A person can walk away from a crash, decline treatment at the scene, and spend the next several weeks developing symptoms of a brain injury nobody caught. Of all the injuries a car accident can cause, traumatic brain injury is the one most likely to be underestimated at first and most consequential later.
This post explains how crashes injure the brain, which symptoms should send you to a doctor, how these injuries are diagnosed, and what New Mexico law allows an injured person to recover.
Why brain injuries are different
A broken arm is visible, diagnosable, and heals on a schedule. The brain doesn't work that way. It controls cognition, mood, movement, memory, and personality, so damage to even a small area can ripple through every part of a person's life without showing up on a standard scan.
Someone with a significant brain injury can look fine in the emergency room. They walk and talk and answer questions. Days later they can't concentrate, can't work, lose their temper without warning, or live with headaches no medication fully controls. Proving that something real happened to someone who looks normal is the central challenge of these cases, medically and legally.
New Mexico's numbers
The New Mexico Department of Health reports approximately 584 brain injury related deaths in the state in 2023, a death rate nearly 39 percent higher than the national rate. The Department names motor vehicle crashes among the most common causes, alongside falls and sports.
Deaths are the visible edge. For every fatal brain injury, many more people survive with effects ranging from a concussion that resolves in weeks to a severe injury that permanently changes what they can do.
How a crash injures the brain
You don't have to hit your head to sustain a brain injury in a collision. The brain floats in fluid inside the skull, and a sudden change in speed or direction throws it against the bone, sometimes on both sides.
- Direct impact. The head strikes the steering wheel, a window, or the roof during a rollover, bruising the brain at the point of contact.
- Acceleration and deceleration. In a rear-end collision the head whips back and then forward. Even with no contact, that motion can stretch and tear nerve fibers throughout the brain.
- Rotational force. Side impacts and rollovers twist the brain inside the skull, which tends to damage wider areas than a single impact.
Crash severity doesn't reliably predict injury severity. A low-speed impact can still cause a significant concussion, particularly in older adults.
Types of injury, from concussion to severe
- Concussion. A mild brain injury from a bump, blow, or jolt that disrupts normal function. "Mild" describes the category, not the experience. When symptoms persist for weeks or months, the condition is called post-concussion syndrome, and repeated concussions raise the risk of long-term problems.
- Contusion. A bruise on a specific area of the brain from direct impact. Contusions can develop hours after a crash, which is one reason imaging done right after the accident may not show them.
- Coup-contrecoup injury. Bruising at the impact site and at the opposite side of the brain, where it rebounded against the skull. The injury on the far side is sometimes the worse of the two.
- Diffuse axonal injury. Stretching and tearing of the nerve fibers that connect regions of the brain, caused by rapid movement inside the skull. It often doesn't appear on a CT scan and may require MRI to detect.
- Intracranial hematoma. Bleeding inside the skull from a ruptured vessel. Depending on location it can range from serious to life-threatening, and it can develop hours or days after the crash.
Symptoms and when to get help
Some symptoms appear immediately. Others show up over hours or days, and that delay is where people get hurt by waiting.
Go to an emergency room now if you notice:
- Loss of consciousness, even briefly
- A headache that keeps getting worse
- Repeated vomiting
- Seizures
- Slurred speech
- Weakness or numbness in the arms or legs
- One pupil larger than the other
- Clear fluid from the nose or ears
- Difficulty waking the person
See a doctor promptly if any of these develop in the days after a crash:
- Persistent headache
- Confusion or feeling "foggy"
- Trouble remembering the crash or forming new memories
- Difficulty concentrating
- Sleeping far more or far less than usual
- Unusual irritability, sadness, or anxiety
- Sensitivity to light or noise
- Blurred vision or ringing in the ears
- Dizziness or balance problems
Symptoms lasting weeks or longer can include chronic headaches, fatigue, trouble with complex tasks, personality changes, and difficulty finding words. None of these should be waited out.
Why emergency rooms miss it
Emergency departments are built to find and treat what will kill you today. A patient who is walking, oriented, and conversational may be discharged without a full brain injury workup. The CT scan used in most ERs is good at finding bleeding and fractures and poor at finding concussions, early contusions, and diffuse axonal injury. MRI is more sensitive and usually isn't part of the initial visit.
Adrenaline and the confusion of a crash also mask symptoms. Many people feel worse two or three days after a collision than they did in the first hour.
That combination creates a window where a real injury goes undiagnosed, and it creates a predictable problem later: the insurer will point to the normal CT and the early discharge, then to the gap before symptoms were reported, to argue that nothing serious happened. Prompt follow-up with a neurologist and consistent documentation of symptoms are how that argument gets answered, with early legal counsel making sure both happen.
Diagnosis and treatment
Diagnosis typically combines a neurological exam and imaging with neuropsychological testing that measures memory, attention, processing speed, and executive function. That testing matters legally as well as medically. It creates an objective record of impairment even when scans look normal.
Treatment depends on severity. Concussion care centers on physical and cognitive rest followed by a supervised return to activity, with particular care to avoid a second impact before the brain has healed. Moderate and severe injuries can involve intensive care and medication to control swelling, and in some cases surgery to relieve pressure or remove a hematoma. Long-term rehabilitation usually means a team, including neurologists, neuropsychologists, therapists, and sometimes psychiatrists, working over months or years.
The long-term reality
The brain can't replace neurons that were destroyed. Some effects of a moderate or severe injury are permanent, and recovery often means adapting to a changed brain rather than returning to the person you were.
For people whose injury results in lasting disability, the consequences extend well past medical bills: the gap between what they would have earned and what they can earn now, ongoing care, home modifications, and lost independence. New Mexico law recognizes future losses, economic and non-economic, as compensable. Establishing them accurately requires expert testimony from economists who can project lost earning capacity and life care planners who can document future needs.
For a broader look at how lifetime costs are calculated, see: The True Cost of a Catastrophic Injury in New Mexico
Brain injury and your claim
Insurers know these injuries are hard to see, and they use it. Their adjusters challenge brain injury claims by pointing to normal imaging, delayed symptoms, prior medical history, and the absence of visible harm. A fair result depends on a few things:
- Continuous medical documentation. Every visit links the injury to the crash. Gaps in care become the insurer's argument.
- Specialist evaluation. A neurologist's findings and neuropsychological test results carry more weight than a general practitioner's note.
- Expert witnesses. In significant cases, neurologists, neuropsychologists, and life care planners establish the nature and future course of the injury.
- A lawyer who understands the medicine. Presenting an invisible injury to an adjuster, and if necessary to a jury, is a specific skill.
New Mexico puts a deadline on injury claims, and it runs whether or not symptoms were obvious at the scene. Don't let a lack of immediate symptoms convince you there's no claim.
At the Law Office of Nathan Cobb, we've recovered over $32 million for clients in Bernalillo County alone. If you were seriously injured in New Mexico, call us at (505) 225-8880 for a free consultation. We've represented injured New Mexicans since 2008, and we only get paid if you win.