A new mouse model study helps explain why some patients with multiple sclerosis have seizures. The findings could lead to the development of drugs aimed at reducing seizures in MS.

MS patients are three to six times more likely to develop seizures compared to the rest of the population. Using a mouse model, a team of scientists at the University of California, Riverside, found chronic demyelination is closely linked to, and is likely the cause of, these seizures. The researchers note that certain neurons in the brain, called "parvalbumin interneurons," which are important for keeping hyperactivity down, are modified and lost when extensive demyelination occurs in the brain's cortex and hippocampus.

In the lab, researchers induced demyelination in mice by feeding them a diet that contained cuprizone, a copper-binding substance that causes damage to oligodendrocytes – the brain cells that produce myelin. After nine weeks of feeding them cuprizone, the majority of mice started having seizures. After nine or twelve weeks, the researchers stopped feeding the mice the cuprizone diet. Oligodendrocytes began to repopulate the demyelinated areas and remyelinate the intact but myelin-stripped axons. Future studies will assess seizure activity with remyelination.

The findings were published in the journal Neuroscience.