What Are the Different Types of Traumatic Brain Injury?

What Are the Different Types of Traumatic Brain Injury?Car and truck accidents can lead to a variety of serious injuries. One of these is a traumatic brain injury, also called a TBI for short. Brain injuries can cause many concerning side effects, including cognitive difficulties, physical pain, and problems regulating emotions. The more severe the accident, the more severe the TBI, and the more severe the patient outcome and potential future complications.

Not every traumatic brain injury is the same, however. In fact, neurologists and other medical professionals categorize TBIs into a variety of types and categories according to how a patient sustains the injury, where in the brain the injury occurs, and the symptoms the patient is experiencing. In today’s blog, we’ll get into the details of the different types of traumatic brain injuries and how physicians generally approach diagnosis and treatment.

What is a traumatic brain injury?

The National Library of Medicine discusses traumatic brain injury:

Traumatic brain injury (TBI) can result from trauma ranging from a simple blow to the head to a penetrating injury to the brain. In the United States, around 1.7 million people suffer a traumatic brain injury [each year], with adolescents between ages 15 and 19 and adults age 65 and older among the most likely to sustain a traumatic brain injury.

 Although mild traumatic brain injuries (mTBIs) like concussions were previously thought to be “benign occurrences” with little future effect on a patient, we now know that mTBIs can cause serious adverse outcomes.

The National Library of Medicine highlights five common types of TBI: concussion, extra-axial hematoma, contusion, traumatic subarachnoid hemorrhage, and diffuse axonal injury.


Concussions are a type of TBI occurring from a blow or jolt to the head, causing the brain to move back and forth in the skull. This rapid movement can cause the brain to stretch and tear, causing damage to brain cells. Although concussions are typically not a life-threatening injury, they require immediate medical attention.

The Concussion Foundation notes that one of the leading causes of concussion is sports, and:

The CDC estimates as many as 3.8 million concussions occur in the U.S. annually through sports and recreational activities. However, only a fraction of sports concussions are recognized by athletes, coaches, and parents, and treated by medical professionals.

One of the reasons concussions can be so dangerous is because of something called Post-Concussion Syndrome (PCS). PCS is when symptoms of concussion persist past the course of a patient’s normal recovery. Concussion symptoms generally resolve in about two weeks; however, if they extend to one or two months or longer, patients are diagnosed with Post-Concussion Syndrome. Per the Concussion Foundation, this can cause them to “withdraw from their usual physical, professional, and social lives.”

Extra-axial hematoma

An extra-axial hematoma is also known as a brain bleed or, more specifically, epidural bleed. Per the Cleveland Clinic, “The brain has three membranes layers (called meninges) that lay between the bony skull and the actual brain tissue. The purpose of the meninges is to cover and protect the brain. Bleeding can occur anywhere between these three membranes.” There are three of these meninges:

  • Pia mater, the inner and most delicate layer
  • Arachnoid, the middle layer (which looks a bit like a spider web) which provides a cushion for the brain
  • Dura mater, the toughest and most outer layer

With an epidural bleed, the bleed occurs between the skull bone and the outermost layer of the brain – the dura mater. The pooling of blood that happens with a hematoma can put pressure on the brain and deprive it of oxygen and nutrients. If this happens for more than two or three minutes, brain cells start to die.

The Cleveland Clinic notes that bleeding in the brain typically happens suddenly and can be caused by head trauma from car accidents and truck accidents, or slips and falls.


A contusion is a bruise to the brain, which can occur when the brain is violently jostled around in the skull. Contusions can also occur with skull fractures. Moderate to serious contusions can cause swelling and bleeding inside the brain at the point of impact, also called an intracerebral hemorrhage. The Cleveland Clinic reports that “this bleeding occurs in the lobes, pons and cerebellum of the brain (bleeding anywhere within the brain tissue itself including the brainstem).”

The lobes are “zones” of the brain – how scientists explain where a specific injury occurs. The pons links up your brain and spinal cord. The cerebellum is the part of the brain that controls motor function; it’s located in the back of the brain.

Traumatic subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is bleeding in the area between the brain and the tissues that protect it, specifically below the arachnoid layer. This is a life-threatening condition and requires immediate medical attention. Per the Cleveland Clinic, “SAH caused by injury most commonly happens to older people who’ve fallen and hit their heads. Among younger people, the most common injury leading to subarachnoid hemorrhage is vehicle crashes.”

Every year, about 10 to 14 of every 100,000 people experience a subarachnoid hemorrhage.

Diffuse axonal injury

Diffuse axonal injury (DAI) is an extremely serious traumatic brain injury. Healthline explains it as follows:

It happens when the brain rapidly shifts inside the skull as an injury is occurring. The long connecting fibers in the brain called axons are sheared as the brain rapidly accelerates and decelerates inside the hard bone of the skull. DAI typically causes injury to many parts of the brain, and people who suffer a DAI are usually left in a coma. The changes in the brain are often very tiny and can be difficult to detect using CT or MRI scans.

They also note DAIs often occur during motor vehicle accidents, falls from heights, violent assaults, and sports injuries and accidents.

A quick note about coup-contrecoup injuries

Despite the delicacy of the brain, the skull is pretty rough. When an object hits the skull and the brain is injured, it is a coup injury. But often, the brain bounces around a bit within the skull, often striking another part of it. The injury at this secondary point of impact is called a contrecoup injury. Coup-contrecoup injuries are common in car accidents.

Coup-contrecoup injuries are typically a type of contusion, which is why the National Library of Medicine doesn’t give them their own category. But they are also very common – and very serious – injuries, which is why we wanted to mention them here.

Diagnosing traumatic brain injuries

Prompt medical intervention is crucial for the best outcome for a traumatic brain injury, no matter what the type. Physicians generally use the same types of diagnostic tools and tests, including:

  • Physical examination
  • Digital imaging, like X-rays, CT scans, and MRIs
  • Measurements using the Glasgow Coma Scale
  • Neurophysiological assessments
  • Blood tests, in some instances

After a diagnosis, a medical team can get a patient started on a personalized treatment regimen.

And, the legal team at Larson Law can get started investigating your case, finding out who was responsible for causing the accident that resulted in your traumatic brain injury. While you recover from your TBI, we will work to name all liable parties for your personal injury claim and determine the proper and full amount of compensation to which you are entitled. We understand it may take some time to understand the extent of your injuries, so we won’t rush you into a settlement that won’t cover your future expenses. To learn more and schedule a consultation with a Minot car and truck accident lawyer, call our offices or fill out our contact form. We proudly serve Bismarck, Minot, and Fargo.