Stevens et al. (2012) recently showed that even minor brain injury can result in disruption of functional brain networks. The study, published in the March 2012 issue of Brain Imaging and Behaviour may have clinical implications in predicting the likelihood of problems after minor head injuries.
The researchers examined 30 minor head injury patients and 30 healthy control participants. The patients all met established criteria for minor brain injury, including a Glasgow Coma Scale score between 13 and 15 and no more than 30 minutes of unconsciousness. The vast majority showed no abnormalities on CT scans. Functional magnetic resonance imaging (fMRI) was performed to look at the activity of brain areas and a statistical technique used to look at connectivity between them. Overall, twelve resting state brain networks were observed (networks active when no activity is being carried out), including the 'default mode network' previously described.
The results showed that connections in all of the networks were disrupted in the patients. Abnormalities observed included many weakened connections, but also some enhanced and strengthened ones. The suggestion is that when established networks are disrupted our brains may try to compensate by increasing connections between other networks and regions. The study also linked disruption in networks to severity of post-concussion symptoms, with weakened connections between certain regions occurring regularly in those with more severe difficulties.
This study advances the understanding of an often misunderstood condition and provides the promise of improved diagnostic and predictive tests in the future.
Reference
Stevens, M. C., Lovejoy, D., Kim, J., Oakes, H., Kureshi, I., Witt, S. T. (2012). Multiple resting state functional connectivity abnormalities in mild traumatic brain injury. Brain Imaging and Behaviour, 6: 293-318.
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