Can Head Trauma Cause a Stroke?

With increased awareness of the serious impact of head trauma over the past few years, a frequent question is whether head trauma can cause strokes. Many well-known athletes have spoken about traumatic brain injury (TBI) and how it has affected their lives years after discontinuing sports. Research in traumatic brain injury has also pointed to an association between TBI and stroke.

This article will discuss the risk of stroke in people who have had a traumatic brain injury.

Traumatic Brain Injury

Traumatic brain injury can cause brain damage. After head trauma, there may be bleeding in the brain, which irritates brain tissue. Bleeding also decreases blood flow to the brain due to blood leakage from the torn blood vessel. Swelling may occur, putting pressure on brain tissue. Bruises in the brain may take a long time to heal.

A concussion is a specific type of TBI that is also now recognized as a cause of long-term problems. A concussion is head trauma that results in short-term impairment, such as dizziness, memory loss, blurred vision, or loss of consciousness.

Even after recovery from a concussion, people may have long-term neurological and psychological problems, often referred to as post-concussive symptoms or post-concussive syndrome.

A concussion may be called a mild TBI, but it is still a serious injury requiring medical care.

Increased Hemorrhagic Strokes

There is an association between head trauma and an increased incidence of hemorrhagic strokes in the years that follow. Hemorrhagic strokes are episodes of bleeding in the brain, which may be due to a defect in the blood vessel or severe high blood pressure.

A hemorrhagic stroke causes brain irritation in the area of bleeding, as well as extreme changes in blood pressure and blood vessel diameter, which may cause even further damage. Hemorrhagic strokes progress quickly and can cause serious harm.

A 2019 study following over 16,000 people with TBI and a control group of over 32,000 people found over six times the risk for a hemorrhagic stroke in those who had a TBI. The greatest incidence of stroke was in the first year after the TBI diagnosis but remained elevated in five years of follow-up.

Increased Ischemic Strokes

Ischemic strokes are strokes due to the blockage of a blood vessel in the brain, causing diminished blood supply to a region of the brain. Studies show that there is an increased lifetime risk of ischemic strokes in the years after head trauma.

This is likely due to clotting problems associated with alterations in the body’s ability to form blood clots after an episode of head trauma. The changes in blood clotting after head trauma are erratic and unpredictable and thus may cause either increased ischemic strokes or increased hemorrhagic strokes.

A 2022 study of over 12,000 people grouped them into those who had a mild traumatic brain injury (such as a concussion), a moderate to severe traumatic brain injury, and those without a TBI. All subjects were healthy (no clinical comorbidities) before their TBI, which occurred from 2000 to 2015.

The risk of ischemic stroke or transient ischemic attack (a brief interruption in blood flow in the brain) was over twice as high in the group with mild TBI and 3.6 times higher in the group with moderate to severe TBI compared to the group with no TBI. The groups with TBI also had a higher risk of developing hypertension or diabetes.

Prevention of Traumatic Brain Injury 

Prevention of brain injury is now recognized as a way to protect yourself against a future stroke.

The best approach is to prevent traumatic brain injury. Fortunately, one of the most effective deterrents to head trauma is just a simple safety belt in the car. It's also important to wear helmets and proper headgear for sports and adventure activities, including biking, skiing, and snowboarding.

Another valuable safety measure for preventing head trauma includes avoiding alcohol and drugs that alter perception and judgment when operating heavy machinery—including cars, motorcycles, lawnmowers, and factory equipment.