Researchers link glutamate levels to post-traumatic epilepsy
A new study has posited a possible cause for epilepsy when experienced as a result of a traumatic brain injury.
Researchers at Tufts University, led by David Cantu and Chris Dulla, studied how this type of injury affects the cerebral cortex’s levels of gamma-aminobutyric acid (GABA) – a compound that normally inhibits the activity of neurotransmitters in the brain.
In a study of mice, published in this month’s edition of Cerebral Cortex, they found that in subjects with traumatic brain injury, the cells that create GABA – called interneurons – die off.
This allows the compound’s precursor, glutamate – which has the opposite effect to GABA, stimulating neurotransmission – to build up to toxic levels, the researchers found.
As a result, the subject’s brain becomes overstimulated, leading to the increased levels of neuronal firing associated with the onset of a seizure in epilepsy patients.
Dr Cantu argued, therefore, that if interneuron function could be restored in people with traumatic brain injury, the subsequent development of epilepsy might be mitigated.
“If we can preserve these important cells, we may be able to decrease the negative impacts of traumatic brain injury,” he commented. “Interneurons play a critical role in preventing seizures from starting.”
According to US charity the Epilepsy Foundation, between 15 and 34 per cent of traumatic brain injury patients have post-traumatic epilepsy. Among patients who served in active military roles, the figure increases to as high as 52 per cent.
Dr Dulla described the results of traumatic brain injury as “devastating and life-altering”, noting the condition often leads to difficulties with “walking, talking and living independently”. He added that while it can be called the ‘signature injury’ of servicemen and women in Iraq and Afghanistan, the condition also affects many athletes and people who experience falls.
“Understanding how brain injury disrupts normal brain function will allow scientists and physicians to develop new treatments and therapies to help people recover from post-traumatic epilepsy,” said Dr Cantu.
Posted by Steve Long