Traumatic Brain Injury

What is traumatic brain injury?

A traumatic brain injury (TBI) happens when an outside force changes how the brain works. There are two main types:

• Penetrating injuries – when something like a bullet, shrapnel, or bone fragment breaks through the skull and enters the brain.
• Non-penetrating injuries – also called blunt or closed head injuries, caused by a strong hit or force that makes the brain move inside the skull. Sometimes, this can lead to a skull fracture, which may harm the brain and surrounding tissues.

Common causes of TBI

• Falls
• Blunt trauma accidents
• Assaults and violence
• Vehicle related crashes
• Sports injuries
• Penetrating injuries
• Explosions and blasts

Classifications by severity

Severity of TBI is often measured using the Glasgow Coma Score (GCS).

• Mild TBI: GCS 13 to 15
• Moderate TBI: GCS 9 to 12
• Severe TBI: GCS 3 to 8

Mild TBIs (like concussions) can temporarily affect brain function and typically require several days to months to heal. They may cause headaches, confusion, or brief loss of consciousness.

Moderate to severe TBIs are typically caused by stronger forces and cause long-lasting physical and cognitive problems. In some cases, they can be life-threatening.

Potential physical symptoms

• Headache
• Convulsions or seizures
• Blurred or double vision
• Unequal eye pupil size or dilation
• Clear fluids draining from the nose or ears
• Nausea and vomiting

Potential cognitive and behavioral symptoms

• Loss of or change in consciousness
• Confusion or disorientation
• Problems remembering, concentrating, or making decisions
• Changes in sleep patterns
• Frustration or irritability

Potential perception and sensation symptoms

• Light-headedness, dizziness, vertigo, or loss of balance or coordination
• Blurred vision
• Hearing problems, such as ringing in the ears
• Unexplained bad taste in the mouth
• Sensitivity to light or sound
• Mood changes or swings, agitation, combativeness, or other unusual behavior
• Feeling anxious or depressed
• Fatigue or drowsiness, including a lack of energy or motivation

Common imaging tests used to diagnose TBI

• Computerized tomography scan (CT) uses a series of X-rays to create a detailed image to visualize fractures and uncover evidence of bleeding in the brain, blood clots, bruised brain tissue, and brain tissue swelling.
• Magnetic resonance imaging (MRI) uses powerful radio waves and magnets to create a more detailed view of the brain. This test may be used once the patient’s condition is stable or if symptoms don’t improve soon after injury.

Recovery from a TBI is influenced by multiple factors. To optimize outcomes, patients receive specialized, individualized care from a multidisciplinary team focused on managing the initial brain injury and reducing the risk of secondary damage. Most long-term complications arise from secondary injury, which can occur days or even weeks after the initial trauma. Prompt medical evaluation at a designated trauma center is critical to ensure timely intervention and improve recovery.

Mild TBI (Such as concussions)

Treatment includes rest and relaxation and taking over-the-counter pain relievers for headaches as needed. Patients should limit activities that require cognitive attention and concentration.

Moderate and severe TBI

Treatment includes:

• Stabilizing the person’s spinal cord, heart, lungs, and other vital organ functions
• Ensuring proper oxygen delivery and breathing
• Controlling blood pressure
• Preventing further brain damage

Surgery

In cases of moderate and severe TBI emergent surgical intervention may be warranted to limit additional damage to brain tissues:

• Stop bleeding in the brain
• Remove debris, dead brain tissue, or hematomas
• Repair skull fractures
• Opening a window in the skull to allow for brain swelling if needed

Medications

Sometimes medications are prescribed to limit secondary brain injury.

• Anti-seizure drugs: moderate to severe TBI patients are at higher risk for seizures. Anti-seizure medications are prescribed to limit/prevent the occurrence of seizures.
• Coma-inducing drugs: moderate to severe TBI patients are sometimes put into medically induced comas to reduce the brain’s need for oxygen.
• Diuretics: these medications reduce the amount of fluid in tissues and increase urine output to reduce pressure inside the brain.

Rehabilitation

Individuals with TBI, regardless of severity, benefit from comprehensive cognitive and physical assessments. These evaluations are conducted by specialized clinicians during acute hospitalization and extend into inpatient rehabilitation, residential programs, or outpatient services. Interdisciplinary rehabilitation teams focus on restoring functional independence by retraining activities of daily living (ADLs), including ambulation, communication, self-care, and feeding.

Rehabilitation specialists include:

• Occupational therapist
• Physical therapist
• Speech and language therapist
• Social worker/case manager

Learn more about rehabilitation services at North Memorial Health.

• Midwest Spine & Brain Institute
• Minnesota Brain Injury Alliance
• Trauma Survivors Network (TSN) is a community for survivors and their families to connect and rebuild after a traumatic physical injury.

1. Center for Disease Control: Traumatic Brain Injury & Concussion; Facts about TBI. Facts About TBI | Traumatic Brain Injury & Concussion | CDC. Accessed Dec. 8, 2025.
2. Mayo Clinic: Traumatic Brain Injury. Traumatic brain injury – Diagnosis & treatment – Mayo Clinic. Accessed Dec. 8, 2025.
3. National Institute of Neurological Disorders and Stroke: Traumatic Brain Injury. Traumatic Brain Injury (TBI) | National Institute of Neurological Disorders and Stroke. Accessed Dec. 8, 2025.