A concussion is a form of traumatic brain injury (TBI). It occurs when the brain is exposed to force — either from a direct blow to the head or from rapid acceleration and rotation of the head and neck.
Contrary to common belief, a concussion does not require:
Loss of consciousness
A visible bruise
A skull fracture
Bleeding on a scan
A concussion is primarily a functional and biological injury. That means it affects how brain cells work and communicate — even when no structural damage is visible.
Common causes include:
Car wrecks
Falls
Sports injuries
Physical contact or assault
In car wrecks especially, the mechanism is often a trigger. When the head suddenly whips forward and backward, the brain can stretch inside the skull. This stretching can disrupt delicate nerve fibers called axons — the communication pathways of the brain.
Even without direct head impact, these forces can produce injury.
We now understand that far more people are suffering TBI than previously recognized, particularly following motor vehicle trauma.
Concussion symptoms vary, but often include:
Headache
Dizziness
Brain fog
Memory difficulty
Trouble concentrating
Sensitivity to light or noise
Irritability
Fatigue
Sleep disturbance
Mood changes
Some people feel symptoms immediately. Others notice them hours or days later.
It is also common for concussion to occur alongside neck pain, especially after a car wreck where the cervical spine experiences rapid acceleration.
Yes. This is one of the most important shifts in how concussion is understood today. For years, patients were told:
“Your MRI is normal, so you’re fine.”
Modern research has shown that this conclusion is incomplete.
Routine CT scans and standard MRI are designed to detect:
Bleeding
Skull fractures
Large structural abnormalities
They are excellent tools for identifying life-threatening injuries. However, concussion often involves microscopic injury, particularly to axons and support cells in the brain. These subtle injuries may not appear on standard imaging.
In many cases of TBI — especially post-concussion syndrome — routine MRI shows no abnormalities. This creates a frustrating gap: patients experience real symptoms, yet imaging appears normal.
Older systems classified brain injury as:
Mild
Moderate
Severe
The term “mild traumatic brain injury” can be misleading. A person may be labeled “mild” in the emergency department but still experience persistent symptoms that affect work, school, and daily life. There is growing consensus that a one-size-fits-all diagnostic approach is obsolete.
Modern understanding recognizes:
Concussion is a biological process, not just a single event
Recovery varies from person to person
The clinical label does not always match real-world impact
Research continues to show a disconnect between the term “mild” and the functional consequences patients experience.
A biomarker, explained simply, is an objective measure of a disease or injury process.
After a brain injury, certain proteins can be released into the bloodstream. Measuring those proteins helps provide biological evidence that injury occurred.
Examples include:
GFAP – associated with injury to support cells in the brain
UCH-L1 – associated with injury to neurons
NF-H – associated with stress to axons
These biomarkers do not replace clinical evaluation. They are interpreted alongside history, symptoms, and examination findings.
However, they can help answer an important question:
Is there measurable biological evidence of brain injury — even if routine imaging is normal?
Current concussion guidelines increasingly bring together clinical examination, biomarkers, and advanced imaging when appropriate to improve accuracy.
In sports, concussion often follows a direct blow to the head or repetitive ones.
In car wrecks, injury frequently results from rapid acceleration and deceleration forces. The brain can experience significant stress without visible bleeding or skull fracture.
A person may leave the scene feeling shaken but stable. Symptoms may develop later as the injury process evolves. Delayed symptom onset does not mean the injury is imagined. It reflects how concussion unfolds biologically over time.
For patients already seeking care from a car accident chiropractor, persistent headaches, dizziness, or cognitive changes despite normal imaging may warrant further evaluation.
Modern research describes concussion as involving a neurometabolic cascade. After injury, the brain may experience:
Energy imbalance
Inflammation
Cellular stress
Disruption in communication between brain regions
Some individuals recover quickly. Others develop prolonged symptoms. This variability is one reason modern concussion care has moved beyond simple severity labels.
Chiropractic and Concussion Management focuses on understanding how trauma affects both the brain and the cervical spine.
Following a car wreck or sports injury, patients often experience overlapping symptoms from:
Brain injury
Cervical spine dysfunction
Soft tissue strain
A comprehensive evaluation looks at both neurological symptoms and biomechanical contributors.
Patients who seek care from a sports injury chiropractor may also experience concussion symptoms that require coordinated evaluation.
The goal is not to overstate injury. The goal is to accurately identify the source of symptoms and guide recovery appropriately.
If you’ve been told:
“Your MRI is normal, so nothing is wrong,” what that typically means is:
No bleeding.
No fracture.
No large structural damage.
It does not mean:
No microscopic injury occurred
No axonal stress occurred
No metabolic disturbance occurred
Modern concussion evaluation recognizes this gap and works to bridge it using a more comprehensive, evidence-informed approach.
Yes — you can have a concussion even if your MRI is normal. Science continues to evolve. We now recognize:
Far more people suffer TBI than previously understood
Routine imaging may miss subtle but meaningful injury
The term “mild” does not always reflect functional impact
One-size-fits-all diagnostic models are outdated
If you have experienced a car wreck and continue to struggle with headaches, cognitive changes, mood symptoms, or persistent discomfort despite normal imaging, further evaluation may be appropriate.
Concussion is not just about what appears on a scan. It is about understanding the biological injury process and guiding recovery thoughtfully.
For those interested in reviewing current scientific discussions on biomarkers and evolving concussion understanding:
Biomarkers for Traumatic Brain Injury - National Academies of Sciences, Engineering, and Medicine is a great resource. This research provides an in-depth overview of emerging biomarkers and modern approaches to traumatic brain injury.
