What is a diffuse axonal injury?

By Matt Lalande in Brain Injuries on March 04, 2022

What is a diffuse axonal injury?

A Diffuse axonal injury (DAI) is a type of closed head traumatic brain injury (TBI) that results from a blunt injury to the brain, often caused in serious car accidents, pedestrian accidents, motorcycle accidents, trucking accidents and bicycle accidents. This type of specific brain injury is one the most common – and one of the most devastating.

The major cause of damage in DAI is the tearing or shearing of axons, the neural processes that allow neurons to communicate with another. It is characterizes by extensive generalized damage to the “white matter” of the brain that often occurs during high speed acceleration – deceleration or rotational forces. It is a terrible type of brain injury which can cause cognitive, physical, and behavioral changes that can totally compromise a person’s social reintegration, return to productivity, and quality of life.


Why is it called a Diffuse Axonal Injury?

 A diffuse axonal injury falls under the category of a “diffuse” (or spread) brain injury. This means that instead of occurring in a specific area, like a focal brain injury, the shearing of axons happen over a more widespread area.

Is a Diffuse Axonal Injury a Permanent Brain Injury?

Diffuse axonal injury, and more generally TBI, often results in physical, cognitive, and behavioral impairments that can be temporary or permanent.

What is a Diffuse Axonal Injury?

Diffuse axonal injury (DAI), also known as shear injury or traumatic axonal injury, refers to intracranial injury caused by rapid and sustained deceleration or acceleration of the brain.

What is an Intracranial Injury?

An intracranial injury is a head injury that exists or occurs within the cranium – in other words, a closed head injury.

How is a Diffuse Axonal Injury Diagnosed?

A diffuse axonal injury is normally diagnosed by MRI.

Will my loved one recover from a Diffuse Axonal Injury?

diffuse axonal injury is a serious brain injury, and every person’s case is unique. However, as a medical term, there are categories and levels of diffuse axonal injuries, ranging from being completely comatose (extremely severe) to having a concussion, for example (less severe). 

A Diffuse Axonal Injury is a Devastating Type of Traumatic Brain Injury

A person can suffer a brain injury which is traumatic or non-traumatic. A traumatic brain injury (TBI) occurs when an intentional or unintentional hard blow to the head causes brain damage. A traumatic brain injury can range from a low-level concussion to severe brain damage. A TBI is caused by a bump, blow, or jolt to the head or a penetrating head injury that disrupts the normal function of the brain. Signs and symptoms vary by severity, ranging from loss of consciousness (LOC) lasting a few seconds to seizures, to coma, or even death. Serious traumatic brain injury can lead to chronic debilitating conditions, which can unfortunately have acute and chronic outcomes both for those who survive the brain trauma, as well as their families and or caregivers.

There are many different types of traumatic brain injuries that we see in our practice, including:

Concussions – The term “concussion” comes from the Latin concussio —meaning “to strike together” – Concussion are often diagnosed as mild traumatic brain injuries, without any structural damage.  A concussive injury can leave a person with with different levels of altered mental status that range from being confused to completely unconsciousness for a few minutes. Prognosis is usually good, and most patients experience complete resolution of symptoms.

Cerebral Contusions – is a form of bruising to brain tissue. Cerebral contusions can be cost by multiple micro hemorrhaging or in other words, small blood vessels which leak into the brain tissue. Cerebral contusions are often caused by direct blows to the head. Cerebral contusions commonly occur due to localized trauma and along the frontal and temporal lobes of the brain. Cerebral contusions are often likely to heal on their own without ongoing medical treatment or intervention.

Intracerebral Hemorrhage – is a very common type of brain injury which occurs in car accidents. Blood vessels such as arteries and veins, carry blood to and from the brain. In a serious accident, these blood vessels can be damaged and rupture, causing bleeding into the brain tissue. While high blood pressure is an extremely common cause of intracerebral hemorrhage, other causes can include traumatic brain injury. Often times, surgery is required to relieve pressure on the brain and repair torn arteries.

Subdural Hematoma – is when blood builds up on the surface of the brain, particularly in the space between the protective layers that surround your brain. When this occurs, blood leaks out of torn vessels into the space below what is called the “dura matter” which is the membrane between your brain and your skull bone. It is technically the type of brain bleed that occurs inside your cranium, but outside your brain. It is reported that subdural hematoma is can happen in up to 25% of victims that suffer serious head injuries. If the severely mental most serious enough, surgery may be required to relieve pressure in the brain and drain the blood, which would then relieve pressure that the buildup is caused onto the brain itself.

Epidural Hematoma – can be a life-threatening condition. Normally epidural hematoma’s require immediate medical attention for the brain can suffer serious brain damage, or possibly death. And epidural hematoma is to build up of blood between your skull and your “dura matter”, which is the owner most productive member the coverage your brain. In most cases, a craniotomy or hematoma evacuation is necessary. This is a type of surgery in which a piece of the skull is removed and, any obvious signs of bleeding are stopped or slowed. Other types of surgery would include drilling one or more holes in the cranium to relieve pressure and drain the blood.

Intraventricular Hemorrhage (IVH) – is bleeding inside or around the ventricles in the brain. Inside the brain, ventricles Tare known as the spaces in the brain which contain the cerebral spinal fluid. Intraventricular hemorrhaging can occur during a traumatic birth, or from complications after delivery. The condition is most often seen in premature babies, and the smaller and more premature the infant, the higher the risk for IVH.

Traumatic Subarachnoid Hemmorrhage – is when blood which escapes from a ruptured blood vessel leaks into the space that surrounds the brain is described as a subarachnoid hemorrhage. The subarachnoid space is the fluid-filled space around the brain between the arachnoid membrane and what is called the pia mater (the delicate innermost membrane enveloping the brain and spinal cord) through which major blood vessels pass. The cerebrospinal fluid in this space forms a floating cushion the brain hovers in for protection. When an injury causes some of the small arteries to tear, the blood flow spreads all over the surface of the brain, causing widespread traumatic effects.

Diffuse Axonal Injury – as mentioned, a DAI is a serious and life threatening form of brain injury. Axons, which compose what is also known as the white matter of the brain, connect nerve cells throughout the brain. When the brain reverberates (quickly moves back and forth inside the skull), the nerve axons can be torn and damaged. During automobile accidents, for example, rapid rotation or deceleration of the brain causes stretching of these nerve cells on a cellular level, the brain’s normal transmission of signals (information) is disrupted, and this can dramatically impact the person’s alertness and wakefulness.

Diffuse Axonal Injuries and Motor Vehicle Accidents

Diffuse axonal injury (DAI) is a type of traumatic brain injury (TBI) that results from a blunt injury to the brain or by severe acceleration, deceleration forces. It is often called the “shear injury” and is one of the most frequent types of primary brain injury that is seen in car accident victims with severe head trauma. The blunt trauma, or the trauma caused by severe acceleration /deceleration forces causes the brain’s axons to be stretched and torn. Axons are microscopic nerve fibers that are found within the inner part of the brain, known as white matter.   The stretching pairing of the axons are caused because the unmoving brain lags behind the movement of the skull, causing nerve structures to tear. The carrying of the axons then, in turn, disrupts the brain’s regular communication and chemical process  – which can then lead to permanent and widespread brain damage, or even death. No matter what the end result, diffuse axonal injury traditionally has been associated with very poor clinical outcome. Many victims go on to suffer severe verbal short-term memory, frontal lobe cognitive dysfunction, slowed information processing and overall, long-lasting neuropsychological impairments to the  memory and executive functioning of the brain.

Diffuse Axonal Injuries – The Long-Term Problems

Unfortunately many people that suffer diffuse axonal injuries do not survive. The injury carries a very high mortality rate. Then, victims suffering from diffuse axonal brain trauma who survive will more likely than not go on to suffer cognitive physical and behavioral changes which can be temporary or permanent. In some cases the brain may gradually return to normal function given that  with diffuse axonal injuries, brain tissue is functionally impaired and not destroyed.

For those victims who unfortunately do not recover well, they can go on to suffer from cognitive deficits (meeting memory problems, issues with judgment, loss of sense and time and space, and ability to multitask, forgetfulness, concentration issues etc.). Victims can also going to suffer sensory deficits, such as vision problems and depth perception problems. Victims can also suffer from communication and language difficulties, such as difficulty speaking, word finding problems, stuttering, hesitant speech and decreased vocabulary.

Other types of issues can be functional deficits, such as impaired ability to maintain one’s activity of daily living, problems with organizing and being in the community, problems with driving etc. Often times,victims with diffuse axonal injuries can also suffer from impaired social capacities, suffer interpersonal relationship problems, they can miss social cues and have difficulties understanding and responding to the nuances of social interactions in general.

Victims with diffuse axonal injuries can also suffer from ongoing issues such as anger, irritability, anxiety, depression, disinhibition, fatigue and in severe cases, traumatic epilepsy.

Often times, people who suffer ongoing permanent issues due to brain trauma caused by diffuse axonal injury (and of course depending on the severity) will require either temporary or permanent ongoing brain injury rehabilitation. Clinical providers will be required to help maximize a brain injury victims capabilities both in his or her home, and in the community. Often times, psychological treatment is required, as is assistance by occupational therapists and speech therapists.

Depending on the severity of the diffuse axonal injury, brain treatment programs may also be required either in terms of acute management, community rehabilitation behavioral management and assistance with independent living.

Diffuse Axonal Injuries and Accident Benefits

When a driver and/or passengers are injured in an automobile accident, heavy financial burdens can result. When the driver is not responsible for an accident, he or she and any passengers may be in a good position to recover compensation from the person (his or her insurance company) from the at-fault driver. The problem is that auto litigation in Ontario can take many years before liability is established and trials or settlements can be reached. In the meantime, there may be ongoing medical and rehabilitation expenses that need to be paid.

As part of a standard auto policy in Ontario, accident benefits (no-fault) are provided to policyholders who have been injured in motor vehicle accidents. If you pay for an auto insurance policy in Ontario, accident benefits are payable to you as a hurt victim regardless of whether you were driving or not at the time of the accident. You are entitled to claim accident benefits if you or a passenger, pedestrian or cyclist. If you do not have your own auto insurance policy, then you are entitled to claim accident benefits from the auto policy belonging to the at fault driver that caused your accident. Accident benefits can provide critical relief both from a financial and rehabilitation perspective immediately after an accident.

Motor vehicle accident victims who suffer serious brain trauma are entitled to claim both medical and rehabilitation benefits as well as attendant care benefits to try and assist them with the reintegration into the life they once knew. Now, the amounts of medical, rehabilitation and attendant care benefits available vary significantly depending on the severity of one’s injuries.

For example, people at suffer serious orthopedic injuries or minor brain trauma causing severe psychological or cognitive issues are eligible to receive up to $65,000 in medical, rehabilitation and attendant care benefits. Attendant care benefits are payable up to $3000 a month.

Now, in certain circumstances, the person is entitled to enhanced benefits up to $1 million for life. These benefits are reserved for the most seriously injured claimants such as victims that suffer severe traumatic brain injuries or paralyzed victims. These victims of the access to the widest array of accident benefits.

Within the statutory accident benefits schedule, there is a definition of catastrophic impairment with reference to adults over the age of 18 who suffer serious brain:

  • (a) paraplegia or tetraplegia;
  • (b) severe impairment of ambulatory mobility or use of an arm, or amputation;
  • (c) total loss of vision in both eyes;
  • (d) if the insured person was 18 years of age or older at the time of the accident, a traumatic brain injury that meets the following criteria:
    • • The injury shows positive findings on a computerized axial tomography scan, a magnetic resonance imaging or any other medically recognized brain diagnostic technology indicating intracranial pathology that is a result of the accident, including, but not limited to, intracranial contusions or hemorrhages, diffuse axonal injury, cerebral edema, midline shift or pneumocephaly.

It is important to get in touch with a brain injury lawyer early so that we can inquire whether there are positive finding of a catastrophic impairment that can be identified on medical imaging. Medical imaging may be a computerized axial tomography scan, magnetic resonance imaging or any other medically recognized brain diagnostic technology indicating intracranial pathology that is a result of the accident, including, but not limited to, intracranial contusions or hemorrhages, diffuse axonal injury, cerebral edema, midline shift or pneumocephaly. If catastrophic impairment can be determined – you or your loved one will be eligible for enhanced accident benefits of $1,000,000 for life to help with your medical, rehabilitation and attendant care needs.

If your loved one has suffered a diffuse axonal injury in a car accident, our brain injury lawyers can help

If your loved one has suffered a serious traumatic brain injury – or in particular a diffuse axonal injury, caused by someone who was careless, we would  be more than happy to talk and discuss your legal options with you. Call us no matter where you are in Ontario at 1-844-LALANDE (525-2633) or local in the Hamilton / Burlington / Niagara areas at 905-333-8888tell. Alternatively, you can reach us by sending an email through our website and someone will get back to you within reasonable time.

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