Dizziness, loss of balance and visual problems are the typical consequences of concussion. They are characteristic of a condition known as vestibulopathy, which is among the most common and serious problems for people who have suffered a concussion. So far, vestibulopathy has been associated with the inner ear structure but a US research team has established that the condition is linked to regional brain damage in concussion patients. Their discovery was made through a review of MRI material and the technique employed could significantly benefit concussion patients by accelerating the start of effective treatment.
The retrospective review was led by Dr Lea Alhilali from the University of Pittsburgh Medical Center. Her team analysed MRI material for 30 patients with vestibular symptoms as well as 25 suffering from ocular convergence insufficiency. The images were obtained through an MRI technique known as diffusion tensor imaging (DTI). This technique provides a fractional anisotropy (FA) value, which is in turn used to establish damage to signal-transmitting white matter in the brain. As Alhilali explained, a lower FA value indicates greater injury to the white matter.
The DTI results for the concussed patients were compared to those for 56 subjects with no vestibular or ocular problems. The comparison revealed that concussion patients experiencing vestibular problems had lower FA values in brain areas that were not previously thought to have any connection to post-traumatic vestibulopathy. These subjects were found to have matter injury in the area controlling balance and movement (the so-called cerebellar area). Injury was also found in the fusiform gyri – the area responsible for integrating the visual fields of the left and right eye.
According to Alhilali, vestibular therapy usually proves very effective and these findings can be of great importance for concussion patients. With the help of DTI, doctors can determine the appropriate treatment and start applying it earlier, she added.