play protocols, and an understanding of the current evidence base -- not reliance on assumptions that were outdated years ago.

As clinicians, our obligation is clear. We must align our practice with the best available evidence, update our protocols to reflect the Amsterdam Consensus, and critically examine the assumptions we carry from our training. The evidence has moved on. Our practice must move with it.