Technique helps predict likelihood of migraines in concussion patients

February 1, 2016, Radiological Society of North America
Sample histograms for, A, a control subject and, B, a patient with mild traumatic brain injury. Despite the overall similar appearance of the curves, subjective differences in the complexity of the histogram shape are seen between the patient and the control subject. Credit: Radiological Society of North America

Researchers are using a mathematical tool to help determine which concussion patients will go on to suffer migraine headaches, according to a new study published online in the journal Radiology.

Post-traumatic migraine headaches are common in people who suffer concussions. In recent years, researchers have been using diffusion tensor imaging, a type of MRI, to assess concussion-related damage to the brain's signal-transmitting white matter and look for associations with symptoms like headaches. MRI can be used to create a frequency distribution graph of the whole brain called a histogram, and from that a mean fractional anistropy (FA), a measure of how easily water moves through the brain, can be derived to assess white matter injury. However, mean FA has shortcomings.

"Mean FA represents an average," said study author Lea M. Alhilali, M.D., from the University of Pittsburgh Medical Center in Pittsburgh. "If someone has a higher FA to begin with and they lose white matter integrity from trauma, they still might average out to have a normal mean FA."

Instead, the researchers analyzed the MRI results using information theory, a branch of mathematics based on mathematical laws surrounding the behavior of data as it is retrieved, transferred or stored. Shannon entropy, an information theory model that looks at areas of entropy, or disorder, in a complex system like the brain, has advantages over mean FA in the analysis of brain histograms, according to Dr. Alhilali.

Histogram of the time to presentation for patients with mild traumatic brain injury (mTBI) shows that the majority of the patients (83 percent) presented within 2 months of injury. The remaining nine patients with mTBI presented more than 12 weeks after the initial injury. Credit: Radiological Society of North America

"A healthy brain has high entropy, but people with injuries to the from trauma may lose some of that complexity and have less entropy," she explained.

In the first study of its kind, Dr. Alhilali and colleagues assessed the performance of Shannon entropy as a diagnostic tool in concussion patients with and without post-traumatic migraines.

They obtained FA maps and neurocognitive testing results in 74 concussion patients, including 57 with post-traumatic migraines and 17 without. FA maps were obtained in 22 healthy controls and 20 control patients with for comparison. Mean FA and Shannon entropy were extracted from total brain FA histograms and compared between concussion patients and controls and between those with and without post-traumatic migraine.

Graphs displaying the diagnostic performance of mean fractional anisotropy (FA) and Shannon entropy (SE). Receiver operating characteristic curves measure the diagnostic performance of a given test based on the area underneath the curve, with large areas indicating high performance and smaller areas indicating poor performance. These graphs demonstrate that (A) mean FA performs acceptably differentiating patients with mild traumatic brain injury from control subjects, with a substantial amount of area under the curve. However, SE was an even better test to distinguish patients with mild traumatic brain injury, with a significantly greater area under the curve, indication better diagnostic performance. The difference becomes more pronounced in attempting to predict the presence of posttraumatic migraine, where, in C, mean FA performed poorly, with very little area under the curve, but SE continues to demonstrate excellent performance, with a relatively large area under the curve (D). Credit: Radiological Society of North America

Shannon entropy analysis of FA histograms performed better than mean FA as a diagnostic test to differentiate between concussion patients and controls and also performed better in determining which concussion patients developed post-traumatic migraines. The concussion patients had significantly lower Shannon entropy compared to controls, and those with post-traumatic migraines had significantly lower Shannon entropy than other concussion patients. Patients with Shannon entropy below 0.750 were approximately 16 times more likely to have experienced concussion and three times more likely to develop post-traumatic migraines.

Shannon entropy inversely correlated with time to recovery, meaning that people with lower entropy took longer to recover.

The results suggest that Shannon may provide a convenient, reproducible biomarker that can be calculated in automated fashion to help triage patients after initial injury and predict which ones will go on to get more severe symptoms.

"This approach requires just one histogram for the entire brain," Dr. Alhilali said. "If it continues to show promise, then it could be added to the regular MRI as part of the study."

Explore further: Brain injury patterns linked to post-concussion depression and anxiety

More information: "White Matter Injuries in Mild Traumatic Brain Injury and Posttraumatic Migraines: Diffusion Entropy Analysis." Radiology, 2016.

Related Stories

Brain injury patterns linked to post-concussion depression and anxiety

June 16, 2015
A new MRI study has found distinct injury patterns in the brains of people with concussion-related depression and anxiety, according to a new study published online in the journal Radiology. The findings may lead the way ...

MRI pinpoints region of brain injury in some concussion patients

April 15, 2014
Researchers using information provided by a magnetic resonance imaging (MRI) technique have identified regional white matter damage in the brains of people who experience chronic dizziness and other symptoms after concussion.

Imaging shows some brains compensate after traumatic injury

November 26, 2012
Using a special magnetic resonance imaging (MRI) technique to image patients with mild traumatic brain injury (MTBI), researchers have identified a biomarker that may predict which patients will do well over the long term, ...

Gender may contribute to recovery time after concussion

May 6, 2014
A study of concussion patients using diffusion tensor imaging (DTI) found that males took longer to recover after concussion than females did. Results of the study, which show that DTI can be used as a bias-free way to predict ...

High school football players show brain changes after one season

December 1, 2014
Some high school football players exhibit measurable brain changes after a single season of play even in the absence of concussion, according to a study presented today at the annual meeting of the Radiological Society of ...

Frequent soccer ball 'heading' may lead to brain injury

June 11, 2013
Soccer players who 'head' the ball with high frequency demonstrate poorer performance on memory tests and have brain abnormalities similar to those found in traumatic brain injury patients, according to a study published ...

Recommended for you

How do we lose memory? A STEP at a time, researchers say

March 23, 2018
In mice, rats, monkeys, and people, aging can take its toll on cognitive function. A new study by researchers at Yale and Université de Montréal reveal there is a common denominator to the decline in all of these species—an ...

Brain's tiniest blood vessels trigger spinal motor neurons to develop

March 23, 2018
A new study has revealed that the human brain's tiniest blood vessels can activate genes known to trigger spinal motor neurons, prompting the neurons to grow during early development. The findings could provide insights into ...

Being hungry shuts off perception of chronic pain

March 22, 2018
Pain can be valuable. Without it, we might let our hand linger on a hot stove, for example. But longer-lasting pain, such as the inflammatory pain that can arise after injury, can be debilitating and costly, preventing us ...

From signal propagation to consciousness: New findings point to a potential connection

March 22, 2018
Researchers at New York University have discovered a novel mechanism through which information can be effectively transmitted across many areas in the brain—a finding that offers a potentially new way of understanding how ...

Using simplicity for complexity—new research sheds light on the perception of motion

March 22, 2018
A team of biologists has deciphered how neurons used in the perception of motion form in the brain of a fly —a finding that illustrates how complex neuronal circuits are constructed from simple developmental rules.

Focus on early stage of illness may be key to treating ALS, study suggests

March 22, 2018
A new kind of genetically engineered mouse and an innovation in how to monitor those mice during research have shed new light on the early development of an inherited form of amyotrophic lateral sclerosis (ALS).


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.