«Public Input Requested for the Brain Injury Summit | Home | New Shock Reducing Foorball Helmet May Prevent Concussions»

Diffusion Tensor Imaging Can Detect Brain Damage Even in Mild TBI

Researchers report that diffusion tensor imaging can identify structural changes in the white matter of the brain that correlates to cognitive deficits even in patients with mild traumatic brain injury.

The study is published in the October issue of the journal Brain.

"We studied patients with all severities of traumatic brain injury -- mild to severe -- and found that abnormalities in white matter existed on the spectrum," said Dr. Marilyn Kraus, associate professor of psychiatry and neurology at the University of Illinois at Chicago College of Medicine and lead author of the study. "Even in patients with mild TBI -- those identified as having minimal or no loss of consciousness -- there were structural deficits."

Diffusion tensor imaging uses magnetic resonance imaging technology to examine the integrity of white matter that is especially vulnerable to traumatic brain injury. This imaging modality allows researchers to quantify and qualify structural changes in white matter, particularly in chronic TBI patients.

Thirty-seven TBI patients (20 mild and 17 moderate to severe) and 18 healthy volunteers underwent diffusion tensor imaging and neuropsychological testing to evaluate memory, attention, and executive function. All subjects were at least six months post-injury, and the majority were high-functioning people who were employed or in school at the time of evaluation.

The researchers found that structural changes in the white matter correlate to observable cognitive deficits related to thinking, memory and attention. Patients with more severe injuries had greater white matter abnormalities, representing a permanent change in the brain.

"We know that discreet brain areas are important for specific types of functioning, such as thinking, memory, cognition and motor skills," said Kraus. "But what's also very important is that the white matter serves as the connection between these significant areas of the brain."

In some ways, the brain is similar to a computer, said Deborah Little, director of MRI research in the department of neurology and rehabilitation medicine at UIC and co-author of the study. "You have the CPU and the memory, but they are worthless unless they are connected to each other. The white matter of the brain has the same function as the cables of the computer."

When white matter is damaged, areas of the brain may appear healthy but they are actually "unplugged" and cannot function.

Patients who have a contusion, or bruising of the brain, can also suffer from subtle and diffuse damage to the white matter. The researchers believe that not only the focal lesion but the damage to the white matter is very important.

In the study, the researchers were also able to determine axonal damage (tearing of the axons that allow one neuron to communicate with another) in white matter versus abnormalities in the myelin (the protective sheath that, if damaged, can disrupt signals between the brain and other parts of the body.) If an axon is severed, the damage generally cannot be repaired.

|

TrackBack

TrackBack URL for this entry:
Trackback link

Listed below are links to weblogs that reference Diffusion Tensor Imaging Can Detect Brain Damage Even in Mild TBI:

Comments

The comments to this entry are closed.