Researchers at the University of California uncovered a potential new link between epilepsy and multiple sclerosis (MS), an auto-immune disease where the immune system attacks the myelin sheath that covers nerve fibres. This new finding could lead to potential new treatments against epilepsy as well as MS.
The study that was published in the journal Neuroscience, showed that people with MS were three to six times more likely to develop epilepsy than the general population. When nerve cells loose their myelin, they are not able to function properly. When this happens in a subset of nerve cells called parvalbumin interneurons, whose role is to prevent hyperactivity, seizures occur.
To test whether it is really the loss of myelin that cause seizures in MS, researchers led by Dr Seema Tiwari-Woodruff fed mice a compound called cuprizone, which is known to damage the myelin-producing cells in the nervous system. They saw that after nine weeks, the mice started having seizures. “Without myelin, axons are vulnerable,” explained Dr Tiwari-Woodruff in a press release. “In both MS and our mouse model, parvalbumin interneurons are more vulnerable and likely to die. This causes the inhibition to be removed and induce seizures.”
When the researchers stopped feeding cuprizone to the mice, the nerve fibres started becoming myelinated again. However it is not know if this decreases seizures.
“Does remyelination affect seizure activity? Could we accelerate the remyelination with drugs? …We are interested in addressing these questions,” Dr Tiwari-Woodruff said. She added that they now have a mouse model with which they can work to test and suggest some therapeutic cures. Such drugs aimed at reducing neuronal hyperactivity could reduce the incidence of seizures and could help both epilepsy and MS patients.