Epilepsy linked to structural abnormalities in multiple brain regions

Written by Roisin Conneely

Researchers from UCL (London, UK) and the Keck School of Medicine, USC (CA, USA) have linked epilepsy to structural abnormalities in several regions of the brain. The study highlights more widespread physical changes associated with the disease than have ever previously been described, even in idiopathic generalized epilepsy, characterized by its lack of observable changes in the brain.
The team took brain structural measurements from MRI scans of 2149 epilepsy patients, compared with 1727 healthy controls. The trial was conducted by the global ENIGMA-Epilepsy consortium, combining data from 24 research centers across 14 countries throughout Europe, Asia, Australia and North and South America.

Brain structures were ranked in order of greatest difference between patients and controls. All epilepsy patients exhibited reduced grey matter thickness in areas of the cortex as well as decreased volume in subcortical regions compared with the control group. Additionally, lowered volume and thickness was associated with a longer duration of the disease.

Epilepsy patients exhibited decreased volume in the right thalamus along with reduced thickness in the motor cortex. Researchers were also able to identify differences between epilepsy subgroups, which they speculate may be due to underlying genetic variation. However, the abnormalities identified are subtle and have not yet been connected to any loss of function.

Therefore, further research is required to establish the significance of this association, as summarized by study author Sanjay Sisodiya (UCL): “While we haven’t yet assessed the impact of these differences, our findings suggest there’s more to epilepsy than we realise, and now we need to do more research to understand the causes of these differences.”

Sources: Whelan CD, Altmann A, Botaia JA, et al. Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study. Brain doi:10.1093/brain/awx341. (2018) (Epub ahead of print); www.ucl.ac.uk/news/news-articles/0118/220118-epilepsy-neuroimaging/