Watch: Dr. Kuwamura Explains Traumatic Brain Injuries

In this video, Dr. Kuwamura discusses how a concussion can occur even without a direct blow to the head. He also highlights developments in concussion research and testing, including assessments that examine eye movements and certain blood-based biomarkers.

Understanding what happens during a concussion is an important first step. Recognizing symptoms and obtaining appropriate medical care can help determine the next steps after a possible brain injury.

What Is a Traumatic Brain Injury?

A traumatic brain injury (TBI) occurs when an external force injures the brain and affects how it functions. TBIs range from mild injuries, including concussions, to severe injuries that may cause major neurological damage.

A concussion is commonly described as a mild traumatic brain injury. The word "mild" refers to the injury classification, not a guarantee that the effects will be insignificant. A concussion can temporarily affect thinking, emotions, sleep, coordination, and physical comfort. Some people also experience symptoms that last longer than expected.

Brain injuries can occur during contact sports, vehicle collisions, falls, workplace incidents, and other events involving a blow or jolt to the head or body. The severity and effects depend on many factors, including the forces involved and the individual circumstances.

Can You Have a Concussion Without Hitting Your Head?

Yes. A concussion can result from a sudden blow or jolt to the body that makes the head and brain move rapidly back and forth. A direct impact to the skull is not required.

The brain sits inside the skull and is surrounded by cerebrospinal fluid, which provides cushioning. During a sudden acceleration, deceleration, or rotational movement, the brain can move within the skull. These forces can affect brain cells and disrupt normal brain function.

For example, during a vehicle collision, a person's body may stop abruptly while the head continues moving. A similar rapid movement can occur in sports or during a fall. Depending on the forces involved, the movement can stretch or strain delicate brain tissue even if the head never directly strikes another object.

Why the movement of the brain matters

The brain is a complex organ made up of interconnected cells and networks. A traumatic force can temporarily disrupt the way these networks function. Changes in brain chemistry and the stretching of brain cells may contribute to symptoms such as headaches, dizziness, confusion, and difficulty concentrating.

Not every jolt causes a concussion, and symptoms alone cannot establish exactly what happened inside the brain. A healthcare professional can evaluate the injury mechanism, symptoms, and examination findings to determine whether further assessment is needed.

What Are the Symptoms of a Concussion or Traumatic Brain Injury?

Symptoms can vary significantly from person to person. Some appear immediately, while others develop over the following hours or days. Symptoms may affect physical comfort, thinking, emotions, balance, vision, and sleep.

What if symptoms appear days after the injury?

Delayed symptoms can occur after a concussion. Someone may initially feel relatively normal but later notice headaches, trouble concentrating, sleep changes, or increased sensitivity to light and noise.

These symptoms can overlap with other health conditions, so it is important not to assume that every symptom is caused by a brain injury. If symptoms appear after a blow or jolt to the head or body, contact a healthcare professional for guidance.

Can a Concussion Cause Long-Term Problems?

Many people with a mild traumatic brain injury improve within days to a few weeks. However, recovery varies, and some people experience symptoms that persist for weeks or months. Persistent symptoms can affect work, school, relationships, physical activity, and quality of life.

Symptoms that continue after a concussion may include headaches, dizziness, sleep difficulties, fatigue, memory problems, irritability, and difficulty concentrating. These symptoms can have several contributing factors, and a comprehensive evaluation may be needed when they do not improve as expected.

More severe traumatic brain injuries can have substantial long-term effects. The possible consequences depend on the nature and severity of the injury, the parts of the brain affected, other medical factors, and the recovery process.

Repeated head impacts are also an important concern, particularly in contact sports and activities with a risk of repeated injury. Anyone who may have sustained a concussion should follow appropriate medical guidance before returning to sports or other activities that could cause another head injury.

How Are Concussions and Traumatic Brain Injuries Diagnosed?

There is no single assessment that identifies every concussion or explains every symptom. Diagnosis generally involves understanding what happened, reviewing symptoms, performing a clinical examination, and deciding whether additional tests are appropriate.

Medical history and injury assessment

A clinician may ask how the injury occurred, whether there was a loss of consciousness, what symptoms developed, and whether the symptoms have changed. Information from a witness, family member, coach, or other person who observed the incident may also be helpful.

Neurological and cognitive assessment

The examination may include assessments of alertness, memory, concentration, coordination, balance, strength, sensation, and other neurological functions. Standardized tools may help clinicians evaluate certain aspects of cognitive or physical performance.

When is brain imaging needed?

A CT scan may be used when a clinician is concerned about bleeding or other serious complications after a head injury. Not everyone with a concussion needs imaging, and a normal CT scan does not rule out every concussion.

MRI may be considered in certain situations, depending on the clinical presentation and the question being investigated. The appropriate imaging study and timing depend on the patient's condition and medical evaluation.

Why a complete evaluation matters

Symptoms following a head injury can overlap with other medical conditions. A careful evaluation helps determine whether emergency care, observation, imaging, cognitive testing, follow-up, or referral is appropriate.

Advanced Brain Injury Testing: Blood Tests and Eye Movement Assessments

As Dr. Kuwamura explains in the video, research into traumatic brain injury has led to growing interest in additional ways to assess people who may have sustained a concussion. These approaches may complement a clinical examination, but their capabilities and limitations differ.

1. Blood tests for brain injury biomarkers

Researchers have studied proteins released into the bloodstream after injury to brain tissue. These substances, called biomarkers, can provide information that may help clinicians evaluate certain patients with suspected traumatic brain injury.

Some blood-based tests have been cleared for specific uses in evaluating adults with suspected mild traumatic brain injury. Depending on the test and clinical circumstances, results can help clinicians assess the need for a head CT scan following an acute injury.

These tests have defined intended uses. They are not universal tests that can independently diagnose every concussion, determine every long-term effect, or reliably establish the cause of symptoms months or years after an injury. Results must be interpreted alongside the patient's history, examination, and other findings.

2. Eye movement and visual assessments

The brain plays an important role in controlling eye movements, visual tracking, balance, and coordination. For this reason, clinicians and researchers have explored eye movement assessments as part of evaluating certain neurological conditions, including concussion.

Specialized systems may measure how the eyes move while following a target or responding to visual stimuli. Depending on the technology, these assessments may provide additional information about visual or neurological function.

Retinal imaging and eye movement testing are not interchangeable. Their clinical uses differ, and a retinal scan should not be described as a standalone confirmation of traumatic brain injury unless that specific test has been validated and authorized for that purpose. The availability and role of these technologies vary by provider and clinical setting.

3. Cognitive and neuropsychological testing

Cognitive testing may assess attention, memory, processing speed, learning, and problem-solving. These evaluations can help clinicians understand how symptoms affect daily functioning and may be useful when recovery is prolonged or complex.

4. Why test results need clinical interpretation

Newer tests can add useful information, but no test should be interpreted in isolation. A clinician needs to consider when the injury occurred, which symptoms are present, what the test was designed to measure, and whether other conditions could affect the result.

What Is the Treatment for a Concussion?

Treatment depends on the injury's severity, the patient's symptoms, and the recovery course. People with a suspected concussion should be evaluated by a healthcare professional, who can provide guidance on activity, monitoring, and follow-up.

Early care and relative rest

Following a concussion, a brief period of relative rest is generally recommended. This means avoiding strenuous physical activity and limiting activities that significantly worsen symptoms during the early recovery period, while gradually returning to everyday activities as tolerated under appropriate guidance.

Prolonged complete inactivity is not generally the goal for an uncomplicated concussion. The timing and pace of returning to work, school, exercise, and sports should be individualized, especially when symptoms persist.

Gradual return to everyday activities

A gradual return to usual activities can help people resume daily routines while monitoring symptoms. If symptoms become worse or do not improve, the recovery plan may need to be adjusted with guidance from a healthcare professional.

Targeted rehabilitation when needed

Some patients benefit from targeted treatment for persistent problems such as dizziness, balance difficulties, neck pain, visual symptoms, or headaches. Depending on the findings, a clinician may recommend appropriate rehabilitation or referral to a specialist.

Follow-up and symptom monitoring

Follow-up helps clinicians assess recovery and identify symptoms that require further evaluation. Patients should ask when it is safe to drive, return to sports, resume strenuous work, or participate in activities that carry a risk of another head injury.

There is no single recovery timeline that applies to everyone. Medical guidance should reflect the person's symptoms, injury, overall health, and response to activity.

When Is a Head Injury a Medical Emergency?

Most concussions are not life-threatening, but a head injury can sometimes cause bleeding or other serious complications. Warning signs should never be dismissed because the initial impact seemed minor.

These warning signs can indicate a serious injury that needs immediate medical attention. Do not wait for a routine appointment or a specialized blood test if any of these symptoms are present.

When Should You Seek a Specialist for Persistent Symptoms?

If symptoms continue after a concussion, it may be helpful to speak with a healthcare professional about further assessment. Persistent headaches, dizziness, cognitive changes, sleep problems, or difficulties returning to everyday activities deserve attention.

The appropriate specialist depends on the symptoms and suspected cause. Depending on the situation, care may involve a primary care clinician, neurologist, rehabilitation specialist, neuropsychologist, ophthalmologist, or another qualified professional.

MD Spine Care focuses on back, neck, and spine-related conditions. If symptoms also involve neck pain or another spinal concern following an accident, an appropriate evaluation may help determine whether the spine is contributing to those symptoms. A suspected acute brain injury requires appropriate medical assessment and should not be managed solely as a spine condition.

Learn more about the back and neck conditions evaluated at MD Spine Care, or contact the practice to ask whether a spine evaluation may be appropriate.

Frequently Asked Questions About Traumatic Brain Injuries