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.”
As kids prepare for school sports, and many adults look ahead to fall activities, the U.S. Food and Drug Administration is researching TBI—and encouraging the development of new medical devices to help diagnose and treat it.
Symptoms and Diagnosis
A 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 a 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). A concussion is a form of mild TBI.
About 2.5 million emergency department visits were associated with TBI in 2010, and these injuries contribute to about 30 percent of all injury-related deaths in the United States, according to the Centers for Disease Control and Prevention (CDC).
Symptoms of mild TBI include headache, confusion, 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. (The National Institute of Neurological Disorders and Stroke has more information on symptoms.)
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. Universally accepted “gold standard” diagnostic standards have not yet 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).
Those 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, occupational, or psychiatric therapy and other support.
More sensitive and objective diagnostic methods to detect TBI are needed. Timely diagnosis is important to prevent repetitive injury and to help develop new therapies. So the FDA is researching 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., an FDA neuroscientist who is researching TBI with principal investigator Cristin Welle, Ph.D.
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—and healthy people—for more research.
FDA Regulation: Moving Devices to Patients
The FDA does not develop medical devices for marketing, but it does review and evaluate them. When evaluating medical devices—including those that might treat and diagnose TBI—the agency considers the safety and effectiveness of a product by evaluating the potential benefits and risks that it poses. Input from patients, based on their experiences and preferences, also gives FDA scientists valuable information.
To date, the FDA has cleared devices that can help determine the need for imaging following a head injury. And it recently allowed marketing of two new devices that assess cognitive function following suspected brain injury in adults and children. But the FDA has not cleared medical products that are intended to specifically diagnose or treat TBI.
“A key part of our work is to continue to review and evaluate new devices for safety and effectiveness that may eventually aid in the diagnosis and treatment of TBI,” explains FDA medical device reviewer and neuropsychologist Peter Como, Ph.D.
The FDA works with companies early in the process to make sure they collect the right evidence for their products and to confirm the obligations for marketing a device in the United States.
The FDA also is working with the research and clinical community to develop better-designed clinical studies so new medical products can be developed. For instance, the FDA hosted a public meeting in March 2016 and plans to provide recommendations to address challenges in biomarker development in the future.
“We’re excited about today’s advances in research and development,” adds Como. “And we hope these advances will lead to patient access to new diagnostics and treatments.”
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 (NINDS).
Little can be done to reverse the initial brain damage caused by trauma, NINDS 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.
This article appears on the FDA’s Consumer Updates page, which features the latest on all FDA-regulated products.