A car accident. A football tackle. An unfortunate fall. These things—and more—can cause head injuries. Head injuries can happen to anyone, at any age, and they can damage the brain.
Here’s how damage can happen: A sudden movement of the head and brain can cause the brain to bounce or twist in the skull, stretching and injuring brain cells and creating chemical changes. This damage is called a traumatic brain injury, or “TBI.”
Today, the U.S. Food and Drug Administration continues to research TBI—and encourage the development of new medical devices to help diagnose and treat it.
Causes and Symptoms of TBI
TBI is often caused by a bump, blow, jolt, or explosive blast to the head, or a penetrating head injury that disrupts the brain’s normal function. Not all hits to the head result in TBI. But when it happens, TBI can range from “mild” (such as a brief change in mental status or consciousness) to “severe” (such as an extended period of unconsciousness or major problems with thinking and behavior after injury).
In 2013, about 2.8 million TBI-related emergency department (ED) visits, hospitalizations, and deaths occurred in the United States, according to the Centers for Disease Control and Prevention (CDC).
A concussion is a form of mild TBI—and about 75 percent of TBIs that occur each year are this type.
Symptoms of mild TBI include:
- blurred vision, and
- behavioral changes.
Moderate and severe TBI can include those symptoms plus:
- repeated vomiting or nausea,
- slurred speech,
- weakness in the arms or legs, and
- problems with thinking abilities.
Diagnosis of TBI
A medical exam is the first step in diagnosing potential head injury. Assessment usually includes a neurological exam, a typically painless exam that includes an evaluation of thinking, motor function (movement), sensory function, coordination, and reflexes.
But it can be hard to officially diagnose TBI. No universally accepted “gold standard” for diagnosing TBI has been established, though the CDC, the American College of Rehabilitation Medicine, and some others have published guidelines for diagnosing TBI.
Imaging tests, including computerized tomography scans (“CT” scans) and magnetic resonance imaging (MRI) tests do not diagnose TBI, but they can help doctors rule out a life-threatening injury to the brain (particularly bleeding that resulted from the traumatic injury that can require immediate medical or surgical attention).
How the FDA Supports Getting Medical Devices to Patients in the United States
In 2016, the FDA, which reviews and evaluates medical devices for safety and effectiveness, allowed the marketing of two devices that assess cognitive function following suspected brain injury in adults and children.
In 2018, the FDA also allowed marketing of the first blood test to evaluate concussion (mild TBI) in adults. This test works by measuring levels of proteins (known as UCH-L1 and GFAP) that are released from the brain into blood and measured within 12 hours of a head injury. Levels of these blood proteins after a concussion can help predict which patients may have an injury to the brain that would be visible by CT scan—and which patients won’t. So the test, along with other patient-specific information and testing, helps health care providers determine the need for CT scans, in patients at minimal risk, which can help prevent unnecessary follow-up testing.
The FDA also is working with the research and clinical community to develop better-designed clinical studies so new medical products can be developed.
But the FDA has not yet cleared or approved standalone medical products that are intended to specifically diagnose or treat TBI.
“We’re excited about today’s advances in research and development,” says Christian Shenouda, M.D., a clinician and medical device reviewer in the FDA’s Division of Neurological and Physical Medicine Devices. “We hope these advances will lead to further patient access to additional diagnostics and treatments.”
FDA Research on TBI
More sensitive and objective diagnostic methods to detect mild TBI are needed. Timely diagnosis is important to prevent repetitive injury and to help develop new therapies. So the FDA continues to research diagnostic measures of mild TBI.
“Repetitive injury carries the risk of ‘second impact syndrome.’ If people who have not recovered from a head injury have a second head injury, this can result in more significant injury to the brain and more neurological deficits. And, in some cases, repetitive injury can be fatal,” explains Meijun Ye, Ph.D., a neuroscientist in the FDA’s Office of Science and Engineering Laboratories.
FDA scientists are studying biomarkers (measurable, biological indicators of a particular state or condition), such as brain imaging, biofluid (specific proteins in blood), and physical indicators such as eye tracking and electroencephalography (EEG). “EEG is the measurement of electrical activity in the brain along the scalp. It holds promise because it’s fast, portable, and typically less expensive than MRI and CT,” Ye says.
Highlights? After scientists developed a small animal “blast” TBI model with high-intensity focused ultrasound, and checked accuracy (called “validation”), they found EEG can detect mild TBI in this model. “These results, and others by FDA regulatory science labs, contribute to the TBI scientific community and efforts to develop diagnostic devices,” Ye notes.
The FDA is now validating results from other animal models (such as when injuries are produced by a bump or jolt). Scientists also are working with human volunteers with Walter Reed National Military Medical Center in Bethesda, Maryland. And they’re recruiting more adult patients—including those with and without TBI—for continued research.
In addition to EEG, they are investigating using other portable imaging devices to detect mild TBI, such as diffuse correlation spectroscopy that can monitor blood flows in the brain from the scalp
What to Do if You Suspect Traumatic Brain Injury
Anyone with signs of moderate or severe TBI should receive medical attention as soon as possible, advises the National Institute of Neurological Disorders and Stroke.
People who survive TBI can face short- or long-term complications that affect thinking, sensation (including sight or balance), language, or emotions.
People with their first, mild TBI may just need to rest and reduce vigorous activity for a short period of time, while those with moderate to severe TBI may require physical therapy (to help with body movement), occupational therapy (to help with conducting daily activities), or psychiatric therapy and other support.
Little can be done to reverse the initial brain damage caused by trauma, the institute reports. But medical professionals will work to stabilize the patient and try to prevent further harm.
Long-term effects depend on the seriousness of the injury, location of the injury, and the age and general health of the patient.
For any TBI, it’s important to follow up with medical professionals as needed.