Scientists from the US and The Netherlands have found how electrical activity from epilepsy can disrupt new memories forming during sleep.
Spikes in electrical activity in epilepsy can disrupt the pathway through which three regions of the brain work together to strengthen new memories during sleep, a study in PNAS suggests.
During sleep, the brain firms up new memories through the interaction of three regions – orbitofrontal cortex, thalamus and hippocampus.
US researcher and assistant professor Anirudh Wodeyar from Maastricht University and his colleagues say this is the first study in which the interactions of these three parts of the brain to consolidate memories have been seen in humans.
The group used a validated behavioural task and brain recordings of the three areas in 19 people with epilepsy to see the interactions and what could be disrupting them.
The researchers found that rhythmic activity in the three areas of the brain synchronise during sleep, and that spikes in electrical activity due to epilepsy can interrupt these rhythms.
How much synchronisation happened predicted better performance in the test, while how much the rhythm was interrupted by electrical activity predicted poorer performance.
Co-author, Dr Catherine Chu, from Johns Hopkins University and Kennedy Krieger Institute, said: “We haven’t understood why patients with epilepsy have problems with memory. This helps to close the gap.”
Sleep and epilepsy
The connection between sleep and epilepsy is known but complicated. Epilepsy can impact sleep, if a person has sleep seizures, for example. Medication side effects or conditions often occurring with epilepsy, such as depression, can impact on sleep too.
People with epilepsy are also more likely to have a sleep disorder, such as sleep apnoea, restless leg syndrome or insomnia, compared to people without the condition.
Lack of sleep can also be a seizure trigger for some people, making good sleep important for both memory problems associated with epilepsy and managing seizures.
Epilepsy Action says there are ways to combat tiredness, including eating regularly, getting active cutting down on caffeine and alcohol and having a good sleep routine. There are suggestions for a good sleep routine on the Epilepsy Action website.
New memories and epilepsy
Epilepsy can affect memory in different ways, which are different from person to person and can depend on things like seizures, medication, brain surgery, sleep problems, stress or anxiety.
These can be common in people with epilepsy, and can affect day-to-day life or can have a profound effect for a certain period of time. Epilepsy Action’s recent Missing Memories campaign highlights the experience of people whose epilepsy has caused them to lose momentous and once-in-a-lifetime events, like the birth of a child, their wedding, graduations and holidays.
Memory problems can also impact people daily, affecting everything, from work, to remembering to take medications to friendships and relationships.
Epilepsy Action has tips and advice on managing daily memory problems including
- Follow a daily routine
- Use a notice board or important information
- Keep essential items like keys in the same place
- Make lists
- Use aids like phone reminders, calendars, Post-It notes and pill reminder boxes to help
- Explore occupational therapy support
- + Lots more tips and advice on the Epilepsy Action website
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