Brain Injury Types: TBI, Anoxic & Diffuse Axonal Injury
Brain injury covers several different conditions, each with its own cause, severity, and path to recovery. Understanding which type is involved is the first step toward the right care.
Neurological care can help evaluate lasting effects and guide recovery planning.
This guide explains the main types of brain injury β traumatic and non-traumatic β along with symptoms, treatment, and what recovery looks like.
A serious brain injury is a medical emergency. Call 911 for any head injury with loss of consciousness, repeated vomiting, seizures, worsening or severe headache, weakness, slurred speech, unequal pupils, or confusion. This page is about understanding brain injury and ongoing care β not a substitute for emergency treatment.
What Is a Brain Injury?
A brain injury is any damage to the brain that disrupts how it normally works. Broadly, brain injuries fall into two categories:
Traumatic Brain Injury (TBI)
Caused by an external force, such as a blow, bump, or jolt to the head from falls, car accidents, sports, or assaults.
Acquired Brain Injury
Caused by something inside the body, such as lack of oxygen, stroke, infection, tumor, or another medical event.
Both can range from mild to severe, and both can leave lasting symptoms that benefit from neurological care.
Traumatic Brain Injury (TBI)
A traumatic brain injury results from an outside force damaging the brain. TBIs are classified by severity:
- Mild TBI, or concussion β the most common type. A concussion temporarily affects brain function, often without loss of consciousness.
- Moderate TBI β longer loss of consciousness or confusion, with more significant symptoms.
- Severe TBI β extended unconsciousness or memory loss after the injury, often requiring hospital and rehabilitation care.
Even after the acute injury is treated, many people have lingering symptoms β headaches, dizziness, memory and concentration problems, mood changes, and sleep issues β that a neurologist can help evaluate and manage.
Diffuse Axonal Injury (DAI)
Diffuse axonal injury is a type of TBI caused by strong rotational or shaking forces β common in high-speed car accidents β that stretch and damage the brain's nerve fibers, called axons, across widespread areas.
Because the damage is spread out rather than in one spot, DAI can significantly affect consciousness and function. It is a serious injury that requires specialized care and a careful, long-term approach to recovery.
Anoxic and Hypoxic Brain Injury
Not all brain injuries come from a blow to the head. Anoxic and hypoxic brain injuries happen when the brain is deprived of oxygen:
Anoxic Brain Injury
The brain is completely cut off from oxygen.
Hypoxic Brain Injury
The brain receives some oxygen, but not enough.
These injuries can result from cardiac arrest, near-drowning, choking, severe asthma attacks, carbon monoxide poisoning, or complications during surgery or birth.
Recovery depends on the duration of oxygen loss and the areas affected, and often involves rehabilitation and ongoing neurological care.
Brain Lesions
A brain lesion is an area of damaged or abnormal tissue in the brain. Lesions can result from injury, but also from stroke, multiple sclerosis, infections, tumors, or other conditions.
They are often discovered on an MRI or CT scan. Finding a lesion does not tell you the cause by itself β a neurologist interprets the lesion in the context of your symptoms and history to determine what it means and what to do next.
Brain Injury Symptoms
Symptoms vary by type, location, and severity, but commonly include:
- Headaches
- Dizziness or balance problems
- Memory, concentration, and thinking difficulties
- Confusion
- Mood or personality changes
- Fatigue and sleep problems
- Sensory changes, including vision, hearing, or sensitivity to light or noise
- In more severe injuries: weakness, seizures, or loss of consciousness
Can seizures cause brain damage? Most brief, isolated seizures do not cause lasting brain damage. However, very prolonged seizures, called status epilepticus, or the underlying conditions causing seizures can affect the brain β which is why seizures should always be evaluated by a neurologist.
How Brain Injuries Are Diagnosed
Evaluating a brain injury involves identifying the type, extent, and effects. This may include:
- A detailed history of the injury or event and your symptoms
- A neurological exam, including thinking, memory, strength, coordination, reflexes, and vision
- Brain imaging, such as CT or MRI, to identify damage or lesions
- Cognitive testing to measure thinking and memory
- Additional testing as needed
Treatment and Recovery
Brain injury recovery is highly individual and often takes time. While severe injuries are first treated in hospital and rehabilitation settings, ongoing neurological care plays a key role in long-term recovery.
Care may include:
- Managing lingering symptoms such as headaches, dizziness, sleep, mood, and cognitive issues
- Coordinating rehabilitation, including physical, occupational, and speech therapy
- Cognitive support for memory and concentration difficulties
- Treating complications such as seizures
- Ongoing monitoring and follow-up as you recover
Many people continue to improve over months, and the right support makes a meaningful difference.
When to See a Neurologist
See a neurologist if you have ongoing symptoms after a brain injury β such as persistent headaches, memory or concentration problems, dizziness, or mood changes β or if a brain lesion has been found and you need it evaluated.
At Mir Neurology, our board-certified neurologists evaluate and help manage the effects of brain injury β guiding recovery and coordinating care. With offices in Cumberland and Hagerstown, we serve patients across Western Maryland, the Eastern Panhandle of West Virginia, and South-Central Pennsylvania.
Serving Western Maryland & the Tri-State Area
With offices in Cumberland and Hagerstown, we provide neurological evaluation and ongoing care for brain injury recovery across the region.
Maryland
Cumberland, Hagerstown, LaVale, Frostburg, Cresaptown, Hancock, Williamsport, Smithsburg, Boonsboro
West Virginia
Martinsburg, Keyser, Romney, Berkeley Springs, Paw Paw
Pennsylvania
Waynesboro, Greencastle, Chambersburg, Mercersburg
Cumberland office: 924 Seton Dr Suite C, Cumberland, MD 21502 β MonβSat, 7:30 AM β 4:30 PM
Hagerstown office: 11110 Medical Campus Rd Unit 151, Hagerstown, MD 21742 β MonβFri, 7:30 AM β 5:00 PM
Frequently Asked Questions
What are the main types of brain injury?
Brain injuries are broadly traumatic, caused by an external force like a TBI or concussion, or acquired/non-traumatic, caused by something internal like a lack of oxygen, stroke, infection, or tumor. Diffuse axonal injury is a specific, serious type of TBI.
What is the difference between anoxic and hypoxic brain injury?
Anoxic brain injury means the brain was completely deprived of oxygen, while hypoxic means it received some oxygen but not enough. Both can cause damage because brain cells are very sensitive to low oxygen.
Is a concussion a type of brain injury?
Yes. A concussion is a mild traumatic brain injury. It is the most common type of TBI and is covered in detail on our concussion page.
Can seizures cause brain damage?
Brief, isolated seizures usually do not cause lasting damage, but very prolonged seizures or their underlying causes can affect the brain. Seizures should always be evaluated by a neurologist.
Can you recover from a brain injury?
Many people recover significantly, especially with rehabilitation and ongoing care, though recovery is individual and can take time. Mild injuries often resolve, while more severe injuries may have lasting effects that can still be managed and improved.
Dealing With the Lasting Effects of a Brain Injury?
Mir Neurology evaluates and helps manage brain injury and recovery in Cumberland and Hagerstown.