New Insights into Seizures in Multiple Sclerosis: Research Identifies Key Connection Between Demyelination and Epilepsy

Scientists at the University of California, Riverside, have made a groundbreaking discovery in understanding why people with multiple sclerosis (MS) often experience seizures. A preclinical study published in Neurobiology of Disease found a strong connection between demyelination, the loss of the protective myelin sheath coating the axons of neurons, and seizure activity. Using a mouse model of MS, the researchers discovered that as myelin deteriorates, especially in the hippocampus, seizures become more likely. This region is essential for memory and learning and is a known hotspot for seizure activity.

Key Takeaways:

• The study found that about 4 to 5% of people with MS develop seizures, which can lead to worse cognitive outcomes and faster disease progression.
• The research identifies a strong connection between demyelination and seizure activity, suggesting that addressing the root cause of seizures in MS could be a new treatment approach.
• Current seizure medications often suppress overall brain activity, leading to side effects like fatigue and cognitive dulling.
• The study used a mouse model of MS, which simulated progressive demyelination, and found that nearly 80% of mice developed seizure activity after 12 weeks of demyelination.
• The research highlights the hippocampus as a key area affected, with inhibitory neurons in this region, some of which are myelinated, being particularly vulnerable to damage.
• The study offers new hope for people living with MS, providing an explanation for seizures, which is the first step toward better treatment.
• The research team is now investigating changes in neural circuits and receptors in the hippocampus and how astrocyte dysfunction contributes to seizure risk.

Statistics:

• 4-5% of people with MS develop seizures
• 80% of mice in the study developed seizure activity after 12 weeks of demyelination
• Glutamate, an excitatory neurotransmitter, rose by 20% in demyelinated mice
• GABA, the brain's main inhibitory neurotransmitter, declined by 15% in demyelinated mice
• The study was supported by institutional grants and funding from the National Institute of Neurological Disorders and Stroke

Sources:

• "Demyelination-induced glutamatergic imbalance mediates hippocampal Hyperexcitability" (Neurobiology of Disease, 2025)
• University of California, Riverside (www.ucr.edu)
• National Institute of Neurological Disorders and Stroke (NINDS) (ninds.nih.gov)