Brain imaging findings correlate with recovery prognosis and long-term injury.
Patterns of injury picked up by CT scans of the brain can give radiologists details about the risk of long-term impairment and possible recovery in patients who have suffered a concussion.
Links between features seen on CT images and the impacts of moderate-to-severe traumatic brain injuries have already been established. This is the first time such associations have been identified with concussion, said a team from the University of California at San Francisco (UCSF).
The team published their results July 19 in JAMA Neurology.
“Radiologists who routinely read trauma scans know intuitively that patterns of intracranial injury on CT are not random,” said first author Esther Yuh, M.D., Ph.D., professor of radiology and biomedical imaging. “We showed there are patterns of injury, that some of these are associated with worse outcome than others, and that they provide a window into mechanisms of injury that is reproducible across large studies.”
Being able to identify these patterns is critical, added senior author Geoffrey Manley, M.D., Ph.D., UCSF professor and vice chair of neurological surgery and chief of neurosurgery at Zuckerberg San Francisco General Hospital, because patients who experience concussion can also develop lingering problems.
“Patients with concussion may suffer from prolonged headache, poor sleep, and impaired concentration, and they are at higher risk for self-medicating with drugs and alcohol,” he said. “Concussion can also contribute to depression and anxiety and increase the risk for suicide. We need to view concussion not as an event but as a disease requiring physician follow-up after a patient is discharged from the hospital.”
For their study, the team examined CT scans from 1,935 patients who averaged age 41. All patients were evaluated at three, six, and 12 months post-injury, and 66 percent of the group were male. They were enrolled from Manley’s brain injury research initiative, TRACK-TBI, and all of them had been seen at level 1 trauma centers. Consequently, 37 percent of study participants a positive CT compared to the roughly 9 percent of positive CTs that occur in emergency departments nationwide.
Based on their evaluations, the team determined that different types of injuries not only had different imaging features, but they also had different recovery trajectories.
More than half of CT-positive patients had a combination of subarachnoid hemorrhage (SAH), subdural hematoma (SDH), and/or contusion. These injuries typically result from falling, and at the 12-month follow-up, investigators determined patients in this group failed to make a complete recovery and were experiencing mild-to-more severe impairments.
The next most common injury group, affecting approximately 7 percent of patients, involved intra-ventricular hemorrhage (IVH) or petechial hemorrhage. These injuries are typically caused by head rotation from sports and scooter or car accidents. At the 12-month mark, these patients had more severe impairments that resulted in lower-moderate disabilities that can affect employment, socializing, and leisure activities.
The last group which constituted 5 percent of enrolled patients had findings of epidural hematoma (EDH) that frequently results from sport injury, such as being hit in the head with a baseball. These patients demonstrated complete recovery at six months.
Equally as concerning as these imaging findings, the team said, is the fact that only 39 percent of patients who have a positive CT scan actually receive follow-up care from a physician. Follow-up should be routine for all concussion patients, including those who do not have abnormal CT features.
The team did clarify that these findings do not support expanded use of CT. The scan should still only be used in these circumstances with patients who have known or suspected concussion, loss of consciousness, amnesia, as well as other factors, such as older age, physical trauma evidence, and severe headache.
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