Mild Brain Injury Can Have Long-Term Effects

The only objective method for detecting or confirming mTBI is specialized medical imaging. “CT and MRI scans of patients suffering persistent cognitive impairment as a result of mild traumatic brain injury usually look totally normal. When you look at the raw images, you can't really see anything abnormal. What you need to do is look at the images quantitatively,” said Dr. Michael Lipton of the department of radiology at Albert Einstein College of Medicine in New York. He and his colleagues use MRI-based diffusion tensor imaging (DTI) to map the location, orientation, and anisotropy of the brain's white matter tracts. “We analyze each and every voxel of the brain looking for statistically significant differences between [mTBI] patients and healthy controls.”

The ability to detect subtle neuronal injury has important clinical implications for the management of mTBI, Dr. Lipton said. Identifying individuals with mild injury would allow the use and evaluation of candidate therapies designed to arrest the progression of damage.

Although the clinical utility of DTI has been established and the technology is being used at many academic centers for clinical measurement, “with the current state of the art, it requires specialized expertise to be able to extract information from the images,” he said.

The early identification and management of mTBI should get a boost from evidence-based clinical guidelines by the American College of Emergency Physicians and the CDC. Although the 2008 guidelines are written primarily for emergency physicians, “many patients with mild traumatic brain injury seek care from other practitioners such as internists,” said Dr. Andy Jagoda of Mount Sinai School of Medicine in New York, and chair of the guideline writing panel. For that reason, all clinicians should be made aware of them.

Diffusion tensor imaging reveals subtle neuronal damage (red) in mild traumatic brain injury. Images courtesy Dr. Michael Lipton