Aknock on the head that causes even minor traumatic brain injury (TBI) may significantly increase risk of a future stroke, according to new research published in the June 26, 2013 online issue of the journal Neurology.
TBI affects an estimated 1.7 million Americans every year, 80 percent of whom are adults over 65 years of age. The link between TBI and greater vulnerability to ischemic stroke—in which blood flow to part of the brain is blocked—can last for months or years, the study found.
WHAT YOU CAN DO
Because older adults may have more complications from TBI and take longer to recover, prevention is especially important, Dr. Tanev says. These simple strategies can help lower the risk for TBI:
- Eliminate fall hazards in and around the home
- Wear seatbelts while driving or riding in a vehicle
- Wear helmets while biking or skating
- Get treatment for dizziness and other symptoms that affect balance
Researchers analyzed data on 435,630 hospital patients or visitors to hospital emergency rooms who suffered a TBI and another 736,723 visitors over the same five-year period who suffered trauma, but no brain injury. After adjusting for other stroke risk factors such as age, hypertension, and high cholesterol, TBI rivaled the strongest stroke risk factor, hypertension, or high blood pressure, as a major predictor of stroke.
The findings are similar to those of an earlier study that found that hospital patients who had suffered a TBI had 10 times the stroke risk of patients without TBI in the first three months after injury, more than four times the risk in the first year after injury, and more than twice the risk after five years.
“While the chances of an individual having a stroke following a brain injury are still relatively small (about one percent), the Neurology study suggests a connection between head injury and stroke, and points to a need for careful monitoring of TBI patients over time,” says Kaloyan S. Tanev, MD, Director of Clinical Neuro-psychiatry Research at MGH.
“We know that head injury often involves factors that might result in stroke, such as injury to blood vessels, temporary changes in blood clotting, inflammation that may affect brain blood vessels, and changes in behavior, such as depression or reduction in physical activity that might expose the person to other stroke risk factors, such as high blood pressure or obesity. Additional research is required to help us understand the mechanism of stroke after TBI and find ways to prevent it.”
Research suggests that, aside from its influence on future stroke risk, even mild TBI is associated with greater likelihood of short- or long-term changes that negatively affect brain function, including:
- Problems with memory, attention, organizing, and reasoning
- Slowed thinking
- Emotional problems, such as depression, anxiety, personality changes, aggression, and apathy
- Sensory problems affecting taste, smell, and/or touch
- Difficulty with language that negatively affects understanding and ability to communicate
- Increased risk for additional falls
- Possible increased vulnerability to Alzheimer’s disease, Parkinson’s disease, and other neurological disorders that become more prevalent with age.
“Warning signs of a possible TBI may occur hours, days, or weeks after a blow or jolt to the head and require medical assessment,” says Dr. Tanev. “Symptoms may include persistent pain in the neck or head; increased sensitivity to lights, sounds, or distractions; blurred vision; ringing in the ears; persistent fatigue; dizziness or impaired balance; slowed thinking, speaking, acting, or reading; trouble with cognitive tasks such as remembering, decision-making, or concentrating; changes in sleep patterns; changes in mood; and getting lost or easily confused. I recommend that any blow on the head that results in ‘seeing stars,’ feeling dazed, or even brief loss of consciousness be assessed by a medical professional.
“Treatment for TBI varies according to the nature and severity of the injury and secondary symptoms, as well as the individual’s overall health. Individuals with mild TBI generally are given a thorough examination and advised to rest for a few days and resume usual activities as their symptoms permit. More serious injuries may require hospitalization and multi-specialty rehabilitation. TBI patients are usually monitored closely for some time to make sure their symptoms improve and to treat any possible consequences of TBI, such as vulnerability to a future stroke that is suggested in the current study. Although improvement from TBI may be gradual, it is certainly possible in most cases.”