Epilepsy in MS is due to cortical lesions

People with MS are at increased risk for having epileptic seizures, and these can occur both early in the disease as well as in later stages. The question of what exactly causes seizures in people with MS was recently taken up by a team of researchers from Italy. They used an advanced MRI technique (double inversion recovery (DIR) sequence) to detect cortical lesions in 100 people with MS. Almost all (90%) of the 20 people who'd had seizures had intracortical lesions, vs. just under half (48%) of the 80 people without seizures.

The seizure group also had a greater number of cortical lesions, and their lesions were bigger, than the non-seizure group. However, there was no difference between the groups for number or size of lesions that abutted the cortex or overall brain lesion volume. These findings indicate that inflammation in the cortex increases the risk of epileptic seizures in MS.

This related (via cortical imaging, not epilepsy) study found that higher-strength MRI is not good at seeing all types of cortical lesions, it is better than standard-strength for some.