Detecting Brain Injury, especially in trauma cases, is difficult. Usually emergency medical technicians and emergency room physicians focus on the most pressing and visible injuries: blood gushing wounds and the like.
When a person comes to the ER with a TBI, doctors must determine if there is any bleeding in the brain. Bleeding can cause a pool of blood that puts pressure on the surrounding brain tissue, causing more damage. Subdural and epidural hematoma being most common. Currently, the best, quick way to look for intracranial bleeding is with a CT scan. Unfortunately this test provides little resolution to actually see anything other than big masses of blood.
CT scans are used to detect a number of potential problems for ER patients. So the demand for the units is often high and the wait for a scan for a TBI patient can be long. In addition, in 95 percent of patients with mild TBI, the CT scans are normal. So CT is not the best detector of brain injury, it is simply practical in that it is least invasive to the injured patient, takes realtively less time then other tests such as MRI, EEG, DTI and PET.
Researchers are looking at another way to detect potential brain damage from a TBI, using a blood test instead of an imaging technique. The blood test looks for a marker, called S-100B, a type of protein from a type of brain cell known as an astrocyte. Studies show this marker is elevated in patients with a brain bleeding after a TBI.
The blood test takes about 20 minutes to perform. However, studies suggest that the test must be done within three hours to ensure accuracy. If the test is negative, it’s most likely the patient doesn’t need a CT scan.
The S-100B test is approved for use in Europe, but it is still under study in the U.S. Researchers are still enrolling patients in the US trial. In the future, a portable screener may be developed so that rescue workers can administer the test before the patient gets to the hospital. That will save time in the emergency room and enable doctors to start appropriate treatment faster.