Researchers at the University of Pittsburgh Medical Center recently utilized Shannon entropy, which is a mathematical information theory model that looks at areas of entropy or disorder in the brain, to determine which concussion patients would go on to suffer migraine headaches following a traumatic brain injury.

Researchers have been using Diffusion Tensor Imaging to assess concussion-related damage to the brain’s signal-transmitting white matter to look for symptoms like headaches. Fractional anistropy (FA), which measures how easily water moves through the brain, represents an average. As a result, someone with a higher FA to begin with may lose white matter integrity from trauma, but still might average out to have a normal mean FA, according to the study’s author Lea M. Alhilali, M.D.

Utilizing Shannon entropy, Dr. Alhilali and her colleagues assessed the performance of Shannon entropy as a diagnostic tool in concussion patients with and without post-traumatic migraine. This study utilized three groups of patients, which totaled 74 concussion patients, 57 with post-traumatic migraines and 17 without. FA maps were attained in 22 healthy controls and 20 controlled patients with migraine headaches for comparison. Mean FA and Shannon entropy were then extracted from total brain FA histograms and compared between concussion patients and controls, and between those with and without post-traumatic migraine.

The study found 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 also inversely correlated with time to recovery, meaning that people with lower entropy took longer to recover.