MRI Finds Possible Vascular Injury After Mild Head Injury

San Diego, California — Using MRI, researchers have detected linear hemorrhagic brain lesions suggestive of primary injury to the vasculature early after mild traumatic brain injury (mTBI), a finding that could have implications for acute treatment.

These "discrete linear-shaped lesions we think may represent vascular injury," study investigator Gunjan Parikh, MD, from the National Institute of Neurological Disorders and Stroke and the University of Maryland R Adams Cowley Shock Trauma Center in Baltimore, noted in an interview with Medscape Medical News.

If confirmed, they could potentially be used as "an imaging-based biomarker to select out [mTBI] patients who may benefit from medications that target the endothelium or the vasculature in general. That's one down-the-road clinical implication that I can see," he added.

The findings, from the Traumatic Head Injury Neuroimaging Classification (THINC) study, were released March 12, ahead of their presentation at the American Academy of Neurology (AAN) 65th Annual Meeting, to be held from March 16 to 23 in San Diego, California.

THINC Study

The study involved 256 adults who were admitted to the emergency department during a 2-year period after mild head injuries, most due to falls or road accidents.

The median time between injury and imaging was 17 hours. "Hyperacute imaging in the first 24 hours after TBI is not standard of care," Dr. Parikh said. "Traditionally acute imaging using MRI after TBI could be considered in a time frame as far out as 1 week; here the average time from injury to MRI was 17 hours, so I think we are capturing injury that wasn't captured before in a sense," he added.

A total of 104 patients (41%) had evidence of cerebral hemorrhage on MRI; 67% had experienced a loss of consciousness and 65% had amnesia. Their scores on the Glasgow Coma Scale on arrival were 13 to 15 in 91% of cases.

Twenty-one (20%) of the patients with cerebral hemorrhage had microbleeds (punctate), whereas 34 (33%) had linear lesions (tube-shaped, branching, multiple axial slices).

Microbleeds were distributed throughout the brain, whereas linear lesions were found primarily in the anterior corona radiata (82%) and traversing the white matter, gray matter, and sulcus (59%).

"We think the small hemorrhagic lesions are tracking into the deep white matter from the meninges," Dr. Parikh said. "This type of injury was routinely seen in more severe patients on postmortem histopathology, so it's interesting to see that we have imaging findings in patients who are considered mild that mimic those findings that we see in more severe patients," he commented.

Dr. Parikh noted that this was an observational study, "and the next step is to confirm our suspicion based on this evidence" that these are in fact vascular lesions.

The study was supported by the National Institutes of Health, the National Institute of Neurological Disorders and Stroke, and the Center for Neuroscience and Regenerative Medicine at the Uniformed Services University of the Health Sciences.

American Academy of Neurology (AAN) 65th Annual Meeting. Abstract P04.273. March 16-23, 2013.