What’s the science?
Epilepsy is a complex disorder characterized by seizures. The way that brain structure relates to the severity of epilepsy is not well understood. This week in Brain, Whelan and colleagues report structural brain changes in a large sample of epilepsy patients.
How did they do it?
Epilepsy patients were recruited from 24 research centers across 14 different countries. This resulted in 2149 epilepsy patients that were divided into 4 subgroups based on epilepsy type. The patients were scanned using MRI and the brain scans were analyzed to measure brain volumes and cortical thickness (the thickness of the outermost layer of the brain: the cerebral cortex) compared to healthy control participant brains.
What did they find?
They found that in all types of epilepsy, there was reduced brain volume in the right and left thalamus and reduced cortical thickness in the right and left precentral gyrus (motor cortex), which are both important brain regions involved in movement. In the subgroup of medial temporal lobe epilepsy patients, there was reduced brain volume in the hippocampus (a region involved in memory). Lower brain volumes and cortical thickness were associated with a longer duration of epilepsy.
What’s the impact?
This is the largest brain imaging study of epilepsy that has ever been done. Before this study, we didn’t know the extent to which structural brain changes occur in epilepsy. We now know that there are significant structural brain changes in the thalamus and precentral gyrus in epilepsy, which are both very important brain regions for movement and should be investigated further.
C. D. Whelan et al., Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study. Brain. 0, 1–18 (2018).